Infusion system and method of use which prevents over-saturation of an analog-to-digital converter

Patent metadata

Field	Value
Publication number	US-12059551-B2
Application number	US-202318178332-A
Country	US
Kind code	B2
Filing date	Mar 3, 2023
Priority date	May 29, 2013
Publication date	Aug 13, 2024
Grant date	Aug 13, 2024

Abstract

To detect air in a fluid delivery line of an infusion system, infusion fluid is pumped through a fluid delivery line adjacent to at least one sensor. A signal is transmitted and received using the at least one sensor into and from the fluid delivery line. The at least one sensor is operated, using at least one processor, at a modified frequency which is different than a resonant frequency of the at least one sensor to reduce an amplitude of an output of the signal transmitted from the at least one sensor to a level which is lower than a saturation level of the analog-to-digital converter to avoid over-saturating the analog-to-digital converter. The signal received by the at least one sensor is converted from analog to digital using an analog-to-digital converter. The at least one processor determines whether air is in the fluid delivery line based on the converted digital signal.

First claim

What is claimed is:

1. A system configured to calibrate a sensor for operating with a fluid delivery line, said system comprising one or more hardware processors configured to:
control an operating frequency of a first sensor, said first sensor configured to transmit a first signal in a fluid delivery line;
receive a digital signal from an analog to digital converter, said analog to digital converter configured to convert a detected signal responsive to the transmitted first signal from analog to digital;
determine that the detected first signal is saturated; and
change the operating frequency of the sensor based on the determination of saturation.

2. The system of claim 1 , wherein the changed operating frequency is different than a resonant frequency of the sensor.

3. The system of claim 2 , wherein the resonant frequency of the sensor is predetermined.

4. The system of claim 1 , wherein the sensor is responsive to signals above a minimum level.

5. The system of claim 4 , wherein the changed operating frequency exceeds the minimum level for detected signals.

6. The system of claim 1 , wherein the changed operating frequency is within ±50% of a resonant frequency.

7. A method of calibrating a sensor for operating with a fluid delivery line in an infusion pump, the method comprising:
controlling an operating frequency of a first sensor, wherein said first sensor is configured to transmit a first signal in a fluid delivery line;
receiving a digital signal from an analog to digital converter, said analog to digital converter configured to convert a detected signal responsive to the transmitted first signal from analog to digital;
determining that the detected first signal is saturated; and
changing the operating frequency of the sensor based on the determination of saturation.

8. The method of claim 7 , wherein the changed operating frequency is different than a resonant frequency of the sensor.

9. The method of claim 7 , further comprising transmitting a second signal at the changed operating frequency.

10. The method of claim 7 , further comprising determining a minimum level for received signals.

11. The method of claim 10 , wherein the changed operating frequency causes the detected signals to exceed the minimum level.

12. The method of claim 7 , wherein the changed operating frequency is within ±50% of a resonant frequency.

Assignees

• Icu Medical Inc

Inventors

• Dumas Iii John Hicks
• Kotnik Paul T
• Sur Kunal
• Belkin Anatoly S
• Ruchti Timothy L

Classifications

• H03M1/129

  Means for adapting the input signal to the range the converter can handle, e.g. limiting, pre-scaling (H03M1/18 takes precedence); Out-of-range indication · CPC title

• G01N29/42

  by frequency filtering {or by tuning to resonant frequency} · CPC title

• G01N29/348

  with frequency characteristics, e.g. single frequency signals, chirp signals (measuring frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04; measuring frequency or analysing frequency spectra G01R23/00) · CPC title

• G01N2291/02433

  Gases in liquids, e.g. bubbles, foams · CPC title

• G01N2291/014

  Resonance or resonant frequency · CPC title