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A sensor for detecting contact of a fluid delivery probe with a fluid surface and for detecting fluid flow through the probe includes a first electrode disposed along a fluid flow path of the probe upstream from a distal tip of the probe and a second electrode longitudinally spaced and electrically

A sensor for detecting contact of a fluid delivery probe with a fluid surface and for detecting fluid flow through the probe includes a first electrode disposed along a fluid flow path of the probe upstream from a distal tip of the probe and a second electrode longitudinally spaced and electrically isolated from the first electrode and disposed at the distal tip of the probe. An oscillating signal is transmitted through the first electrode, and at least a portion of the signal is received through the second electrode. Through changes in the received signal due to the distal tip of the probe coming into contact with a fluid surface or due to fluid flow through the conduit between the first and second electrodes, fluid surface contact and fluid flow can be detected. A pressure sensor can be employed to monitor internal fluid pressure within the fluid conduit of the fluid delivery probe as a secondary, redundant mechanism for detecting fluid flow through the conduit.

대표청구항 ▼

1. A fluid transfer probe comprising:a fluid flow conduit including a first electrically conductive portion and a second electrically conductive portion longitudinally spaced from said first electrically conductive portion, said first and second electrically conductive portions being separated by a

1. A fluid transfer probe comprising:a fluid flow conduit including a first electrically conductive portion and a second electrically conductive portion longitudinally spaced from said first electrically conductive portion, said first and second electrically conductive portions being separated by a substantially non-conductive portion disposed between said first and second electrically conductive portions; a signal-generating circuit electrically coupled to said first electrically conductive portion for generating a signal transmitted by said first electrically conductive portion and a signal-receiving circuit electrically coupled to said second electrically conductive portion for receiving, through said second electrically conductive portion, at least a portion of said signal transmitted by said first electrically conductive portion; wherein said signal-receiving circuit further comprises a signal tuning circuit adapted to adjust at least one characteristic of said received signal. 2. The probe of claim 1, further comprising a processing unit that compares said transmitted signal to said received signal.3. The probe of claim 1, wherein said signal-tuning circuit is adapted to adjust a phase difference between said transmitted signal and said received signal.4. The probe of claim 1, wherein said signal-tuning circuit is adapted to adjust an amplitude of said received signal.5. The probe of claim 1, wherein said signal-tuning circuit is adapted to adjust both an amplitude of said received signal and a phase difference between said transmitted signal and said received signal.6. The probe of claim 1, wherein said signal-receiving circuit further comprises an amplifier for increasing an amplitude of said received signal.7. The probe of claim 6, wherein said signal-receiving circuit further comprises an amplitude amplification selecting circuit to control dynamically said operation of said amplifier.8. The probe of claim 1, wherein said signal-receiving circuit further comprises a phase detector circuit for comparing a phase of said transmitted signal to a phase of said received signal and for generating a dc signal having an amplitude corresponding to a phase difference between said transmitted and received signals.9. The probe of claim 1, wherein said first and second electrically conductive portions comprise tubes formed of electrically conductive material and said substantially non-conductive portion comprises a tube formed of substantially non-conductive material insertingly connected at opposite ends thereof to said tubes formed of electrically conductive material.10. The probe of claim 1, further comprising a pressure sensor operatively coupled with said fluid flow conduit and constructed and arranged to detect fluid pressure within said conduit.11. The probe of claim 10, wherein said pressure sensor produces an electronic signal that provides an indication of said detected fluid pressure.12. A fluid transfer probe comprising a fluid flow conduit including a first electrically conductive portion and a second electrically conductive portion longitudinally spaced from said first electrically conductive portion, said first and second electrically conductive portions being separated by a substantially non-conductive portion disposed between said first and second electrically conductive portions;wherein said first electrically conductive portion comprises a first tube formed from an electrically conductive material, said second electrically conductive portion comprises a second tube formed from an electrically conductive material, and said substantially non-conductive portion comprises an intermediate tube formed from a substantially non-conductive material, said intermediate tube being connected at opposite ends thereof to a respective end of each of said first and second tubes. 13. The probe of claim 12, further comprising a signal-generating circuit electrically coupled to said first electrically conductive portion for generating a signal transmitted by said first electrically conductive portion and a signal-receiving circuit electrically coupled to said second electrically conductive portion for receiving, through said second electrically conductive portion, at least a portion of the signal transmitted by said first electrically conductive portion.14. The probe of claim 13, wherein said signal-receiving circuit further comprises a tuning circuit adapted to produce substantially a near resonance in said received signal.15. The probe of claim 13 further comprising a processing unit that compares said transmitted signal to said received signal.16. The probe of claim 13, wherein said signal-receiving circuit further comprises an amplifier for increasing an amplitude of said received signal.17. The probe of claim 16, wherein said signal-receiving circuit further comprises an amplitude amplification selecting circuit to control dynamically the operation of said amplifier.18. The probe of claim 13, wherein said signal-receiving circuit further comprises a phase detector circuit for comparing a phase of said transmitted signal to a phase of said received signal and for generating a dc signal having an amplitude corresponding to a phase difference between said transmitted and received signals.19. The probe of claim 13, further comprising a pressure sensor operatively coupled with said fluid flow conduit and constructed and arranged to detect fluid pressure within said conduit.20. The probe of claim 19, wherein said pressure sensor produces an electronic signal that provides an indication of said detected fluid pressure.21. A fluid transfer probe comprising;a fluid flow conduit including a first electrically conductive portion and a second electrically conductive portion longitudinally spaced from said first electrically conductive portion, said first and second electrically conductive portions being separated by a substantially non-conductive portion disposed between said first and second electrically conductive portions; and a signal-generating circuit electrically coupled to said first electrically conductive portion for generating a signal transmitted by said first electrically conductive portion and a signal-receiving circuit electrically coupled to said second electrically conductive portion for receiving, through said second electrically conductive portion, at least a portion of said signal transmitted by said first electrically conductive portion; wherein said signal-generating circuit is constructed and arranged to generate an RF signal to be transmitted by said first electrically conductive portion. 22. The probe of claim 21, further comprising a processing unit that compares said transmitted signal to said received signal.23. The probe of claim 21, wherein said signal-receiving circuit further comprises an amplifier for increasing an amplitude of said received signal.24. The probe of claim 23, wherein said signal-receiving circuit further comprises an amplitude amplification selecting circuit to control dynamically the operation of said amplifier.25. The probe of claim 21, wherein said signal-receiving circuit further comprises a phase detector circuit for comparing a phase of said transmitted signal to a phase of said received signal and for generating a dc signal having an amplitude corresponding to a phase difference between said transmitted and received signals.26. The probe of claim 21, comprising a pressure sensor operatively coupled with said fluid flow conduit and constructed and arranged to detect fluid pressure within said conduit.27. The probe of claim 26, wherein said pressure sensor produces an electronic signal that provides an indication of said detected fluid pressure.28. A fluid transfer probe comprising:means for conducting a fluid; first means for conducting electricity disposed at a first end of said fluid conducting means; second means for conducting electricity spaced longitudinally from said first electricity conducting means along said fluid conducting means, said first and second electricity conducting means being separated by a means for substantially insulating electricity disposed between said first and second electricity conducting means; means for generating a signal coupled electrically to said first electricity conducting means; and means for receiving said signal coupled electrically to said second electricity conducting means. 29. The probe of claim 28, wherein said signal receiving means further comprises means for tuning said received signal.30. The probe of claim 29, said tuning means comprises means for adjusting at least one characteristic of said received signal.31. The probe of claim 30, wherein said adjusting means comprises means for adjusting a phase difference between said transmitted signal and said received signal.32. The probe of claim 31, wherein said adjusting means comprises means for adjusting an amplitude of said received signal.33. The probe of claim 30, wherein said adjusting means comprises means for adjusting an amplitude of said received signal.34. The probe of claim 28, wherein said signal receiving means further comprises means for comparing said transmitted signal to said received signal.35. The probe of claim 28, wherein said signal receiving means further comprises means for amplifying said signal.36. The probe of claim 28, wherein said signal receiving means further comprises means for controlling dynamically an operation of said signal amplifying means.37. The probe of claim 28, wherein said signal receiving means further comprises means for comparing a phase of said transmitted signal to a phase of said received signal; andmeans for generating a dc signal having an amplitude corresponding to a phase difference between said transmitted and received signals. 38. The probe of claim 28, further comprising means for detecting pressure operatively coupled with said fluid conducting means.39. The probe of claim 38, wherein said pressure detecting means produces an electronic signal that provides an indication of said detected fluid pressure.