System and method for detecting occlusion using flow sensor output

• US 7,880,624 B2
• Filed: 01/08/2008
• Issued: 02/01/2011
• Est. Priority Date: 01/08/2008
• Status: Active Grant

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Inventors: Yardimci, Atif, DelCastilio, Jorge A.
• Primary Examiner(s): TWEEL JR, JOHN ALEXANDER
• Application Number:
  US11/971,048
• Publication Number:
  US 20090177148A1
• Time in Patent Office: 1,120 Days
• Field of Search: 340/608, 600/526, 600/500
• US Class Current: 340/608
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 5/14212 Pumping with an aspiration and an expulsion action
• CPC Class Codes: A61M 5/16831 Monitoring, detecting, signalling or eliminating infusion flow anomalies low-level float-valves causing cut-off A61M5/40; indicating or recording presence, absence or direction of flow in general G01P13/0066

Abstract

A method and system for detecting an inclusion within an infusion system. The method includes monitoring an output signal of a flowrate sensor as fluid flows through an infusion system. The output signal is then converted with a noise reduction filter to obtain a filtered output signal. The filtered output signal is compared to a threshold value and an alarm is activated if the filtered output signal falls below a desired threshold, thereby indicating an occlusion within the infusion system.

Claims

1. A method of detecting an occlusion within an infusion system comprising:

monitoring an output signal from a flowrate sensor as fluid flows through a fluid pathway of the infusion system to a patient;

acquiring a baseline of the output signal of the flowrate sensor;

filtering the baseline with an averaging filter to calculate a baseline average;

calculating a threshold level as a percentage of the baseline average;

filtering the output signal with a noise reduction filter to obtain a filtered output signal; and

activating an alarm if the filtered output signal falls below the threshold level.

2. The method of claim 1, which includes filtering the output signal with a backward averaging filter.

3. The method of claim 1, which includes filtering the output signal with a ten second averaging filter.

4. The method of claim 1, which includes continuously monitoring and filtering the output signal with the noise reduction filter.

5. The method of claim 1, which includes acquiring the baseline of the output signal of the flowrate sensor while priming the infusion system.

6. The method of claim 1, which includes calculating the standard deviation of the baseline average and calculating the threshold level by subtracting the standard deviation from the baseline average.

7. The method of claim 1, which includes acquiring the baseline of the output signal of the flowrate sensor as the fluid is initially infused into the patient.

8. The method of claim 1, which includes filtering the baseline with a backward averaging filter.

9. The method of claim 1, which includes filtering the baseline with a ten second averaging filter.

10. The method of claim 1, which includes monitoring an analog output signal from the flowrate sensor.

11. A system configured to perform the steps of claim 1.

12. An infusion system, comprising:

a fluid pathway between a fluid source and a patient;

a flowrate sensor disposed along the fluid pathway, the flowrate sensor operable to produce an output signal;

a processing device in communication with and receiving the output signal from the flowrate sensor, the processing device configured to (i) acquire a baseline of the output signal of the flowrate sensor, (ii) filter the baseline with an averaging filter to calculate a baseline average, and (iii) calculate a threshold value as a percentage of the baseline average, and (iv) apply a noise reduction filter to the output signal to produce a filtered output signal; and

an alarm operable with the processing device to indicate when the filtered output signal falls below the predetermined threshold value.

13. The infusion system of claim 12, wherein the flowrate sensor is configured to produce an analog output signal.

14. The infusion system of claim 12, wherein at least one of the averaging filter and the noise reduction filter is of a type selected from the group consisting of:

a backend averaging filter, a ten second averaging filter, a central averaging filter and a weighted averaging filter.