Determining acoustic properties of a sample container and a fluid sample therein using reflected acoustic signals

Abstract

The present application relates to a liquid transport system capable of transporting a liquid sample from a first container to a second container using ultrasonic sound signals and measuring properties of both the liquid and the first container using ultrasonic sound signals. The system uses a transducer to transmit a plurality of sound signals and receive a plurality of signals reflected from the sample and bottom walls of the container to measure the liquid and / or container properties. The plurality of transmitted sound signals are generated during a plurality of transducer locations from the first container, and the system identifies signals that converge on various surfaces of the liquid and / or container and uses the reflected signals corresponding to those locations to calculate the sample and container properties.

Description

[Background technology]

[0001] Generally, the present application relates to a multi-cavity microplate for use in an acoustic droplet ejection system and a system and method for determining material properties of the liquid contained therein.

[0002] Acoustic droplet ejection (ADE) is a technique that uses acoustic energy to move liquids without any physical contact. Some examples of ADE techniques are disclosed in U.S. Pat. No. 10,156,499, which is incorporated herein by reference in its entirety. Acoustic energy (e.g., in the form of ultrasonic pulses) is emitted from a transducer toward a volume of liquid (hereinafter, "sample"). In some examples, a beam is focused onto the upper surface of the sample, and the acoustic energy is transferred to a portion of the sample, thereby moving this portion upward (e.g., as a droplet) away from the rest of the sample.

[0003] In these examples, the sample is contained within a container and the transducer is positioned directly below the container. Thus, the acoustic radiation must pass through at least the bottom wall of the container and the liquid before reaching the upper surface of the sample. The transmitted acoustic radiation is reflected back toward the transducer. The properties of the reflected radiation (e.g., the energy transmission path and attenuation) can be measured or inferred to determine certain properties of the medium through which it travels. The accuracy of ADE can be improved by taking these medium properties into account.

[0004] With respect to a container, it may be useful to know properties such as density, the speed at which acoustic energy propagates (hereinafter "speed of sound"), the thickness of the bottom wall of the container, and the extent to which acoustic energy is attenuated. With respect to a sample, it may be useful to know properties such as density, speed of sound, depth of the sample, and the extent to which acoustic energy is attenuated. Knowledge of the sample's properties may also be beneficial, and such properties may include the sample's depth and volume. In addition, determining the sample's density and energy attenuation properties may also be useful, for example, to verify the sample's properties. For example, such verification can be improved by comparing expected and measured values ​​of reflected acoustic radiation.

[0005] One example of a container is a well in a microplate, such as a 96- or 384-well plate (e.g., a 384-PP microplate). Other examples of containers include tubes, flasks, and beakers. With respect to the microplate example, the characteristics of each well (e.g., the base of each well) will vary from one another even on a single microplate due, for example, to manufacturing variations. Such variations may be in the thickness and consistency of the bottom wall of the container. Variations may occur from well to well or from plate to plate.

[0006] Such container characteristics can be determined to some extent before performing ADE. For example, if certain properties of the material used to fabricate a given container are known in advance, the container's characteristics can be estimated. However, in the case of microplates, the material may vary in consistency from batch to batch or plate to plate. In addition, container thickness may also vary (e.g., from plate to plate or well to well) due to process inconsistencies or tolerances. One such process is injection molding. Even slight variations can affect ADE precision or accuracy. As an example, in the case of injection molding, multiple molds or mold cavities may be used (e.g., to increase production rate). These may vary, and it may be difficult or inefficient to reduce such differences to a level where container consistency would not substantially affect ADE. Additionally, inconsistencies in the manufacturing process may lead to inconsistencies between different plates. For example, it may be impossible, impractical, or expensive to tightly control the injection rate, cooling rate, and composition of liquid plastic.

[0007] Another way to improve consistency is to inspect containers after they are formed and reject those that do not pass quality control, which requires resources such as time, money, and labor, and can waste material, consume energy, and reduce output.

[0008] A different approach to improving ADE results is to characterize containers, such as microplates, after manufacture (e.g., on a plate-by-plate or batch-by-batch basis). For example, each container can be separately assessed to determine specific characteristics before adding sample. Containers can be tagged with identifiers so that the ADE system can read the predetermined characteristics when performing the assay. Each container can then be identified using techniques such as RFID, optical scanning, or by using "acoustic barcodes," as described in U.S. Pat. Nos. 10,592,793 and 10,766,027 (incorporated herein by reference in their entireties). As another option, the characteristics for a given container can be manually entered. Summary of the Invention [Means for solving the problem]

[0009] An embodiment of the present technology relates to a system capable of acoustically measuring at least one property of a liquid sample in a container. The system includes a transducer assembly capable of emitting a signal (e.g., an acoustic signal) toward a bottom wall of the container and receiving a corresponding signal (e.g., an acoustic reflection) reflected from the sample and the container. The system also includes a controller for moving the transducer assembly vertically toward the container and enabling the signal to be emitted at various positions spaced apart from the container. A processor uses the various reflected signals to determine properties of the sample and the container. The transducer assembly uses an acoustic lens to focus the emitted signal to a focal point. The emitted signal converges to a convergence point.

[0010] The processor uses the signal focus point and interactions of various surfaces of the sample and container to calculate the sample and container properties. The processor may calculate sample properties including one or more of the depth, acoustic impedance, and speed of sound of the emitted signal through the sample. The processor may also calculate container properties including one or more of the wall thickness, acoustic impedance, longitudinal speed of sound of the emitted signal, and shear speed of sound of the emitted signal.

[0011] For illustrative purposes, in some embodiments, a container may have two or more wells with two or more corresponding samples in the wells. The controller may be capable of moving the transducer assembly horizontally such that the transducer assembly sequentially moves beneath three or more wells. In some embodiments, the controller may be capable of moving the transducer assembly horizontally along two dimensions (e.g., along a horizontal XY-plane, in the X and Y directions). For example, a container may include three or more wells arranged such that the transducer assembly may need to move in both the X and Y directions to access all wells. The system may be capable of calculating sample and container properties with respect to the corresponding well under which the transducer assembly is moved before moving to a subsequent well. The transducer assembly may also be used to acoustically transport droplets from a sample in a container to a second container. Transport of the sample droplets may occur after the system determines the corresponding properties of a given well and sample and prior to the system moving the transducer assembly to a subsequent well.

[0012] The system may include a reference object, which may be used as part of characterizing the well and / or liquid of the container. The reference object may be positioned such that the transducer is capable of emitting at least one signal toward the reference object and receiving a reflected signal from the reference object. The system may be capable of determining at least one characteristic of the reference object. The system may emit multiple signals toward the reference object and receive multiple reflected signals therefrom while moving toward the reference object. The emitted signals toward the reference object and the emitted signals toward the bottom wall of the container may have the same wavelength, duration, and energy level.

[0013] The system may include a temperature sensor and corresponding processor for measuring the temperature of the coupled liquid as well as the coupled liquid between the transducer assembly and the container.

[0014] The transducer assembly may include an acoustic lens maintained at a fixed distance and position from the transducer. The acoustic lens may define a focal point for each of a plurality of emitted signals. The emitted signals may each converge to a focal point. The system may recognize that the focal point is on a first surface of a container or a surface of the liquid. The system may recognize that the focal point is on a second surface of the container or a surface of the liquid.

[0015] In some embodiments, the system may be capable of acoustically measuring at least one property of the container. The system includes a transducer assembly capable of emitting a signal toward a bottom wall of the container and receiving a corresponding signal reflected from the container. The system also includes a controller for moving the transducer assembly vertically toward the bottom wall of the container, allowing signals to be emitted at various heights from the container bottom wall. A processor uses the various reflected signals to determine a property of the container bottom wall. The transducer assembly focuses the emitted signal to a focal point using an acoustic lens. The emitted signal converges to a convergence point.

[0016] The processor uses the interaction of the focal point with various surfaces of the container bottom wall to calculate the container properties, which may include wall thickness, acoustic impedance, longitudinal sound speed of the emitted signal, and shear sound speed of the emitted signal.

[0017] The container may have three or more wells. The controller may be capable of horizontally moving the transducer assembly such that the transducer assembly sequentially moves beneath three or more wells. The system may be capable of calculating container bottom wall properties for the corresponding wells beneath which the transducer assembly is moved before moving to subsequent wells.

[0018] The system may include a reference object in which a transducer is capable of emitting at least one reference signal toward it and receiving a reflected signal. The system may be capable of determining at least one characteristic of the reference object. The system may emit multiple signals toward the reference object and receive multiple reflected signals from the reference object while moving toward the reference object. The emitted signals toward the reference object and the emitted signals toward the container bottom wall may have the same wavelength, duration, and energy level.

[0019] The system may include a temperature sensor and corresponding processor for measuring the temperature of the coupled liquid, along with the coupled liquid between the transducer assembly and the container bottom wall.

[0020] The transducer assembly may include an acoustic lens maintained at a fixed distance and position from the transducer. The acoustic lens may define a focal point for each of a plurality of emitted signals. Each emitted signal may converge to a focal point. The system may recognize that the focal point is on a first surface of a container or a surface of the liquid. The system may recognize that the focal point is on a second surface of the container or a surface of the liquid.

[0021] Some embodiments of the present technology relate to a system capable of acoustically measuring at least one property of a container holding a sample. The system includes a transducer assembly capable of emitting a signal toward a bottom wall of the container and receiving a corresponding signal reflected from the container. The system also includes a processor capable of measuring at least one property of the container by identifying first, second, and third peaks of the reflected signal. The reflected signal includes multiple echoes, and the processor recognizes that each of the three peaks corresponds to a different echo of the multiple echoes. The detected property may include the container's acoustic impedance, bottom wall thickness, longitudinal sound velocity, or shear sound velocity.

[0022] The processor is further configured to identify the first peak as corresponding to an echo from the bottom of the container, the second peak as corresponding to an echo from a longitudinal wave reflecting from an upper surface of the bottom of the container, and the third peak as corresponding to an echo from a shear wave reflecting from an upper surface of the bottom of the container.

[0023] The system may measure a fourth peak in the reflected signal, which corresponds to an echo of the free surface of the liquid. The system may measure the speed of sound, acoustic impedance, or depth of the liquid in the emitted signal.

[0024] In some embodiments, the present technology may relate to a system capable of acoustically measuring at least one property of a liquid sample in a container. The system includes a transducer assembly capable of emitting a signal toward a bottom wall of the container and receiving a corresponding signal reflected from the sample and the container. The reflected signal includes a plurality of echoes. A processor is capable of measuring the at least one property based on a first peak and a second peak of the reflected signal. The processor is further capable of recognizing that one of the peaks corresponds to an echo from a shear wave reflected from a surface of the container, while another peak corresponds to an echo from a longitudinal wave reflected from the container surface. The system may recognize that the first peak and the second peak correspond to echoes reflected from the same container surface. The system may recognize that the first peak and the second peak correspond to echoes reflected from different container surfaces.

[0025] In some embodiments, the present technology may relate to a system capable of acoustically measuring at least one property of a liquid sample in a container. The system includes a transducer assembly capable of emitting a signal toward a bottom wall of the container and receiving a corresponding signal reflected from the sample and the container. The reflected signal includes multiple echoes. A processor is capable of measuring at least one property based on a delay in time of the echoes but not based on the amplitude of the echoes, while measuring a second property based on the amplitude of the echoes but not based on the time of the echoes.

[0026] In some embodiments, the technology may relate to a system capable of measuring at least one characteristic of an item. The system includes a transducer assembly capable of emitting first and second signals toward a base of the item and receiving corresponding signals reflected from the item. The system also includes a controller for moving the transducer assembly along a vertical direction relative to the item. The system includes a processor for measuring the characteristic of the item. The system emits a first signal at a vertical distance from the item and a second signal at a different vertical distance from the item. The emitted signals may be acoustic signals.

[0027] In some embodiments, the present technology may relate to a system capable of acoustically measuring at least one characteristic of an item. The system includes a transducer assembly capable of emitting a signal toward a base of the item and receiving a corresponding signal reflected from the item. The system has a processor capable of processing data corresponding to first, second, and third peaks of the reflected signal and determining that the first, second, and third peaks correspond to different echoes, thereby determining at least one characteristic of the item.

[0028] Some embodiments include a method for determining a property of a liquid in a container. The method includes receiving the container with a measurement system having a transducer. The method also includes transmitting and receiving, with the transducer, a plurality of acoustic signals at a plurality of distances from the container. The method also includes calculating a physical property of the liquid or the container based on a difference between the received signals.

[0029] Some embodiments include a method for determining a property of a container. The method includes receiving the container with a measurement system having a transducer. The method includes transmitting and receiving, with the transducer, a plurality of acoustic signals at a plurality of distances from a plate. The method includes calculating a physical property of the liquid or the container based on a difference between the received signals. The present invention provides, for example, the following. (Item 1) 1. A system for acoustically measuring at least one property, the at least one property comprising at least one of a property of a container or a property of a liquid within the container, the system comprising: a transducer configured to emit a plurality of emission signals toward a container bottom wall and receive a corresponding plurality of reflected signals, the plurality of emission signals comprising a first emission signal and a second emission signal, the plurality of reflected signals comprising a first reflected signal and a second reflected signal, and the plurality of emission signals and the plurality of reflected signals comprising acoustic signals; a controller configured to move the transducer to a plurality of transducer positions along a first dimension relative to the container bottom wall, the plurality of transducer positions comprising a first transducer position and a second transducer position, the first dimension comprising a vertical dimension; a processor configured to measure the at least one characteristic, in part, by processing data associated with the plurality of reflected signals; and Equipped with the transducer is configured to emit the first emission signal when the transducer is in the first transducer position; The system, wherein the transducer is configured to emit the second emission signal when the transducer is in the second transducer position. (Item 2) 2. The system of claim 1, wherein the at least one characteristic comprises at least one of a depth of liquid in the container, an acoustic impedance of liquid in the container, a speed of sound of the emitted signal through the liquid, or an acoustic attenuation of liquid in the container. (Item 3) Item 10. The system of item 1, wherein the processor is further configured to determine at least one of an acoustic impedance of the container, a thickness of the container bottom wall, a longitudinal sound velocity of the emitted signal through the container bottom wall, an acoustic attenuation of the container, or a shear sound velocity of the emitted signal through the container bottom wall. (Item 4) the container comprises a first well, a second well, and a third well; the system is further configured to measure the at least one property for each of the wells; the controller is further configured to move the transducer along a second dimension from below the first well to below the second well, and the controller is further configured to move the transducer along a third dimension from below the second well to below the third well, the second and third dimensions comprising X and Y horizontal dimensions; Item 1. The system of item 1. (Item 5) 5. The system of claim 4, wherein the container further comprises a first liquid, a second liquid, and a third liquid contained in the first well, the second well, and the third well, respectively, and the system is further configured to measure at least one property for each of the liquids when measuring the at least one property for each of the wells. (Item 6) 6. The system of claim 5, wherein the at least one property for each of the wells comprises, for each well, at least one of a respective acoustic impedance of the liquid, a respective acoustic attenuation of the liquid, or a respective speed of sound of the emitted signal through the liquid. (Item 7) 7. The system of claim 6, wherein the processor is further configured to determine, for each well, at least one of an individual acoustic impedance of the container bottom wall of the well, an individual thickness of the container bottom wall of the well, an individual acoustic attenuation of the container bottom wall of the well, a longitudinal sound velocity of the emitted signal of the container bottom wall of the individual well, or a shear sound velocity of the emitted signal of the container bottom wall of the individual well. (Item 8) The system further comprises a reference object; The transducer is further configured to emit at least one emitted signal toward the reference object and receive at least one reflected signal from the reference object; the processor is further configured to measure the at least one property by, in part, processing data corresponding to the at least one emitted signal toward the reference object and the at least one reflected signal from the reference object. Item 1. The system of item 1. (Item 9) the at least one emitted signal toward the reference object comprises a plurality of emitted signals toward the reference object; the at least one reflected signal from the reference object comprises a plurality of reflected signals from the reference object, each corresponding to a distinct emitted signal toward the reference object; the transducer is further configured to emit the plurality of emitted signals toward the reference object and receive the plurality of reflected signals from the reference object at corresponding positions spaced apart from the container bottom wall; Item 9. The system according to item 8. (Item 10) 9. The system of claim 8, wherein the at least one emitted signal toward the reference object and each of the plurality of emitted signals toward the container have the same wavelength, duration, and energy level. (Item 11) The system further comprises: a coupling liquid between the transducer and the container bottom wall; a temperature sensor configured to measure a temperature of the coupling liquid; Equipped with the processor is further configured to determine the at least one property, in part, by processing data corresponding to a temperature of the combined liquid. Item 1. The system of item 1. (Item 12) further comprising an acoustic lens, the acoustic lens being maintained at a fixed distance and position from the transducer such that the acoustic lens defines a focal point for each of the plurality of emitted signals; each of the plurality of emitted signals converges to a distinct convergence point; the container bottom wall and the liquid further comprise at least a first surface and a second surface; the processor is further configured to recognize that a focal point of the first emission signal is aligned with a bottom wall of the container and a first surface of the liquid; the processor is further configured to recognize that a focal point of the second emission signal is aligned with a bottom wall of the container and a second surface of the liquid. Item 1. The system of item 1. (Item 13) 1. A system for acoustically measuring at least one property, the at least one property comprising at least one of a property of a container or a property of a liquid within the container, the system comprising: a transducer configured to emit an emission signal toward a bottom wall of the container and to receive a reflected signal from the container bottom wall and the liquid, the emitted signal and the reflected signal comprising an acoustic signal; and a processor configured to measure the at least one characteristic by processing data corresponding to each of a first peak, a second peak, and a third peak of the emitted signal and the reflected signal, the reflected signal comprising a plurality of echoes, the processor further configured to recognize that each of the first, second, and third peaks corresponds to a different echo of the plurality of echoes; A system comprising: (Item 14) Item 14. The system of item 13, wherein the processor is further configured to measure at least one characteristic of the container bottom wall by recognizing that the first peak corresponds to an echo from a bottom surface of the container bottom wall, the second peak corresponds to an echo from a longitudinal wave reflecting from an upper surface of the container bottom wall, and the third peak corresponds to an echo from a shear wave reflecting from an upper surface of the container bottom wall. (Item 15) Item 14. The system of item 13, wherein the at least one characteristic of the container comprises at least one of an acoustic impedance, an acoustic attenuation, a bottom wall thickness, a longitudinal sound velocity of the emitted signal, or a shear sound velocity of the emitted signal. (Item 16) Item 14. The system of item 13, wherein the processor is further configured to process data corresponding to a fourth peak of the reflected signal and measure at least one property of the liquid by recognizing that the fourth peak corresponds to an echo from a free surface of the liquid. (Item 17) Item 17. The system of item 16, wherein the at least one property of the liquid comprises at least one of a sound speed, an acoustic impedance, an acoustic attenuation, or a depth of the emitted signal. (Item 18) 1. A system for acoustically measuring at least one property, the at least one property comprising at least one of a property of a container or a liquid within the container, the system comprising: a transducer configured to emit an emission signal toward a container bottom wall and to receive a reflected signal from the container and the liquid, the emitted signal and the reflected signal comprising an acoustic signal, and the reflected signal comprising a plurality of echoes; a processor configured to determine the at least one characteristic by, in part, processing data corresponding to the emitted signal and a first peak and a second peak of the reflected signal to recognize that the first peak corresponds to an echo from a shear wave impinging on a surface of the container bottom wall, and that the second peak corresponds to an echo from a longitudinal wave impinging on a surface of the container bottom wall; and A system comprising: (Item 19) Item 19. The system of item 18, wherein the processor is further configured to recognize that the first peak and the second peak correspond to echoes from the same portion of a bottom wall of the container. (Item 20) Item 19. The system of item 18, wherein the processor is further configured to recognize that the first peak and the second peak correspond to echoes from different surfaces of a bottom wall of the container. (Item 21) 1. A system for acoustically measuring at least one property, the at least one property comprising at least one of a property of a container or a property of a liquid within the container, the system comprising: a transducer configured to emit an emission signal toward a container bottom wall and to receive a reflected signal from the container bottom wall and the liquid, the emitted signal and the reflected signal comprising an acoustic signal; and a processor configured to identify a first peak and a second peak of the reflected signal, the first peak corresponding to a first echo and the second peak corresponding to a second echo, the processor further comprising: measuring a first one of the at least one characteristic based in part on a delay between the first peak and the second peak, but not on amplitudes of the first and second peaks; measuring a second of the at least one characteristic based in part on a difference in amplitude between the first peak and the second peak, but not on a delay between the first peak and the second peak; a processor configured to: A system comprising: (Item 22) 1. A system for measuring at least one characteristic of an item, the system comprising: a transducer configured to emit a plurality of emitted signals toward the item and receive a corresponding plurality of reflected signals from the item, the plurality of emitted signals comprising a first emitted signal and a second emitted signal, and the plurality of reflected signals comprising a first reflected signal and a second reflected signal; a controller configured to move the transducer to a plurality of transducer positions along a first dimension relative to the item, the plurality of transducer positions comprising a first transducer position and a second transducer position, the first dimension comprising a vertical dimension; a processor configured to measure the at least one characteristic, in part, by processing data associated with the plurality of reflected signals; and Equipped with the transducer is configured to emit the first emission signal when the transducer is in the first transducer position; The system, wherein the transducer is configured to emit the second emission signal when the transducer is in the second transducer position. (Item 23) 1. A system for measuring at least one characteristic of an item, the system comprising: a transducer configured to emit an emitted signal towards the item and receive a reflected signal from the item, the emitted signal and the reflected signal comprising an acoustic signal, and the reflected signal comprising a plurality of echoes; a processor configured to measure the at least one characteristic by, in part, processing data corresponding to each of a first peak, a second peak, and a third peak of the emitted signal and the reflected signal, the processor further configured to recognize that each of the first, second, and third peaks corresponds to a different echo; A system comprising: (Item 24) 1. A method for determining at least one property of a container or at least one property of a liquid in said container, said method comprising: receiving the container holding the liquid with a measurement system, the measurement system including a transducer; transmitting and receiving a plurality of acoustic signals at a plurality of distances from the container bottom wall with the transducer; calculating, by the system, at least one property of the liquid or at least one property of the container bottom wall based on the difference in the received signals; A method comprising: (Item 25) 1. A method for determining at least one characteristic of a container, the method comprising: receiving the container with a measurement system, the measurement system having a transducer; transmitting and receiving a plurality of acoustic signals at a plurality of distances from the container bottom wall with the transducer; calculating, by the system, at least one characteristic of the container bottom wall based on the difference in the received signals; A method comprising: [Brief explanation of the drawings]

[0030] [Figure 1]FIG. 1 shows a representation of an ADE system, including a cross-sectional view of a container plate containing multiple containers holding individual samples, a receiver plate, a transducer assembly, and a block diagram of the electronic circuitry.

[0031] [Figure 2] FIG. 2 shows a block diagram of the transducer assembly.

[0032] [Figure 3] FIG. 3 shows a representation of the movement of the transducer assembly relative to the container plate when ADE is performed on multiple samples.

[0033] [Figure 4] FIG. 4 shows a top view of a container plate with multiple containers.

[0034] [Figure 5] FIG. 5 shows a top view of multiple containers in a container plate and a flow illustrating the sequence for performing ADE on each container in turn.

[0035] [Figure 6] FIG. 6 shows a representation of the vertical movement of the transducer assembly and emitted acoustic radiation along the z-axis over time for a single container and sample, according to one embodiment.

[0036] [Figure 7] FIG. 7 illustrates a representation of vertical movement of a transducer assembly relative to a reference object and emitted acoustic radiation along the z-axis over time, according to one embodiment.

[0037] [Figure 8] FIG. 8 is a graph of the acoustic signal reflected from the container and the sample.

[0038] [Figure 9] FIG. 9 is a graph of the acoustic signal reflected from the reference object.

[0039] [Figure 10] FIG. 10 shows the BB-sweep curve for the lower surface of the bottom wall of the container and the reference-sweep curve for the bottom surface of the reference object.

[0040] [Figure 11] FIG. 11 shows the sweep BB curve for the lower surface of the container bottom wall, the TBL-sweep curve and the TBS-sweep curve for the upper surface of the container bottom wall, and the SR-sweep curve for the free surface of the liquid sample.

[0041] [Figure 12A] FIG. 12A shows a geometric representation of an acoustic beam focused onto the bottom surface of a reference object.

[0042] [Figure 12B] 12B-12E show geometric representations of acoustic beams focused at different locations on the container and sample during a sweep, according to one embodiment. [Figure 12C] 12B-12E show geometric representations of acoustic beams focused at different locations on the container and sample during a sweep, according to one embodiment. [Figure 12D] 12B-12E show geometric representations of acoustic beams focused at different locations on the container and sample during a sweep, according to one embodiment. [Figure 12E] 12B-12E show geometric representations of acoustic beams focused at different locations on the container and sample during a sweep, according to one embodiment.

[0043] The foregoing description of certain techniques of the present application will be better understood when read in conjunction with the accompanying drawings. For purposes of illustration, certain techniques are shown in the drawings. It should be understood, however, that the claims are not limited to the arrangements and instrumentation shown in the accompanying drawings. DETAILED DESCRIPTION OF THE INVENTION

[0044] Detailed Description FIG. 1 depicts an exemplary ADE system 100, including a cross-sectional view of a container plate 120 (e.g., a microplate) including multiple containers 122 (e.g., wells of a microplate) that hold multiple individual samples 101, a receiver plate 130 including multiple receiver wells that receive liquid 102 ejected from the samples 101, and a block diagram of electronics 140. ADE system 100 further includes a transducer assembly 110, a coupling liquid 160, an X / Y / Z motor 150, and a temperature sensor (not shown). FIG. 2 further illustrates transducer assembly 110, which includes a transducer 112 and an acoustic lens 113. ADE system 100 can determine properties of both the containers 122 and the samples 101 and eject the liquid. The samples 101 are liquids of interest held in specific containers 122. Although this disclosure focuses on containers that are wells of a microplate, the techniques described herein can be used to characterize other containers, such as tubes, flasks, and beakers, and any samples contained therein.

[0045] To eject the ejected liquid 102 from the sample 101, the transducer 112 generates acoustic energy (e.g., ultrasonic energy), which is then focused by the acoustic lens 113 into a beam 170. In the figures, the beam 170 is shown in two dimensions, but it should be understood that it is three-dimensional. Furthermore, while the beam 170 in FIGS. 1-7 is shown as a perfect triangle, in practice, the beam 170 may have a different shape, as depicted, for example, in FIGS. 12C-12E. Strictly speaking, a triangular beam 170 has a focal point that coincides with the convergence point. All of the beams 170 in FIGS. 1, 3, 6, and 7 are triangular to simplify matters and make the discussion clearer. However, it will be apparent that some of the beams in these figures are not triangular in practice.

[0046] In the context of ADE, the term "focal point" refers to a focal point associated with an acoustic lens and can also be used to refer to the point at which acoustic waves converge (i.e., the convergence point). In many cases, this usage can be useful and provide clarity. However, certain techniques disclosed herein distinguish between the concepts of focal point and convergence point. Therefore, these concepts are described separately.

[0047] 1, the beam 170 is focused onto the upper surface of the sample 101. First, the beam 170 passes through the coupling liquid 160, the bottom wall 124 of the container 122, then through the depth of the sample 101, until it reaches the free surface 103 of the sample 101.

[0048] Electronic circuitry 140 includes processor 143, motor controller 142, signal transmission circuitry 144, signal reception circuitry 145, and temperature sensor circuitry 141. While shown as separate components for purposes of illustration, portions of electronics 140 may be combined or integrated. Furthermore, some components may include multiple different subcomponents. For example, processor 143 may include multiple processors.

[0049] The processor 143 causes the signal transmission circuitry 144 to generate an analog electrical signal, which is communicated to the transducer 112. The transducer 112 then vibrates in response to the analog signal (amplitude and frequency) such that a corresponding acoustic signal is emitted. The transducer assembly 110 may also receive and vibrate in sync an acoustic signal (e.g., an acoustic signal reflected from the container or liquid within the container in response to the emitted acoustic signal). This may generate an analog electrical signal, which is then communicated to the signal reception circuitry 145. The information in the reflected acoustic signal will be analyzed by the processor 143.

[0050] The processor 143 can also communicate with a motor controller 142 to control the location of the transducer assembly 110. The motor controller 142 controls one or more of the X / Y / Z motors 150 to move the transducer assembly 110 relative to the container plate 120. As shown, the X / Y / Z motors 150 are coupled (directly or indirectly) to the transducer assembly 110, although these or other motors may be coupled (directly or indirectly) to the container plate 120 and / or receiving plate 130 to control the relative movement between the transducer assembly 110, the container plate 120, and / or the receiving plate 130.

[0051] In some embodiments, ADE system 100 may include a temperature sensor (not shown), which may be located in coupling liquid 160, in the region between container plate 120 and receiver plate 130, or elsewhere. Temperature sensor circuitry 141 receives a signal (e.g., electrical or wireless) from the sensor and communicates with processor 143 so that the temperature (e.g., of coupling liquid 160, container 122, sample 101, air temperature) may be measured.

[0052] In some embodiments, the transducer assembly 110 may have a cylindrical shape. In some embodiments, instead of using a single transducer 112 to both transmit and receive acoustic signals, the transducer assembly 110 may include separate transmitter and receiver transducers, as disclosed in, for example, U.S. Pat. No. 10,787,670, which is incorporated herein by reference in its entirety. According to one technique, the receive transducer may substantially surround the transmit transducer and acoustic lens.

[0053] FIG. 3 shows a representation of the movement of the transducer assembly 110 relative to the container plate 120 when performing ADE on multiple samples 101. The transducer assembly 110 is moved from container to container 122 along the x-axis. The transducer assembly 110 can also be moved along the y-axis to additional containers 122 (not shown), as further described with respect to FIG. 5. For each container 122, the transducer assembly 110 is centered directly beneath the container 122. Then, to characterize the container 122 and / or the sample 101, as described herein, the transducer assembly 110 moves vertically along the z-axis, emitting a sequence of acoustic signals at different z-positions directly beneath the container 122. This process is sometimes referred to herein as a "sweep." Following characterization, the transducer assembly 110 can be positioned along the z-axis to focus the subsequent beam 170 onto the free surface 103 of the sample 101 and eject the ejected liquid 102. In some embodiments, characterization and ejection can be performed on a container-by-container basis in an alternating manner (e.g., characterizing a first container 122 and / or sample 101, then ejecting droplets 102 before the process is repeated on a second container 122 and sample 101). Alternatively, multiple containers 122 can be characterized before the liquid ejection phase is performed.

[0054] 3 illustrates five sweeps 310 performed on five different containers 122. While this disclosure focuses on ejection of droplets 102, this disclosure also contemplates other actions once the containers 122 have been characterized. For example, rather than ejecting droplets 102 from containers 122, system 100 may be used to perturb sample 101 within containers 122 by a predetermined amount using a sub-ejection acoustic signal that is below the threshold amount required to eject droplets 102.

[0055] FIG. 4 shows a top view of a container plate 120 having a plurality of containers 122. The container plate 120 shown is a 384-well microplate (e.g., a polypropylene microplate designated as 384-PP). FIG. 5 shows a top view of the plurality of container wells 122 and an exemplary pattern (a serpentine pattern) for performing characterization and / or ADE on each container well 122 and the samples 101 therein, as described with respect to FIG. 3. In this example, a motor 150 would move the transducer assembly 110 along the x- and y-axes to position it under the various container wells 122. Any other suitable pattern may also be used (e.g., a raster pattern).

[0056] FIG. 6 shows the movement of the transducer assembly 110 during the sweep of one container 122 and sample 101 from time T1 to T5. Each acoustic energy beam 170 emitted from the transducer assembly 110 has a focal point 171. An acoustic lens 113 focuses the beam 170 to a focal point. The focal point 171 may or may not coincide with the focal point, depending on the properties of the medium through which the beam 170 travels, as will be further explained below. Examples of focal points 171 that are different from the focal point are depicted in FIGS. 12C-12E (the focal points are referred to as 172).

[0057] The focal point 171 moves along the z-axis with the transducer assembly 110. During a sweep, the transducer assembly 110 moves along the z-axis while remaining centered directly beneath a given container 122. In this example, the transducer assembly 110 emits beams 170 at five z-positions (H1, H2, H3, H4, and H5) at corresponding times (T1, T2, T3, T4, and T5). The transducer assembly 110 also receives reflected acoustic energy in response to each transmitted beam 170. The transducer assembly 110 may or may not be at the same z-position during transmission and reception (and the ADE system 100 may mathematically take this into account when processing the received reflected signal). FIG. 6 does not show the coupling liquid 160, but as shown in FIGS. 1 and 3, this is interposed between the transducer assembly 110 and the container 122.

[0058] 6 provides an overview of the detailed discussion that follows. At time T1, the transducer assembly 110 is positioned at z-position H1 such that the convergence point 171 of the beam 170 is below the lower surface 121 of the container bottom wall 124. At time T2, the transducer assembly 110 is positioned at z-position H2 such that the convergence point 171 is aligned with the lower surface 121 of the container bottom wall 124. At time T3, the transducer assembly 110 is positioned at z-position H3 such that the convergence point 171 of the longitudinal waves is at the upper surface 123 of the container bottom wall 124. At time T4, the transducer assembly 110 is positioned at z-position H4 such that the convergence point 171 of the shear waves is at the upper surface 123 of the container bottom wall 124. The significance of shear waves and longitudinal waves will be further explained below. At time T5, the transducer assembly 110 is positioned at z-position H5 such that the focal point 171 is at the free surface 103 of the sample 101. While FIG. 6 shows five z-positions along the z-axis, sweeps may be performed at any suitable number of z-positions of the transducer assembly 110. In some embodiments, the z-position of the transducer assembly 110 may increase incrementally by a defined distance between each transmission. In other embodiments, the system 100 may predict a z-position of interest for the transducer assembly 110 and perform incremental transmissions within ranges below and above the predicted z-position of interest, omitting transmissions when outside those predicted ranges.

[0059] FIG. 7 is similar to FIG. 6 , except that instead of container 122, transducer assembly 110 is directly below reference object 180 during the sweep. In some embodiments, the reference object may be a flat plate. Reference object 180 is used to take reference measurements, as described further below. Reference object 180 may comprise a rigid material, such as metal (e.g., stainless steel), glassy carbon, or fused quartz. The material properties of reference object 180 may be known to ADE system 100. Reference object 180 has a bottom surface 181.

[0060] At time TR1, the transducer assembly 110 is positioned at z-position HR1 such that the convergence point 171 is below the bottom surface 181 of the reference object 180. At time TR2, the transducer assembly 110 is positioned at z-position HR2 such that the convergence point 171 is aligned with the bottom surface 181 of the reference object 180. At time TR3, the transducer assembly 110 is positioned at z-position HR3 such that the convergence point 171 is above the bottom surface 181. While FIG. 7 shows three z-positions along the z-axis, sweeps may be performed at a different number of z-positions of the transducer assembly 110.

[0061] Each step in the sweep shown in FIGS. 6 and 7 depicts an acoustic energy emission in the form of a beam 170. Each emission includes an acoustic signal in which energy varies over time (“emission signal”). The frequency and / or amplitude of the energy may vary over the duration of a given emission signal. The emission signals used during a sweep do not cause droplets to be ejected from the sample 101. However, the emission signals used during a sweep may have similar or the same frequency as those in the emission signals used during the phases in which droplets 102 are ejected from the sample 101. For example, each emission signal during a sweep may use the same constant frequency. The selected frequency may depend on the type of sample 101 and the intended transport volume, as described in U.S. Pat. No. 10,156,499 (incorporated herein by reference in its entirety). To prevent or limit liquid ejection, the emission signals during a sweep may be shorter and have lower amplitude (less energy) than those used to eject droplets 102.

[0062] A portion of the emitted energy is reflected back to the transducer 112 in the form of a reflected acoustic signal ("reflected signal"). Generally, acoustic energy is reflected at interfaces between different media. In the case of acoustic energy emitted toward the container 122 and the sample 101 (see FIG. 6), these interfaces are: (1) the coupling liquid 160 and the lower surface 121 of the container bottom wall 124; (2) the upper surface 123 of the container bottom wall 124 and the sample 101; and (3) the top of the sample 103 and the air above. For convenience, the first interface will be referred to as the bottom wall lower surface 121. The second interface will be referred to as the bottom wall upper surface 123. The third interface will be referred to as the free surface of the sample 103.

[0063] 8 is a graph 800 illustrating a single reflected signal 802 received in response to a single emitted signal. The x-axis indicates time after the emitted signal is emitted, and the y-axis indicates the intensity of the reflected signal 802 (referred to as "amplitude" in the y-axis label). The y-axis indicates the amplitude of the reflected signal 802 at any given time in terms of voltage (V). This is the voltage across the electrical terminals of the transducer 112 (or the voltage corresponding to the voltage measured at the terminals of the transducer 112). The reflected signal 802 may define an envelope 804. As depicted, the envelope 804 outlines the extrema of the reflected signal 802.

[0064] Envelope 804 has four distinct peaks corresponding to four different reflections or "echoes" from the medium interfaces. Peak 806 corresponds to an echo from the bottom wall lower surface (numbered 121 in FIG. 6) and is referred to herein as BB, an abbreviation for "bottom of bottom" time-of-flight. Peaks 808 and 810 both correspond to echoes from the bottom wall upper surface (numbered 123 in FIG. 6). The reason for the two echoes is that the emitted signal transmitted from bottom wall lower surface 121 to the bottom wall upper surface contains two types of waves: longitudinal and shear. Peak 808 corresponds to a longitudinal wave echo from bottom wall upper surface 123 and is referred to herein as TBL, an abbreviation for "top of bottom" time-of-flight of a longitudinal wave echo. Peak 810 corresponds to a shear wave echo from the bottom wall upper surface 123 that is reflected as a longitudinal wave back toward the transducer assembly 110 and is referred to as TBS (an abbreviation for "top of bottom" time of flight of the shear wave echo). For clarity, the TBS signal has both shear and longitudinal portions. The physics that results in two separate echoes, TBL and TBS, from the same interface occurring at different times will be discussed further below. Peak 812 corresponds to an echo from the free surface 103 of the sample 101 and is referred to herein as SR (an abbreviation for "surface reflection"). Each reflected signal 802 during a sweep may have identical BB, TBL, TBS, and SR peaks. However, the times and amplitudes for the peaks will vary based on the z-position of the transducer assembly 110.

[0065] 9 is similar to FIG. 8, but is a graph 900 of a reflected signal 902 reflected from a reference object 180 (see FIG. 7). The reflected signal 902 may define an envelope 904. A peak 906 within the envelope 904 corresponds to an echo from the bottom surface 181 of the reference object 180.

[0066] 10 is a graph 1000 showing two different curves, a BB-sweep curve 1010 and a reference sweep curve 1050, each having peaks 1012 and 1052, respectively. Curves 1010 and 1050 were generated from two different sweeps, with curve 1010 generated from one sweep 1010 and curve 1050 generated from a different sweep. Peak 1012, referred to herein as the BB-sweep curve peak 1012, effectively indicates the z-position of bottom wall lower surface 121. Peak 1052, referred to as the reference-sweep curve peak 1052, effectively indicates the z-position of bottom surface 181 of reference object 180.

[0067] BB-sweep curve 1010 is generated from data from a single sweep. Unlike the sweep shown in FIG. 6 , in which the transducer has five z-positions, the sweep used to generate curve 1010 included more transmissions at different z-positions. At each z-position, a signal is emitted and reflected by the transducer 112. The x-axis of graph 1000 represents TOF (time of flight), which indicates the distance between the transducer 112 and the bottom wall lower surface 121. More specifically, TOF represents the time between the emitted signal and the reflected signal, which can then be used to determine distance. The y-axis represents the amplitude of BB peak 806. BB-sweep curve peak 1012 then indicates the z-position of the bottom wall lower surface 121. More specifically, the BB-sweep curve peak 1012 indicates the distance between the transducer 112 and the bottom wall lower surface 121 at time T2 when the convergence point 171 aligns with the bottom wall lower surface 121, as shown in FIG. 6.

[0068] Reference sweep 1050 is generated similarly to BB sweep curve 1010, except that reference sweep curve 1050 results from reflections from bottom surface 181 of reference object 180 (see BB peak 906 in FIG. 9). Reference-sweep curve peak 1052 then indicates the distance between transducer 112 and bottom surface 181 of the reference plate when convergence point 171 is aligned, at time TR2, as shown in FIG. 7. Unlike the sweep shown in FIG. 7, in which the transducer has three z-positions, the sweep used to generate curve 1050 included more transmissions at different z-positions.

[0069] Figure 11 also shows the BB sweep curve 1010 of Figure 10, as well as three other sweep curves: a TBL-sweep curve 1120, a TBS-sweep curve 1130, and an SR-sweep curve 1140. Each of these curves can be generated from the same sweep or from separate or multiple sweeps. Like Figure 10, graph 1100 has an x-axis that indicates TOF, which effectively indicates distance. The y-axis is also similar to that of Figure 10 in that it indicates the intensity of the reflected signal.

[0070] Curves 1120, 1130, and 1140 are similar to the BB sweep curve 1010. Each has its own peak, namely, TBL-sweep curve peak 1122, TBS-sweep curve peak 1132, and SR-sweep curve peak 1142. Both TBL-sweep curve peak 1122 and TBS-sweep curve peak 132 indicate the distance along the z-axis between the transducer 112 and the bottom wall upper surface 123 of the container 122, except that TBL-sweep curve peak 1112 corresponds to the time of flight between the transducer 112 and the bottom wall upper surface 123 for longitudinal waves, while TBS-sweep curve peak 1132 corresponds to the time of flight between the transducer 112 and the bottom wall upper surface 123 for shear waves. SR-sweep curve peak 1142 indicates the distance along the z-axis between the transducer 112 and the free surface 103 of the sample 101.

[0071] These peaks 1122, 1132, and 1142 respectively indicate the z-position of the transducer 112 when the convergence point 171 aligns with a material interface. The TBL-sweep curve peak 1122 indicates the time T3 when the convergence point 171 of the longitudinal wave aligns with the bottom wall upper surface 123 of the container 122, as depicted in Figure 6. The TBS-sweep curve peak 1132 indicates the time T4 when the convergence point 171 of the shear wave aligns with the bottom wall upper surface 123 of the container 122, as depicted in Figure 6. The SR-sweep curve peak 1142 indicates the time T5 when the convergence point 171 of the longitudinal wave aligns with the free surface 103 of the sample 101, as depicted in Figure 6.

[0072] All of the curves in Figures 10 and 11 were generated using more emissions in the sweep than those shown in Figures 6 and 7. The spacing between z-positions of the transducer 112 per emission can be the same or can vary. In some embodiments, the system 100 can prevent the transducer 112 from emitting a signal at z-positions that would result in unuseful reflected signal data. Such z-positions can be positions where the convergence point 171 and the medium interface are not expected to align.

[0073] Figures 12A-12E illustrate the geometry that occurs between the sweep used for the reference (Figure 12A) and the sweeps used to determine the properties of the container 122 and sample 101 (Figures 12B-12E). These figures define the variables that will be used in the mathematical equations that follow.

[0074] 12A shows a geometric representation of an acoustic beam 170 emanating from the transducer assembly 110 and focused onto the bottom surface 181 of the reference object 180. The transducer assembly 110 has a z-position (also shown in FIG. 7 at HR2) where the focal point 171 is aligned with the bottom surface 181 of the reference object 180. The diameter and radius of the beam 170 at its base are D, respectively. ref and R ref The top surface of the transducer assembly 110 is a distance L from the bottom surface 181 of the reference object 180.ref The angle of the beam 170 (beam angle) is denoted as θ1 (its reciprocal is θ ° 1). The time it takes for acoustic energy to travel back and forth between the transducer assembly 110 and the bottom surface 181 is ref (shown by the reference-sweep curve peak 1052 in FIG. 10).

[0075] 12B-12E illustrate different stages of one sweep of the transducer assembly 110 performed on the container 122, similar to the sequence shown in FIG. 6. In FIG. 12B, the focal point 171 of the acoustic beam 170 is aligned with the bottom wall lower surface 121. In both FIGs. 12C and 12D, the focal point 171 of the acoustic beam 170 is aligned with the bottom wall upper surface 123. In FIG. 12E, the focal point 171 of the acoustic beam 170 is aligned with the free surface 103 of the sample 101.

[0076] In Figure 12B (similar to Figure 12A), acoustic beam 170 has a beam angle of θ1 and a convergence point 171 at bottom wall lower surface 121. Figure 12B corresponds to the reflected signal corresponding to z-position H2 in Figure 6 and BB-sweep curve peak 1012 in Figure 10. The time for acoustic energy to travel round trip between transducer assembly 110 and bottom wall lower surface 121 is BB b The flight time is expressed as:

[0077] 12C and 12D are similar in that they both show the position where the waveform from beam 170 converges to a convergence point 171 at the upper surface 123 of the container bottom wall 124. FIG. 12C corresponds to a transducer assembly located at a z-position at H4 in FIG. 6 and a reflected signal corresponding to the TBL-sweep curve peak 1122 in FIG. 11. FIG. 12D corresponds to a transducer assembly located at a z-position at H3 in FIG. 6 and a reflected signal corresponding to the TBS-sweep curve peak 1132 in FIG. 11. As explained below, the z-positions in FIGS. 12C and 12D are slightly different. The focal point 172 is different from the convergence point 171. This difference is a result of beam 170 intersecting the container bottom wall 124. The focal point 172 is located at a point D ref 12C-12E, the difference in z-position between convergence point 171 and focal point 172 is due to the beam angle, which in the case of FIG. 12E changes once the acoustic energy begins to travel through the thickness of container bottom wall 124 and sample 101. If the beam angle did not change, convergence point 171 would coincide with focal point 172, as shown by the dash-dot wavy line.

[0078] In general, the beam angle of an acoustic wave changes at the interface between two different media, which in the case of Figures 12C and 12D are the container bottom wall 124 and the coupling liquid 160 below the container 122.

[0079] 12C and 12D depict different types of acoustic wave transmission through the bottom wall of container 122. FIG. 12C depicts longitudinal wave transmission through container bottom wall 124. That is, as beam 170 enters container bottom wall 124, a first portion of the acoustic energy from beam 170 is transmitted as a longitudinal wave through the material of the bottom wall of container 122, which is depicted in FIG. 12C. Another portion of the acoustic energy is transmitted as a shear wave through container bottom wall 124, and FIG. 12D depicts this shear wave transmission. Longitudinal and shear waves behave differently. For example, longitudinal waves have higher velocities than shear waves. Due to the difference in speed, the beam angles inside container 122 are different, i.e., beam angle θ2 (longitudinal wave) in FIG. 12C exceeds beam angle θ3 (shear wave) shown in FIG. 12D. This difference in beam angle necessitates that the z-position of the transducer assembly 110 be slightly different to allow for convergence at the bottom wall upper surface 123, corresponding to the slight difference in z-positions H3 and H4 in FIG. 6. FIGS. 12C and 12D are not drawn to scale. For example, in some embodiments, there is only a 5% change in the z-position of the transducer between FIGS. 12C and 12D (e.g., D bbs is D bbl (It can be 5% greater than

[0080] 12C and 12D also show the time for acoustic energy to travel between multiple surfaces. With respect to FIG. 12C, the time for acoustic energy to travel back and forth between the transducer assembly 110 and the bottom wall lower surface 121 and bottom wall upper surface 123 is BB l and TBL l The reflected signal (similar to FIG. 8) corresponding to the TBL-sweep curve peak 1122 is represented by BB l and TBL l Similarly, with reference to FIG. 12D, the time for acoustic energy to travel round trip between the transducer assembly 110 and the bottom wall lower surface 121 and bottom wall upper surface 123 is given by B, B, C, and C, respectively. s and TBS s The reflected signal, which corresponds to the TBS-sweep curve peak 1132, is represented by BBs and TBS s provides time-of-flight values ​​for

[0081] FIG. 12E depicts a longitudinal wave beam 170. FIG. 12E corresponds to z-position H4 in FIG. 6 and SR-sweep curve peak 1142 in FIG. 11. Similar to FIG. 12C, the focal point 172 is located above the bottom wall upper surface 123 and may also be located above the sample free surface 103. Similar to FIG. 12C, the beam angle changes from θ1 in the coupling liquid 160 to θ2 within the container 122. As the beam 170 continues beyond the bottom wall upper surface 123 into the sample liquid 101, the beam angle again changes to θ4. Again, this change is due to another interface between different media, in this case the container bottom wall 124 and the sample 101.

[0082] With reference to FIG. 12E, the time for acoustic energy to travel back and forth between the transducer assembly 110 and the bottom wall lower surface 121 and bottom wall upper surface 123 is BB f and TBL f The time for acoustic energy to travel round trip between the transducer assembly 110 and the sample free surface 103 is represented by SR f The reflected signal corresponding to the SR-sweep curve peak 1142 is represented by BB f , TBL f , and S.R. f provides a time value for

[0083] 12A-12E illustrate some additional geometric relationships. These are the distances D between the transducer assembly 110 and the bottom wall lower surface 121 at locations H4, H3, and H5, respectively. bbl (See Figure 12C), D bbs (See Figure 12D), and D bbf (See FIG. 12E), the thickness of the container bottom wall 124, T p (See FIGS. 12C-12E), L, which is the vertical distance between the bottom wall lower surface 121 and the focal point 172 pl (See Figure 12C), L ps (See Figure 12D), and LSR (See FIG. 12E), R is the radius of the beam 170 at the bottom wall lower surface 121 when the convergence point 171 is at the bottom wall upper surface 123. l (See Figure 12C) and R s (see FIG. 12D), R is the radius of the beam 170 at the bottom wall upper surface 123 when the convergence point 171 is at the sample free surface 103. f (See Figure 12E).

[0084] 12C-12E also illustrate the times it takes for sound to travel round trip between additional portions of the system. These times are the transit times, t, for the signal to pass through and enter the container bottom surface 121 after reflecting from the bottom wall upper surface 123 before exiting it. pl (See Figures 12C and 12E) and t ps (see FIG. 12D), and t f (See FIG. 2E).

[0085] As will be explained further below, the above-described geometry and principles shown in Figures 12A-12E can be used in combination with the methods illustrated in Figures 6 and 7, along with measurements of reflected signals shown in Figures 8-11, to determine certain properties of a sample.

[0086] The processor 143 controls the operation of the system 100 and can receive data as discussed above to determine one or more properties of the sample 101 and the container 122 using techniques described below. The properties of the sample 101 can include the speed of sound v f (i.e., the speed at which the sound progresses through sample 101), the depth T of sample 101 f , and acoustic impedance Z f The container bottom wall 124 has the following characteristics: pl , shear sound velocity v ps , the thickness of the container bottom wall T p , and acoustic impedance Zp Includes:

[0087] Additionally, the system calculates the speed of sound v for the coupling liquid 160 based on the temperature of the coupling liquid 160 measured at the temperature sensor by the temperature sensor circuitry 141 and known properties based on the type of coupling liquid 160. w Similarly, the system can determine the density of the air ρ based on the temperature of the air above the container 122 at the temperature sensor in the temperature sensor circuitry 141 and known properties of the air. a and the speed of sound in air, v a It can be determined that: Longitudinal sound velocity in the container and thickness of the container bottom wall

[0088] Longitudinal sound speed v in container 122 pl and its thickness T p can be determined simultaneously. First, the distance L ref (1) the time of flight BB of sound traveling round trip through the coupling liquid 160 between the transducer assembly 110 and the reference object bottom surface 181 ref (see FIG. 12A), and (2) the speed of sound in the coupling liquid 160, v w The speed of sound in the coupling liquid, v, can be determined based on the w can be determined based on its temperature and other known properties. Once these values ​​are determined, L ref can be solved as shown in Equation 1.

number

[0089] Next, θ1 (and therefore its inverse θ1°) is (1)L ref and (2) R ref (which is known based on the shape of the beam 170 emanating from the transducer assembly 110) and the angular correction term φ. The angular correction term φ is calculated based on the D refConsidering the difference between the diameter φ and the angle θ, φ can be determined in advance. Then, θ can be solved for as shown in Equation 2.

number

[0090] Next, the container bottom wall thickness T p and the longitudinal sound velocity v in container 122 pl is calculated based on the relationship in Figures 12A and 12C. p is the vertical distance between the bottom wall lower surface 121 and the bottom wall upper surface 123. pl is the speed at which a longitudinal sound wave travels through the bottom wall of the container 122. For subsequent calculations, the system processor 143 also uses additional equations based on Snell's law.

number

[0091] In general, Snell's Law relates the wave speed and angle of incidence through one medium to the wave speed and resulting angle of refraction in a second medium. Thus, Snell's Law relates the transmitted signal 170 as it passes through the coupling liquid 160 at a corresponding beam angle θ1 to the bottom wall lower surface 121 compared to the deflected signal passing through the container 122 at a transmission angle θ2. As shown in FIG. 12C, the transmission angle θ2 is greater than the beam angle θ1. This is because the container well longitudinal sound speed v pl is the combined liquid sound speed v w This result exceeds the previous one.

[0092] Next, the container longitudinal sound speed v pl is solved. First, the transition time t pl is the measured bottom top time of flight TBL l and the bottom flight time BB l The thickness of the container bottom wall T is calculated based on the difference between the pHowever, the container longitudinal sound velocity v pl is solved as shown in Equation 4.

number

[0093] Next, the container longitudinal beam radius R l First, the container bottom distance D bbl But the speed of sound in the bonded liquid is v w and the bottom flight time BB l and Equation 1. Then, L pl But, L ref and D bbl (See Figure 12C.) Then, R l is calculated by θ1 and R as shown in Equation 5. l And, L pl (See FIG. 12C)

number

[0094] Sin θ2 can also be solved. θ2 and R l And, T p The spatial relationship between (see FIG. 12C) results in Equation 6:

number

[0095] Finally, T p can be solved. At this point, v pl , sin θ2, θ1, R l In addition, φ and v w is known. By applying Snell's Law from Equation 3 and substituting known values ​​and variables, the thickness of the container's bottom wall, T p This leads to equation 7, which can be solved numerically for

number

[0096] Container longitudinal sound speed v pl can be solved numerically at this point. p and t pl is applied to equation 4, and v pl The value of can be calculated. Shear sound velocity in the container and thickness of the container bottom wall

[0097] Shear sound velocity v in container 122 ps and container bottom wall thickness T p can also be determined based on the relationship of Figures 12A and 12D.

[0098] First, the container shear sound velocity v ps is solved. First, the transition time t ps is the measured bottom top time of flight of the shear wave echo, TBS s and the bottom flight time BB s (See FIG. 12D.) In FIG. 12D, the shear wave component of the acoustic beam propagates through the container bottom wall, resulting in a longitudinal wave reflection from the top of the container bottom wall towards the bottom of the container bottom wall. The transit time t ps corresponds to the total time for this penetration, propagation, and reflection within the container bottom wall. For clarity, the transition time T ps consists of a unidirectional shear signal and a unidirectional longitudinal signal. The shear sound velocity v ps is the transition time t as given in Equation 4 psl and longitudinal time delay t pl The container bottom wall thickness T p is treated as an unknown value even though it is pre-calculated in Equation 7. The container shear sound velocity, v ps is solved as shown in Equation 8.

number

[0099] Snell's law is applied to FIG. 12D, resulting in Equation 9.

number

[0100] Container shear beam radius R s can be solved. First, the shear container bottom distance D bbs But the speed of sound in the bonded liquid is v w and the bottom flight time BB s and Equation 1. Then, L ps But, L ref and D bbs (See Figure 12D). Then, R s is calculated by θ1 and R as shown in Equation 10. s And, L ps (See FIG. 12D) based on the relationship between

number

[0101] Sin θ3 can also be solved. θ3 and R s And, T p The spatial relationship between (see FIG. 12D) results in Equation 11:

number

[0102] Finally, T p can be solved for the second time. At this point, v ps , sin θ3, angle θ1, R s is solved. Also, φ and v w is still known. By applying Snell's Law from Equation 9 and substituting known values ​​and variables, we can determine the thickness of the container's bottom wall, T p This leads to equation 12, which can be solved numerically for

number

[0103] T from solving equations 7 and 12 p The values ​​for are both the thickness T of the container bottom wall 124 p However, v in Equation 4 pl The calculation of TBL corresponds to the specific reflection signal selected for the TBL-sweep curve peak 1122. l and B.B. l Similarly, the value of v in Equation 8 is sensitive to the value used for ps The calculation of TBS-sweep curve peak 1132 corresponds to the specific reflection signal selected for TBS s and B.B. s is sensitive to the value used for v pl Based on, and v ps Based on both T p By separately calculating T for both sets of equations, the iterative process p can be used to determine the specific reflected signals and their corresponding time-of-flight values ​​for the individual TBL-sweep curve peaks 1122 and TBS-sweep curve peaks 1132 that provide the closest approximation of .times. ... Sound speed in liquids and sample depth

[0104] Once the calculations for container 122 are complete, the sound velocity v of sample 101 f and depth T of sample 101 f can be determined. SR f and TBL f The difference between the liquid transition time t f Provide. T f is used as a variable. f and t f The relationship between provides the following equation 13:

number

[0105] T f and θ4 can also be determined using pre-calculated values. p , θ1, and θ2. In addition, L SR But as before, D bbf and v w Similarly, v f can be calculated by using Snell's law: w , v pl , θ1, and θ2 are all calculated, so T f and v f can be calculated numerically using application of the relationship in FIG. 12E, resulting in equations 14 and 15.

number

number

[0106] These calculations identify specific measured values ​​and corresponding calculations as described above, but those skilled in the art will recognize other similar calculations based on similar or equivalent measurement points, or equations based on the geometry and corresponding reflected signals established by the system during a sweep, as shown in Figures 12A-E. Acoustic impedance of the container and sample

[0107] The acoustic impedances of the container bottom wall 124 and the sample 101 are calculated. The reference-sweep curve peak 1052 and the BB-sweep curve peak 1012 in FIG. 10 and the TBL-sweep curve peak 1122 and the SR-sweep curve peak 1142 in FIG. 11 are used to calculate corresponding impedance values ​​for both the container bottom wall 124 and the sample 101. A pressure reflection coefficient R relates the acoustic impedance Z1 of the first interface to the acoustic impedance Z2 of the second interface, and the sound wave reflects at the interface between the first interface and the second interface. The pressure reflection coefficient R can be related as Equation 16:

number

[0108] The pressure transmission coefficient T relates the acoustic impedance Z1 of the first interface to the acoustic impedance Z2 of the second interface when a sound wave passes through the interface between the first and second interfaces. The pressure reflection coefficient T can be related as Equation 17:

number

[0109] With a known density ρ and a known speed of sound v, the acoustic impedance of a material is based on Equation 18:

number

[0110] Impedance Z of coupling liquid 160 w again uses temperature sensor circuitry 141 to determine the temperature of the coupled liquid 160 and calculate the coupled liquid density ρ w and the combined liquid sound speed v w Similarly, the system processor 143 determines the corresponding temperature sensed by the temperature sensor circuitry 141 and the corresponding air density ρ a and the air speed of sound v a and the impedance Z of the air space above the sample 101 aIn addition, the system processor 143 also calculates the impedance Z of the reference object 180 based on a reference object made from a known material. ref The value corresponding to the

[0111] The initial sound pressure p0 is calculated. REF is derived from the amplitude of the reference-sweep curve peak 1052 in FIG. 10. Z ref , Z a , REF, and Equation 16, the interface between the coupling liquid 160 and the reference object in FIG. 12A can be expressed as Equation 19:

number

[0112] The initial sound pressure p0 is solved as Equation 20.

number

[0113] Next, the container impedance Z p But it is solved. Z w and p0 remain the same. The amplitude of the BB-sweep curve peak 1012 in FIG. 11 is p BB 12B also provides the physical relationship. Z p can be solved numerically using equation 21.

number

[0114] Similarly, the sample impedance Z f is calculated. Z p , Z w , and p0 remain the same as above. The amplitude of the TBL-sweep curve peak 1122 in FIG. 11 is p TB Figure 12C provides the physical relationship. f can be solved numerically using Equation 22.

number

[0115] Container wall impedance Z p and sample impedance Z f The value of can be further refined. f , Z p , Z w , Z a , and p0, along with the surface reflection amplitude p SR By using TB The signal path is represented by Figure 12E. The resulting equation is:

number

[0116] By using equations 21-23, the container wall impedance Z p and sample impedance Z f The value for the bottom amplitude p BB , the upper amplitude of the bottom p TB , and the surface reflection amplitude p SR The parameter can be iteratively adjusted to identify the value that best correlates with the parameter. Container and sample acoustic attenuation

[0117] Acoustic attenuation is a measure of the energy loss of sound as it propagates through a medium. Acoustic attenuation is a property of a given medium. Using the techniques described herein, it may be possible to measure the acoustic attenuation of the material of the container 122 (or more simply, the container 122 attenuation). In particular, the additional sweep or set of sweeps described in connection with FIGS. 12A-12E may be performed without the sample 101. In other words, sweeps are performed both with and without the sample 101. The order of the sweeps (with and without the sample 101) may not matter. Furthermore, the additional sweep data may resemble that shown in FIGS. 8, 9, 10, and 11 without the sample free-surface reflection 812 ( FIG. 8 ), the SR-sweep curve 1140 ( FIG. 11 ), and the SR-sweep curve peak 1142 ( FIG. 11 ). Furthermore, the sweep data may be different when sample 101 is not present, but the general principles, particularly regarding timing, may remain similar.

[0118] To determine the container 122 attenuation, the container 122 may be empty, i.e., the container 122 does not hold a sample 101, before the measurement is taken. f , Z p , Z w、 Z a , T p , and the method for determining p0 can remain the same as described above. The amplitude of the TBL-sweep curve peak 1122 in FIG. 11 without the presence of the sample 101 is p TB, empty The amplitude of the TBL-sweep curve peak 112 may be higher when measured without the sample 101. FIG. 12C illustrates the geometry and relationship, but as noted, the sample 101 may not be present when determining the container 122 attenuation. In this case, the container 122 attenuation α p can be solved using equation 24 (adapted from equation 22).

number

[0119] Once α p Once this is determined, the acoustic attenuation of the sample 101 is calculated as Z f , Z p , Z w、 Z a , T p , and p0 together with p SR The amplitude of the SR-sweep curve peak 1142 in FIG. SR The signal path is represented by Figure 12E. The resulting equation (adapted from Equation 23) is:

number

[0120] As used in equations 20-22 and 24-25 (or others), the bottom amplitude p BB , the upper amplitude of the bottom p TB , and the surface reflection amplitude p SR Values ​​for may be adjusted to calibrate measurement instrumentation. Other aspects of the techniques disclosed herein may similarly be calibrated for a given measurement system, such as a portion of system 100 (e.g., transducer assembly 110, electronics 140, and / or motor 150). This may be done by performing measurements using one or more containers and samples, each having known properties as relevant to the techniques described herein. Because the properties of the container and sample are known, the measured properties would also be known if system 100 were ideal. As will be appreciated, the system is rarely, if ever, ideal. The predicted measurements may be compared to the actual measurements. This may provide calibration information, i.e., sufficient information to calibrate a portion of system 100 (e.g., transducer assembly 110, electronics 140, and / or motor 150). Once a portion of system 100 (e.g., transducer assembly 110, electronics 140, and / or motor 150) is calibrated, no further adjustments may be required. In an ideal system, p BB , p TB, and / or p SR Further adjustment of the experimentally determined value of may not be necessary. However, it may be useful to perform additional adjustments due to possible nonlinearities in the electronics 140 and / or the transducer assembly 110 (including the transducer 112 and acoustic lens 113), e.g., any deviation from a plane wave at the transducer's focal point. Thus, the aforementioned peak value (or other values, as will be understood) may be adjusted to account for equipment behavior, performance variations, or deviations from the theoretical value. Calibration information may be used to adjust the operation of the system 100 and / or to adjust the processing of data generated during the measurement process. Calibration, as discussed, may be performed only once for a given component of the system 100, or may be performed periodically or from time to time as components of the system 100 age or are moved to different environments.

[0121] Once some or all of the characteristics of the sample 101 and container 122 are determined, they can be used by the system to determine parameters for ADE, resulting in more precise and accurate droplet ejection.

[0122] In some embodiments, a machine learning model employing one or more neural networks may be used to determine parameters related to ADE based on the concepts disclosed herein. For example, data associated with the waveform of reflections from a sweep may be used to train a machine learning model (which may be trained using supervised learning, unsupervised learning, etc.), and this trained model may be used to determine ADE parameters. In some embodiments, one or more of the relationships disclosed herein may be input as constraints for the machine learning model (e.g., one or more of Equations 4, 8, and 13).

[0123] Many of the techniques described herein may be implemented on or in conjunction with a computer storage product with a non-transitory computer-readable medium (which may also be referred to as a non-transitory processor-readable medium) having thereon instructions or computer code for performing various computer-implemented operations, as will be understood. The medium may include one or more distinct media. The code may execute on one or more processors, such as processor 143. The computer-readable medium (or processor-readable medium) is non-transitory in the sense that it does not itself include a transient, propagating signal (e.g., a propagating electromagnetic wave that carries information over a transmission medium such as space or cable). The medium and computer code (which may also be referred to as code) may be designed and constructed for a specific purpose or purposes. Examples of non-transitory computer-readable media include, but are not limited to, magnetic storage media such as hard disks, floppy disks, and magnetic tape, optical storage media such as compact discs / digital video discs (CD / DVDs), compact disc read-only memories (CD-ROMs), and holographic devices, magneto-optical storage media such as optical discs, carrier wave signal processing modules, and hardware devices specially configured to store and execute program code such as application specific integrated circuits (ASICs), programmable logic devices (PLDs), read-only memory (ROM), and random access memory (RAM) devices. Other embodiments described herein relate to computer program products, which may include, for example, the instructions and / or computer code discussed herein.

[0124] Some embodiments and / or methods described herein can be implemented by software (executing on hardware), hardware (e.g., processor 143), or a combination thereof. Hardware modules may include, for example, general-purpose processors, field programmable gate arrays (FPGAs), and / or application-specific integrated circuits (ASICs). Software modules (executing on hardware) may be implemented in C, C++, Java, Ruby, Visual Basic, TM , and / or other object-oriented, procedural, or other programming languages ​​and development tools. Examples of computer code include, but are not limited to, microcode or microinstructions, machine instructions such as those produced by a compiler, code used to produce web services, and files containing higher-level instructions that are executed by a computer using an interpreter. For example, embodiments may be implemented using imperative programming languages ​​(e.g., C, Fortran, etc.), functional programming languages ​​(Haskell, Erlang, etc.), logic programming languages ​​(e.g., Prolog), object-oriented programming languages ​​(e.g., Java, C++, etc.), interpreted languages ​​(Java Script, Typescript, Perl), or other suitable programming languages ​​and / or development tools. Additional examples of computer code include, but are not limited to, control signals, encrypted code, and compressed code.

[0125] It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the novel techniques disclosed herein. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the novel techniques without departing from their scope. Therefore, the novel techniques are not limited to the particular techniques disclosed, but are intended to include all techniques that fall within the scope of the appended claims.

Claims

1. 1. A system for acoustically measuring at least two properties, the at least two properties comprising at least one property of a container and at least one property of a liquid within the container, the system comprising: a transducer configured to emit a plurality of emission signals toward a bottom wall of a container containing a liquid and to receive a corresponding plurality of reflected signals, the plurality of emission signals comprising a first emission signal and a second emission signal, the plurality of reflected signals comprising a first reflected signal and a second reflected signal, and the plurality of emission signals and the plurality of reflected signals comprising acoustic signals; a controller configured to move the transducer to a plurality of transducer positions along a first dimension relative to the container bottom wall, the plurality of transducer positions comprising a first transducer position and a second transducer position, the first dimension comprising a vertical dimension; a processor configured to measure the at least one characteristic, in part, by processing data associated with the plurality of reflected signals; Equipped with the transducer is configured to emit the first emission signal when the transducer is in the first transducer position; the transducer is configured to emit the second emission signal when the transducer is in the second transducer position; the processor is further configured to determine at least one of an acoustic impedance of the container or an acoustic attenuation of the container; The at least two characteristics are: at least one of a longitudinal sound velocity of the emitted signal through the container bottom wall, and a shear sound velocity of the emitted signal through the container bottom wall; at least one of a depth of the liquid in the container, an acoustic impedance of the liquid in the container, a speed of sound of the emitted signal through the liquid in the container, and an acoustic attenuation of the liquid in the container; Including, the system.

2. the container comprises a first well, a second well, and a third well; the system is further configured to measure the at least one property for each of the first well, the second well, and the third well; the controller is further configured to move the transducer along a second dimension from below the first well to below the second well, and the controller is further configured to move the transducer along a third dimension from below the second well to below the third well, the second and third dimensions comprising X and Y horizontal dimensions, respectively; The system of claim 1 .

3. 3. The system of claim 2, wherein the container is configured to contain a first liquid, a second liquid, and a third liquid in the first well, the second well, and the third well, respectively, and the system is further configured to measure at least one property for each of the first liquid, the second liquid, and the third liquid when measuring at least one property for each of the first well, the second well, and the third well, respectively.

4. 4. The system of claim 3, wherein the at least one characteristic comprises, for each well, at least one of a respective acoustic impedance of the contained liquid, a respective acoustic attenuation of the contained liquid, or a respective speed of sound of the emitted signal through the contained liquid.

5. 5. The system of claim 4, wherein the processor is further configured to determine, for the container bottom wall of each well, at least one of an acoustic impedance, a thickness, an acoustic attenuation, a longitudinal sound velocity of the emitted signal through the container bottom wall, or a shear sound velocity of the emitted signal through the container bottom wall.

6. The system further comprises: a coupling liquid between the transducer and the container bottom wall; a temperature sensor configured to measure a temperature of the coupling liquid; Equipped with the processor is further configured to determine the at least one property, in part, by processing data corresponding to a temperature of the coupled liquid. The system of claim 1 .

Images