Cell lysis system and method

Abstract

A cell lysis device that uses ultrasound to lyse cells.SOLUTION: A cell lysis device comprising: a housing; a sonication chamber provided in the housing, the sonication chamber being at least partially filled with an ultrasound transmitting medium, the housing including an opening configured to receive a sample container such that a portion of the sample container protrudes into the ultrasound transmitting medium; and an ultrasonic transducer for generating ultrasonic waves in the ultrasound transmitting medium in the sonication chamber, the ultrasonic transducer comprising: An ultrasonic transducer, wherein ultrasonic waves are transmitted from the ultrasonic transducer to the sample container by an ultrasonic transmission medium to lyse cells when the cells are contained in the sample container.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a cell lysis system and method, and more particularly to a cell lysis system and method that uses ultrasound to lyse cells. [Background technology]

[0002] This application claims the benefit of priority to European Patent Application No. 26245.7, filed April 6, 2020, U.S. Patent Application No. 16 / 889667, filed June 1, 2020, U.S. Patent Application No. 17 / 065992, filed October 8, 2020, U.S. Provisional Patent Application No. 63 / 111592, filed November 9, 2020, and U.S. Patent Application No. 17 / 122025, filed December 15, 2020, each of which is incorporated by reference in its entirety.

[0003] Polymerase chain reaction (PCR) is a process that uses two matching strands of DNA to amplify and analyze billions of copies of a desired DNA sequence from a small sample.

[0004] The first step in the PCR process involves cell lysis, which disrupts or ruptures the lipid bilayer of cells in the sample to provide a gateway through which cellular components, including DNA and / or RNA, can be extracted. Cell lysis is typically accomplished chemically, electromechanically, or by a combination of both.

[0005] The cell lysis process extracts components from cells in a liquid solution. The solution is then filtered to separate the nucleic acids (DNA / RNA) from other cellular components. The extracted DNA / RNA can then be amplified and analyzed in the remaining steps of the PCR process.

[0006] Conventional PCR instruments perform cell lysis on samples as they are input into the PCR instrument. The components that perform the cell lysis process are typically integrated within the PCR instrument. The problem with this type of conventional PCR instrument is that the instrument is generally expensive and cumbersome. Furthermore, the integrated components that perform cell lysis are typically limited to use only within the same PCR instrument.

[0007] Although stand-alone cell lysis devices have been proposed, these stand-alone devices often have reduced efficiency and performance compared to the cell lysis function of a complete PCR device.

[0008] Thus, there is a need in the art for improved cell lysis systems and methods that seek to address at least some of the problems described herein.

[0009] (overview) According to some arrangements, a cell lysis system includes a driver device providing an electrical connection between the driver device and the cell lysis device and having a plurality of driver output terminals for driving an ultrasonic transducer in the cell lysis device; an AC driver for generating an AC drive signal at a predetermined frequency and outputting the AC drive signal from the driver output terminals to drive the ultrasonic transducer in the cell lysis device; an operating power monitoring arrangement for monitoring operating power used by the ultrasonic transducer when the ultrasonic transducer is driven by the AC drive signal and for providing a monitoring signal indicative of the operating power used by the ultrasonic transducer; a processor for controlling the AC driver and receiving the monitoring signal from the operating power monitoring arrangement; and a memory, the memory being configured to, when executed by the processor, cause the processor to: A. Controlling an AC driver to output an AC drive signal at a predetermined sweep frequency to an ultrasonic transducer; B. calculating the operating power being used by the ultrasonic transducer based on the monitoring signal; C. Controlling the AC driver to modulate the AC drive signal to maximize the operating power used by the ultrasonic transducer; D. storing in memory a record of the maximum operating power used by the ultrasonic transducer and the sweep frequency of the AC drive signal; E. repeating step AD a predetermined number of times, increasing the sweep frequency with each repetition, such that after the predetermined number of repetitions, the sweep frequency has increased from the sweep start frequency to the sweep end frequency; F. Identifying from the record stored in memory an optimal frequency of the AC drive signal, which is the sweep frequency of the AC drive signal at which maximum operating power is used by the ultrasonic transducer; and G. Controlling the AC driver to output an AC driving signal at an optimal frequency to the ultrasonic transducer. and a memory storing instructions for causing the cell lysis system to perform the steps of:

[0010] In some arrangements, the operational power monitoring arrangement includes a current sensing arrangement that senses a drive current of an AC drive signal that drives the ultrasonic transducer, and the operational power monitoring arrangement provides a monitor signal indicative of the sensed drive current.

[0011] In some arrangements, the memory stores instructions that, when executed by the processor, cause the processor to repeat steps AD while increasing the sweep frequency from a sweep start frequency of 2800 kHz to a sweep end frequency of 3200 kHz.

[0012] In some arrangements, the memory stores instructions that, when executed by the processor, cause the processor to perform step G of controlling the AC driver to output an AC drive signal to the ultrasonic transducer at a frequency that is shifted by approximately 1-10% of the optimal frequency.

[0013] In some arrangements, the AC driver pulse width modulates the AC drive signal to maximize the operating power used by the ultrasonic transducer.

[0014] In some arrangements, the memory stores instructions that, when executed by the processor, cause the processor to alternately control the AC driver to output an AC drive signal to the ultrasonic transducer at an optimal frequency for a first predetermined time period and not output an AC drive signal to the ultrasonic transducer for a second predetermined time period.

[0015] In some arrangements, the memory stores instructions that, when executed by the processor, cause the processor to alternately output the AC drive signal and not output the AC drive signal according to an operating mode selected from the table below:

[0016] [Table 1]

[0017] In some arrangements, the cell lysis system further includes a cell lysis device releasably attached to the driver device, the cell lysis device including: a housing; a plurality of electrical terminals electrically connected to the plurality of driver output terminals; an ultrasonic treatment chamber disposed within the housing, the ultrasonic treatment chamber being at least partially filled with an ultrasonic transmission medium, the housing including an opening configured to receive a sample container such that a portion of the sample container protrudes into the ultrasonic transmission medium; and an ultrasonic transducer that generates ultrasonic waves in the ultrasonic transmission medium within the ultrasonic treatment chamber, the ultrasonic waves being transmitted from the ultrasonic transducer to the sample container by the ultrasonic transmission medium to lyse cells contained in the sample container.

[0018] In some arrangements, the driver device includes a first interface fit attachment and the cell lysis device includes a second interface fit attachment, the first interface fit attachment being releasably attached to the second interface fit attachment to releasably attach the cell lysis device to the driver device.

[0019] A cell lysis device is provided, comprising: a housing; an ultrasonic treatment chamber disposed within the housing, the ultrasonic treatment chamber being at least partially filled with an ultrasonic transmission medium, the housing including an opening configured to receive a sample container such that a portion of the sample container protrudes into the ultrasonic transmission medium; and an ultrasonic transducer that generates ultrasonic waves in the ultrasonic transmission medium within the ultrasonic treatment chamber, the ultrasonic waves being transmitted from the ultrasonic transducer to the sample container by the ultrasonic transmission medium to lyse cells contained in the sample container.

[0020] In some arrangements, the ultrasound transducer is at least partially a compound comprising lead, zirconium, and titanium.

[0021] In some configurations, the ultrasound transducer is circular disc-shaped, with a diameter of 16 mm and a thickness of 0.7 mm.

[0022] In some arrangements, the ultrasonic transducer includes a first electrode and a second electrode disposed on opposite sides of the ultrasonic transducer, the first electrode and the second electrode comprising silver, and a capacitance between the first electrode and the second electrode is between 800 pF and 1300 pF.

[0023] In some arrangements, the first electrode is at least partially covered with a glass coating.

[0024] In some arrangements, the ultrasound transducer is held by a transducer holder that is made of silicone rubber.

[0025] In some arrangements, the ultrasound transmission medium includes vegetable glycerin.

[0026] In some arrangements, the sample vessel is a microtube.

[0027] According to some arrangements, a method for lysing cells in a sample includes: placing a liquid sample containing cells to be lysed in a sample container; positioning the sample container through an opening in a housing of a cell lysis apparatus such that a portion of the sample container protrudes into an ultrasound transmission medium provided in an ultrasonic treatment chamber in the housing; attaching the cell lysis apparatus to a driver device, the driver device being an AC driver that generates an AC drive signal at a predetermined frequency and outputs the AC drive signal from a driver output terminal to drive an ultrasonic transducer in the cell lysis apparatus; and an operating power monitoring arrangement that monitors operating power used by the ultrasonic transducer when the ultrasonic transducer is driven by the AC drive signal and provides a monitoring signal indicative of the operating power used by the ultrasonic transducer, the method comprising: A. controlling an AC driver by a processor to output an AC drive signal at a predetermined sweep frequency to an ultrasonic transducer; B. calculating, by the processor, the operating power being used by the ultrasonic transducer based on the monitoring signal; C. controlling, by the processor, the AC driver to modulate the AC drive signal to maximize the operating power used by the ultrasonic transducer; D. storing in memory a record of the maximum operating power used by the ultrasonic transducer and the sweep frequency of the AC drive signal; E. repeating step AD a predetermined number of times, increasing the sweep frequency with each repetition, such that after the predetermined number of repetitions, the sweep frequency has increased from the sweep start frequency to the sweep end frequency; F. identifying, by the processor, from the records stored in the memory, an optimal frequency of the AC drive signal, which is the sweep frequency of the AC drive signal at which maximum operating power is used by the ultrasonic transducer; and G. A method is provided further including controlling, by the processor, an AC driver to output an AC drive signal at an optimal frequency to the ultrasonic transducer.

[0028] In some arrangements, the method further comprises repeating steps AD while increasing the sweep frequency from a sweep start frequency of 2800 kHz to a sweep end frequency of 3200 kHz.

[0029] In some arrangements, the method further includes alternately controlling, by the processor, the AC driver to output an AC drive signal at the optimal frequency to the ultrasonic transducer for a first predetermined time period and not output an AC drive signal to the ultrasonic transducer for a second predetermined time period. [Brief explanation of the drawings]

[0030] In order that the invention may be more readily understood, embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, in which:

[0031] [Figure 1] 1A-1C are perspective views of the system in several configurations. [Figure 2] 1A-1D are perspective views of several configurations of the cell lysis device. [Figure 3] FIG. 3 is a cross-sectional view of the cell lysis device of FIG. 2. [Figure 4] 1A-1C are perspective views of several configurations of driver devices. [Figure 5] FIG. 5 is a cross-sectional view of the driver device of FIG. [Figure 6] FIG. 1 illustrates a piezoelectric transducer modeled as an RLC circuit. [Figure 7] 1 is a graph showing the change in impedance with increasing frequency in an RLC circuit. [Figure 8] 1 is a graph illustrating how a piezoelectric transducer acts as a capacitor or an inductor. [Figure 9] 1 is a table showing the timing of the operating modes of the system for several configurations. DETAILED DESCRIPTION OF THE INVENTION

[0032] Aspects of the present disclosure are best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be noted that, according to standard industry practice, various features have not been drawn to scale. In fact, the dimensions of various features may be arbitrarily increased or decreased for clarity of discussion.

[0033] The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components, concentrations, applications, and arrangements are described below to simplify the disclosure. Of course, these are merely examples and are not intended to be limiting. For example, the attachment of a first feature and a second feature in the following description may include embodiments in which the first feature and the second feature are attached in direct contact, or may include embodiments in which additional features may be disposed between the first feature and the second feature such that the first feature and the second feature do not need to be in direct contact. Additionally, the present disclosure may repeat reference numerals and / or letters in various examples. This repetition is for simplicity and clarity and does not, in itself, dictate a relationship between the various embodiments and / or configurations discussed.

[0034] The following disclosure describes representative arrangements or examples. Each example may be considered an embodiment, and in this disclosure, references to "arrangements" or "examples" may be changed to "embodiments."

[0035] Referring initially to Figure 1 of the accompanying drawings, some configurations of a cell lysis system 1 include a driver device 2 and a cell lysis device 3. The driver device 2 includes a first interface fit attachment 4 that is releasably attached to a second interface fit attachment 5 provided on the cell lysis device 3. The interface fit attachments 4, 5 allow the cell lysis device 3 to be releasably attached to the driver device 2 when the cell lysis device 3 is placed on the driver device 2, as generally indicated by arrow 6 in Figure 1.

[0036] The components of the cell lysis system 1 will be described below, starting with the cell lysis device 3.

[0037] 2 and 3 of the accompanying drawings, some configurations of the cell lysis apparatus 3 include a housing 7. In this configuration, the housing 7 is generally cylindrical and has a side wall 8, a generally circular cover 9 at one end, and a generally circular base 10 at the other end. In this configuration, the cell lysis apparatus 3 is a disposable, single-use capsule.

[0038] A sonication chamber 11 is provided within the housing 7. The sonication chamber 11 is at least partially filled with an ultrasound transmission medium (not shown). In some arrangements, the sonication chamber 11 is pre-filled with the ultrasound transmission medium. In other arrangements, the sonication chamber 11 is filled with the ultrasound transmission medium when the cell lysis apparatus is being prepared for use.

[0039] In some arrangements, the ultrasound transmission medium is a liquid that has a higher acoustic impedance than water, and in some arrangements, the ultrasound transmission medium is vegetable glycerin because vegetable glycerin has a higher acoustic impedance than water.

[0040] The cell lysis device 3 includes an ultrasonic transducer 12. An upper side 13 of the ultrasonic transducer 12 faces the ultrasonic treatment chamber 11 so that the ultrasonic waves generated by the ultrasonic transducer 12 are directed towards the ultrasonic treatment chamber 11.

[0041] In some configurations, the ultrasonic transducer 12 is circular and disk-shaped. In this configuration, the ultrasonic transducer 12 has a diameter of approximately 16 mm and a thickness of approximately 0.7 mm. In this configuration, the ultrasonic transducer 12 is polarized to vibrate in a thickness mode.

[0042] In this arrangement, the ultrasound transducer 12 is held by a ring-shaped transducer holder 14 that at least partially surrounds the ultrasound transducer 12. In this arrangement, the transducer holder 14 is made of silicone rubber. Aside from holding the ultrasound transducer 12 in place, the transducer holder 14 also ensures minimal damping of the vibrations of the ultrasound transducer 12. Furthermore, the transducer holder 14 minimizes the risk of the liquid ultrasound transmission medium leaking out of the base 10 of the cell lysis apparatus 3.

[0043] In some arrangements, the ultrasound transducer 12 is at least partially a compound containing lead, zirconium, and titanium. The compound of the ultrasound transducer 12 is selected to provide the ultrasound transducer 12 with the properties to oscillate at frequencies between 2.8 MHz and 3.2 MHz. This frequency range is the preferred frequency range for the ultrasound transducer 12 to generate ultrasound waves that lyse or rupture cells.

[0044] In some arrangements, the ultrasound transducer 12 includes a first electrode on an upper side 13 and a second electrode on a lower side 15 located on the opposite side of the ultrasound transducer 12. In some arrangements, the first electrode and the second electrode include silver, for example, in the form of a silver stamp paint. In some arrangements, the capacitance between the first electrode and the second electrode is 800 pF-1300 pF.

[0045] In some arrangements, the first electrode on the upper side 13 of the ultrasound transducer 12 is at least partially covered with a glass coating. The glass coating minimizes or prevents possible contamination of the ultrasound transmission medium by the material of the first electrode. The glass coating also minimizes or prevents erosion of the silver on the first electrode due to, for example, the collapse of cavitation bubbles caused by ultrasound waves traveling through the ultrasound wave transmission medium during use of the cell lysis device 3.

[0046] The first and second electrodes of the ultrasonic transducer 12 are electrically connected to first and second electrical terminals 16 and 17, respectively, provided on the lower surface of the base 10 of the cell lysis apparatus 3.

[0047] A plurality of protrusions 18, 19 (only two of which are visible in FIG. 2) extend outward from the side of the base 10 of the cell lysis apparatus 3. The protrusions 18, 19 are part of the second interface fit attachment 5 of the cell lysis apparatus 3. In other arrangements, the second interface fit attachment 5 includes only one protrusion, and in further arrangements, the second interface fit attachment 5 includes two or more protrusions.

[0048] A cover 9 is provided at the end of the cell lysis apparatus 3 opposite the base 10. The cover 9 generally presents a flat, circular surface and is integrally formed with the side wall 8 of the housing 7. In this arrangement, a chamfered edge 19 is provided around the periphery of the cover 9 where the cover 9 and the side wall 8 intersect.

[0049] The cover 9 is provided with an opening 20. In this arrangement, the opening 20 is a generally circular opening located in the center of the cover 9. In other arrangements, the opening 20 may be a different shape and located in a different portion of the cover 9.

[0050] In this arrangement, a cylindrical collar 21 is aligned with the opening 20 and extends from the opening 20 into the interior of the sonication chamber 11. The opening 20 and collar 21 are configured to receive a sample container 22 such that a portion of the sample container 22 protrudes into the ultrasound transmission medium within the sonication chamber 11.

[0051] In some arrangements, the sample container 22 is a microtube. In some arrangements, the sample container 22 is an Eppendorf tube. In some arrangements, the sample container 22 is a microtube or an Eppendorf tube that holds a liquid volume of 0.5 ml, 1.5 ml, or 2 ml.

[0052] Sample vessel 22 includes a conical first portion 23 joined to a cylindrical body portion 24. The distal end of body portion 24 is provided with a sample vessel opening 24 through which a sample can be introduced into sample vessel 22. A cap 25 is movably attached to body portion 24 and configured to seal opening 24 and retain the sample within sample vessel 22.

[0053] The sample container 22 closes and seals the opening 20 when the sample container 22 is inserted into the opening 20. In this manner, the housing 7 of the cell lysis apparatus 3 is sealed, retaining the ultrasound transmission medium within the housing 7. In some arrangements, the sonication chamber 11 is initially empty, and the sonication chamber 11 is filled with the ultrasound transmission medium just before the sample container 22 is inserted into the opening 20.

[0054] 4 and 5 of the accompanying drawings, the driver unit 2 includes a housing 26 which contains the electronic components of the driver unit 2. In this arrangement, the driver unit 2 is a portable, stand-alone unit.

[0055] Housing 26 includes a main housing 27 and a base projection 28. Main housing 27 includes an interior chamber 29 that receives a battery 30 and at least a portion of a printed circuit board (PCB) 31. PCB 31 carries electronic components that provide the driver functionality of driver device 2.

[0056] In this arrangement, battery 30 is rechargeable. In some arrangements, battery 30 is a lithium polymer (LiPo) battery. In some arrangements, the capacity of battery 30 provides sufficient power to enable driver device 2 to operate for at least 24 hours. In this arrangement, driver device 2 includes a charging connection (not shown) configured to receive power from an external power source to charge battery 30.

[0057] In some arrangements, the battery 30 is omitted and the driver device 2 instead includes a power input connection for receiving power from an external power source. In some arrangements, the external power source is a power adapter that converts the mains voltage to a suitable voltage (e.g., 5-12V) for powering the driver device 2.

[0058] The base protrusion 28 has a reduced thickness compared to the housing 26 in this embodiment. The base protrusion 28 includes a recess 32 configured to receive the base 10 of the cell lysis apparatus 3. In this arrangement, the recess 32 is generally circular. The recess 32 includes indentations 33, 34 that are positioned over a generally circular channel 35 to form the first interface fit attachment 4 of the driver device 2. The indentations 33, 34 are positioned to align with the protrusions 18, 19 on the cell lysis apparatus 3. In other embodiments, there may be a different number of indentations that correspond to a different number of protrusions on the cell lysis apparatus 3.

[0059] Two driver output terminals 36, 37 are provided at the bottom of the recess 32. In this arrangement, one of the driver output terminals 36 is provided centrally within the recess 32, and the other driver output terminal 37 is provided adjacent to the side of the recess 32. In this arrangement, each of the driver output terminals 36, 37 is a spring contact probe that protrudes upward from the bottom surface of the recess 32. The driver output terminals 36, 37 are arranged to engage and form an electrical connection with first and second electrical terminals 16, 17 provided on the underside of the base 10 of the cell lysis apparatus 3 when the cell lysis apparatus 3 is attached to the driver device 2. In some arrangements, the driver output terminals 36, 37 and / or the electrical terminals 16, 17 are made of brass material coated with a first 3 μm thick layer of nickel and a second 0.05 μm thick layer of gold.

[0060] In some arrangements, the driver output terminals 36, 37 extend through the bottom of the recess 32 to the PCB 31, and the driver output terminals 36, 37 are soldered to form electrical connections with the PCB 31 and electronic components mounted on the PCB 31.

[0061] In this arrangement, the cell lysis apparatus 3 is releasably attached to the driver device 2 by placing the base 10 of the cell lysis apparatus 3 into the recess 32 with the protrusions 18, 19 passing through the indentations 33, 34 until the protrusions 18, 19 are aligned with the channel 35. The cell lysis apparatus 3 is then rotated with the protrusions 18, 19 within the channel 35. The protrusions 18, 19 are then retained within the channel 35, providing an interface fit attachment that releasably attaches the cell lysis apparatus 3 to the driver device 2.

[0062] The interface fit attachments 4, 5 allow a user to releasably attach the cell lysis device 3 to the driver device 2 by pushing and rotating the cell lysis device 3 to lock it onto the driver device 2. This process is then performed in reverse to remove the cell lysis device 3 from the driver device 2 after the lysis process is completed.

[0063] When the cell lysis device 3 is pressed into the recess 32, the driver output terminals 36, 37 elastically deform and align with the electrical terminals 16, 17 on the cell lysis device 3. The elastically deformed driver output terminals 36, 37 are pressed against the electrical terminals 16, 17 to form an electrical connection. When the cell lysis device 3 is releasably attached to the driver device 2 in this manner, the cell lysis device 3 can be driven by the driver device 2 to lyse cells within the cell lysis device 3.

[0064] An AC driver 38 is provided on the PCB 31. The AC driver 38 generates an AC drive signal at a predetermined frequency and outputs the AC drive signal to driver output terminals 36 and 37 to drive the ultrasonic transducer 12 in the cell lysis apparatus 3. In some configurations, the AC driver 38 includes an H-bridge circuit. In some configurations, the H-bridge circuit includes four MOSFETs connected to convert DC to AC at a high frequency (e.g., a frequency in the range of 2.8 MHz to 3.2 MHz).

[0065] The operating power monitoring arrangement 39 is provided on the PCB 31. The operating power monitoring arrangement 39 monitors the operating power used by the ultrasonic transducer 12 when the ultrasonic transducer 12 is driven by the AC drive signal. The operating power monitoring arrangement 39 provides a monitor signal indicative of the active power used by the ultrasonic transducer 12. In some arrangements, the operating power monitoring arrangement 39 includes a current sensing arrangement that senses a drive current of the AC drive signal that drives the ultrasonic transducer 12 and provides a monitor signal indicative of the sensed drive current.

[0066] The PCB 31 is provided with a processor 40 which controls the AC driver 38 and receives monitoring signals from an operational power monitoring arrangement 39. The PCB 31 is also provided with a memory 41 which stores executable instructions for execution by the processor 40.

[0067] In some arrangements, the driver device 2 includes a frequency controller configured to control the frequency at which the ultrasonic transducer 12 operates. The frequency controller is implemented by executable code stored in the memory 41 that, when executed by the processor 40, causes the processor 40 to perform at least one function of the frequency controller.

[0068] The memory 41 stores executable instructions that, when executed by the processor, cause the processor to control the ultrasonic transducer 12 to oscillate at multiple frequencies within a predetermined sweep frequency range and to select a driver frequency for the ultrasonic transducer 12 that is between a first predetermined frequency and a second predetermined frequency for lysing cells in the sample container 22.

[0069] In some arrangements, the frequency is determined by the type of cell being lysed, as some cells may require different frequencies due to their physical characteristics (size, shape, presence of cell walls, etc.).

[0070] There is an optimal frequency or frequency range for lysing cells, which depends on at least four parameters:

[0071] 1. Transducer manufacturing process In some arrangements, the ultrasonic transducer 12 comprises a piezoelectric ceramic. Piezoelectric ceramics are manufactured by mixing compounds to create a ceramic mass, and this mixing process may not be consistent throughout production. This inconsistency can result in variations in the resonant frequency of the cured piezoelectric ceramic.

[0072] If the resonant frequency of the piezoelectric ceramic does not correspond to the required operating frequency, the cell lysis process will not be optimal. Even a slight deviation in the resonant frequency of the piezoelectric ceramic will affect the lysis process and mean that the system will not function optimally.

[0073] 2. Load on the transducer During operation, changes in the load applied to the ultrasonic transducer 12 disrupt the overall displacement of the vibration of the ultrasonic transducer 12. To achieve optimal displacement of the vibration of the ultrasonic transducer 12, the driver frequency must be adjusted to provide enough power for maximum displacement.

[0074] The type of load that can affect the efficiency of the ultrasonic transducer 12 can include the amount of liquid on the transducer (ie, the amount of liquid in the sonication chamber 11).

[0075] 3.Temperature The ultrasonic vibrations of the ultrasonic transducer 12 are partially damped by its assembly in the driver device 2. This damping of the vibrations can cause a local temperature rise on and around the ultrasonic transducer 12.

[0076] An increase in temperature affects the oscillation of the ultrasonic transducer 12 due to changes in the molecular behavior of the ultrasonic transducer 12. Increasing the temperature means that the ceramic molecules receive more energy, temporarily affecting their crystalline structure. Reducing the temperature reverses the effect, but modulating the supply frequency is necessary to maintain optimal oscillation.

[0077] Increasing the temperature also reduces the viscosity of the solution within the sonication chamber 11 and may therefore require a change in driver frequency to optimize lysis of cells within the sonication chamber 11 .

[0078] 4. Distance to power source The oscillation frequency of the ultrasonic transducer 12 can be changed by the length of the wiring between the ultrasonic transducer 12 and the AC driver 38. The frequency of the electronic circuit is inversely proportional to the distance between the ultrasonic transducer 49 and the controller 23.

[0079] The distance parameters are largely fixed in this arrangement, but may vary during the manufacturing process of the system 1. Therefore, it may be desirable to vary the driver frequency of the ultrasonic transducer 12 to compensate for variations and optimize the efficiency of the system.

[0080] A piezoelectric transducer can be modeled as an RLC circuit in an electronic circuit, as shown in Figure 6. The four parameters mentioned above can be modeled as changes to the overall inductance, capacitance, and / or resistance of the RLC circuit, changing the resonant frequency range supplied to the transducer. As the frequency of the circuit increases near the resonance point of the transducer, the logarithmic impedance of the overall circuit drops to a minimum, then rises to a maximum, and settles in the middle range.

[0081] 7 is a graph illustrating the change in overall impedance with increasing frequency in an RLC circuit. s In the first capacitive region at frequencies below a second predetermined frequency f p At the above frequencies, the piezoelectric vibrator acts as a capacitor in the second capacitive region. s , f p In order to maintain optimum oscillation of the transducer, and therefore maximum efficiency, the current through the transducer must be kept at a frequency within the induction region.

[0082] The driver device 2 in some configurations is configured to maintain the frequency of oscillation of the piezoelectric transducer 12 within the induction region to maximize the efficiency of cell lysis.

[0083] The driver device 2 is configured to perform a sweep operation in which the frequency controller drives the transducer at a frequency that gradually tracks across a predetermined sweep frequency range. In other words, the driver device 2 drives the transducer at a plurality of different frequencies across the predetermined sweep frequency range, for example, at frequencies that increase by a predetermined frequency from one end of the sweep frequency range to the other end.

[0084] As will be explained in more detail below, the driver device 2 in some configurations determines the operating power being used by the ultrasonic transducer 12 by monitoring the current flowing through the transducer 12 .

[0085] The mechanical deformation of an ultrasonic (piezoelectric) transducer is coupled to the AC voltage amplitude applied to it, and maximum deformation must always be supplied to the ultrasonic transducer to ensure optimal system function and delivery. Pulse width modulation (PWM) of the AC voltage applied to the ultrasonic transducer ensures that the mechanical amplitude of vibration remains the same. In some arrangements, the system actively adjusts the duty cycle of the AC voltage waveform to maximize the deformation of the ultrasonic transducer to ensure optimal system function and delivery.

[0086] One method is to use a digital-to-analog converter (DAC) to change the AC voltage applied to the ultrasonic transducer. This reduces the energy delivered to the ultrasonic transducer, but also reduces the mechanical deformation, resulting in less than maximum deformation. The effective voltage across the ultrasonic transducer is the same as with voltage modulation, but the operating power delivered to the ultrasonic transducer is degraded. In practice, this is given by the following equation:

[0087] The operating power delivered to the ultrasonic transducer is:

[0088]

number

[0089] where φ is the phase difference between the current and voltage, I rms is the root mean square current, V rms is the root mean square voltage.

[0090] When considering the first harmonic, pulse width modulation varies the duration of the voltage supplied to the ultrasonic transducer, controlling Irms, which is a function of the actual voltage amplitude applied to the ultrasonic transducer.

[0091] In this arrangement, memory 41 stores instructions that, when executed by processor 40, cause processor 40 to: A. Controlling the AC driver 38 to output an AC drive signal at a predetermined sweep frequency to the ultrasonic transducer 12 B. Calculate the operating power being used by the ultrasonic transducer 12 based on the monitoring signal. C. Controlling the AC driver 38 to modulate the AC drive signal to maximize the operating power used by the ultrasonic transducer 12 D. storing in memory 41 a record of the maximum operating power used by the ultrasonic transducer 12 and the sweep frequency of the AC drive signal; E. Repeating steps A and D a predetermined number of times, increasing the sweep frequency with each repetition, such that after the predetermined number of repetitions, the sweep frequency has increased from the sweep start frequency to the sweep end frequency. F. Identifying from the records stored in memory 41 the optimum frequency of the AC drive signal, which is the sweep frequency of the AC drive signal at which maximum operating power is used by the ultrasonic transducer 12; and G. Controlling the AC driver 38 to output an AC drive signal at an optimal frequency to the ultrasonic transducer 12

[0092] In some arrangements, the starting sweep frequency is 2800 kHz and the ending sweep frequency is 3200 kHz. In other arrangements, the starting and ending sweep frequencies are the lower and upper frequencies of a frequency range within the range of 2800 kHz-3200 kHz.

[0093] In some arrangements, the processor 40 controls the AC driver 38 to output an AC drive signal to the ultrasonic transducer 12 at a frequency shifted by between 1-10% of the optimal frequency. In these arrangements, the frequency shift is used to extend the life of the ultrasonic transducer 12 by minimizing potential damage to the ultrasonic transducer 12 when it is continuously driven at the optimal driver frequency that produces maximum displacement.

[0094] In some arrangements, the AC driver 38 modulates the AC drive signal by pulse width modulation to maximize the operating power used by the ultrasonic transducer 12 .

[0095] In some arrangements, the processor 40 alternately controls the AC driver 38 to output an AC drive signal to the ultrasonic transducer 12 at an optimal frequency for a first predetermined period of time and not output an AC drive signal to the ultrasonic transducer 12 for a second predetermined period of time. This alternating activation and deactivation of the ultrasonic transducer 12 has been found to optimize the process of lysing cells in a sample within the cell lysis apparatus 3.

[0096] In some embodiments, the driver unit 2 operates in a recursive mode to ensure optimal operation of the ultrasonic transducer 12. When the driver unit 2 operates in a recursive mode, the driver unit 2 periodically performs a frequency sweep in steps AD during system operation.

[0097] In some arrangements, the driver device 2 automatically activates to begin the lysing process when the cell lysing device 3 is attached to the driver device 2. In some arrangements, the driver device 2 automatically stops the lysing process after a predetermined period of time. Once the lysing process is complete, the cell lysing device 3 is removed from the driver device 3.

[0098] In some arrangements, the processor 40 controls the AC driver 38 to alternately output an AC drive signal and not output an AC drive signal according to the operating mode. The timing of the 12 operating modes in some arrangements is shown in the table of Figure 9 of the accompanying drawings.

[0099] In some arrangements, the driver device 2 is automatically activated when the cell lysis device 3 is attached to the driver device 2. In other arrangements, the driver device 2 is provided with a switch or other control that allows a user to activate and deactivate the driver device 2.

[0100] Once the system is activated and has performed the lysis process for a predetermined time, the cell lysis device 3 is separated from the driver device 2. The liquid in the cell lysis device 3 containing the lysed cells is removed for use in another process, such as a PCR process. The cell lysis device 3 can then be discarded.

[0101] While the above-described configuration includes one recess 32 and one set of driver output terminals 36, 37, other configurations include multiple recesses and multiple sets of output terminals. In these other configurations, driver unit 2 can be used simultaneously with multiple cell lysis devices. In these configurations, driver unit 2 controls each of the multiple cell lysis devices to perform cell lysis individually.

[0102] The foregoing outlines features of several examples or embodiments to enable those skilled in the art to better understand various aspects of the present disclosure. Those skilled in the art should appreciate that this disclosure may readily serve as a basis for designing or modifying other processes and structures to carry out the same purposes and / or achieve the same advantages of the various examples or embodiments introduced herein. Those skilled in the art should also appreciate that such equivalent structures do not depart from the spirit and scope of the present disclosure, and that various changes, substitutions, and alterations can be made herein without departing from the spirit and scope of the present disclosure.

[0103] Although the subject matter has been described in language specific to structural features or methodological acts, it is understood that the appended claimed subject matter is not necessarily limited to the particular features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing at least a portion of the claims.

[0104] Various operations of examples or embodiments are provided herein. The order in which some or all of the operations are described should not be construed to imply that these operations are necessarily order dependent. Alternative ordering is appreciated to benefit this description. Furthermore, it will be understood that not all operations are necessarily present in each embodiment provided herein. It will also be understood that not all operations are required in some examples or embodiments.

[0105] Furthermore, as used herein, the term "exemplary" means serving as an example, instance, illustration, or the like, but not necessarily advantageous. As used herein, "or" is intended to mean an inclusive "or," not an exclusive "or." Additionally, as used in this application and the appended claims, "a" and "an" are generally construed to mean "one or more," unless otherwise specified or unless the context clearly dictates a singular reference. Furthermore, to the extent that "comprises," "has," "having," "has," or variations thereof are used, such terms are intended to be inclusive in the same manner as the term "comprises." Furthermore, unless otherwise specified, terms such as "first," "second," and the like are not intended to imply temporal aspects, spatial aspects, order, or the like. Rather, such terms are used merely as identifiers, names, or the like of features, elements, items, and the like. For example, a first element and a second element generally correspond to element A and element B, or two different elements or two identical elements, or the same element.

[0106] Moreover, while the present disclosure has been shown and described with respect to one or more embodiments, equivalent alterations and modifications will occur to others skilled in the art upon reading and understanding this specification and the accompanying drawings. The present disclosure includes all such alterations and modifications, and is limited only by the scope of the following claims. In particular, with respect to the various functions performed by the above-described features (e.g., elements, resources, etc.), the terms used to describe such features are intended, unless otherwise indicated, to correspond to any feature (e.g., functional equivalent) that performs the specified function of the described feature, even if it is not structurally equivalent to the disclosed structure. In addition, while a particular feature of the present disclosure may be disclosed with respect to only one of several embodiments, such feature may be combined with one or more other features of other embodiments as desired and advantageous for any given or particular application.

[0107] Examples or embodiments of the subject matter and functional operations described herein can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed herein and their structural equivalents, or in combinations of one or more of them.

[0108] Some examples or embodiments are implemented using one or more modules of computer program instructions encoded on a computer-readable medium for execution by or to control the operation of a data processing apparatus. The computer-readable medium may be an article of manufacture, such as a hard drive in a computer system or embedded system. The computer-readable medium may be obtained separately and later encoded with one or more modules of computer program instructions, such as by distribution of one or more modules of computer program instructions over a wired or wireless network. The computer-readable medium may be a machine-readable storage device, a machine-readable storage substrate, a storage device, or a combination of one or more thereof.

[0109] The terms "computing apparatus" and "data processing apparatus" encompass all apparatuses, devices, and machines for processing data, including, by way of example, a programmable processor, computer, or multiple processors or computers. In addition to hardware, an apparatus may include code that establishes an execution environment for the computer program, such as code comprising processor firmware, a protocol stack, a database management system, an operating system, a runtime environment, or one or more combinations thereof. Furthermore, the apparatus may employ a variety of different computing model infrastructures, such as web services, distributed computing, and grid computing infrastructures.

[0110] The processes and logic flows described herein may be implemented by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output.

[0111] Processors suitable for the execution of a computer program include, by way of example, general-purpose and special-purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read-only memory, a random-access memory, or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Typically, a computer will be operatively coupled to, or include, one or more mass storage devices for storing data, e.g., magnetic, magneto-optical, or optical disks, to receive data from, or transfer data to, either one or both. However, a computer need not have such devices. Devices suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and memory devices.

[0112] As used herein, "comprises" means "includes or comprises" and "comprising" means "includes or comprises."

[0113] The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, may be expressed in their specific form, or in terms of means for performing a disclosed function, or a method or process for achieving a disclosed result, as appropriate, and may be utilized to realize the invention in its various forms, either separately or in any combination of those features.

Claims

1. A cell lysis device comprising: Housing and an ultrasonic treatment chamber disposed within the housing, the ultrasonic treatment chamber being at least partially filled with an ultrasonic transmission medium, the housing including an opening configured to receive the sample vessel such that a portion of the sample vessel protrudes into the ultrasonic transmission medium; an ultrasonic transducer that generates ultrasonic waves in an ultrasonic transmission medium within the sonication chamber, the ultrasonic waves being transmitted from the ultrasonic transducer to a sample container by the ultrasonic transmission medium to lyse cells contained in the sample container; A cell lysis device comprising:

2. 10. The apparatus of claim 1, wherein the ultrasonic transducer is at least partially a compound comprising lead, zirconium, and titanium.

3. 3. The apparatus of claim 1 or claim 2, wherein the ultrasonic transducer is configured to vibrate at a frequency of 2.8 MHz to 3.2 MHz.

4. 4. The device of claim 1, wherein the ultrasonic transducer is circular and disc-shaped, has a diameter of 16 mm, and a thickness of 0.7 mm.

5. 5. The device of claim 1, wherein the ultrasonic transducer comprises a first electrode and a second electrode disposed on opposite sides of the ultrasonic transducer, the first electrode and the second electrode comprising silver, and a capacitance between the first electrode and the second electrode is between 800 pF and 1300 pF.

6. The apparatus of claim 5 , wherein the first electrode is at least partially covered with a glass coating.

7. 7. The device of claim 1, wherein the ultrasonic transducer is held by a transducer holder made of silicone rubber.

8. The apparatus of claim 7 , wherein the transducer holder is in the shape of a ring that at least partially surrounds the ultrasound transducer.

9. 9. The apparatus of claim 1, wherein the ultrasound transmission medium has a higher acoustic impedance than water.

10. 10. The apparatus of claim 1, wherein the ultrasound transmission medium comprises vegetable glycerin.

11. 11. The device of claim 1, wherein the sample vessel is a microtube.

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