Method and apparatus for reducing biocarryover using induction heating

Abstract

Methods, systems, devices, and machine-readable media for reducing biological carryover are disclosed. An exemplary method includes: generating an alternating electromagnetic field; and introducing an aspiration and dispensing device into the electromagnetic field. The exemplary method also includes: inductively heating the aspiration and dispensing device using the electromagnetic field to at least denature or inactivate at least one of a protein or a biological entity on a surface of the aspiration and dispensing device.

Description

[0001] Related Applications

[0002] The present invention claims priority to U.S. Provisional Patent Application Serial No. 61 / 580,913, filed on December 28, 2011, entitled “Methods and Apparatus to Reduce Biological Carryover Using Induction Heating,” which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present disclosure relates generally to medical diagnostic instruments and, more particularly, to methods and apparatus for reducing bio-carryover using induction heating. Background Art

[0004] Probes are used in medical diagnostic instruments to draw samples and reagents into sample tubes and reaction vessels and / or distribute the samples and reagents from sample tubes and reaction vessels. The possibility of biological carryover or cross contamination can be increased when the probes are reused. Some existing methods for preventing protein cross contamination require replacement of probes. Probe replacement has produced significant waste and increased operating costs and time. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 It is a schematic diagram of electromagnetic induction.

[0006] Figure 2A-2C An exemplary aspiration and dispense device that is inductively heated and cleaned is illustrated.

[0007] Figure 3A-3E Another exemplary aspiration and dispense device that is inductively heated and cleaned is illustrated.

[0008] Figure 4 is a schematic diagram of an exemplary configuration of an electromagnetic field generator.

[0009] Figure 5 is a schematic diagram of another exemplary configuration of an electromagnetic field generator.

[0010] Figure 6 is a schematic diagram of another exemplary configuration of an electromagnetic field generator.

[0011] Figure 7 is a schematic diagram of another exemplary configuration of an electromagnetic field generator.

[0012] Figure 8 is a flow chart representing an example process that may be performed to implement the example systems disclosed herein.

[0013] Fig. 9An exemplary processor platform is illustrated that may be used to implement any or all of the exemplary methods, systems, and / or apparatus disclosed herein. DETAILED DESCRIPTION

[0014] Automatic medical diagnostic instrument and automatic pipette system use one or more suction and / or distribution device (such as, for example pipette or probe), to sample (such as biological sample) and / or reagent are sucked into reaction vessel (such as, for example one or more holes on multi-well plate) and / or distribute sample and / or reagent from described reaction vessel.The outer surface and inner surface of suction and / or distribution device contact with sample and / or reagent, and after having distributed sample and / or reagent, a part of sample and / or reagent may remain on the outer and / or inner surface.The subsequent use of suction and / or distribution device can cause sample carrying or reagent carrying.This carrying is the transfer of residual sample and / or reagent to another sample and / or reagent, which has contaminated sample and / or reagent and can cause inaccurate analysis or diagnosis.

[0015] Some systems include a flushing station to flush the surface of the suction and / or dispensing device. However, the flushing station requires a large amount of flushing solution. In addition, any defects, scratches, notches or other imperfections or irregularities on the surface of the suction and / or dispensing device can hide biological samples and / or reagents, making the suction and / or dispensing device not clean enough after the flushing cycle.

[0016] In other systems, electrostatic induction is used to heat the suction and / or distribution device to the disinfection level. Such systems produce non-alternating potentials (e.g., voltage) across the suction and / or distribution device via resistors. These systems require relatively high voltage and current, and therefore increase the risk of electrical short circuits. In addition, these systems heat the entire suction and / or distribution device conventionally, and therefore only local heating and cleaning of contaminated areas are not possible. In addition, electric current flows through the suction and / or distribution device along the path of minimum resistance in an uneven manner. The surface areas including defects, scratches, dents or other irregularities of the suction and / or distribution device have higher resistance. Therefore, these areas that are particularly sensitive to biological accumulation are subjected to less electric current, and are less heated than other areas of the suction and / or distribution device. Therefore, the device cleaned by electrostatic induction may not be enough to eliminate biological carryover.

[0017] The exemplary systems, methods and apparatus disclosed herein use electromagnetic induction heating to clean the suction and / or dispensing device. In the examples disclosed herein, heat generated via electromagnetic induction is used to inactivate and / or denature reactive proteins and / or other biological entities on the surface of the suction and / or dispensing device. Inactivation or denaturation of biological substances prevents biological carryover by reducing or eliminating cross-contamination between independent reactions.

[0018] Induction heating is achieved by a continuous conductive medium of a metal coil or any other shape, wherein the size and shape are designed to provide a desired heating pattern, through which a high-frequency, high-current electrical signal flows to induce an opposite current in a target object (e.g., a suction and / or dispensing device to be cleaned) according to Faraday's law of induction. The opposite current heats the suction and / or dispensing device and the residual protein and / or other biological material attached thereto. Proteins and / or other biological materials are heated to above a critical temperature to change the way these materials affect and bind to other objects or materials, which reduces the chance of unplanned reactions. The examples disclosed herein reduce or eliminate the possibility of contamination between separate fluid movements or reactions without the need for a large amount of flushing, expensive coatings or disposable probes.

[0019] The exemplary methods disclosed herein include generating an alternating electromagnetic field and introducing an aspiration and / or dispensing device into the electromagnetic field. The exemplary methods also include: using the electromagnetic field to inductively heat the aspiration and / or dispensing device to at least denature or inactivate at least one of a protein or a biological entity on a surface of the aspiration and / or dispensing device.

[0020] Some examples disclosed herein include rinsing the suction and / or dispensing device before introducing the suction and / or dispensing device into the electromagnetic field. In addition, some examples include rinsing the suction and / or dispensing device after inductively heating the suction and / or dispensing device using the electromagnetic field. In some examples, rinsing includes rinsing with a cooling rinsing fluid to reduce the temperature of the suction and / or dispensing device. In addition, some examples include rinsing the suction and dispensing device during inductive heating of the suction and dispensing device using the electromagnetic field.

[0021] Some examples disclosed herein include generating an electromagnetic field by passing an electric current through a conductive medium using a frequency based on the diameter of the suction and / or dispensing device. In addition, some examples disclosed herein include generating an electromagnetic field by passing an electric current through a conductive medium using a frequency based on the thickness of a housing or wall of the suction and / or dispensing device. In some examples, the conductive medium includes a coil. In other examples, the conductive medium includes a continuous conductive medium of any other shape, wherein the size and shape are designed to provide a desired heating pattern.

[0022] In some of the disclosed examples, the suction and / or dispense device is raised and / or lowered through an electromagnetic field to inductively heat the suction and / or dispense device along the length of the suction and / or dispense device. Additionally, in some examples, the thickness of the housing varies along the length of the suction and / or dispense device, adjusting the frequency as the suction and / or dispense device is raised or lowered.

[0023] In some examples disclosed herein, only a portion of the suction and / or dispense device is inductively heated. In other examples, using an electromagnetic field to inductively heat the suction and / or dispense device includes heating the suction and / or dispense device via an electrical and / or electrostatic connection without directly contacting the suction and dispense device.

[0024] In some examples, generating the alternating electromagnetic field includes utilizing a standard electrical wall outlet. Additionally, some of the disclosed examples include placing the rinse cup between the aspiration and / or dispense device and a conductive medium (such as, for example, a coil for generating the electromagnetic field); and preventing the aspiration and dispense device and the conductive medium from directly contacting the rinse cup.

[0025] Exemplary systems disclosed herein include an electromagnetic field generator and a suction and / or dispensing device to be introduced into the electromagnetic field and inductively heated by the electromagnetic field. The exemplary system also includes a rinse cup sandwiched between the electromagnetic field generator and the suction and dispensing device to prevent direct contact therebetween. In some exemplary systems, the suction and dispensing device is not coupled to an electrical connector on a surface of the suction and dispensing device, and the suction and dispensing device is electrically insulated.

[0026] Some exemplary systems also include a flusher to flush the suction and / or dispensing device before the suction and / or dispensing device is introduced into the electromagnetic field and / or after the suction and / or dispensing device is inductively heated using the electromagnetic field. In some examples, the flusher flushes with a cooling flushing liquid to reduce the temperature of the suction and / or dispensing device.

[0027] In some embodiments, the electromagnetic field generator includes a frequency generator and a coil, and the frequency generator is used to generate a variable frequency current flowing through the coil. The frequency is based on the diameter of the suction and / or dispensing device. In addition, in some examples, the electromagnetic field generator includes a frequency generator and a conductive medium (e.g., a coil or any other continuous conductive medium of a shape and size designed to provide a desired heating pattern), and the frequency generator is used to generate a variable frequency current flowing through the conductive medium. The frequency is based on the thickness of the housing of the suction and / or dispensing device.

[0028] Some exemplary systems include an arm to raise or lower the suction and dispense device through an electromagnetic field to inductively heat the suction and / or dispense device along the length of the suction and dispense device. Some exemplary systems include a frequency generator to adjust the frequency as the suction and / or dispense device is raised or lowered. Such frequency can be adjusted at locations where the thickness of the housing changes along the length of the suction and / or dispense device.

[0029] In some examples, the electromagnetic field inductively heats only a portion of the aspiration and / or dispensing device. In some examples, the aspiration and / or dispensing device is heated but does not directly contact the electrical connection device. In some exemplary systems disclosed herein, a surface of the aspiration and / or dispensing device is heated to denature or inactivate at least one of a protein or a biological entity on the surface.

[0030] Some exemplary systems include a controller and a feedback loop. The feedback loop provides data to the controller, the data including one or more of frequency, impedance, presence of the suction and dispensing device in the electromagnetic field, voltage readings, or current readings, and the controller changes the frequency based on the data to change the strength of the electromagnetic field, thereby changing the heating temperature of the suction and / or dispensing device.

[0031] Also disclosed is an exemplary tangible machine-readable medium having stored thereon instructions that, when executed, cause the machine to generate an alternating electromagnetic field and introduce an aspiration and / or dispensing device into the electromagnetic field. The exemplary instructions further cause the machine to utilize the electromagnetic field to inductively heat the aspiration and / or dispensing device to denature and / or inactivate at least one of a protein or a biological entity on a surface of the aspiration and / or dispensing device.

[0032] Referring now to the accompanying drawings, Figure 1 Figure 2 shows a schematic diagram of electromagnetic induction. Figure 1 As shown, the coil 100 includes a high frequency alternating current (AC) flowing in a first direction indicated by the white arrow. The interior of the loop of the coil 100 forms a working area 102. When the current flows through the coil 100, the alternating magnetic field 104 extends through the working area 102 and surrounds the coil 100. A workpiece 106 (which may, for example, represent a portion of a probe or other suction and / or dispensing device) may be inserted into the working area 102. The alternating magnetic field 104 generates eddy currents in the workpiece 106. The eddy currents flow in a direction opposite to the alternating current in the coil 100, as indicated by the larger arrows. Hysteresis losses and ohmic heating increase the temperature of the workpiece 106. The heat changes the binding properties of any proteins or other biological entities that may be present on the surface of the workpiece 106 to denature and inactivate such proteins and biological entities. The above process is equally applicable to ferrous metals, non-magnetic metals and / or other conductive materials.

[0033] Figure 2A-2CA portion of an exemplary system 200 for reducing biocarrying during three operations is illustrated. The exemplary system 200 includes an electromagnetic field generator 202, which in this example includes a metal coil 204, such as, for example, a copper coil. The coil 204 has a first conductor 206 and a second conductor 208 to electrically couple the coil 204 to a power source, such as, for example, an AC power source. The interior of the coil 204 forms a workspace into which one or more workpieces may be placed, as described below. As shown in FIG. Figure 1 As described, when current flows through the coil 204, a magnetic field is generated and an opposing current is induced in the workpiece.

[0034] The exemplary system 200 also includes an exemplary rinse cup 210. In the present example, the rinse cup 210 is an open-ended splash container that can be made of, for example, glass, ceramic, plastic, electrically insulating material, and / or any other suitable non-metallic material. The rinse cup 210 includes an inlet 212 that enables the introduction of a rinse liquid into the rinse cup 210. The system 200 also includes a pipette probe or other aspiration and / or dispensing device 214. In the present example, the aspiration and / or dispensing device 214 is a metal probe such as, for example, stainless steel. Figure 2A In the embodiment of the present invention, the suction and / or dispensing device 214 is located above or outside the coil 204. The suction and / or dispensing device 214 includes a liquid 216, which can be, for example, a sample, a reagent, a flushing solution, or any combination thereof. In the present example, the outer surface of the suction and / or dispensing device 214 is contaminated with protein or biological material 218. The protein or biological material 218 can adhere to scratches or other surface deformities of the outer surface and / or adhere to the outer surface due to hydrophobicity, ionic charge, electrostatic charge, protein adsorption, and / or surface energy.

[0035] exist Figure 2B In the embodiment, the suction and / or dispensing device 214 is lowered into the rinse cup 210, and the coil 204 is energized to generate an alternating electromagnetic field. In the present example, the rinse cup 210 is inserted into the suction and / or dispensing device 214 to prevent direct contact between them. Therefore, the suction and / or dispensing device 214 is remotely inductively heated using the coil 204, thereby preventing biological contamination. The advantage of this structure is that a standard suction and / or dispensing device (e.g., a probe) can be used. No electrical connector is required to match the suction and / or dispensing device. Therefore, the suction and / or dispensing device is electrically insulated. Electrical insulation reduces the chance of an operator receiving an electric shock due to accidental (or intentional) contact with the suction and / or dispensing device. Current is generated in the suction and / or dispensing device only when there is a strong alternating magnetic field, and the current is only generated in the material of the suction and / or dispensing device. More specifically, the operator does not provide a ground path for the current generated in the workpiece (eg, the suction and / or dispense device) because the current is generated only within the immediate magnetic field and is in a self-contained and independent loop.

[0036] The current in the coil 204 generates a magnetic field, which induces a current in the suction and / or dispensing device 214. The current in the suction and / or dispensing device 214 generates heat, thereby inductively heating the suction and / or dispensing device 214. In the present example, the suction and / or dispensing device 214 can be heated to a temperature of, for example, 300°C, and any residual protein and / or biological material is coagulated, denatured and inactivated. Temperatures as low as, for example, 43°C denature some proteins. 300°C incinerates most proteins. The temperature can be raised much higher, including, for example, 760°C. If there are scratches or other surface deformities on the suction and / or dispensing device 214, the current changes direction around the root of the defect, which increases the local current density and thus increases the local heat generation, and ensures that these areas are cleaned. When there are cracks, scratches or defects, the current is concentrated and guided below the cracks, scratches or defects, so that the bottom experiences increased heating, which is where contaminants can accumulate. Prior to or during this operation, liquid 216 may be dispensed from aspiration and / or dispensing device 214 .

[0037] In addition, in the disclosed examples, the electromagnetic field inductively heats only a portion of the suction and / or dispense device 214 to improve targeted cleaning of the suction and / or dispense device 214 and does not require heating of the entire suction and / or dispense device 214. For example, only the portion of the suction and / or dispense device 214 located within the working area defined by the coil 204 is heated. Some exemplary systems include an arm (see Figure 6 ) so that the suction and / or dispensing device 214 is raised or lowered through the electromagnetic field to inductively heat different portions of the suction and / or dispensing device 214 along the length of the suction and / or dispensing device 214.

[0038] Additionally, as described in more detail below, in some examples, the current flowing through the coil 204 varies according to the diameter of the portion of the suction and / or dispense device 214 in the working area and / or according to the thickness of the housing of the portion of the suction and / or dispense device 214 in the working area. In some examples, the thickness and / or diameter of the housing varies along the length of the suction and / or dispense device 214, and the frequency of the current is adjusted when the suction and / or dispense device 214 is raised or lowered.

[0039] In some examples, there is a pre-treatment process, such as, for example, a pre-rinse before the suction and / or dispensing device 214 enters the working area of ​​the coil 204 to clean the surface of the suction and / or dispensing device 214. In addition, in some examples, there is a post-treatment process, such as, for example, Figure 2CIn this example, the power to the coil 204 is stopped, and the probe flushing device in operation causes the flushing fluid 220 to flow in through the inlet 212 to flush the outer surface of the aspiration and / or dispensing device 214, thereby removing residual proteins and / or other biological materials. The flushing fluid 220 has a relatively lower temperature to reduce the temperature of the aspiration and / or dispensing device 214, thereby returning the temperature of the aspiration and / or dispensing device to, for example, ambient temperature. Figure 2B After operation of and / or 2C, the suction and / or dispensing device 214 is ready to be used again.

[0040] Figure 3A-3E Another exemplary aspiration and / or dispensing device 300 is shown which is inductively heated and flushed. The aspiration and / or dispensing device 300 is used to transport a sample or reagent 302 ( Figure 3A The outer and inner surfaces of the pumping and / or dispensing device 300 include contaminants 304 ( Figure 3B In some examples, the aspiration and / or dispensing device 300 is flushed to remove contaminants 304 and the aspiration and / or dispensing device 300 is placed in the center of the coil 306 ( Figure 3C The interior of the aspiration and / or dispensing device 300 may also be cleaned, but residual contaminants 308 may remain ( Figure 3D ).although Figure 3B-Figure 3D The aspiration and / or dispense device 300 is shown positioned within the coil 306 during a pre-rinse step and aspiration / dispense to clean the device 300 , but these processes or operations may occur prior to inserting the aspiration and / or dispense device 300 into the coil 306 .

[0041] The alternating current is passed through the coil 306 ( Figure 3D ), which generates a magnetic field that induces eddy currents in the aspiration and / or dispense device 300. The eddy currents generate heat, as disclosed above, to denature and inactivate any contaminants on and / or in the aspiration and / or dispense device 300. In some embodiments, a post-rinse treatment is provided to remove carbonized proteins 310 ( Figure 3E ) or otherwise inactivate and / or disengage proteins 310 that may remain in the fluid channel and / or cool the aspiration and / or dispensing device 300.

[0042] Figure 4An exemplary circuit configuration of an electromagnetic field generator 400 is shown, which can be included in, for example, a medical diagnostic system or a laboratory automation instrument (such as an automatic pipetting system). Examples include a main power supply 402. In this example, the main power supply 402 is the same power supply used for the entire medical diagnostic system. Therefore, the line voltage and frequency of the main power supply 402 are the same as those used by the rest of the system and are the same as those received from a standard wall-mounted electrical outlet. Therefore, in this example, there is no dedicated line voltage or high voltage power supply for powering the electromagnetic field generator 400. Instead, the main power is a low current high voltage power. The exemplary generator 400 includes a frequency generator 404 that generates the frequency required to operate the generator 400. In this example, the frequency can be, for example, about 637kHz. The frequency is adjustable and can be changed based on the characteristics of the suction and / or dispensing device or other workpieces located in the magnetic field and heated.

[0043] In some examples, the frequency can also be adjusted based on the type of reagent and / or sample, including, for example, whether the contents of the suction and / or distribution device were previously a blood sample or will be a blood sample in the upcoming use. For example, the frequency can be adjusted based on the amount of bound protein expected by a particular type of sample. Thus, for example, for a "cleaner solution" (i.e., a solution with a lower amount of bound protein or other biological carryover expected), the frequency / power can be reduced. The sample itself does not affect the heat rate or generation in the suction and / or distribution device.

[0044] In addition, if, for example, the test to be performed is particularly sensitive to carryover, the frequency may also be adjusted. In such examples, the frequency may be adjusted to maximize the heat used to reduce and / or eliminate carryover. For example, if the assay is particularly sensitive to carryover, higher and / or maximum available power and heat generation may be used to reduce and / or eliminate carryover.

[0045] In addition, in other examples, the frequency can be adjusted to use the minimum effective heat for a specific heating / cleaning cycle to reduce material stress on the probe, shorten cycle time and / or maximize energy efficiency. In some examples, power usage and / or frequency are adjusted based on the amount of pollutants sucked. In such examples, higher power can be used for cleaning cycles that include relatively larger amounts of probe lengths to be cleaned. In addition, in some examples, lower power can be used to clean smaller areas. In these two types of examples, even if the power used and the probe length cleaned are different, the cleaning time can be consistent. In addition, in some examples, when, for example, a small area of ​​a suction and / or distribution device (e.g., a probe) is to be cleaned and relatively higher power is used, the time used for cleaning can be reduced and the time spent in heating the suction and / or distribution device in an electromagnetic field can be reduced. In some examples, the suction and / or distribution device is not subjected to heat levels near a critical temperature, at which the material of the suction and / or distribution device begins to exhibit heat-related problems. In addition, the control of frequency and the control of heat levels can be used to reduce material stress, increase the service life of the suction and / or distribution device and reduce failures. Furthermore, in some examples, when less power is needed in the induction heater (e.g., in the coil), the frequency can be increased relative to the nominal. This results in less strain on the semiconductor switch (e.g., in the exemplary systems 400, 500, 600, 700 disclosed herein) when the drive frequency is above the resonant frequency because the switch is not "hard switched" to the potential.

[0046] The exemplary generator 400 also includes a power controller 406 to control the power flow from the main power source 402 at the frequency generated by the frequency generator 404. A square wave signal or waveform is used in this example, but other waveforms may be used, including, for example, sinusoidal, triangular, or sawtooth waveforms. An exemplary input power may be about 450 watts.

[0047] The exemplary generator 400 also includes a transformer 408. The transformer 408 steps down voltage and increases current. The transformer 408 also provides isolation between the resonant or tank circuit 410 and the main power supply 402. The transformer 408 also provides a means for electrically matching the tank circuit 400 to the main power supply 402 and the power controller 406 by amplifying or reducing the impedance of the tank circuit 410 seen by the main power supply 402 and the power controller 406 so that the generator 400 does not draw excessive current. In some examples, the transformer 408 may have a turns ratio of about 5.45:1. Therefore, in this embodiment, the current after the transformer 408 is about 5.45 times the current before the transformer 408, and the voltage after the transformer 408 is reduced to 1 / 5.45.

[0048] The oscillation circuit 410 is a parallel inductor-resistor-capacitor (LRC) circuit including a resistor 412 (including the resistance of the system of transmission lines and the inherent resistance of the following components), an inductor 414 (the inductance of both the coil 416 coupled to the transformer 408 and the work coil 418), and a capacitor 420 connected in parallel, the capacitor 420 having a value selected so that the oscillation circuit 410 resonates at the frequency of the frequency generator 404. The capacitor 420 provides the capacitance required for the resonant circuit, and the work coil 418 provides at least some of the inductance and resistance in the oscillation circuit 410. In this example, the capacitor 420 is about 0.45 μF when connected in parallel, and the work coil 418 has an inductance of about 1.4 μH. The oscillation circuit 410 further increases the current for the work coil 418. The exemplary work coil 418 operates as disclosed above to generate an alternating magnetic field, which results in a magnetic field that is opposite to the magnetic field generated by the workpiece, and thus increases the surface temperature of any workpiece located within the work zone 422 inside the work coil 418. In this example, the current before the transformer is about 4.4 A, and the current after the transformer is about 24 A. In this example, the oscillating circuit 410 further increases the current to about 240 A, resulting in a 53.4-fold total current increase at the work coil 412. In addition, the exemplary work coil 418 can increase the surface temperature of the workpiece, such as increasing the temperature of the suction and / or dispense device by 0-100° C. in less than 1 second, 0-300° C. in 1-2 seconds, and 700-800° C. in 7 seconds.

[0049] There are several design factors for optimizing the operation of the exemplary generator 400, including, for example, coil design and selection (inductance size, resistance value, small spacing between coil and workpiece), the part to be heated (physical size, material composition), the amount of primary power available (voltage, current), the desired heating rate, the desired maximum temperature, and the desired type of heating (through heating, surface heating). These factors affect the components used for the exemplary generator 400, including, for example, the nominal frequency generated at the frequency generator 404 (for heating the workpiece), the required capacitance (farad value and kVAR value), the multiplication value (Q) of the oscillating circuit 410, the phase angle (φ) of the oscillating circuit 410 (unity power factor of cos(φ)=1), the ratio and location of the transformer 408, the power supply design, and the connection line selection (to minimize stray inductance and voltage drop).

[0050] Specifically, the frequency used for a particular workpiece depends on the desired or physical shell thickness of the workpiece, and the thickness depends on the outer diameter of the workpiece (assuming but not limited to a cylindrical profile), wall thickness, and material composition. Shell thickness is defined as the depth at which approximately 86% of the induced power is generated, for example.

[0051] The optimum depth for a tubular or cylindrical workpiece is defined by the following equation (1).

[0052]

[0053] In equation (1), the shell thickness is represented by δ, t = wall thickness (m), and d = tube diameter (m). Equation (1) can be solved to obtain the shell thickness, which can be used in the following equation (2) to calculate the frequency f.

[0054]

[0055] In Equation 2, the resistivity is represented by ρ (μΩm), and μ represents the magnetic permeability (H / m). Equation (2) can be solved to determine the frequency f (Hz).

[0056] The selection of components for the oscillator circuit 410 depends on the desired frequency f (Hz), capacitance C (F), and inductance L (H), as shown in equation (3) below.

[0057]

[0058] In addition, as shown in the following equation (4), the reactive kilovolt-ampere (kVAR), power (W), angular frequency ω (radian / s), capacitance C (F), voltage (V), current I (A), resistance R (Ω), inductance L (H) and / or inductive resistance X L (Ω) is used to control or manipulate the Q factor of the oscillation circuit 410.

[0059]

[0060] A higher Q value produces a smaller bandwidth, which is more difficult to tune to resonance, but provides a higher current multiplication in the tank circuit 410. Conversely, a smaller Q value allows a larger bandwidth, which is easier to tune to resonance and more tolerant to detuning, but provides a lower current multiplication in the tank circuit 410. After the components for the tank circuit have been selected, the impedance Z (Ω) of the circuit can be calculated and the turns ratio of the transformer 408 can be selected so that the proper matching is made and no excessive current is drawn from the main power supply 402. Impedance Z of the Tank Circuit eq (Ω) depends on the angular frequency ω (radians / s), capacitance C (F), and the equivalent series resistance R of the capacitor C (Ω), the series resistance of the inductor R L (Ω), inductance L(H), equivalent circuit resistance R eq (Ω) and equivalent circuit impedance X eq (Ω), as shown below in equations (5), (6) and (7).

[0061] Z eq =R eq +jX eq =|Z|ejφ Equation (5)

[0062]

[0063]

[0064] Optimal transformer turns ratio Y t Depends on the power supply voltage V ps (V), the maximum current that can be safely drawn from the power supply I max (A) and the impedance Z of the oscillation circuit eq (Ω), and the resistance R as seen from the power supply ps (Ω), as shown below in equations (8) and (9).

[0065]

[0066]

[0067] The above equation describes the turns ratio of transformer 408 that provides the maximum amount of power drawn from power supply 402. If a turns ratio greater than that shown in Equation 9 is selected, the current drawn from main power supply 402 will be reduced and the overall power consumption of generator 400 will be reduced.

[0068] Figure 5 Another exemplary circuit configuration for an electromagnetic field generator 500 is illustrated, which may be included in, for example, a medical diagnostic system or an automated pipetting system. Components similar to those described in other examples will not be repeatedly described in this example or subsequent examples, although the values ​​of the components may be different. For example, current sources, frequencies, capacitors, etc. may have different values, but operate in a similar manner as disclosed above. Figure 5 The exemplary generator 500 includes a transformer having a turns ratio greater than the optimal choice. Figure 5 In the example shown, the frequency generator 404 can generate a 643kHz square wave. In this example, the Figure 4 The current source 506 of some aspects of the main power supply 402 and the power controller 406 produces a current of about 3.3A. In the present example, the first transformer 502 and the second transformer 504 together form a transformer with a turns ratio of about 16:1. Therefore, after the transformers 502, 504, the current multiplication number is 16 times. In the present example, the current after the transformer is about 52.8A. In the present example, the oscillating circuit 410 further increases the current to about 160A, resulting in a total increase of about 48 times at the working coil 412. In the present example, the total system power is reduced, but the draw on the current source 506 is reduced to match the desired demand in the present example.

[0069] Figure 6 Another exemplary circuit configuration is illustrated for an electromagnetic field generator 600 that may be included in, for example, a medical diagnostic system or an automated pipetting system. Figure 6 The exemplary generator 600 includes a controller 602 and one or more feedback loops 604. The feedback loop 604 provides data about various metrics of the generator 600 to the controller 604, such as, for example, frequency, impedance, temperature, the presence of the suction and / or dispensing device 606 in the electromagnetic field of the work coil 412, voltage readings and / or current readings at any point in the system. The presence of the suction and / or dispensing device 606 can be detected by temperature or load changes at the work coil 412. In addition, when the arm 608 moves the suction and / or dispensing device 606 up or down through the work coil 412, the physical properties of the suction and / or dispensing device 606 can be changed to change the surface of the suction and / or dispensing device 606 that is located in the electromagnetic field and is thus inductively heated. For example, the exemplary suction and / or dispensing device 606 has a diameter that decreases toward the end 610 (i.e., is tapered). The optimal frequency for properly heating the end 610 is different from the frequency required to properly heat the larger diameter portion of the suction and / or dispensing device 606. Thus, the controller 602 can adjust the frequency to change the strength of the electromagnetic field based on the data to optimize the heating temperature of the aspiration and / or dispensing device 606.

[0070] The controller 602 also acts as a calibrator to enable the generator 600 to self-calibrate based on the drift of capacitance or impedance over time. In addition, the controller 602 can also sense short circuits and / or other problems with any component of the generator 600 or the interconnections between them.

[0071] Figure 7 Another exemplary circuit configuration is illustrated for an electromagnetic field generator 700 that may be included in, for example, a medical diagnostic system or an automated pipetting system. Figure 7The exemplary generator 700 of includes a step-up / step-down transformer 702 and a rectifier 704 coupled to the main power source 402. The step-up / step-down transformer 702 and the rectifier 704 are separate components in some examples and are integrally formed with the power source 402 in other examples. The step-up / step-down transformer 702 and the rectifier 704 enable the generator 700 to draw power from the power source 402 and process the power into a direct current (DC) signal having an appropriate voltage and current capacity. Thus, the generator 700 can be coupled to a wall outlet in any country, and the step-up / step-down transformer 702 and the rectifier 704 can be selected and / or adjusted to adjust to the power available from the wall outlet. Thus, the transformer 702 and / or the rectifier 704 can be selected so that the system does not draw excessive current from the main power source 402. In some examples, the step-up / step-down transformer 702 and rectifier 704 modify the power to change the AC voltage supplied by the power source 402 to a DC voltage having a voltage of 120V and a current of 10A and / or otherwise adjust the supplied power. The exemplary generator 700 also includes an additional feedback loop 706 to provide further data to the controller 602, such as, for example, current readings, voltage readings, or any other suitable data.

[0072] Although in Figure 4-Figure 7 Exemplary ways of implementing generators 400, 500, 600, 700 have been illustrated in FIG. Figure 4-Figure 7 One or more of the elements, processes and / or devices shown in the drawings may be combined, separated, rearranged, omitted, eliminated and / or implemented in any other manner. In addition, the exemplary frequency generator 402, the power controller 406, the current source 506, the system controller 602, the rectifier 704 and / or more generally, Figure 4-Figure 7 The exemplary generators 400, 500, 600, 700 of the present invention may be implemented by hardware, software, firmware and / or any combination of hardware, software and / or firmware as part of a medical diagnostic device or as a stand-alone induction heating cleaning device. Thus, for example, the exemplary frequency generator 402, the power controller 406, the current source 506, the system controller 602, the rectifier 704 and / or more generally, Figure 4-Figure 7Any of the exemplary generators 400, 500, 600, 700 may be implemented by one or more circuits, programmable processors, application specific integrated circuits (ASICs), programmable logic devices (PLDs), and / or field programmable logic devices (FPLDs), etc. When any apparatus or system claim of the present invention is interpreted as covering only software and / or firmware implementations, at least one of the exemplary frequency generator 402, power controller 406, current source 506, system controller 602, and / or rectifier 704 is thereby expressly defined as including a tangible computer-readable medium storing software and / or firmware, such as a memory, DVD, CD, Blu-ray disc, etc. In addition, Figure 4-7 The exemplary generators 400, 500, 600, 700 of Figure 4-Figure 7 Those shown may also include one or more elements, processes and / or devices, and / or may include more than one of any or all of the elements, processes and devices shown.

[0073] Figure 8 shows that representation can be used to implement Figure 1-Figure 7 In this example, the process includes a program executed by a processor, such as in the following connection Fig. 9 The processor 912 shown in the exemplary computer 9000 discussed above. The program may be embodied as software stored on a tangible computer-readable medium such as a CD-ROM, floppy disk, hard disk, digital versatile disk (DVD), Blu-ray disk, or memory associated with the processor 912, but the entire program and / or a portion of the program may alternatively be run by a device other than the processor 912 and / or embodied as firmware or dedicated hardware. In addition, although reference is made to Figure 8 The flowchart shown describes an exemplary procedure, but many other methods of implementing the exemplary systems and devices disclosed herein may be used instead. For example, the order of execution of the blocks may be changed, and / or some of the blocks described may be changed, eliminated, or combined.

[0074] As mentioned above, Figure 8 The exemplary processes of may be implemented using coded instructions (e.g., computer readable instructions) stored on a tangible computer readable medium, such as a hard drive, flash memory, read only memory (ROM), compact disk (CD), digital versatile disk (DVD), cache, random access memory (RAM), and / or any other storage medium in which information may be stored for any duration (e.g., long-term, permanent, short-term, temporary buffering and / or information caching). As used herein, the term "tangible computer readable medium" is expressly defined to include any type of computer readable memory and does not include propagating signals. Additionally or alternatively, Figure 8 The exemplary processes may be implemented using coded instructions (e.g., computer readable instructions) stored on a non-transitory computer readable medium, such as a hard drive, flash memory, read-only memory, compact disk, digital versatile disk, cache, random access memory, and / or any other storage medium in which information may be stored for any duration (e.g., long-term, permanent, short-term, temporary buffering, and / or information caching). As used herein, the term "non-transitory computer readable medium" is expressly defined to include any type of computer readable memory and does not include propagating signals. As used herein, when the phrase "at least" is used as a transition term in the preamble of a claim, like the term "including" is open-ended, "at least" is also open-ended. Therefore, a claim using "at least" as a transition term in the preamble may include elements in addition to the elements explicitly listed in the claim.

[0075] Figure 8 A process 800 for reducing carryover is illustrated, which includes, for example, denaturing and / or inactivating proteins and / or other biological materials, disinfecting, cleaning, etc. In some examples, process 800 includes pre-flushing or otherwise pre-treating a probe or other aspiration and / or dispensing device using, for example, one or more of the pre-flushes of FIGS. 2 and 3 (block 802). Exemplary process 800 also includes generating an electromagnetic field (block 804). Exemplary electromagnetic fields may be generated, for example, by Figure 1-7 Coils 100, 204, 306, 412 and / or Figure 4-Figure 7 The electromagnetic field is generated by a generator 400, 500, 600, 700. In some examples, the electromagnetic field is an alternating electromagnetic field generated by an AC power source.

[0076] exist Figure 8In the exemplary process 800 of , the presence of the probe is detected (frame 806). If the probe is not detected, the control process stays at frame 806 until the probe has been introduced into the generated electromagnetic field. When the probe has been introduced into the electromagnetic field, the exemplary process 800 determines whether the electromagnetic field should be adjusted (frame 808). For example, the controller 602 may sense that the size of the probe in the working coil 412 requires different frequencies to optimize the electromagnetic field and the resulting induction heat, and the process 800 makes adjustments (frame 810). When no adjustment is required or after the adjustment has been made, the process 800 continues and the probe is heated (frame 812). During the heating of the probe (frame 812), the position of the probe can be adjusted (e.g., raised or lowered) relative to the electromagnetic field and the coil to change the portion of the probe that is subjected to the electromagnetic field and the associated induction heating. After the probe is heated to a desired temperature and / or duration to denature and / or inactivate any biological material, one or more optional post-rinsing steps (frame 814) may be performed. For example, a post rinse may wash carbonized proteins and / or other residues off the probe, a cooling rinse may reduce the temperature of the probe, and / or other post-processing may be performed. The exemplary process 800 ends (block 816) and the probe may be reused.

[0077] Fig. 9 Is able to run Figure 8 process to achieve Figure 1-Figure 7 The computer 900 may be, for example, a server, a personal computer, or any other type of computing device.

[0078] The system 900 of the present example includes a processor 912. For example, the processor 912 may be implemented by one or more microprocessors or controllers from any desired family or manufacturer.

[0079] The processor 912 includes a local memory 913 (e.g., cache) and communicates with a main memory including a volatile memory 914 and a non-volatile memory 916 via a bus 918. The volatile memory 914 may be implemented by a synchronous dynamic random access memory (SDRAM), a dynamic random access memory (DRAM), a RAMBUS dynamic random access memory (RDRAM), and / or any other type of random access memory device. The non-volatile memory 916 may be implemented by a flash memory and / or any other desired type of memory device. Access to the main memory 914, 916 is controlled by a memory controller.

[0080] The computer 900 also includes an interface circuit 920. The interface circuit 920 may be implemented by any type of interface standard, such as an Ethernet interface, a universal serial bus (USB), and / or a PCI express interface.

[0081] One or more input devices 922 are connected to the interface circuit 920. The input devices 922 allow a user to enter data and commands into the processor 912. The input devices may be implemented by, for example, a keyboard, a mouse, a touch screen, a touch pad, a trackball, an isopoint, and / or a voice recognition system.

[0082] One or more output devices 924 are also connected to the interface circuit 920. The output device 924 may be implemented, for example, by a display device (e.g., a liquid crystal display, a cathode ray tube display (CRT), a printer, and / or a speaker). Therefore, the interface circuit 920 typically includes a graphics driver card.

[0083] Interface circuit 920 also includes a communication device, such as a modem or network interface card, to facilitate exchanging data with an external computer via network 926 (e.g., Ethernet connection, digital subscriber line (DSL), telephone line, coaxial cable, cellular telephone system, etc.).

[0084] The computer 900 also includes one or more mass storage devices 928 for storing software and data. Examples of such mass storage devices 928 include floppy disk drives, hard drive drives, compact disk drives, and digital versatile disk (DVD) drives.

[0085] To achieve Figure 8 The encoded instructions 932 of process 800 may be stored in mass storage device 928, in volatile memory 914, in non-volatile memory 916, and / or on a removable storage medium such as a CD or DVD.

[0086] Based on the above, it should be understood that the methods, devices, systems and products disclosed above can be used for inductively heating suction and / or dispensing devices in medical diagnostic instruments or automatic pipetting systems. These examples enable heating of such suction and / or dispensing devices without physical or electrical contact with the suction and / or dispensing devices. Reduced risk of electrical short circuits, and lower voltages can be used. In addition, less heat is required to disinfect, denature or inactivate proteins and other biological substances and / or otherwise clean the suction and / or dispensing devices. Therefore, the time required for the exemplary process disclosed herein is also reduced. In addition, the heat is controlled and evenly distributed on the target surface, and it is not necessary to heat the entire suction and / or dispensing device. In addition, the inductive heating of the suction and / or dispensing device allows the device to be reused. Inductive heating produces negligible solid waste and significantly less biohazardous waste. The exemplary systems and devices disclosed herein can be plugged into any wall-mounted electrical outlet and do not require a dedicated power cord for an electromagnetic field generator. Inductive heating provides a safe, controllable, fast and low incremental cost method for preventing and / or eliminating the carryover or cross contamination of proteins and / or other biological substances.

[0087] Although certain exemplary methods, apparatus, and articles of manufacture have been described herein, the scope of coverage of this disclosure is not limited thereto. On the contrary, this disclosure fully covers all methods, apparatus, and articles of manufacture falling within the scope of the claims herein.

Claims

1. A method comprising: An alternating electromagnetic field is generated by passing an electric current through an induction coil; exposing a sample carrier to the alternating electromagnetic field via a movable arm to cause a property of a biological sample to be modulated, the biological sample being carried by the sample carrier; as well as raising or lowering the sample carrier relative to the induction coil via the movable arm; as well as The flow of electrical current through the induction coil is adjusted in response to the raising or lowering of the sample carrier.

2. The method according to claim 1, further comprising: During the exposure of the sample carrier to the alternating electromagnetic field, the sample carrier is exposed to a fluid.

3. The method according to claim 1 or 2, further comprising: During exposure of the sample carrier to the alternating electromagnetic field, at least a portion of the sample carrier is disposed in a receptacle.

4. The method according to claim 1, further comprising: A change in the alternating electromagnetic field is detected in response to at least a portion of the sample carrier being present in the alternating electromagnetic field.

5. The method according to claim 1 or 2, further comprising: The sample carrier is rinsed prior to exposing the sample carrier to the alternating electromagnetic field.

6. The method according to claim 1, wherein: Raising or lowering of the sample carrier will cause different parts of the sample carrier to be inductively heated along the length of the sample carrier.

7. The method according to claim 6, wherein: A portion of the sample carrier is surrounded by the induction coil.

8. The method according to claim 1, further comprising: An algorithm is executed to control heating of the sample carrier via the alternating electromagnetic field.

9. The method according to claim 1, wherein: The sample carrier is exposed to the alternating electromagnetic field in order to inactivate or denature the properties of the biological sample.

10. A device comprising: A generating device for generating an alternating electromagnetic field; A moving device for moving a sample carrier, the moving device: exposing the sample carrier to the alternating electromagnetic field so that a property of a biological sample is modulated, the biological sample being carried by the sample carrier; as well as raising or lowering the sample carrier relative to the generating device; as well as Control means for controlling, said control means regulating the flow of electric current through said generating means in response to raising or lowering of said sample carrier.

11. The device according to claim 10, wherein: The sample carrier is a probe.

12. The device according to claim 10, wherein: The generating device is associated with a diagnostic instrument.

13. The device according to any one of claims 10 to 12, wherein: The sample carrier is exposed to the alternating electromagnetic field in order to cause the temperature of the surface of the sample carrier to change.

14. The apparatus according to claim 10, wherein: The moving device is used to position at least a portion of the sample carrier in a container during exposure of the sample carrier to the alternating electromagnetic field.

15. The apparatus according to claim 10, wherein: The moving device is used to raise or lower the sample carrier relative to the generating device to inductively heat different portions of the sample carrier along the length of the sample carrier.

16. The device according to claim 15, wherein: A portion of the sample carrier is laterally surrounded by the generating device.

17. Apparatus according to any one of claims 10 to 12, further comprising means for exposing the sample carrier to a fluid during exposure of the sample carrier to the alternating electromagnetic field.

18. The apparatus according to claim 10, wherein: The control device detects changes in the alternating electromagnetic field in response to at least a portion of the sample carrier being present in the alternating electromagnetic field.

19. The apparatus of any one of claims 10-12, 14-16 or 18, wherein: The sample carrier is exposed to the alternating electromagnetic field in order to inactivate or denature the properties of the biological sample.

20. Apparatus according to any one of claims 10-12, 14-16 or 18, further comprising means for rinsing the sample carrier prior to exposing the sample carrier to the alternating electromagnetic field.

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