Non-invasive system and method for a fluid flow monitoring system

• US 5,764,539 A
• Filed: 01/21/1994
• Issued: 06/09/1998
• Est. Priority Date: 01/21/1994
• Status: Expired due to Fees

• Current Assignee: Nestec SA (Nestle SA)
• Original Assignee: Novartis Nutrition AG
• Inventors: Rani, Robert G.
• Primary Examiner(s): Voeltz, Emanuel Todd
• Assistant Examiner(s): Wachsman, Hal D.
• Application Number:
  US08/184,884
• Time in Patent Office: 1,600 Days
• Field of Search: 364/524, 364/413.01, 364/557, 364/556, 364/510, 364/509, 364/571.01, 364/571.03, 364/550, 364/551.01, 73/195, 73/196, 73/202, 73/202.5, 73/204.11-204.19, 73/204.21-204.24, 73/861, 73/861.01-861.03, 73/861.95 , 73/861.17, 73/861.19, 73/861.24, 73/861.39, 73/861.44, 73/861.51, 73/861.66-861.68, 73/1.01, 73/1.02, 73/1.16 , 73/1.34, 73/1.73, 73/1.83, 210/737, 210/739, 210/742, 210/85-90, 210/104, 210/744, 210/97, 210/98, 210/103, 128/672, 128/713, 128/736, 128/692, 128/633, 128/DIG. 12, 128/DIG. 13, 374/107, 374/112, 374/116, 374/118, 374/128, 374/132, 374/133, 374/135, 374/137, 374/141, 374/142, 374/148, 374/170, 604/128, 604/131, 604/151, 604/153, 604/8, 604/9, 604/65-67
• US Class Current: 702/130
• CPC Class Codes: A61M 2202/0482 Enteral feeding product
• CPC Class Codes: A61M 5/16886 for measuring fluid flow rate, i.e. flowmeters
• CPC Class Codes: G01F 1/6847 where sensing or heating elements are not disturbing the fluid flow, e.g. elements mounted outside the flow duct
• CPC Class Codes: G01F 1/696 Circuits therefor, e.g. constant-current flow meters

Abstract

A non-invasive system and method is provided for a fluid delivery system of the type including a fluid delivery pump delivering fluid in pulses through a fluid delivery tube. The non-invasive monitoring system and method includes a sensor which is brought into engagement with an outer surface of the fluid delivery tube. The sensor is adapted for being calibrated at an initial temperature and is responsive to the fluid when passing through the fluid delivery tube. In particular, the present system and method is adapted to monitor the sensor and receives data corresponding to the changes in the initial temperature of the sensor as influenced by the temperature of the fluid when passing through the fluid delivery tube. The non-invasive monitoring system and method is further adapted to process the data from the sensor indicative of both the initial and changed temperatures for determining the status of the fluid in the fluid delivery tube. A display can also be provided for notifying the user of the device of the status of the fluid in the fluid delivery tube.

Claims

1. A non-invasive monitoring system comprising, with a fluid delivery system having a fluid delivery pump delivering fluid having a particular fluid temperature in pulses through a fluid delivery tube:

sensor means which comprises a self-heated temperature sensor calibrated at an initial temperature, with the initial temperature being different from the temperature of the fluid, the sensor means being adapted to engage an outer surface of the fluid delivery tube and thereafter responsive to the fluid when passing through the fluid delivery tube for changing the initial temperature of the sensor means as a result of the fluid temperature when the fluid is being passed through the fluid delivery tube, the sensor means returning to the initial temperature when the fluid is not being passed through the fluid delivery tube, the sensor means also being adapted for generating data corresponding with the initial temperature and the changing of the initial temperature thereof;

means for monitoring the data from the sensor means for detecting the changes in the initial temperature as influenced by the temperature of the fluid when passing through the fluid delivery tube; and

means for processing the data from the sensor means corresponding to the initial temperature and the changing of the initial temperature thereof for determining the status of the flow of fluid in the delivery tube, wherein said processing means comprises analyzing means adapted to identify steady data conditions corresponding to a steady temperature patern indicating that either no fluid is moving inside the fluid delivery tube or that the fluid delivery tube is empty and identifying oscillating data conditions corresponding to an oscillating temperature pattern indicating that fluid is being passed in pulses through the fluid delivery tube.

2. A non-invasive monitoring system according to claim 1, wherein the processing means comprises means for analyzing the data from the sensor means associated with the initial temperature and the changes in the initial temperature thereof against known data conditions for determining the status of the flow of the fluid in the fluid delivery tube.

3. A non-invasive monitoring system according to claim 2, further including display means in association with the analyzing means adapted for providing a display of the status of the fluid in the fluid delivery tube.

4. A non-invasive monitoring system according to claim 1, wherein the sensor means generates data in the form of analog signals representative of the initial and changed temperatures thereof for analysis.

5. A non-invasive monitoring system according to claim 4, wherein the monitoring means includes conversion means adapted for placing the data generated by the sensor means in form for analysis, wherein the conversion means comprises:

analog to digital convertor means for converting the analog signals generated by the sensor means to digital signals; and

computer means coupled to the analog to digital convertor means adapted for receiving the digital signals therein.

6. A non-invasive monitoring system according to claim 1, wherein the initial temperature of the sensor is elevated above the temperature of the fluid.

7. A non-invasive monitoring system according to claim 1, wherein the self-heated temperature sensor comprises a thermistor.

8. A non-invasive method for monitoring a fluid delivery system of the type including a fluid delivery pump delivering fluid having a particular fluid temperature in pulses through a fluid delivery tube, the non-invasive method comprising the steps of:

providing a sensor means calibrated at an initial temperature and adapted for monitoring a temperature of a source external thereto, the sensor means being responsive to the temperature of the sensor means as a result of the external source temperature when in communication therewith, the sensor means being adapted to return to the initial temperature when not in communication with the external source and generating data corresponding with the initial temperature and the changing of the initial temperature thereof;

calibrating the initial temperature of the sensor means different from the temperature of the fluid;

contacting the sensor means with an outer surface of the fluid delivery tube;

monitoring the data from the sensor means for detecting the changes in the initial temperature thereof as influenced by the temperature of the fluid when passing through the fluid delivery tube; and

processing the data from the sensor means corresponding to the initial temperature and the changes in the initial temperature thereof for determining the status of the flow of the fluid in the fluid delivery tube, wherein the processing step involves identifying steady data conditions corresponding to a steady temperature pattern indicating that either no fluid is moving inside the fluid delivery tube or that the fluid delivery tube is empty and identifying oscillating data conditions corresponding to an oscillating temperature pattern indicating that fluid is being passed in pulses through the fluid delivery tube.

9. A non-invasive method for monitoring a fluid delivery system according to claim 8, wherein the step of processing the data from the sensor means associated with the initial and changed temperatures thereof further comprises the step of analyzing the data from the sensor means against known data conditions for determining the status of the fluid in the fluid delivery tube.

10. A non-invasive method for monitoring a fluid delivery system according to claim 9, wherein the step of analyzing the data from the sensor means further includes the step of displaying the status of the fluid in the fluid delivery tube.

11. A non-invasive method for monitoring a fluid delivery system according to claim 8, wherein the sensor means generates data in the form of analog signals representative of the initial and changes in the initial temperatures thereof for analysis.

12. A non-invasive method for monitoring a fluid delivery system according to claim 11, wherein the step of monitoring the sensor means includes the step of converting the analog signals generated by the sensor means to digital signals for analysis.

13. A non-invasive method for monitoring a fluid delivery system according to claim 12, wherein the step of processing the data from the sensor means further includes the step of analyzing the digital signals to determine the status of the flow of the fluid in the fluid delivery tube.

14. A non-invasive method for monitoring a fluid delivery system of the type including a fluid delivery pump delivering fluid having a particular fluid temperature in pulses through a fluid delivery tube, the non-invasive method comprising the steps of;

providing a self-heated temperature sensor in engagement with an outer surface of the fluid delivery tube;

calibrating the self-heated temperature sensor to an initial temperature different from the temperature of the fluid;

monitoring the self-heated temperature sensor for determining the changes in the initial temperature thereof as influenced by the temperature of the fluid when passing through the fluid delivery tube; and

processing the changes in the initial temperature of the self-heated temperature sensor for determining the status of the flow of the fluid in the fluid delivery tube, wherein said processing step includes identifying steady data conditions corresponding to a steady temperature pattern indicating that either no fluid is moving inside the fluid delivery tube or that the fluid delivery tube is empty and identifying oscillating data conditions corresponding to an oscillating temperature pattern indicating that fluid is being passed in pulses through the fluid delivery tube.

15. A non-invasive method for monitoring a fluid delivery system according to claim 14, wherein the step of processing the data from the sensor corresponding to the initial and changed temperatures thereof further comprises the step of analyzing the data from the sensor against known data conditions for determining the status of the flow of the fluid in the fluid delivery tube.

16. A non-invasive method for monitoring a fluid delivery system according to claim 15, wherein the step of analyzing the data from the sensor further includes the step of displaying the status of the fluid in the fluid delivery tube.

17. A non-invasive method for monitoring a fluid delivery system according to claim 14, wherein the sensor generates data in the form of analog signals representative of the initial and changed temperatures thereof for analysis.

18. A non-invasive method for monitoring a fluid delivery system according to claim 17, wherein the step of monitoring the sensor includes the step of converting the analog signals generated by the sensor to digital signals for analysis.

19. A non-invasive method for monitoring a fluid delivery system according to claim 18, wherein the step of processing the data from the sensor further includes the step of analyzing the digital signals to determine the status of the fluid in the fluid delivery tube.

20. A non-invasive method for monitoring a fluid delivery system according to claim 14, wherein the initial temperature of the self-heated temperature sensor is elevated to a temperature above the temperature of the fluid.