Systems and methods for detection and measurement of elements in a medium

• US 6,969,865 B2
• Filed: 02/14/2002
• Issued: 11/29/2005
• Est. Priority Date: 02/15/2001
• Status: Active Grant

• Current Assignee: ACIST Medical Systems Incorporated (Bracco SPA)
• Original Assignee: ACIST Medical Systems Incorporated (Bracco SPA)
• Inventors: Jester, Steven, Duchon, Douglas
• Primary Examiner(s): PYO, KEVIN K
• Application Number:
  US10/076,837
• Publication Number:
  US 20020145122A1
• Time in Patent Office: 1,384 Days
• Field of Search: 250/573, 250/574, 250/576, 250/214.R, 250/214.A, 250/205, 356/436, 356/437, 356/440, 73/191, 73/614.1, 73/614.3, 604/181, 604/186
• US Class Current: 250/573
• CPC Class Codes: A61M 1/3626 Gas bubble detectors
• CPC Class Codes: G01N 21/59 Transmissivity G01N21/25 takes precedence
• CPC Class Codes: G01N 2291/014 Resonance or resonant frequency
• CPC Class Codes: G01N 2291/0215 Mixtures of three or more gases, e.g. air
• CPC Class Codes: G01N 2291/02433 Gases in liquids, e.g. bubbles, foams
• CPC Class Codes: G01N 2291/048 Transmission, i.e. analysed material between transmitter and receiver
• CPC Class Codes: G01N 2291/102 one emitter, one receiver
• CPC Class Codes: G01N 29/032 by measuring attenuation of acoustic waves
• CPC Class Codes: G01N 29/036 by measuring frequency or resonance of acoustic waves
• CPC Class Codes: G01N 29/42 by frequency filtering or by tuning to resonant frequency
• CPC Class Codes: G01N 29/4427 with stored values, e.g. threshold values
• CPC Class Codes: G01N 29/48 by amplitude comparison

Abstract

Systems and associated methods are provided for improving detection and measurement of elements in a medium, particularly the measurement of gaseous bubbles in liquid medium, such as blood injected into a patient'"'"'s body. The systems include a radiation emitter to emit radiation for traversing through a medium, and an analyzer subsystem to receive and to analyze the traversed radiation for presence and/or absence of gaseous elements in the medium. The methods include receiving at least one collection of data corresponding to at least one emitted radiation traversed through a medium, analyzing said collection of data for at least one predetermined condition; and generating a response upon detection of at least one predetermined condition.

Claims

1. A system for use in a detector, said system comprising:

at least one radiation emitter subsystem to emit at least one radiation emission for traversing through a medium;

at least one analyzer subsystem to receive and to analyze said radiation for presence and/or absence of gaseous elements in said medium;

a filtering subsystem to separate the emitted radiation from ambient radiation in said received radiation;

at least one ambient-light-sample-and-hold subsystem to receive said received radiation in form of an electrical and/or optical signal and to determine ambient light components in said signal;

at least one summation subsystem to receive said received radiation in the form of a representative electrical signal, to receive ambient light components in said signal from said ambient-light-sample-and-hold subsystem and to subtract said components from said signal; and

at least one amplifier for amplifying said subtracted signal.

2. The system of claim 1, wherein said radiation emitter subsystem is a calibration-driven emitter subsystem to alter intensity and/or frequency of said emitted radiation.

3. The system of claim 2, further comprising:

a calibration-driver subsystem to receive analysis data from said analyzer subsystem and to recalibrate said calibration-driven emitter subsystem based on said analysis data.

4. The system of claim 1, said analyzer subsystem further comprising:

a differentiator subsystem to receive said separated emitted radiation, to determine presence and/or absence of gaseous elements in said medium and to differentiate between said gaseous elements.

5. The system of claim 1, wherein said analyzer subsystem further analyzes said radiation for presence and/or absence of a tubing and/or state of a sensor door mechanism.

6. The system of claim 4, wherein said differentiator subsystem differentiates between said gaseous elements based on size of their resultant gaseous bubbles.

7. The system of claim 6, wherein said differentiator subsystem differentiates between said gaseous elements based on a predetermined routine.

8. The system of claim 4, said differentiator subsystem further comprising:

a gas-bubble detect subsystem to detect and report presence and/or absence of gaseous bubbles in said medium;

a gas-column detect subsystem to detect and report presence and/or absence of gaseous columns in said medium; and

a processor subsystem to receive and analyze said reports from said detect subsystems.

9. The system of claim 8, said processor subsystem to issue calibration instructions based on said analyzed reports to a calibration driver subsystem.

10. The system of claim 8, said gas-bubble detect subsystem further comprising:

at least one band-pass filter to receive said received radiation in the form of a representative electrical signal and to minimize undesirable components of said signal;

at least one inverting amplifier to receive said minimized signal from said band-pass filter, to generate a positive amplified signal based on said received minimized signal and to output said amplified signal;

an adjustable signal generator subsystem to generate an adjustable predetermined signal; and

a bubble-detect comparator subsystem to receive said outputted amplified signal, to compare said signal with said outputted amplified predetermined signal to determine presence and/or absence of gas bubbles in medium and to output a comparison result to said processor subsystem.

11. The system of claim 10, said band-pass filter further comprising:

a high-pass filter to reduce noise component in said signal, said high-pass filter outputting to a low-pass filter to further minimize undesirable components of said signal.

12. The system of claim 8, said gas-column detect subsystem further comprising:

an adjustable signal generator subsystem to generate an adjustable predetermined signal; and

a gas-column comparator subsystem to receive said received radiation in the form of a representative electrical signal, to compare said signal with said predetermined signal to determine presence and/or absence of gaseous columns in the medium, and to output a comparison result to said processor subsystem.

13. The system of claim 1, said filtering subsystem further comprising:

at least one sampler-sample-and-hold subsystem to periodically sample said subtracted signal.

14. The system of claim 8, said processor subsystem further comprising:

at least one interrupt-driven subsystem to interrupt flow of operation of said system and to provide a warning upon detection of a predetermined undesirable condition in said reports.

17. The system of claim 1, wherein said medium is a substantially liquid medium.

18. The system of claim 1, wherein said radiation emitter subsystem emits radiation in frequencies of visible light.

15. The system of claim 15, wherein said predetermined undesirable condition is indication of presence and/or absence of at least one gaseous bubble and/or gaseous columns in said reports.

16. The system of claim 15, wherein said predetermined undesirable condition is a time-out interrupt or a malfunction within the system.

19. A method for analyzing data to determine presence and/or absence of predetermined conditions in a medium, said method comprising:

receiving at least one collection of data corresponding to at least one emitted radiation traversed through a medium;

analyzing said collection of data for at least one predetermined condition wherein said analyzing includes separating said emitted radiation from ambient radiation in said received collection of data; and

generating a response upon detection of at least one said predetermined condition wherein said response includes interrupting flow of operations and/or providing a warning,

wherein said separating includes receiving said collection of data in the form of a representative electrical signal in at least one ambient radiation sample-and-hold circuit for determining an ambient radiation component in said collection of data;

receiving said collection of data in the form of a representative electrical signal in at least one summation circuit, receiving said ambient light component in said signal from said ambient-light-sample-and-hold circuit and subtracting said ambient light component from said signal; and

amplifying said subtracted signal utilizing at least one amplifier.

20. The method of claim 19, wherein said radiation is emitted from a calibration-driven emitter subsystem and wherein said response includes issuing of re-calibration instructions to said calibration-driven emitter subsystem.

21. The method of claim 20, wherein said predetermined condition is presence and/or absence of at least one gaseous bubble in said medium.

22. The method of claim 20, wherein said predetermined condition is presence and/or absence of at least one gaseous column in said medium.

23. The method of claim 20, wherein said predetermined condition is a predetermined condition of a timer unit.

24. The method of claim 20, wherein said predetermined condition is a execution of a calibration subroutine.

25. The method of claim 24, said execution of a calibration subroutine further comprising:

adjusting a reference voltage and matching said reference voltage against a voltage reference point for a light-emitting diode; and

repeating said adjusting until said reference voltage matches the voltage reference point of said light-emitting diode.

26. The method of claim 25, said execution of a calibration subroutine further comprising:

resuming the flow of operations upon said matching of the reference voltage to said voltage reference point.

27. The method of claim 25, said execution of a calibration subroutine further comprising:

storing said matched reference voltage in a memory medium.

28. The method of claim 20, wherein said predetermined condition is presence and/or absence of a tubing.

29. The method of claim 20, wherein said predetermined condition is a predetermined state of a sensor door mechanism.

48. The method of claim 19, said separating further comprising periodically sampling said subtracted signal utilizing at least one sampler-sample-and-hold circuit.

30. A method for sensing used in a detector, said method comprising:

emitting at least one radiation emission, said radiation traversing through a medium;

receiving and analyzing said traversed radiation for presence and/or absence of gaseous elements in said medium, wherein said analyzing includes separating said emitted radiation from ambient radiation in said received radiation; and

generating analysis data based on said analyzing,

wherein said separating includes;

receiving said received radiation in the form of a representative electrical signal in at least one ambient-light-sample-and-hold circuit for determining an ambient light component in said signal;

receiving said received radiation in the form of a representative electrical signal in at least one summation circuit, receiving ambient light component in said signal from said ambient-light-sample-and-hold circuit and subtracting said ambient light component from said signal; and

amplifying said subtracted signal utilizing at least one amplifier.

31. The method of claim 30, wherein said emitting is calibration-driven for altering intensity and/or frequency of said emitted radiation.

32. The method of claim 31, further comprising:

receiving said analyzed data and re-calibrating said calibration-driven emitting based on said analyzed data.

33. The method of claim 30, said analyzing further comprising:

receiving said separated emitted radiation and determining presence and/or absence of gaseous elements in said medium; and

differentiating between said gaseous elements.

34. The method of claim 30, said analyzing further comprising:

analyzing said radiation for presence and/or absence of a tubing and/or state of a sensor door mechanism.

35. The method of claim 33, wherein said differentiating between said gaseous elements is based on size of their resultant gaseous bubbles.

36. The method of claim 35, wherein said differentiating between said gaseous elements is based on a predetermined routine.

37. The method of claim 33, differentiating further comprising:

detecting presence and/or absence of gaseous bubbles in medium;

detecting presence and/or absence of gaseous columns in the medium; and

analyzing said detecting and generating at least one analysis report.

38. The method of claim 37, further comprising:

issuing calibration instructions based on said analyzed reports for altering intensity and/or frequency of said emitted radiation.

39. The method of claim 37, said detecting presence and/or absence of gaseous columns further comprising:

receiving said emitted radiation in the form of a representative electrical signal in at least one band-pass filter and minimizing undesirable components of said signal;

receiving said minimized signal from said band-pass filter in at least one inverting amplifier, generating a positive amplified signal based on said received minimized signal and outputting said amplified signal;

generating an adjustable predetermined signal; and

receiving said outputted amplified signal in a bubble-detect comparator circuit, comparing said outputted amplified signal with said predetermined signal to determine presence and/or absence of gas bubbles in medium, and outputting a comparison result for generating at least one said analysis report.

40. The method of claim 39, said minimizing undesirable components of said signal further comprising:

reducing noise component in said signal utilizing a high-pass filter in said band-pass filter, and

outputting said reduced noise signal to a low-pass filter in said band-pass filter for further minimizing undesirable components of said signal.

41. The method of claim 37, said detecting presence and/or absence of

gaseous columns further comprising:

generating an adjustable predetermined signal;

receiving said emitted radiation in the form of a representative electrical signal in a gas-column comparator subsystem; and

comparing said signal with said predetermined signal to determine presence and/or absence of gaseous columns in the medium, and outputting a comparison result for generating at least one said analysis report.

42. The method of claim 30, said separating further comprising:

periodically sampling said subtracted signal utilizing at least one sampler-sample-and-hold circuit.

43. The method of claim 37, said analyzing further comprising:

interrupting the flow of operation and providing a warning upon detection of a predetermined undesirable condition in said analysis reports.

44. The method of claim 43, wherein said predetermined undesirable condition is indication of presence and/or absence of at least one gaseous bubble and/or gaseous columns in said analysis reports.

45. The method of claim 43, wherein said predetermined undesirable condition is a time-out interrupt or indication of a malfunction.

46. The method of claim 30, wherein said medium is a substantially liquid medium.

47. The method of claim 30, wherein said emitting is in frequencies of visible light.