Intravenous flow rate controller

1. An apparatus for determining a rate of 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;

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

c. a flow rate determination element configured to determine a flow rate of fluid passing through the drip chamber, the flow rate determination element comprising, a camera for imaging activity within the drip chamber, a computing device, a memory storage coupled to the computing device, and a set of software instructions stored in the memory storage which when executed by the computing device causes the apparatus to carry out functions, the functions comprising:

detecting a presence of a drop of fluid falling within the drip chamber;

in response to the detecting, triggering the camera to capture a first image of the drip chamber with the drop falling therein;

capturing a second image of the drip chamber with no drop falling therein;

eliminating splash effects from the first image of the drip chamber by subtracting from the first image portions of the second image that appear in substantially the same position in each of the first and second images in order to create a drop image that is substantially free of splash effects; and

determining a volume of the drop based on the drop image.

2. The apparatus of claim 1 , wherein determining the volume of the drop comprises:

computationally rotating the drop image about an axis; and

determining a volume of a shape resulting from the computationally-rotated drop image.

3. The apparatus of claim 1 , wherein detecting the presence of the drop in the drip chamber comprises:

detecting a change in a signal received from a detector having two electrically conductive metal plates, the change in the signal resulting from the presence of a drop within the drip chamber.

4. The apparatus of claim 3 , wherein the cradle comprises a door operable between an open position in which the drip chamber can be placed into or removed from the cradle and a closed position in which the drip chamber is secured within the cradle, and wherein one of the two electrically conductive metal plates is mounted on the door.

5. The apparatus of claim 3 , wherein the camera is positioned substantially perpendicularly to the metal plates.

6. The apparatus of claim 1 , wherein the functions further comprise:

repeating the functions for successive drops detected in the drip chamber for a predetermined period of time; and

summing the determined volumes of drops falling within the drip chamber to generate a volume sum and dividing the volume sum by the predetermined amount of time to generate a flow rate for the predetermined amount of time.

7. The apparatus of claim 1 , wherein detecting the presence of the drop in the drip chamber comprises:

detecting a change in a signal received from a beam emitter and a beam detector.

8. The apparatus of claim 7 , wherein the cradle comprises a door operable between an open position in which the drip chamber can be placed into or removed from the cradle and a closed position in which the drip chamber is secured within the cradle, and wherein one of the beam emitter and beam detector is mounted the door.

9. A method for determining a flow rate of fluid delivered by a fluid delivery system, the fluid delivery system including a drip chamber, the method comprising:

detecting a presence of a drop in the drip chamber;

in response to the detecting, capturing a first image of the drip chamber and the drop falling therein;

capturing a second image of the drip chamber with no drop falling therein;

eliminating splash effects from the first image of the drip chamber by subtracting from the first image any portions of the second image that appear in substantially the same position in both the first and second images in order to create a drop image that is substantially free of splash effects; and

determining a volume of the drop based on said drop image.

10. The method of claim 9 , wherein detecting a presence of a drop in the drip chamber comprises:

detecting a change in a signal received from a detector having two electrically conductive metal plates, the change in the signal resulting from the presence of a drop within the drip chamber.

11. The method of claim 9 , wherein detecting a presence of a drop in the drip chamber comprises:

detecting a change in a signal received from a beam emitter and a beam detector.

12. The method of claim 9 , wherein the second image is captured after the first image is captured.

13. The method of claim 9 , wherein the second image is captured before the first image is captured.

14. The method of claim 9 , further comprising:

for successive detected drops over a predetermined period of time, repeating the preceding steps of detecting, capturing a first image, capturing a second image, eliminating splash effects, and determining a volume; and

summing the determined volumes of successive detected drops and dividing the sum by the predetermined period of time to provide a flow rate.

15. An apparatus for determining a rate of 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;

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

c. a flow rate determination element configured to determine a flow rate of fluid passing through the drip chamber, the flow rate determination element comprising, a camera for imaging activity within the drip chamber, a computing device, a memory storage coupled to the computing device, and a set of software instructions stored in the memory storage which when executed by the computing device causes the apparatus to carry out functions, the functions comprising:

detecting a presence of each one of a plurality of drops of fluid falling within the drip chamber;

in response to the detection of each drop, triggering the camera to capture a first image of the drip chamber with the drop falling therein;

for each captured first image of the drip chamber, capturing a corresponding second image of the drip chamber with no drop falling therein;

subtracting from the first image portions of the corresponding second image that appear in substantially the same position in each of the first and second images in order to create a drop image for each drop; and

determining a volume of each drop based on the drop image created for the drop.

16. The apparatus of claim 15 , wherein the second image is captured after the first image is captured.

17. The apparatus of claim 15 , wherein the second image is captured before the first image is captured.

18. The apparatus of claim 15 , wherein the detecting the presence of each one of the plurality of drops of fluid falling within the drip chamber comprises detecting all drops falling within the drop chamber over a predetermined period of time.

19. The apparatus of claim 18 , wherein the functions further comprise determining a flow rate of fluid passing through the drip chamber by:

determining a volume sum by summing the volumes determined for each drop; and

dividing the volume sum by the predetermined period of time.

20. The apparatus of claim 15 , wherein the functions further comprise failing to detect at least one drop falling within the drip chamber.