Fluid monitoring device

• US 7,327,273 B2
• Filed: 02/11/2005
• Issued: 02/05/2008
• Est. Priority Date: 02/12/2004
• Status: Expired due to Fees

• Current Assignee: David C. Roach, Orlando R. Hung, Peter H. Gregson
• Original Assignee: David C. Roach, Orlando R. Hung, Peter H. Gregson
• Inventors: Gregson, Peter H., Roach, David C., Hung, Orlando R.
• Primary Examiner(s): NGUYEN, TAI T
• Application Number:
  US11/055,063
• Publication Number:
  US 20060030822A1
• Time in Patent Office: 1,089 Days
• Field of Search: 340/619, 340/918, 340/578, 340/583, 604/246, 604/253, 604/251, 604/65, 604/66
• US Class Current: 340/619
• CPC Class Codes: A61M 39/285 Cam clamps, e.g. roller clamps with eccentric axis
• CPC Class Codes: A61M 5/1411 Drip chambers A61M5/162, A61M5/1689, A61M5/40 take precedence
• CPC Class Codes: A61M 5/1684 by detecting the amount of infusate remaining, e.g. signalling end of infusion
• CPC Class Codes: A61M 5/36 with means for eliminating or preventing injection or infusion of air into body dialysis systems, blood oxygenators A61M1/14; haemofiltration equipment A61M1/34; automatic tube cut-off A61M39/281

Abstract

This invention relates to a device to monitor the administration of a fluid through a conduit, such as intravenous fluid, and detect the completion of fluid delivery by monitoring the fluid level inside a chamber. The device will monitor, through an optical fluid sensor comprising a radiation source, two sensors, a logic means, and an indicating means, the bottom half of any “user supplied” drip chamber that is normally full during the administration of fluids. When the fluid level in the chamber drops below a predetermined level, the indicating means will initiate an electromechanical device that releases a pinching device to occlude the conduit. The pinching device is a rotary pincher that derives its force from a torsion spring and is held in the open position by the electromechanical device.

Claims

1. An optical fluid sensor device for detecting presence of fluid in a chamber, comprising:

a radiation source;

a first sensor disposed so that the chamber is situated between the radiation source and the first sensor, and disposed to receive a majority of radiation emitted from the radiation source when the portion of the chamber through which the emitted radiation passes contains no fluid;

a second sensor disposed so that the chamber is situated between the radiation source and the second sensor, and disposed to receive a majority of radiation emitted from the radiation source when the portion of the chamber through which the emitted radiation passes contains fluid;

a logic means for controlling the radiation source, and for detecting as a first signal an amount of radiation falling on the first sensor, and for detecting as a second signal an amount of radiation falling on the second sensor, and for comparing the first and second signals; and

means for indicating when no fluid is detected in the chamber.

2. The optical fluid sensor device according to claim 1, wherein the indicating means is an audible alarm.

3. The optical fluid sensor device according to claim 1, wherein the indicating means is a visual alarm.

7. A method for detecting presence of a fluid using an optical fluid sensor device as defined in claim 1, said method comprising:

activating the radiation source;

detecting radiation using the first sensor to produce a first signal and the second sensor to produce a second signal; and

comparing the first signal to the second signal to detect the presence of fluid in the chamber.

8. The method according to claim 7, further comprising:

detecting ambient radiation with the radiation source de-activated using the first sensor to produce a first reference signal and the second sensor to produce a second reference signal;

correcting the first signal by subtracting the first reference signal giving a corrected first signal;

correcting the second signal by subtracting the second reference signal giving a corrected second signal; and

comparing the corrected first signal to the corrected second signal to detect the presence of fluid in the chamber.

11. Use of an optical fluid sensor device as defined in claim 1 for detecting presence of a fluid in a flow system.

12. The use of claim 11, wherein the flow system is an intravenous system.

4. A pinch-off mechanism for occluding a conduit, comprising:

a torsion spring;

means for loading the torsion spring having a rotary pincher and a pawl; and

an electromechanical device having a lever engaging the pawl,

whereby, when activated, the electromechanical device disengages the lever from the pawl of the loading means releasing stored energy in the torsion spring which rotates the rotary pincher thereby applying pressure against the conduit thereby occluding it.

5. The pinch-off mechanism according to claim 4, wherein the electromechanical device is a solenoid.

13. Use of a pinch-off mechanism as defined in claim 4 for occluding a conduit in a flow system.

14. The use of claim 13, wherein the flow system is an intravenous system.

6. A fluid monitoring device, comprising:

(i) an optical fluid sensor device for detecting presence of fluid in a chamber, comprising;

a radiation source;

a first sensor disposed so that the chamber is situated between the radiation source and the first sensor, and disposed to receive a majority of radiation emitted from the radiation source when the portion of the chamber through which the emitted radiation passes contains no fluid;

a second sensor disposed so that the chamber is situated between the radiation source and the second sensor, and disposed to receive a majority of radiation emitted from the radiation source when the portion of the chamber through which the emitted radiation passes contains fluid;

a logic means for controlling the radiation source, and for detecting as a first signal an amount of radiation falling on the first sensor, and for detecting as a second signal an amount of radiation falling on the second sensor, and for comparing the first and second signals; and

means for indicating when no fluid is detected in the chamber; and

(ii) a pinch-off mechanism for occluding a conduit, comprising;

a torsion spring;

means for loading the torsion spring having a rotary pincher and a pawl, wherein the pincher is located in a position on the conduit distal to the optical fluid sensor device in the direction of fluid flow; and

an electromechanical device having a lever engaging the pawl,

whereby, the indicating means activates the electromechanical device thereby disengaging the lever from the pawl of the loading means releasing stored energy in the torsion spring which rotates the rotary pincher thereby applying pressure against the conduit thereby occluding it.

9. A method for monitoring administration of a fluid using the fluid monitoring device as defined in claim 6, said method comprising:

activating the radiation source;

detecting radiation using the first sensor to produce a first signal and the second sensor to produce a second signal;

comparing the first signal to the second signal to detect the presence of fluid in the chamber; and

activating the pinch-off mechanism to occlude the conduit when no fluid is present.

10. The method according to claim 9, further comprising:

detecting ambient radiation with the radiation source de-activated using the first sensor to produce a first reference signal and the second sensor to produce a second reference signal;

correcting the first signal by subtracting the first reference signal giving a corrected first signal;

correcting the second signal by subtracting the second reference signal giving a corrected second signal; and

comparing the corrected first signal to the corrected second signal to detect the presence of fluid in the chamber.