Intravenous Flow Rate Controller

• US 20130085443A1
• Filed: 09/28/2012
• Published: 04/04/2013
• Est. Priority Date: 09/30/2011
• Status: Active Grant

• Current Assignee: ICU Medical Incorporated
• Original Assignee: Hospira Incorporated (Pfizer Inc.)
• Inventors: Lowery, Michael G., Markey, Brian G., Markey, James A.
• Granted Patent: US 9,134,735 B2
• Time in Patent Office: Days
• US Class Current: 604/65
• CPC Class Codes: A61M 2205/215 Tilt detection, e.g. for warning or shut-off
• CPC Class Codes: A61M 5/1411 Drip chambers A61M5/162, A61M5/1689, A61M5/40 take precedence
• CPC Class Codes: A61M 5/1689 Drip counters
• CPC Class Codes: G01F 1/56 by using electric or magnetic effects G01F1/66 takes precedence
• CPC Class Codes: G01F 1/72 Devices for measuring pulsing fluid flows
• CPC Class Codes: G01F 22/00 Methods or apparatus for measuring volume of fluids or fluent solid material, not otherwise provided for
• 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
• CPC Class Codes: G05D 7/0635 by action on throttling means G05D7/0688, G05D7/0694 take precedence
• CPC Class Codes: G06T 2207/20224 Image subtraction
• CPC Class Codes: G06T 7/62 of area, perimeter, diameter or volume
• CPC Class Codes: G16H 20/17 delivered via infusion or injection

Abstract

Tilting of a drip chamber from its vertical axis during fluid administration can have negative effects upon the accuracy of systems configured for drop counting and/or for volumetric measurement of individual drops passing through the drip chamber. To address these negative effects, in accordance with one embodiment of the present disclosure, a fluid delivery system engages in a fluid control process that comprises determining an error parameter, based at least in part on a tilt signal, generating an error condition, and either holding the fluid flow at the present rate or stopping the flow.

Claims

1. An apparatus for controlling fluid flow in a fluid delivery system comprising a drip chamber and a length of tubing, the apparatus comprising:

a. a cradle configured to receive the drip chamber in a substantially vertical orientation;

b. a valve configured to receive the length of tubing and to control a rate of fluid flow through the length of tubing;

c. a flow rate determination element configured to determine a flow rate of fluid passing through the drip chamber;

d. a tilt-detection element configured to detect tilt of the drip chamber; and

e. a controller configured to adjust the valve based on a signal produced by the tilt-detection element.

2. The apparatus of claim 1, wherein the flow rate determination element comprises a drip-detection element configured to detect drops in the drip chamber.

3. The apparatus of claim 2, wherein at least one of the flow rate determination element and the controller comprises a processor configured to calculate the flow rate of fluid passing through the drip chamber based upon a detected number of drops formed in the drip chamber over a period of time.

4. The apparatus of claim 1, further comprising:

a computing device associated with the controller;

memory storage coupled to the computing device; and

software instructions stored in the memory storage which when executed by the computing device cause the apparatus to carry out functions, the functions comprising;

detecting a degree of tilt of the drip chamber relative a vertical orientation; and

adjusting the valve in response to the detected degree of tilt.

5. The apparatus of claim 4, wherein functions further comprise:

closing the valve when the degree of tilt exceeds a predetermined limit.

6. The apparatus of claim 4, wherein functions further comprise

activating an alarm when the degree of tilt exceeds a predetermined limit.

7. A method for regulating fluid flow in a fluid delivery system including a drip chamber and a length of tubing, the method comprising:

providing a fluid delivery system comprising a cradle configured to receive a drip chamber, a valve configured to receive the length of tubing and to control a rate of fluid flow through the length of tubing, a tilt-detection element configured to detect tilt of the drip chamber, and a controller configured to adjust the valve in response to a signal from the tilt detection element;

detecting a tilt of the drip chamber at a first time using the tilt-detection element and generating a tilt signal indicating a magnitude of detected tilt;

determining whether the magnitude of the tilt signal exceeds a tilt threshold;

generating a tilt warning signal if the magnitude of the tilt signal exceeds the tilt threshold; and

adjusting the valve if a tilt warning signal is generated.

8. The method of claim 7, wherein detecting a degree of tilt of the drip chamber comprises at least one of:

(1) detecting an angular orientation, and

(2) detecting an acceleration.

9. The method of claim 7, wherein the fluid delivery system further comprises a flow rate determination element configured to determine a flow rate of fluid passing through the drip chamber.

10. The method of claim 9, wherein the flow rate determination element generates a signal indicating the determined flow rate, and wherein the further comprises comparing the determined flow rate to a predetermined flow rate and adjusting the valve if the determined flow rate is different than the selected flow rate.

11. The method of claim 7, wherein the method further comprises generating an alarm in response to a tilt warning signal.

12. The method of claim 7, wherein the method further comprises detecting a tilt of the drip chamber at a second time using the tilt-detection element, the first time and second time being temporally spaced by a predetermined time interval, generating a tilt signal indicating a magnitude of detected tilt at the second time, and determining whether the magnitude of the detected tilt at the first time and the magnitude of the detected tilt at the second time both exceed a tilt threshold, and wherein the step of generating a tilt warning signal occurs only if the magnitude of tilt at the first time and the magnitude of tilt at the second time both exceed the tilt threshold.

13. The method of claim 7, wherein the method further comprises detecting a tilt of the drib chamber at a plurality of times during a predetermined time interval, wherein a tilt signal indicating a magnitude of detected tilt is generated for each of the plurality of times at which tilt is detected, and determining whether the magnitude of the detected tilt at each of the plurality of times exceeds a tilt signal threshold, and wherein the step of generating a tilt warning signal occurs only if the magnitude of tilt at each of the plurality of times exceeds the tilt signal