WO2008119425A1 - Method and apparatus for detecting contact of a pipetting needle with a liquid in a vessel - Google Patents

Method and apparatus for detecting contact of a pipetting needle with a liquid in a vessel Download PDF

Info

Publication number
WO2008119425A1
WO2008119425A1 PCT/EP2008/001667 EP2008001667W WO2008119425A1 WO 2008119425 A1 WO2008119425 A1 WO 2008119425A1 EP 2008001667 W EP2008001667 W EP 2008001667W WO 2008119425 A1 WO2008119425 A1 WO 2008119425A1
Authority
WO
WIPO (PCT)
Prior art keywords
needle
pipetting
output signal
pulses
tip
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/EP2008/001667
Other languages
English (en)
French (fr)
Inventor
Oliver Elsenhand
Ulrich Opara
Vuk Siljegovic
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
F Hoffmann La Roche AG
Roche Diagnostics GmbH
Original Assignee
F Hoffmann La Roche AG
Roche Diagnostics GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by F Hoffmann La Roche AG, Roche Diagnostics GmbH filed Critical F Hoffmann La Roche AG
Priority to EP08716187.3A priority Critical patent/EP2132577B1/en
Priority to JP2010500096A priority patent/JP5058333B2/ja
Publication of WO2008119425A1 publication Critical patent/WO2008119425A1/en
Priority to US12/570,319 priority patent/US8100007B2/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N35/00Automatic analysis not limited to methods or materials provided for in any single one of groups G01N1/00 - G01N33/00; Handling materials therefor
    • G01N35/10Devices for transferring samples or any liquids to, in, or from, the analysis apparatus, e.g. suction devices, injection devices
    • G01N35/1009Characterised by arrangements for controlling the aspiration or dispense of liquids
    • G01N35/1011Control of the position or alignment of the transfer device
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01FMEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F23/00Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
    • G01F23/22Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
    • G01F23/28Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring the variations of parameters of electromagnetic or acoustic waves applied directly to the liquid or fluent solid material
    • G01F23/296Acoustic waves
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N35/00Automatic analysis not limited to methods or materials provided for in any single one of groups G01N1/00 - G01N33/00; Handling materials therefor
    • G01N35/10Devices for transferring samples or any liquids to, in, or from, the analysis apparatus, e.g. suction devices, injection devices
    • G01N35/1009Characterised by arrangements for controlling the aspiration or dispense of liquids
    • G01N2035/1025Fluid level sensing

Definitions

  • the invention concerns a method and a level sensor apparatus for detecting contact of a pipetting needle with a liquid contained in a vessel.
  • the invention further concerns a pipetting apparatus for pipetting liquid volumes into and from a liquid contained in a vessel by means of a pipetting needle, and the latter apparatus comprises a level sensor apparatus of the above mentioned kind.
  • Liquid level detection plays an important role for automated chemical analyzers and provides better control of the pipetting process.
  • a pipetting needle contacts liquid contained in a vessel either for aspirating a sample thereof or for delivering a volume of another liquid to the liquid in the vessel.
  • Liquid level detection plays an important role for this purpose.
  • liquid level detection methods are reliable under normal circumstances but fail when operation of the pipetting systems includes piercing of a vessel ' s closure with the pipetting needle or when the pipetting needle encounters foam before it reaches the surface of a liquid contained in a vessel.
  • the level sensor of the pipetting system should be able to detect a liquid level that lies under a cover or closure (membrane, foil) of the vessel.
  • a capacitive level sensor widely used in chemical analyzers, does not work properly in that case and erroneously indicates detection of a liquid surface when it meets a wet cover. Capacitive liquid detectors also often erroneously detect foam lying on a liquid surface as if it were a liquid level.
  • a first aim of the invention is therefore to provide a method and a level sensor apparatus which make possible to reliably detect contact of a pipetting needle with a liquid contained in a vessel and thereby reliable determine the position of the pipetting needle at which the tip thereof contacts the free surface of that liquid.
  • ultrasonic pulses are transmitted through the pipetting needle and pulses reflected at the fluid delivery tip of the pipetting needle are detected. It should be noted that this approach clearly differs from systems wherein continuous wave ultrasound is used. Ultrasonic pulses are generated e.g. by applying pulses of short duration of an electrical signal having a suitable frequency to a piezoelectric transducer. Continuous wave ultrasound is generated e.g. by applying an electrical signal having a constant amplitude and a suitable frequency to a piezoelectric transducer.
  • the main advantages of the method and the level sensor apparatus according to the invention is that by applying ultrasonic pulses instead of continuous waves it is possible to use the time of flight of an ultrasonic pulse to determine the contact and the position or distance at which contact occurs between the transmitting material, in this case the pipetting needle, and any external object or medium. Moreover it is possible to determine also the presence of eventual anomalies of the needle itself.
  • the above mentioned first aim can therefore be achieved even if the pipetting needle has to pierce a cover of the vessel in order to reach the liquid surface, and even if the pipetting needle has to pass through foam in order to reach the liquid surface.
  • the determination of the position of the pipetting needle when the tip thereof contacts the free surface of the liquid achieved with the method and the level sensor apparatus according to the invention makes possible to control the transport of the pipetting needle in such a way that the penetration depth of the tip of the needle in the liquid contained in the vessel is minimized.
  • a second aim of the invention is to provide a level sensor apparatus which in addition makes it possible to verify whether a pipetting needle is present or absent in a pipetting apparatus, whether such a pipetting needle has a deformation or whether there is an undesirable contact of the pipetting needle with a body.
  • the above mentioned second aim is achieved with embodiments of the level sensor apparatus defined by claim 26.
  • a third aim of the invention is to provide a level sensor apparatus which in addition makes it possible to measure the depth of penetration of the tip of said needle in said liquid contained in said vessel. According to a third aspect of the invention the above mentioned third aim is achieved with embodiments of the level sensor apparatus defined by claim 27.
  • a fourth aim of the invention is to provide a pipetting apparatus for reliably pipetting liquid volumes into and from a liquid contained in a vessel by means of a pipetting needle and even if foam lies above said liquid and/or a cap closes an opening of said vessel and has to be pierced by the pipetting needle in order to carry out a pipetting operation.
  • Fig. 1 shows schematically the structure of a pipetting apparatus according to the invention with a pipetting needle at a distance from a liquid in a vessel.
  • Fig. 2 shows schematically the structure of Fig. 1 when the pipetting needle just enters into contact with a liquid in a vessel.
  • Fig. 3 shows an enlarged view of a portion of Fig. 2.
  • Fig. 4 is a schematic representation of the directions of transmitted and reflected ultrasonic waves that propagate through a pipetting needle.
  • Fig. 5 shows schematically the piezoelectric transducers and coupling members used in a variant of the pipetting apparatus represented in Fig. 1.
  • Fig. 6 shows a perspective view of a needle holder 41.
  • Fig. 7 shows a perspective exploded view of the components of needle holder 41 in Fig. 6.
  • Fig. 8 is a perspective cross-sectional view of needle holder 41 in Fig. 6.
  • Fig. 9 is a cross-sectional view of needle holder 41 in Fig. 6.
  • Fig. 10 is a perspective cross-sectional view of the movable part 45 of needle holder 41 in Fig. 6.
  • Fig. 11 shows a block diagram showing more in detail the structure of the electronic circuit 31 in Fig. 2.
  • Fig. 12 shows an amplitude vs. time diagram of the raw output signal of ultrasound sensor 61 delivered at output terminal 73 of demodulator and amplifier 66 of receiver 64 in Fig. 11.
  • Fig.13 shows an example of a signal amplitude (vertical axis) vs. needle penetration depth (horizontal axis) diagram obtained for liquid level detection when vessel 13 is open (has no cover) and there is no foam in vessel 13 and the liquid level lies at a needle penetration depth of 88.3 millimeter measured relative to a reference point located above vessel 13, the signal being the liquid level detection signal delivered at output terminal 77 of DAC (digital analog converter) 68.
  • DAC digital analog converter
  • Fig.14 shows an example of a signal amplitude (vertical axis) vs. needle penetration depth (horizontal axis) diagram obtained for liquid level detection when vessel 13 is open (has no cover) , there is foam in vessel 13 and the liquid level lies at a needle penetration depth of 64 millimeter measured relative to a reference point located above vessel 13, the signal being the liquid level detection signal delivered at output terminal 77 of DAC (digital analog converter) 68.
  • DAC digital analog converter
  • Fig.15 shows an example of a signal amplitude (vertical axis) vs. needle penetration depth (horizontal axis) diagram obtained for liquid level detection when vessel 13 is closed with a cover (so that pipetting needle pierces the cover of vessel 13 as it moves towards the liquid surface 14 in Fig. 1) , there is no foam in vessel 13 and the liquid level lies at a needle penetration depth of 81 millimeter measured relative to a reference point located above vessel 13, the signal being the liquid level detection signal delivered at output terminal 77 of DAC (digital analog converter) 68.
  • DAC digital analog converter
  • V direction of the wave emitted by the electromechanical transducer e.g. a piezoelectric transducer
  • T direction of the reflected wave vibrating in transversal direction as indicated by the double arrow T 1 direction of the incident ultrasonic wave, vibrating in transversal direction.
  • the shape of the vibration is schematically represented on the left side of Fig. 4 close to the letter T 1
  • a first embodiment of a level sensor apparatus according to the invention for detecting contact of a pipetting needle with a liquid contained in a vessel is described hereinafter with reference to Figures 1 to 5.
  • the level sensor apparatus comprises a pipetting needle 11, a needle holder at the end of an arm 21 of a X-Y-Z transport device 22, an electromechanical transducer 15, electronic circuit means 31 connected with the electromechanical transducer 15 and transport means 21, 22 for automatically transporting the needle holder and the needle 11.
  • the electromechanical transducer is e.g. a piezoelectric transducer.
  • the level sensor apparatus comprises a coupling member 16 which is connected to the pipetting needle 11 and to the piezoelectric transducer 15.
  • the piezoelectric transducer 15 is directly connected to the pipetting needle, e.g. by means of an adhesive material, that is without a coupling member located between piezoelectric transducer 15 and the pipetting needle 11.
  • level sensor apparatus including a coupling member located between piezoelectric transducer 15 and the pipetting needle 11 is described hereinafter.
  • Piezoelectric transducer 15 a coupling member 16 and pipetting needle 11 assembled together form an ultrasonic sensor 61 described more in detail hereinafter with reference to Figures 6 to 10.
  • Pipetting needle 11 is made of a material suitable for transmitting ultrasonic waves and has at one end a tip 17 through which liquid is pipetted. The opposite end 29 of needle 11 is connected with a conduit 18 which fluidically connects the pipetting needle with pumping means which make possible to aspirate and to deliver predetermined sample volumes with needle 11.
  • the needle holder at the end of arm 21 holds pipetting needle 11 and transports it in three directions X, Y, Z which are orthogonal to each other.
  • Piezoelectric transducer 15 generates ultrasonic pulses to be transmitted towards needle 11, receives echo pulses reflected at the tip 17 of the needle, and generates an electrical output signal representative of the echo pulses.
  • Two terminals 19 and 20 connect piezoelectric transducer 15 to electrical signal generating means 31 and to electrical signal monitoring means 31 which monitor the output signals delivered by piezoelectric transducer 15.
  • Coupling member 16 is mechanically connected to a part of the needle 11 which is located at a predetermined distance from the tip 17 of the pipetting needle. Coupling member 16 is adapted for applying ultrasonic pulses to the needle 11 and for transmitting to piezoelectric transducer 15 the echo pulses reflected at the tip 17 of the needle.
  • Electronic circuit means 31 comprise: electrical signal generating means for generating a driving signal and for applying this signal to the piezoelectric transducer 15, which generates corresponding ultrasonic pulses which are transmitted through the coupling member 16 and the pipetting needle 11 towards the tip 17 thereof , and electrical signal processing means for receiving and processing the electrical output signal of the piezoelectric transducer 15, for selecting at least one specific component of the output signal by means of a time-of-flight or signal phase analysis, and for evaluating the variation with time of predetermined characteristics of a parameter of the at least one selected component of the output signal in order to detect the position of the needle 11 at which the tip 17 of the pipetting needle 11 contacts the free surface 14 of the liquid 12 contained in the vessel 13 and for providing a resulting signal representative of the result of the evaluation.
  • Transport means 21, 22 transport the needle holder and the needle automatically, position needle 11 at a pipetting position.
  • Transport means 21, 22 are adapted for moving the tip 17 of needle 11 towards and also away from the free surface 14 of the liquid 12 contained in vessel 13.
  • Fig. 4 shows schematically the directions of transmitted and reflected ultrasonic waves that propagate through a pipetting needle.
  • the following directions and angles are represented: V direction of the wave emitted by the piezoelectric transducer
  • T 1 direction of the incident ultrasonic wave vibrating in transversal direction.
  • the shape of the vibration is schematically represented on the left side of Fig. 4 close to the letter T 1
  • FIG. 5 separate transducers and coupling members are used for transmission and for reception of the ultrasonic pulses.
  • a first piezoelectric transducer 25 and a first coupling member 26 connected thereto are used for transmitting ultrasonic waves to needle 11 and a second piezoelectric transducer 27 and a second coupling member 28 connected thereto are used for receiving the ultrasonic echo pulses.
  • Two terminals 32 and 33 connect piezoelectric transducer 25 to electrical signal generating means 31 and to electrical signal monitoring means 31 which monitor the output signals delivered by piezoelectric transducer 25.
  • Two terminals 34 and 35 connect piezoelectric transducer 27 to electrical signal generating means 31 and to electrical signal monitoring means 31 which monitor the output signals delivered by piezoelectric transducer 27.
  • the first piezoelectric transducer 25 and the second piezoelectric transducer 27 are directly connected to pipetting needle 11, i.e. without any coupling member between each transducer and the needle.
  • the coupling member 16 is adapted for transmitting to the needle 11 the longitudinal wave component of ultrasonic waves emitted by the piezoelectric transducer 15.
  • the coupling member 16 is adapted for transmitting to the needle 11 the transversal wave component of ultrasonic waves emitted by the piezoelectric transducer 15.
  • the coupling member 16 is adapted for selectively transmitting to the piezoelectric transducer the longitudinal wave component of ultrasonic echo pulses reflected at the tip 17 of the needle.
  • the coupling member 16 is adapted for selectively transmitting to the piezoelectric transducer the transversal wave component of ultrasonic echo pulses reflected at the tip 17 of the needle.
  • electronic circuit means 31 comprise means for evaluating the variation with time of the amplitude or phase of the at least one selected component of the output signal .
  • the means for evaluating the variation with time of the amplitude and/or phase of the at least one selected component of the output signal comprise means for detecting changes of the amplitude or phase of a reflected untrasonic wave and for generating an output signal which corresponds to discontinuities within needle 11 or contact of the needle 11 with an external object or medium .
  • the means for evaluating the variation with time of the amplitude and/or phase of the at least one selected component of the output signal comprise means for detecting changes of the amplitude or phase of a reflected untrasonic wave and for generating an output signal which corresponds to the depth of penetration of the tip 17 of needle 11 in the liquid 12 contained in vessel 13.
  • the piezoelectric transducer 15 and the coupling member 16 are adapted for applying to the pipetting needle 11 ultrasonic pulses which belong to a selected mode of Lamb wave ultrasonic pulses.
  • a first embodiment of a method according to the invention for detecting contact of the tip of a pipetting needle with a liquid contained in a vessel, the detecting being effected within a time interval during which the pipetting needle is moved towards the liquid in the vessel for performing a pipetting operation, is described hereinafter.
  • the method according to this first embodiment is carried out e.g. with a level sensor apparatus of the type described in this specification and comprises: (a) applying ultrasonic pulses to the pipetting needle 11 by means of a piezoelectric transducer 15 which is mechanically connected to a part of the needle 11 which is located at a predetermined distance from the tip 17 of the pipetting needle 11, (b) transmitting through the pipetting needle 11 mechanical pulses generated by the application of the ultrasonic pulses to the pipetting needle 11,
  • the ultrasonic pulses are applied to the pipetting needle through a coupling member (16) which is mechanically connected to the needle (11) and to a piezoelectric transducer (15) and the coupling member (16) is connected to a part of the pipetting needle (11) which is located at a predetermined distance from the tip (17) of the pipetting needle.
  • a coupling member located between piezoelectric transducer (15) and pipetting needle (11) is described hereinafter.
  • ultrasonic pulses having a selected wave vibration mode are applied to the needle 11.
  • ultrasonic pulses having a longitudinal wave vibration mode are applied to the needle 11.
  • ultrasonic pulses having a transversal wave vibration mode are applied to the needle 11.
  • the coupling member 16 selectively transmits to the piezoelectric transducer 15 the longitudinal wave component of ultrasonic echo waves reflected at the tip 17 of the needle 11.
  • the coupling member 16 selectively transmits to the piezoelectric transducer 15 the transversal wave component of ultrasonic echo waves reflected at the tip 17 of the needle 11.
  • the selecting of at least one specific component of the output signal comprises selecting at least one component thereof which corresponds to a predetermined longitudinal wave mode of the reflected mechanical pulses.
  • the selecting of at least one specific component of the output signal comprises selecting at least one component thereof which corresponds to a predetermined transversal wave mode of the reflected mechanical pulses.
  • the at least one specific component of the output signal is selected by a fixed time- of -flight value of the received output signal.
  • the selecting of the at least one specific component of the output signal comprises selecting a first component thereof which corresponds to a longitudinal wave mode of said reflected mechanical pulses and a second component of said output signal which corresponds to a transversal wave mode of said reflected mechanical pulses.
  • the first component is selected by a first fixed time-of-flight value of the received output signal and the second component is selected by a second fixed time-of-flight value of the received output signal.
  • the evaluating comprises evaluating the variation with time of the amplitude and/or phase of the at least one selected component of the output signal .
  • the evaluating comprises comparing the amplitude and/or phase of the at least one selected component of the output signal with predetermined values for detecting contact of the tip 17 of the pipetting needle 11 with a liquid 12 contained in a vessel 13 and/or foam lying above the liquid 12 and/ or a cap which closes an opening of the vessel.
  • the ultrasonic pulses applied to the pipetting needle 11 belong to a selected mode of Lamb wave ultrasonic pulses.
  • Fig. 6 shows a perspective view of a needle holder 41 which comprises a housing 42.
  • Housing 42 has a connection piece 50 for connecting needle holder 41 to the arm 21 of an X-Y-Z transport device for moving needle holder 41 and thereby pipetting needle 11 in three directions X, Y, Z orthogonal to each other.
  • Needle holder 41 includes an electrical connector 48 which connects an ultrasonic sensor 61 (not shown in Fig. 6) with electronic circuit 31 in Fig. 2.
  • Needle holder 41 further comprises a rotatable knob 51 for adjusting the position of a movable part 45 (not shown in Fig. 6) arranged within housing 42. Rotatable knob 51 is adjacent to a side wall 44 of needle holder 41.
  • the length symmetry axis 30 of a pipetting needle 11 installed within needle holder 41 is aligned with the Z-axis of coordinate axis X, Y, Z represented in Fig. 6.
  • Fig. 7 shows a perspective exploded view of the components of needle holder 41 in Fig. 6.
  • Fig. 7 shows the following components which are arranged within housing 42: a spring 56, a movable part 45, a cam disk 49, an ultrasonic sensor 61 comprising a piezoelectric transducer 15, an acoustical lens 52, a start-up length 55 and the lower portion of pipetting needle 11 which ends in tip 17 thereof.
  • Acoustical lens 52 which is made e.g. of aluminum
  • start-up length 55 which is made e.g. of Plexiglass (trade mark) form a coupling sensor 16 as the one shown in Figures
  • Movable part 45 has an opening 59 which allows the introduction of pipetting needle and comprises a base 60 on which electrical connector 48 is mounted.
  • Fig. 8 is a perspective cross-sectional view of needle holder 41 in Fig. 6.
  • Fig. 9 is a cross-sectional view of needle holder 41 along plane X-Z represented in Fig. 6.
  • Figures 8 and 9 shows how pipetting needle
  • FIG. 8 and 9 show that the upper portion of spring 56 is mounted on wall 43 of housing 42 of needle holder 41 and that the lower part of spring 56 is arranged for exerting a pressure on one side of pipetting needle 11.
  • the position of movable part 45 and thereby the position of needle 11 in X- direction is adjustable by adjusting the angular position of cam disk 49 by means of rotatable knob 51.
  • Rotation of knob 51 and thereby of cam disk 49 in a first sense displaces movable part 45 and thereby needle 11 towards spring 56 and thereby brings needle 11 to its operating position within needle holder 41.
  • Rotation of knob 51 and thereby of cam disk 49 in a second sense opposite to the first sense displaces movable part 45 and thereby needle 11 away from spring 56 and allows removal of needle 11 from its position in movable part 45.
  • Movable part 45 has a chamber 53 which contains ultrasonic sensor 61 formed by the components 15, 52 and 55.
  • Chamber 53 is preferable filled with an electrically conducting pottant which on one side is an acoustical insulation that shields piezoelectric transducer from ultrasonic waves reflected by the walls of the housing 42, and on the other side electrically connect the electrical earth electrode of the piezoelectric transducer 15 with the electrical earth of the level sensor apparatus .
  • the end portion of electrical connection 47 which is in electrical contact with piezoelectric transducer 15 is embedded in an electrical insulator 54.
  • Fig. 10 is a perspective cross-sectional view of the movable part 45 of needle holder 41 in Fig. 6.
  • Fig. 10 shows that the lower part of needle 11 is arranged in a groove 69 in start-up length 55 which is part of coupling member 16.
  • the size of groove 69 is so chosen that about one half of the outer cross-section of needle 11 snuggly fits into groove 69.
  • Fig. 11 shows a block diagram of the electronic circuit 31 in Fig. 2 and also the ultrasonic sensor 61 described above with reference to Figures 6 to 10.
  • electronic circuit 31 comprises a transmitter 62, a microcontroller and ADC (analog to digital converter) circuit 63, a receiver 64 and a DAC (digital to analog converter) circuit 68.
  • Fig. 11 shows the following connections between the various blocks :
  • phase controlled rectifier 67 electrical connection between the output of phase controlled rectifier 67 and an input of microcontroller and ADC 63.
  • Fig. 12 shows an amplitude vs. time diagram of the raw output signal of ultrasound sensor 61 delivered at output terminal 73 of demodulator and amplifier 66 of receiver 64 in Fig. 11.
  • Portion 81 of the raw output signal of ultrasound sensor 61 corresponds to longitudinal vibration modes of pipetting needle 11.
  • Portion 82 of the raw output signal of ultrasound sensor 61 corresponds to transversal vibration modes of pipetting needle 11.
  • Fig.13 shows an example of a signal amplitude (vertical axis) vs. needle penetration depth (horizontal axis) diagram obtained for liquid level detection when vessel 13 is open (has no cover) and there is no foam in vessel 13 and the liquid level lies at a needle penetration depth of 88.3 millimeter measured relative to a reference point located above vessel 13 and indicated with a dashed line on Fig. 13.
  • the signal represented on Fig. 13 is the liquid level detection signal delivered at output terminal 77 of DAC (digital analog converter) 68.
  • Fig.14 shows an example of a signal amplitude (vertical axis) vs. needle penetration depth (horizontal axis) diagram obtained for liquid level detection when vessel 13 is open (has no cover) , there is foam in vessel 13 and the liquid level lies at a needle penetration depth of 64 millimeter measured relative to a reference point located above vessel 13 and indicated with a dashed line on Fig. 14.
  • the signal represented on Fig. 14 is the liquid level detection signal delivered at output terminal 77 of DAC (digital analog converter) 68.
  • Fig.15 shows an example of a signal amplitude (vertical axis) vs. needle penetration depth (horizontal axis) diagram obtained for liquid level detection when vessel 13 is closed with a cover (so that pipetting needle pierces the cover of vessel 13 as it moves towards the liquid surface 14 in Fig. 1) , there is no foam in vessel 13 and the liquid level lies at a needle penetration depth of 81 millimeter measured relative to a reference point located above vessel 13 and indicated with a dashed line on Fig. 15.
  • the signal represented on Fig. 15 is the liquid level detection signal delivered at output terminal 77 of DAC (digital analog converter) 68.
  • the liquid level detection signal delivered at output terminal 77 of DAC (digital analog converter) 68 is further processed, e.g. by comparing the amplitude of the signal with predetermined threshold values or by comparing the first derivative of the signal amplitude with respect to time with predetermined threshold values, in order to generate a signal indicative of contact of the pipetting needle with the free surface 14 of a liquid 12 in vessel 13.
  • DAC digital analog converter
  • Such a signal is suitable used for an optimized operation of the pipetting unit, e.g. for making sure that for pipetting operations the penetration depth of tip 17 of needle 11 in the liquid 12 is equal to a predetermined minimum value.
  • a pipetting apparatus is an apparatus for pipetting liquid volumes into and from a liquid 12 contained in a vessel 13 by means of a pipetting needle.
  • a pipetting apparatus according to the invention is characterized in that it comprises a level sensor apparatus of the type describe above.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Fluid Mechanics (AREA)
  • Electromagnetism (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Acoustics & Sound (AREA)
  • Thermal Sciences (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
  • Automatic Analysis And Handling Materials Therefor (AREA)
  • Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)
PCT/EP2008/001667 2007-03-30 2008-03-03 Method and apparatus for detecting contact of a pipetting needle with a liquid in a vessel Ceased WO2008119425A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP08716187.3A EP2132577B1 (en) 2007-03-30 2008-03-03 Method and apparatus for detecting contact of a pipetting needle with a liquid in a vessel
JP2010500096A JP5058333B2 (ja) 2007-03-30 2008-03-03 ピペット針部と容器内の液体との接触を検出する方法および装置
US12/570,319 US8100007B2 (en) 2007-03-30 2009-09-30 Method and apparatus for detecting contact of a pipetting needle with a liquid in a vessel

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP07006665.9 2007-03-30
EP07006665A EP1975629A1 (en) 2007-03-30 2007-03-30 Method and apparatus for detecting contact of a pipetting needle with a liquid in a vessel

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US12/570,319 Continuation US8100007B2 (en) 2007-03-30 2009-09-30 Method and apparatus for detecting contact of a pipetting needle with a liquid in a vessel

Publications (1)

Publication Number Publication Date
WO2008119425A1 true WO2008119425A1 (en) 2008-10-09

Family

ID=38353764

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2008/001667 Ceased WO2008119425A1 (en) 2007-03-30 2008-03-03 Method and apparatus for detecting contact of a pipetting needle with a liquid in a vessel

Country Status (4)

Country Link
US (1) US8100007B2 (https=)
EP (2) EP1975629A1 (https=)
JP (1) JP5058333B2 (https=)
WO (1) WO2008119425A1 (https=)

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7870797B2 (en) * 2006-04-03 2011-01-18 Artel, Inc. Apparatus and method for aspirating and dispensing liquid
US9086396B2 (en) * 2008-11-28 2015-07-21 Roche Molecular Systems, Inc. System and method for the automated processing of fluids, method for determining the matching of objects
DE102010001229A1 (de) * 2010-01-26 2011-07-28 Hamilton Bonaduz Ag Verfahren und Vorrichtung zur Bestimmung eines flüssigkeitsspezifischen oder vom Benetzungszustand einer Pipettierspitze abhängigen Parameters durch Schwingungsanregung
JP2011169679A (ja) * 2010-02-17 2011-09-01 Nohken:Kk 液面レベル検出装置
US9555407B2 (en) * 2013-03-14 2017-01-31 Protedyne Corporation Laser triangulation for pipette tip position
US10240966B2 (en) * 2013-07-12 2019-03-26 Siemens Healthcare Diagnostics Inc. Fluid level detection system and method
US9273988B2 (en) 2013-08-22 2016-03-01 Frank Olshefsky Precision hydrostatic level and flatness measuring device, system and method
TWI604182B (zh) 2016-04-26 2017-11-01 諾貝爾生物有限公司 取樣組件及其方法
WO2017223214A1 (en) 2016-06-22 2017-12-28 Abbott Laboratories Liquid level sensing apparatus and related methods
DE102017101883A1 (de) 2017-01-31 2018-08-02 Vega Grieshaber Kg Entleerungsvorrichtung zum Entleeren eines Behälters, sowie Befüllungsvorrichtung
TWI651517B (zh) * 2018-03-02 2019-02-21 國立臺灣大學 串接式超音波水位偵測模組及水位計
US12097624B2 (en) * 2019-02-01 2024-09-24 Opentrons LabWorks Inc. Systems and methods for pipette robot time-of-flight functionality
US12578354B2 (en) 2019-10-28 2026-03-17 Siemens Healthcare Diagnostics Inc. Vibrating pipette tips and methods of preventing pipette tip stiction
CN114308156B (zh) * 2021-12-23 2023-03-17 深圳先进技术研究院 一种超声移液装置及方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3737204A1 (de) * 1987-11-03 1989-05-24 Amelung Gmbh Heinrich Vorrichtung zum dosierten umfuellen von fluessigkeiten
FR2628527A1 (fr) * 1988-03-08 1989-09-15 Materiel Auxil Signalisation C Dispositif contacteur a ondes elastiques de lamb pour la detection de la presence d'un liquide a un niveau predetermine
WO1993025914A1 (en) * 1992-06-08 1993-12-23 Behring Diagnostics, Inc. Liquid dispensing system
EP0732598A1 (en) * 1995-03-15 1996-09-18 SANYO ELECTRIC Co., Ltd. Ultrasonic sensor and pipetting apparatus using same
FR2761153A1 (fr) * 1997-03-21 1998-09-25 Noviloire Sa Procede et dispositif pour determiner la position d'un niveau de liquide en relation d'un conduit de prelevement
EP1111351A2 (de) * 1999-12-22 2001-06-27 Endress + Hauser GmbH + Co. Prismen-Lambwellensensor

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06341998A (ja) * 1993-06-03 1994-12-13 Hitachi Ltd 自動分注装置
JPH07146168A (ja) * 1993-11-22 1995-06-06 Suzuki Motor Corp 超音波式液面計測装置
JP3547888B2 (ja) * 1995-10-31 2004-07-28 三洋電機株式会社 超音波センサ及びこれを用いた分注装置
JP3771622B2 (ja) * 1996-03-26 2006-04-26 アロカ株式会社 分注装置
JP3648879B2 (ja) * 1996-10-18 2005-05-18 日立工機株式会社 分注装置
JPH10232239A (ja) * 1997-02-21 1998-09-02 Hitachi Koki Co Ltd 分注装置
JP4110082B2 (ja) * 2003-12-05 2008-07-02 株式会社日立ハイテクノロジーズ 自動分析装置

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3737204A1 (de) * 1987-11-03 1989-05-24 Amelung Gmbh Heinrich Vorrichtung zum dosierten umfuellen von fluessigkeiten
FR2628527A1 (fr) * 1988-03-08 1989-09-15 Materiel Auxil Signalisation C Dispositif contacteur a ondes elastiques de lamb pour la detection de la presence d'un liquide a un niveau predetermine
WO1993025914A1 (en) * 1992-06-08 1993-12-23 Behring Diagnostics, Inc. Liquid dispensing system
EP0732598A1 (en) * 1995-03-15 1996-09-18 SANYO ELECTRIC Co., Ltd. Ultrasonic sensor and pipetting apparatus using same
FR2761153A1 (fr) * 1997-03-21 1998-09-25 Noviloire Sa Procede et dispositif pour determiner la position d'un niveau de liquide en relation d'un conduit de prelevement
EP1111351A2 (de) * 1999-12-22 2001-06-27 Endress + Hauser GmbH + Co. Prismen-Lambwellensensor

Also Published As

Publication number Publication date
JP2010522870A (ja) 2010-07-08
JP5058333B2 (ja) 2012-10-24
EP1975629A1 (en) 2008-10-01
EP2132577A1 (en) 2009-12-16
US8100007B2 (en) 2012-01-24
US20100077853A1 (en) 2010-04-01
EP2132577B1 (en) 2019-12-11

Similar Documents

Publication Publication Date Title
EP2132577B1 (en) Method and apparatus for detecting contact of a pipetting needle with a liquid in a vessel
US10408663B2 (en) Ultrasonic level sensor with reflectors
CA2234627C (en) Method and assembly for overfill detection in liquid level sensing in a vessel by the pulse transit time technique
EP2183564B1 (en) Ultrasonic air and fluid detector
CA2501028C (en) Level sensor apparatus for detecting contact of a pipetting needle with a liquid in a vessel
JP2010522870A5 (https=)
US11137494B2 (en) Distance-detection system for determining a time-of-flight measurement and having a reduced dead zone
US7467560B2 (en) Broadband long pulse ultrasonic inspection
CN101952693A (zh) 检测移液管状态的方法,吸移方法,吸移设备和吸移设备的吸入管
US10739172B2 (en) Measuring device
WO2006042092A2 (en) Ultrasonic fluid level sensor
US20230057737A1 (en) Ultrasound Coupling Shoe
US4403508A (en) Locating interfaces in vertically-layered materials and determining concentrations in mixed materials utilizing acoustic impedance measurements
JP2002340654A (ja) 音響による液位検出方法及び装置
JP7206539B2 (ja) コンクリート充填管理方法
CN212110061U (zh) 一种可变源超声波测试换能器
CN220960188U (zh) 一种外夹式超声波流量传感器
US11609209B2 (en) Flooded member detection by means of ultrasound
KR101489084B1 (ko) 고수위 경보용 음파센서
JP2019124642A (ja) 液面検出装置
JP3048615B2 (ja) 液面検出装置
Arshak et al. Real-Time Tracking of a Moving Object Inside a Tube

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 08716187

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2010500096

Country of ref document: JP

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 2008716187

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: DE