INDUCTION HEATING SYSTEM FOR REDUCING BIOLOGICAL CARRYOVER AND METHOD FOR CONTROLLING AN INDUCTION HEATING SYSTEM - Patent application

Abstract

An induction heating system and method for controlling an induction heating system for reducing biological carryover is provided. The system includes a controller that drives the tank circuit to selectively oscillate at a resonant frequency of the tank circuit to inductively heat a workpiece disposed proximate the tank circuit.

Description

[Technical field]

[0001] This invention claims priority to U.S. Provisional Patent Application No. 62 / 438,250, filed December 22, 2016. U.S. Provisional Patent Application No. 62 / 438,250 is incorporated herein by reference in its entirety.

[0002] The present disclosure relates generally to medical diagnostic equipment, and more particularly to an inductive heating system and method for controlling an inductive heating system to reduce biological carryover. [Background technology]

[0003] Aspirating and dispensing devices, such as pipette probes, are used with automated medical diagnostic instruments to aspirate and / or dispense fluids, such as biological samples (e.g., serum, urine) and / or reagents as part of a diagnostic testing procedure. Aspirating and dispensing devices may be reused to reduce waste and operational costs. However, reusing aspirating and dispensing devices increases the likelihood of biological carryover and / or introducing contaminants into subsequent tests. [Brief description of the drawings]

[0004] [Figure 1] FIG. 1 is a schematic diagram of electromagnetic induction. [Diagram 2] FIG. 1 is a block diagram of an exemplary system for inductively heating a workpiece constructed in accordance with the teachings disclosed herein. [Diagram 3] FIG. 3 is a block diagram of an example induction heater station of the example system of FIG. 2. [Figure 4] FIG. 4 is a schematic diagram of an example circuit that may be used with the example induction heater station of FIG. 3. [Diagram 5] 3 illustrates an example temperature profile for inductively heating a workpiece using the example system of FIG. 2. [Figure 6]3 is a perspective view of an example induction heating coil that may be used with the example system of FIG. 2. [Figure 7] 3 is a perspective view of an example electromagnetic induction shield and an example heat sink for use in connection with the example system of FIG. 2. [Figure 8] 3 is a top view of a first example washing cup for use in connection with the example system of FIG. 2. [Figure 9] 10 is a cross-sectional view of an example first wash cup taken along line 1-1 of FIG. 8. [Figure 10] FIG. 1 is a flow diagram of an example method for resonating a tank circuit at a natural frequency that may be used to implement examples disclosed herein. [Figure 11] FIG. 2 is a flow diagram of an example method for inductively heating a workpiece that may be used to implement examples disclosed herein. [Figure 12] FIG. 1 is a diagram of an example processor platform for use with the examples disclosed herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0005] The figures are not to scale. Rather, layer thicknesses may be exaggerated in the figures to make the multiple layers and regions more clearly visible. Wherever possible, the same reference numbers are used throughout the drawings and accompanying textual description to refer to the same or like parts.

[0006] Automated medical diagnostic instruments, such as clinical chemistry analyzers, may be used to analyze biological samples (e.g., serum, urine) by performing one or more tests on the sample, such as an immunoassay. Aspiration and dispensing devices, such as pipetter probes, may be used with the diagnostic instrument, e.g., as part of an automated pipetting system for transporting fluids within the instrument, such as a sample, one or more reagents, etc. For example, the aspiration and dispensing devices may be used to deliver and / or remove fluids from reaction vessels of the instrument, move fluids between vessels, mix fluids, etc.

[0007] During use, at least a portion of the inner and / or outer surfaces of the aspirating and dispensing device are exposed to the fluid that the aspirating and dispensing device transports. In some instances, residues associated with the sample and / or reagent, such as proteins or viral material, may remain on the inner and / or outer surfaces of the aspirating and dispensing device. As a result, subsequent use of the aspirating and dispensing device may result in carryover of the sample or reagent, or transfer of the sample or reagent to another sample or reagent. Thus, reuse of the aspirating and dispensing device may contaminate the sample and / or reagent exposed to the aspirating and dispensing device in connection with subsequent use of the device. The aspirating and dispensing device may be cleaned to reduce carryover and / or contamination, for example, by sterilizing the device using heat.

[0008] Exemplary systems, methods, and apparatus disclosed herein use electromagnetic induction heating to clean workpieces, such as aspirating and dispensing devices. Examples disclosed herein include induction heaters that may be integrated and implemented with automated diagnostic instruments, such as clinical chemistry analyzers, immunoassay analyzers, and the like. In some examples disclosed herein, the instrument in which the induction heater is integrated is used to provide power to the induction heater and control one or more settings of the induction heater, such as via a graphical user interface. In some disclosed examples, the induction heater includes an induction heating circuit that includes a conductive medium, such as a coil. An electric current is provided to the conductive medium, which induces an electromagnetic field. In disclosed examples, the workpiece is disposed in proximity to the conductive medium (e.g., inserted into an opening in the coil) and heated by the magnetic field. In disclosed examples, heating the aspirating and dispensing device substantially removes and / or alters one or more properties of material remaining on the aspirating and dispensing device to substantially reduce the likelihood of carryover and / or contamination in subsequent uses of the aspirating and dispensing device.

[0009] In some disclosed examples, a cleaning fluid is applied to the workpiece before, during, and / or after inductive heating of the workpiece to flush biological and / or chemical matter from the surface of the device. Some disclosed examples include a cleaning cup to collect the cleaning fluid. In some disclosed examples, a conductive medium is disposed proximate to the cleaning cup, and in some examples is removably secured to a portion of the cleaning cup to facilitate collection of the cleaning fluid during inductive heating of the workpiece.

[0010] In examples disclosed herein, the induction heating circuit includes a tank circuit including a first coil to act as an electrically inductive medium for heating the workpiece. In some disclosed examples, a second coil is wrapped around the first coil to sense the oscillating magnetic field generated by the first coil and synchronize the current provided to the tank circuit with the current already flowing in the first coil. In examples disclosed herein, a signal corresponding to the oscillating magnetic field generated by the first coil is dynamically detected by the second coil. This signal is used to drive the current provided to the tank circuit such that the tank circuit is driven at its resonant frequency rather than a fixed frequency. Driving the tank circuit at its resonant frequency reduces energy losses and provides an increased amount of energy to be transferred to the aspiration and dispensing device heated by the first coil compared to driving the tank circuit at a fixed frequency. In this manner, the disclosed examples improve the efficiency of the induction heating of the aspiration and dispensing device. Driving the tank circuit to resonate at its natural frequency also compensates for manufacturing variations on components such as the coil and capacitors. Driving the tank circuit to resonate at its natural frequency also accommodates dynamic load variations for changes in the resonant frequency of the tank circuit due to the introduction into the magnetic field of workpieces having different diameters, coating thicknesses, etc.

[0011] In some disclosed examples, the conductive medium (e.g., coil) of the induction heating circuit is coated with one or more substances to prevent corrosion from biological and chemical interactions between the workpiece, cleaning fluid, and the conductive medium. Some disclosed examples detect and / or predict failure of one or more components of the induction heater by monitoring heater performance data such as voltage, current, and frequency. Some disclosed examples also include a heat sink to reduce the risk of overheating the coil and the printed circuit board on which components such as the capacitor of the tank circuit are mounted. Thus, the disclosed examples provide a stable and reliable means for induction heating, as well as aspirating and dispensing devices.

[0012] An example system disclosed herein includes an induction heater including a tank circuit, and a controller that drives the tank circuit to selectively oscillate at a resonant frequency of the tank circuit to inductively heat a workpiece disposed proximate to the tank circuit.

[0013] In some examples, the controller selectively drives the tank circuit to oscillate at a resonant frequency based on characteristics of the workpiece.

[0014] In some examples, the controller drives the tank circuit to selectively oscillate between a resonant frequency and a fixed frequency.

[0015] In some examples, the tank circuit includes a work coil and a sense coil, hi such examples, the sense coil is wrapped around the work coil.

[0016] In some examples, the controller drives the tank circuit to oscillate at a resonant frequency based on a signal generated by the sense coil.

[0017] In some examples, the system further includes a heat sink coupled to the induction heater.

[0018] In some examples, the system further includes a shield comprising a thermally conductive material coupled to the induction heater.

[0019] In some examples, the tank circuit includes a work coil, the work coil being disposed within the wash cup. In some such examples, the work piece is exposed to the fluid during induction heating. In some such examples, the fluid undergoes a phase change during induction heating.

[0020] In some examples, the controller accesses at least one of temperature data, current data, or voltage data from the induction heater, hi such examples, the controller predicts a performance condition of the induction heater based on the data.

[0021] In some examples, the workpiece includes a first portion and a second portion. In such examples, the controller selectively adjusts heating settings in the tank circuit for the first portion and the second portion. In some such examples, the controller adjusts the heating settings for the first portion based on a first temperature profile for the first portion and adjusts the heating settings for the second portion based on a second temperature profile for the second portion.

[0022] An example method disclosed herein includes providing current to an inductive heater including a tank circuit by executing instructions with a processor. The example method includes driving the tank circuit to selectively oscillate at a resonant frequency of the tank circuit by executing instructions with a processor. The example method includes inductively heating a workpiece disposed proximate to the tank circuit.

[0023] In some instances, driving the tank circuit to selectively oscillate at a resonant frequency is based on a characteristic of the workpiece.

[0024] An example tangible computer readable medium disclosed herein includes instructions that, when executed, cause a processor to provide current to an induction heater including at least a tank circuit, the instructions causing the processor to drive the tank circuit to selectively oscillate at a resonant frequency of the tank circuit and to inductively heat a workpiece disposed proximate to the tank circuit.

[0025] In some examples, the instructions, when executed, further cause the processor to drive the tank circuit to selectively vibrate at a resonant frequency based on a characteristic of the workpiece.

[0026] In some examples, the instructions, when executed, further cause the processor to drive the tank circuit to selectively oscillate between the resonant frequency and the fixed frequency.

[0027] In some examples, the workpiece includes a first portion and a second portion, and the instructions, when executed, further cause the processor to selectively adjust heating settings in the tank circuit for the first portion and the second portion.

[0028] In some examples, the instructions, when executed, further cause the processor to adjust a heating setting for the first portion based on a first temperature profile for the first portion and adjust a heating setting for the second portion based on a second temperature profile for the second portion.

[0029] Turning now to the figures, FIG. 1 is a schematic diagram of electromagnetic induction. As shown in FIG. 1, at least a portion of a workpiece 100 (e.g., an aspiration and dispensing device) to be heated is removably disposed within a conductive medium, such as, for example, a coil 102. In the example of FIG. 1, the workpiece 100 comprises a metal. An alternating current is provided to the coil 102 (e.g., from a current source) and flows through the coil 102 as represented by arrows 104 in FIG. 1. The alternating current flowing through the coil 102 induces a magnetic field 106 in an area around the coil 102. The magnetic field 106 induces eddy currents in the workpiece 100 as represented by arrows 108 in FIG. 1. The eddy currents generate localized heat that increases the temperature of the workpiece 100 without direct contact between the workpiece 100 and the coil 102. In an example where the workpiece 100 is an aspiration and dispensing device, the heat affects the properties of one or more substances (e.g., residual biological substances) on the interior and / or exterior surfaces of the workpiece 100, allowing the substances to be removed or altered and the workpiece 100 to be cleaned.

[0030] 2 is a block diagram of an example system 200 for reducing biological carryover via inductive heating. The example system 200 includes a diagnostic instrument 202. The diagnostic instrument 202 can be, for example, a clinical chemistry analyzer, an immunoassay analyzer, or the like. The example diagnostic instrument 202 includes a processor 204 to control one or more functions performed by the instrument 202, such as manipulating a test sample, performing a readout of the test sample, positioning a reaction vessel, delivering fluid to and / or removing fluid from the reaction vessel. The example diagnostic instrument 202 includes a power source 206. The power source 206 can include, for example, a battery, an electrical outlet, or the like. The example diagnostic instrument 202 includes a display 208. The display 208 can present one or more graphical user interfaces (GUIs) 209 to a user of the diagnostic instrument 202, for example, receiving user input via the GUI 209, displaying analysis results via the GUI 209, or the like. The diagnostic instrument 202 may include a timer 211 to monitor, trigger, or more generally provide timing control of one or more functions performed by the diagnostic instrument 202 in connection with analyzing a sample.

[0031] In the example system 200 of FIG. 2, the diagnostic instrument 202 includes an induction heater control station 210. The example induction heater control station 210 includes an induction heater 212 to clean or sterilize a workpiece 214 (e.g., the workpiece 100 of FIG. 1) by induction heating substantially as disclosed in connection with FIG. 1. The workpiece 214 may include aspirating and dispensing devices that may be used to perform one or more functions related to the experiments and / or analyses performed by the diagnostic instrument 202, such as transporting biological samples, delivering reagents, etc. As a result of use of the workpiece 214 with the diagnostic instrument 202, the workpiece 214 may include biological and / or chemical residues on one or more surfaces of the workpiece 214, such that reuse of the workpiece 214 may contaminate other samples and / or reagents.

[0032] The workpiece 214 may include one or more portions having different properties 215 with respect to, for example, coating thickness, diameter, cross-sectional shape, material, etc. The properties 215 of the workpiece 214 may affect the magnetic properties of the workpiece 214 with respect to heating the workpiece 214 with a magnetic field. For example, as illustrated in FIG. 2, the workpiece 214 may include a first portion 217 having a first diameter and a second portion 219 having a second diameter smaller than the first diameter. In some examples, the workpiece 214 is moved relative to the induction heater 212, for example, by a robotic arm 221 of the diagnostic instrument 202, to selectively heat and clean the first portion 217 and the second portion 219 of the workpiece 214. The workpiece 214 may include additional portions or fewer portions than those illustrated in FIG. 2. In some examples, the workpiece 214 is a probe that includes an opening defined by and extending through portions 217, 219 of the workpiece.

[0033] 2, the induction heater 212 is disposed proximate to the wash cup 216. In some examples, the induction heater 212 is coupled to the wash cup 216. For example, the induction heater 212 may be coupled to the interior of the wash cup 216. In the example of FIG. 2, at least a portion of the workpiece 214 is disposed within the wash cup 216. In some examples, the workpiece 214 is rinsed with a fluid 218 (e.g., liquid) before, during, and / or after being heated by the induction heater 212. The wash cup 216 collects the fluid 218.

[0034] The example induction heater control station 210 of Figure 2 includes a power driver unit 220. In the example of Figure 2, the power supply 206 of the diagnostic instrument 202 provides power (e.g., in the form of direct current (DC)) to the power driver unit 220, as represented by arrow 222 in Figure 2. Power received by the power driver unit 220 from the power supply 206 is used to drive the induction heater 212 with a drive signal, as represented by arrow 224 in Figure 2. In some examples, the power driver unit 220 includes a DC-DC converter to convert the DC received from the power supply 206 from one voltage level to another voltage level.

[0035] The example induction heater control station 210 of FIG. 2 includes an induction heater controller 226. The induction heater controller 226 includes a processor 227 to perform one or more control functions for the induction heater 212 and / or the power drive unit 220. For example, the induction heater controller 226 generates one or more instructions to activate and / or deactivate the induction heater 212 and monitors the status and / or performance of the induction heater 212 and / or other components of the induction heater control station 210 (e.g., the power drive unit 220). The power drive unit 220 provides power to the induction heater controller 226, as represented by arrow 228 in FIG. 2.

[0036] In the example system 200 of FIG. 2 , the induction heater controller 226 is communicatively coupled to the processor 204 of the diagnostic instrument 202. The induction heater controller 226 includes a serial communication port to facilitate the transfer of data between the induction heater controller 226 and the processor 204 of the diagnostic instrument 202, as represented by arrow 230 in FIG. 2 . For example, one or more user commands received via the GUI 209 of the diagnostic instrument 202 may be transmitted to the induction heater controller 226 via the serial communication port 230. The induction heater controller 226 may also transmit performance data generated, for example, by monitoring the induction heater 212 to the diagnostic instrument 202 via the serial communication port 230. As another example, the timer 211 of the diagnostic instrument 202 transmits a trigger signal 232 to the induction heater controller 226 to provide timing control for one or more induction heating events, such as activation and deactivation of the induction heater 212.

[0037] 2 is communicatively coupled to the power drive unit 220. The example induction heater controller 226 provides one or more instructions 234 to the power drive unit 220 regarding, for example, activation of the induction heater 212, the temperature to which the workpiece 214 is heated, etc. The example power drive unit 220 generates a drive signal 224 to drive the induction heater 212 based on the instructions 234 received from the induction heater controller 226.

[0038] 2, the power drive unit 220 communicates data such as a status 236 of the induction heater 212, monitors data regarding the current and / or voltage in the induction heater 212, etc. Based on the data received from the power drive unit 220, the induction heater controller 226 can communicate, for example, a present / ready status signal 240 of the induction heater control station 210, a pass / fail status signal 242 regarding the performance status of one or more components of the induction heater control station 210, such as the power drive unit 220 and / or the induction heater 212, and / or other signals including data that may be used by the diagnostic instrument 202 to control the induction heater control station 210.

[0039] As disclosed below, in some examples, the induction heater controller 226 receives feedback 244 from the induction heater 212, for example, regarding the frequency at which the circuit of the induction heater 212 is oscillating. In some examples, the induction heater controller 226 receives analog feedback signals from the power drive unit 220 and / or the induction heater 212. The induction heater controller 226 converts the analog signals to digital data (e.g., via processor 227) for analysis by the induction heater controller 226 and / or the processor 204 of the diagnostic instrument 202.

[0040] 2 may include a pump 246 to control the flow of fluid 218 used to clean the workpiece 214. The operation of the pump may be controlled by the power drive unit 220, for example, based on instructions 234 received from the processor 227 of the induction heater controller 227. In another example, the pump 246 is controlled by the processor 204 of the diagnostic instrument 202. The instructions may, for example, control the speed at which the pump 216 pumps the fluid 218.

[0041] Figure 3 is a block diagram of the example induction heater control station 210 of Figure 2. The example induction heater control station 210 includes a heater board 300 (e.g., a printed circuit board) that includes one or more electrical components (e.g., circuits) coupled thereto. The example heater board 300 of Figure 3 is operably coupled to an induction heater controller 226.

[0042] In some examples, the heater board 300 includes the power drive unit 220 (e.g., the power drive unit 220 is mechanically and electrically coupled to the heater board 300). In other examples, the power drive unit 220 is separate from the heater board 300 but operably coupled thereto. As disclosed above, the power drive unit 220 receives power from the power supply 206 of the diagnostic instrument 202 of FIG. 2. The power drive unit 220 delivers power to, for example, the inductive heater controller 226, other components of the heater board 300, etc.

[0043] The example heater board 300 of Figure 3 is operably coupled to the inductive heater 212. The example inductive heater 212 of Figure 3 includes a tank circuit board 302 (e.g., a printed circuit board). In some examples, the tank circuit board 302 and the heater board 300 form a single board. In other examples, the heater board 300 and the tank circuit board 302 are separate boards.

[0044] The example tank circuit board 302 of FIG. 3 includes a tank circuit 304 (e.g., an inductance-capacitance or LC circuit) formed by a capacitor 306 and an inductor or work coil 308 (e.g., coil 102 of FIG. 1). The work coil 308 includes a conductive material, such as a metal. The example power drive unit 220 provides a current 310 to the tank circuit 304 and / or generates a voltage in the tank circuit 304. In some examples, the power drive unit 220 provides the current 310 to the tank circuit 304, for example, via a shielded or coaxial cable. As disclosed above with respect to FIG. 1, when the current 310 flows through the work coil 308, a magnetic field (e.g., magnetic field 106 of FIG. 1) is generated by the work coil 308. The magnetic field can be used to heat the workpiece 214 of FIG. 2 when the workpiece 214 is disposed in proximity to the work coil 308 (e.g., at least partially disposed within an opening of the work coil 308).

[0045] The example tank circuit board 302 of Figure 3 includes a sense coil 312. In the example induction heater 212 of Figures 2 and 3, the sense coil 312 is wrapped around the work coil 308. The example sense coil 312 detects or senses the magnetic field generated by the work coil 308. The sense coil 312 generates one or more sense signals 314 that are transmitted to the heater board 300. As disclosed below, the sense signals 314 generated by the sense coil 312 are detected by a frequency control circuit 316 of the heater board 300 to drive the tank circuit 304 at a resonant frequency.

[0046] The example tank circuit board 302 includes a coil temperature sensor 318. The coil temperature sensor 318 detects the temperature of the work coil 308 and / or the sense coil 312, for example, during generation of a magnetic field by the work coil 308. The coil temperature sensor 318 transmits coil temperature data 320 to a temperature monitor 322 of the example heater board 300. In some examples, the temperature monitor 322 also collects temperature data related to the temperature of the heater board 300 and / or one or more electrical components of the board, for example, based on one or more temperature sensors coupled to the heater board 300. The temperature monitor 322 transmits heater temperature data 323 related to the temperature of the work coil 308, the sense coil 312, the heater board 300, etc. to the induction heater controller 226.

[0047] 3 also includes a current monitor 324. The current monitor 324 generates data regarding the current 310 being provided to the tank circuit 304, such as the amount of current, the frequency of the current, etc. For example, the current monitor 324 can detect an overcurrent, or a current that exceeds a threshold current that should be received by the tank circuit 304. The current monitor 324 can detect a change in the current in the inductive heater 212. The current monitor 324 generates one or more current signals 325 based on its detection and transmits the current signals 325 to the inductive heater controller 226.

[0048] The example heater board 300 of FIG. 3 includes a voltage monitor 326. The voltage monitor 326 generates data regarding the voltage in the tank circuit 304. In some examples, the voltage monitor 326 detects an overvoltage, or a voltage in the tank circuit 304 that exceeds a threshold limit of the tank circuit 304. The voltage monitor 326 can detect the voltage based on a voltage measurement obtained from the tank circuit 304 (e.g., by a voltmeter). The voltage monitor 326 can also detect a change in voltage at the induction heater 212. The voltage monitor 326 generates one or more voltage signals 327 based on its detection and transmits the voltage signals 327 to the induction heater controller 226.

[0049] As disclosed above, the example heater board 300 includes a frequency control circuit 316. The frequency control circuit 316 transmits one or more sense coil detection signals 328 to the example induction heater controller 226 of FIG. 3 based on a sense signal 314 generated by the sense coil 312 regarding the oscillation of the tank circuit 304. The example heater board 300 also includes a fixed frequency clock 330. As disclosed below, the frequency control circuit 316 selectively enables the fixed frequency clock 330 to generate one or more fixed frequency signals or disables the fixed frequency clock 330 based on the sense signal 314. The fixed frequency signals generated by the fixed frequency clock 330 cause the current 310 in the tank circuit 304 to oscillate at a fixed frequency.

[0050] As such, the example induction heater controller 226 receives one or more signals 323, 325, 327, 328 from the circuitry of the example heater board 300. The induction heater controller 226 processes the data 323, 325, 327, 328, for example, by converting the data from analog to digital, filtering the data, removing noise from the data, etc. The example induction heater controller 226 of FIG. 3 analyzes the data received from the heater board 300 to generate one or more instructions regarding operation of the induction heater 212 and / or transmits the data to the diagnostic instrument 202 of FIG. 2 for display to a user via the GUI 209. Any of the functions of the example induction heater controller 226 of FIG. 3 disclosed herein may be performed by a processor 227 associated with the induction heater controller 226.

[0051] The example induction heater controller 226 of FIG. 3 includes a drive manager 332. The drive manager 332 generates instructions 234 that are transmitted to the power drive unit 220, causing the power drive unit 220 to generate, for example, a current 310 provided to the tank circuit 304 and / or a voltage to be generated in the tank circuit 304. The instructions 234 generated by the drive manager 332 include, for example, an amount of current 310 to be provided to the tank circuit 304 and / or a voltage to be generated in the tank circuit 304, a duration for which the current 310 is to be provided, etc. In some examples, the drive manager 332 generates the instructions 234 based on reference data 334 stored in a database 336 of the induction heater controller 226. The reference data 334 may include, for example, data regarding current and / or voltage thresholds of the tank circuit 304, the respective inductances of the work coil 308 and / or the sense coil 312, the capacitance of the capacitor 306, etc.

[0052] 3 includes a frequency manager 338. The frequency manager 338 processes the sense coil detection signal 328 generated by the frequency control circuit 316. In some examples, the frequency manager 338 generates one or more frequency instructions 339 for operation of the frequency control circuit 316 and / or the fixed frequency clock 330 to selectively oscillate the tank circuit 304 at a resonant frequency or a fixed frequency, as disclosed below.

[0053] 3 includes a performance manager 340. The current monitor 324 and / or voltage monitor 326 send respective current signals 325 and / or voltage signals 327 indicative of, for example, changes in current and / or voltage in the induction heater 212 (e.g., in the tank circuit 304) to the performance manager 340. The example performance manager 340 generates one or more instructions for a power drive unit based, for example, on the monitoring of the current and / or voltage.

[0054] In some examples, the change in voltage and / or current detected at the induction heater 212 is based on one or more of the characteristics 215 of the workpiece 214 of FIG. 2 introduced into the induction heater 212. For example, the workpiece 214 of FIG. 2 includes a first portion 217 and a second portion 219 having a diameter smaller than the first diameter of the first portion 217. In some examples, the thickness of the coating on the first portion 217 is greater than the thickness of the second portion 219. As disclosed above, the first and second portions 217, 219 of the workpiece 214 may be selectively disposed in proximity to the workcoil 308 due to heating of the magnetic field generated by the current 310 in the workcoil 308. The presence of the first portion 217 and / or the second portion 219 relative to the workcoil 308 may affect the load on the workcoil 308.

[0055] In some examples, the current monitor 324 of FIG. 3 detects a change in current in the tank circuit 304 when the second portion 219, having a thinner coating, is disposed proximate to the work coil 308 compared to when the first portion 217 is disposed proximate to the work coil 308. For example, the current monitor 324 may detect that the current 310 in the tank circuit 304 is reduced when the second portion 219 is proximate to the work coil 308 compared to when the first portion 217 is disposed proximate to the work coil 308. The current monitor 324 generates a current signal 325 related to the change in current (e.g., reduced current) in the induction heater 212. In some examples, the voltage monitor 326 detects a change in voltage in the tank circuit 304 based on a load change in the work coil 308 due to the presence of the first portion 217 or the second portion 219 proximate to the work coil 308. The voltage monitor 326 generates a voltage signal 327 related to the change in voltage detected at the induction heater 212 .

[0056] A performance manager 340 of the induction heater controller 226 analyzes the current signal 325 and / or voltage signal 327 in conjunction with a temperature profile 342 for the workpiece 214 stored in the example induction heater controller 226 database 336 of FIG. 3. The temperature profile 342 includes prescribed data (e.g., provided by one or more user inputs to the processor 227 of the induction heater controller 226) regarding a minimum temperature for heating the workpiece 214 over the length of the workpiece 214 to clean or sterilize the workpiece 214, for example. The temperature profile 342 is used by the performance manager 340 to determine power settings over time for power to be provided to the induction heater 212 in conjunction with one or more portions 217, 219 (e.g., loads) of the workpiece 214 to be heated by the induction heater 212.

[0057] The temperature profile 342 may be based, for example, on known data regarding the characteristics 215 of the workpiece 214 and the response of the workpiece 214 to a magnetic field based on the characteristics 215. The characteristics 215 of the workpiece 214 result in load impedance variations at the induction heater 212 based on differences in, for example, coating thickness, diameter, etc., at different portions 217, 219 of the workpiece 214. The performance manager 340 uses the temperature profile 342 to control the power delivered to the workpiece 214 to heat the workpiece 214 at each position of the workpiece 214 relative to the induction heater 212 over time.

[0058] In some examples, the temperature profile 342 is a time-based profile regarding the temperature to which one or more portions 217, 219 of the workpiece 214 will be heated over time. In some examples, the temperature profile 342 is generated by the performance manager 340 of the induction heater controller 226 based on data previously collected during heating of the workpiece 214 and / or one or more other workpieces (e.g., calibration or reference data). In some examples, the temperature profile 342 is based on one or more user inputs received via the GUI 209 of the diagnostic instrument 202 regarding, for example, the voltage to be generated in the tank circuit 304 over time in relation to the position of the workpiece 214 in the induction heater 212. In some examples, the temperature profile 342 represents an optimal temperature for heating the first portion 217 and / or the second portion 219 of the workpiece 214 over time.

[0059] 3 directs the drive manager 332 to provide instructions 234 to the power drive unit 220 based on the temperature profile 342. In some examples, the performance manager 340 determines the instructions 234 to be sent to the power drive unit 220 based on a start time of heating of the workpiece 214 relative to a start position of the workpiece 214 in the induction heater 212 (e.g., whether the first portion 217 or the second portion 219 will be heated first). In some examples, the performance manager 340 determines the position of the workpiece 214 relative to the work coil 308 based on, for example, data from the processor 204 of the diagnostic instrument 202 regarding the movement and / or position of the robot arm 221 and / or other positional data (e.g., position data). The performance manager 340 determines additional instructions 234 to be sent to the power drive unit 220 based on an expected position of the workpiece 214 relative to the induction heater 212 as reflected in the temperature profile 342.

[0060] The performance manager 340 uses the temperature profile 342 to determine the current and / or power to be provided to the induction heater 212 and / or the voltage to be generated in the induction heater 212 at different times during heating of the workpiece 214 in the induction heater 212. In some examples, the performance manager 340 of FIG. 3 analyzes the current signal 325 and / or voltage signal 327 indicative of the changes in the current and / or voltage in the induction heater 212 associated with the temperature profile 342. Based on the analysis, the example performance manager 340 generates instructions 234 for the power drive unit 220 regarding the current, voltage, and / or power in the induction heater 212 for different heating settings associated with the temperature profile 342.

[0061] For example, based on the current signal 327, the performance manager 340 may detect a drop in current in the tank circuit 304 due to, for example, a second portion 219 of the workpiece 214 having a thinner coating being disposed closer to the work coil 308 as compared to a first portion 217 of the workpiece 214. The performance manager 340 analyzes the temperature profile 342 to determine that a higher temperature is required to heat the second portion 219 compared to the first portion 217 due to the thinner coating of the workpiece 214 (e.g., due to the thinner portion 219 of the workpiece heating less efficiently than the thicker portion 217 of the workpiece 214). The example performance manager 340 generates instructions 234 for the power drive unit 220 to increase the current 310 provided to the tank circuit 304 when the second portion 219 is disposed closer to the workpiece 308 as compared to the first portion 217 of the workpiece 214.

[0062] In some examples, the DC-DC converter of the power drive unit 220 serves as a power source to generate a voltage in the induction heater 212. In such examples, the temperature profile 342 includes a voltage value. The instructions 234 sent to the power drive unit 220 include a voltage to be generated at a particular time interval based on the temperature profile 342. In such examples, for a given heating setting (e.g., voltage), the power changes when the load impedance in the tank circuit 304 changes as a result of the movement of the workpiece 214 between the first portion 217 and the second portion 219 (e.g., by the robot arm 221 of FIG. 2).

[0063] In another example, the temperature profile 342 includes power values ​​representing desired power output values ​​(e.g., wattage) at different times. In such an example, the performance manager 340 calculates the power based on the current data 325 from the current monitor 324 and the voltage data 327 from the voltage monitor 326. The performance manager 340 adjusts the output voltage provided by the DC-DC converter to obtain the desired output power. In such an example, for a given heating setting (e.g., wattage), the power is substantially constant as the load impedance changes as a result of the movement of the workpiece 214 between the first portion 217 and the second portion 219 (e.g., by the robot arm 221 of FIG. 2).

[0064] In another example, the power driver unit 220 includes a fixed voltage source. In such an example, the output voltage is regulated by the duty cycle of the FET gate signal of the power driver unit 220.

[0065] 3 provides dynamic adjustment of the current and / or voltage in the tank circuit 304 and, consequently, the power provided to the workpiece 214 to heat the workpiece 214. The performance manager 340 takes into account the characteristics 215 of the workpiece 214 and the load impedance variations due to the position of the workpiece 214 relative to the induction heater 212 based on monitoring the current by the current monitor 324 and / or the voltage by the voltage monitor 326. The example performance manager 340 uses the temperature profile 342 to respond to dynamic load variations resulting from different portions 217, 219 of the workpiece 214 to be heated. The current, voltage, and / or power adjustments achieved via the power drive unit 220 substantially improve the performance of the induction heater 212, taking into account the different characteristics 215 of the workpiece 214 at the different portions 217, 219 to efficiently heat the workpiece 214.

[0066] 3 also includes a fault monitor 344. The fault monitor 344 analyzes the temperature data 323 generated by the temperature monitor 322 for potential overheating of one or more components of the heater board 300 (e.g., frequency control circuit 316) and / or the induction heater 212, for example. The fault monitor 344 analyzes the current signal 325 and / or the voltage signal 327 for overcurrent and / or overvoltage that could damage the induction heater 212 based, for example, on the amount or frequency of the current 310 being provided to the tank circuit 304.

[0067] Based on analysis of the temperature, current, and / or voltage data 323, 325, 327, the fault monitor 344 predicts whether one or more of the components of the induction heater control station 210 are likely to malfunction and / or fail (e.g., overheat, short circuit). The fault monitor 344 can predict performance conditions, for example, with respect to the induction heater 212, based on reference data 334 stored in a database 336 of the induction heater controller 226. For example, the fault monitor 344 can detect an overcurrent based on predefined current thresholds for the tank circuit 304, stored in the database 336.

[0068] If the fault monitor 344 determines that one or more components of the induction heater control station 210 are not working properly and / or functioning properly and / or if the fault monitor 344 predicts that one or more components are likely to fail, the fault monitor 344 generates one or more fault instructions 346. The fault instructions 346 may include, for example, instructions for the problematic component to shut down, instructions for other components to take the place of the problematic component, etc. In some examples, the instructions 234 sent to the power drive unit 220 include instructions to address a potential failure due to, for example, overcurrent and / or overvoltage in the tank circuit 304 by reducing and / or stopping the delivery of current to the tank circuit 304. In some examples, the fault monitor 344 stores historical data regarding performance tracking of the heater board 300 and / or the tank circuit board 302 in the database 336. The historical data may be used by the fault monitor 344 to predict component failure.

[0069] The fault monitor 344 may also update the present / ready status signal 240 and / or the pass / fail status signal 242 (as shown in FIG. 2 ) transmitted to the processor 204 of the diagnostic instrument 202 based on an analysis of the performance data of the induction heater control station 210. For example, if the fault monitor 344 detects an error in the induction heater 212, the fault monitor 344 may update the pass / fail status signal 242 to indicate an error condition of the induction heater 212. The fault monitor 344 may generate other alerts for display, for example, via the GUI 209 of the diagnostic instrument 202, regarding faults and / or historical data indicative of changes in performance over time that may indicate a future failure.

[0070] 3 includes a communicator 348 to transmit one or more of the instructions 234, 339, 346 to the heater board 300. The communicator 348 may also transmit a present / ready status signal 240 and / or a pass / fail status signal 242 to the processor 204 of the diagnostic instrument 202.

[0071] FIG. 4 is a diagram of an example frequency control circuit 316, fixed frequency clock 330, and tank circuit 304 of the example induction heater control station 210 of FIG. 3. As disclosed above with respect to FIG. 3, the tank circuit 304 includes a capacitor 306 and a work coil or inductor 308. The tank circuit 304 stores energy via an oscillating current between the capacitor 306 and the work coil 308. The oscillation of the current can result in energy loss in the tank circuit 304. For example, energy can be lost due to the resistance of the work coil 308, resonance of the capacitor 306, and the tank circuit board 302. Energy can also be lost as a result of the workpiece 214 being heated by the magnetic field generated by the work coil 308. In the example induction heater control station 210 of FIGS. 2-4, energy is provided to the tank circuit 304 in the form of an alternating current that is synchronized with the current already circulating in the tank circuit 304.

[0072] In the example of FIG. 4, the introduction of the workpiece 214 in the tank circuit 304 changes the effective inductance of the work coil 308. Variations in the properties 215 of the workpiece 214, such as density and / or shape (e.g., in different portions 217, 219), may also cause changes in the effective inductance of the work coil 308. The changes in the effective inductance of the work coil 308 affect the resonant frequency of the tank circuit 304, or the frequency at which the current oscillates in the tank circuit 304 with the least energy loss. In the example of FIG. 4, the alternating current injected into the tank circuit 304 has a frequency that varies based on the changing effective inductance in the work coil 308 to maximize the efficiency of synchronizing the current introduced into the tank circuit 304 with the current already circulating in the tank circuit 304. Such frequency adjustment allows the tank circuit 304 to oscillate at its resonant frequency and provides a dynamic response to load variations in the tank circuit 304 due to the introduction and / or manipulation of the workpiece 214.

[0073] As disclosed above, the tank circuit 304 includes a sense coil 312 disposed in proximity to (e.g., wrapped around) the work coil 308. The sense coil 312 senses the magnetic field (e.g., magnetic field 106 in FIG. 1 ) generated by the work coil 308 and generates a sense signal 314. The sense signal 314 is used to synchronize the alternating current 310 injected into the tank circuit with the current 401 already flowing in the tank circuit 304.

[0074] For example, at the beginning of a heating cycle (e.g., when the workpiece 214 is disposed proximate to the work coil 308), the variable DC power supply 400 (e.g., of the power drive unit 220) is enabled, for example, by command 234 from the induction heater controller 226 of FIG. 3. The variable DC power supply 400 is set to a low power level by the drive manager 332 of the induction heater controller 226. The low power level setting of the variable DC power supply 400 limits the oscillation of the tank circuit 304 when it is oscillating at a frequency that may or may not be its resonant frequency, thereby limiting energy loss. In other examples, the power level of the variable DC power supply is not adjustable.

[0075] In the example of Figure 4, the fixed frequency clock 330 is enabled by a frequency manager 338, which is an example of the induction heater controller 226 of Figure 3. The frequency manager 338 sets the fixed frequency clock 330 (e.g., based on predefined data) to generate a fixed frequency signal 402 close to the resonant frequency current of the tank circuit 304. The fixed frequency signal 402 goes through a switch 404 (e.g., a single-pole, double-throw, or SPDT switch) to a SYNC input pin 406 of a switched resonant frequency (RF) current driver circuit 408. The fixed frequency signal 402 causes the current 310 provided by the variable DC source and the current 401 already in the tank circuit 304 to oscillate at a fixed frequency.

[0076] The example sense coil 312 of FIG. 4 senses an oscillating magnetic field induced in the work coil 308 as a result of current flowing through the work coil 308 and generates a sense signal 314. The example frequency control circuit 316 of FIG. 4 includes a signal scaler 410. The signal scaler 410 scales the sense signal 314 with respect to the SYNC input pin 406 of the switched RF current driver 408 (e.g., voltage scaling). The signal scaler 410 also applies a delay to the sense signal 314 to optimize current synchronization and generate a scaled sense signal 412. In the example of FIG. 4, the signal scaler 410 includes circuitry to detect the validity of the sense signal 314 with respect to, for example, scaling the signal to a predefined voltage, signal amplitude, etc.

[0077] When the signal scaler 410 detects the validity of the sense signal 314, a switch 404 (e.g., a SPDT switch) is switched such that the frequency control circuit uses the sense signal 314 to drive the SYNC input pin 406 of the switched RF current driver 408 instead of the fixed frequency signal 402. As a result, the tank circuit 304 is freed from being driven by the fixed frequency clock 330 and instead is driven at its resonant frequency with respect to the current 310 provided by the variable DC power supply 400 and the current 401 already circulating in the tank circuit 304.

[0078] In the example of FIG. 4, when the tank circuit 304 is driven at its resonant frequency, the variable DC power supply 400 is adjusted (e.g., based on instructions 234 from the drive manager 332) to a high power level. Also, when the workpiece 214 is disposed in proximity to (e.g., inserted into) the work coil 308, the resonant frequency of the tank circuit 304 changes as the effective inductance of the work coil 308 changes due to the presence of the workpiece 214. The sense coil 312 generates a sense signal 314 that reflects the (e.g., modified) resonant frequency in the tank circuit 304. As a result, the current passing through the switched RF current drive circuit 408 is synchronized with the current 401 in the tank circuit 304. In this manner, the frequency control circuit 316 dynamically responds to the introduction of the workpiece 214 to the tank circuit 304 to enable the tank circuit 304 to be driven at its resonant frequency as the workpiece 214 is heated by the work coil 308. The sense coil 312 and frequency control circuit 316 form a feedback loop that responds to variations in the resonant frequency in the induction heater 212 .

[0079] In the example of FIG. 4 , driving the tank circuit 304 at its resonant frequency substantially minimizes energy losses in the tank circuit 304. As a result, more energy is transferred to the workpiece 214 for heating the workpiece 214 compared to when the tank circuit 304 is oscillated at a fixed frequency that is not the resonant frequency of the tank circuit 304. Thus, the self-oscillation of the tank circuit 304 at its resonant frequency increases the efficiency of the induction heater 212. Also, in allowing the tank circuit 304 to oscillate at its resonant frequency rather than driving it to resonate at a fixed frequency, the example frequency control circuit 316 substantially compensates for the effects of manufacturing variations and / or aging of the components of the induction heater control station 210, such as the work coil 308, the capacitor 306, the circuit boards 300, 302, etc. Manufacturing variations and / or aging may change the vibration behavior of the tank circuit 304 and thus result in inefficiencies when the tank circuit 304 is driven to oscillate only at a fixed frequency. 4 dynamically responds to load variations due to the introduction of a workpiece 214 into the tank circuit 304 and / or exposure of different portions 217, 219 of the workpiece 214 having different characteristics 215 to the induction heater 212. The example of FIG. 4 accommodates the resulting effect on the effective impedance of the work coil 308 and the resonant frequency of the tank circuit 304 due to load variations by adjusting to a modified resonant frequency.

[0080] At the end of the heating cycle, the drive manager 332 of the induction heater controller 226 adjusts the variable DC power supply 400 to a low power setting and turns off the variable DC power supply 400 after a predefined period of time (e.g., delay). As a result, the energy in the tank circuit 304 decreases. Over time, the sense coil 312 no longer generates a sense signal 314 large enough to be recognized as valid by the signal scaler 410. In such an example, the SYNC input pin 406 of the switched RF current driver 408 is switched to be driven by the fixed frequency clock 330. As a result, any residual energy in the tank circuit 304 dissipates. After a predefined period of time (e.g., delay), the drive manager 332 sends a command 234 for the fixed frequency clock 330 to be disabled.

[0081] Figure 5 is an example diagram of a temperature profile 500, such as temperature profile 342 of Figure 3, for a workpiece 502 having two or more portions with different characteristics, such as size, coating thickness, etc. Workpiece 502 can be, for example, workpiece 214 of Figure 3. Workpiece 502 can include, for example, an aspiration and dispensing device.

[0082] 5, an example temperature profile 500 includes a plot of temperature versus time for an example first portion 504 of a workpiece 502 and a second portion 506 of the workpiece 502. The first portion 504 of the workpiece 502 may have, for example, a first thickness and the second portion 506 may have a second thickness that is different from the first thickness. The second portion 506 may have one or more other different characteristics than the first portion 504, such as a different size, cross-sectional shape, etc.

[0083] 5, the example temperature profile 500 includes a first temperature profile 508 for a first portion 504 of the workpiece 502 having a temperature for heating the first portion 504 over time when the first portion 504 is disposed proximate to the work coil 308. The example temperature profile 500 includes a second temperature profile 510 for a second portion 506 of the workpiece 502 having a temperature for heating the second portion 506 over time when the second portion 506 is disposed proximate to the work coil 308. In some examples, the first and second temperature profiles 508, 510 represent minimum temperatures for heating the first and second portions 504, 506, respectively, of the workpiece 502, for example, to clean (e.g., sterilize) the workpiece 502. In other examples, the first and second temperature profiles 508, 510 represent optimal temperatures for heating the first and second portions 504, 506, respectively, to clean (e.g., sterilize) the workpiece 502 within a predetermined time period. The optimal temperature data may be based on data collected, for example, from one or more previous induction heating cycles of the workpiece 502 and / or other workpieces. In some examples, the performance manager 340 of FIG. 3 uses the example temperature profile 500 to generate instructions 234 regarding, for example, the current and / or power to be provided to the tank circuit 304 and / or the voltage to be generated in the tank circuit 304 to heat the first and second portions 504, 506 of the workpiece 502 over time at one or more predefined temperatures or heating settings.

[0084] FIG. 6 is a perspective view of an example work coil 600 (e.g., example work coil 308 of FIG. 3) that may be used with the induction heater 212 of the example induction heater control station 210 of FIGS. 2-4. The example work coil 600 includes a housing 602. In the example of FIG. 6, the housing 602 is a magnetic concentrator made, for example, of Ferrotron. The housing 602 includes a litz wire 604 disposed therein. The litz wire 604 includes multiple interwoven insulated wire strands. In some examples, the litz wire 604 is wound around a mandrel (e.g., a PEEK™ mandrel).

[0085] The example housing 602 of Figure 6 also includes a magnetic wire 606 that is wound around the Litz wire 604. The magnetic wire 606 includes, for example, an insulated copper wire. In the example of Figure 6, the magnetic wire 606 serves as a sense coil (e.g., sense coil 312 of Figures 3 and 4) for sensing the magnetic field generated by the work coil 600. In the example of Figure 6, the windings of the Litz wire 604 and the magnetic wire 606 are in the same direction.

[0086] One or more electrical leads 608 may be coupled to the example workcoil 600. The leads may be disposed in shrink tubing to protect the leads from heat generated by the workcoil 600. The example workcoil 600 of FIG. 6 includes a thermistor 610 or resistor used to measure the temperature of the housing 602 (e.g., a Ferrotron magnetic concentrator). Data generated by the thermistor 610 may be transmitted, for example, to the fault monitor 344 of the example induction heater controller 226 of FIG. 3.

[0087] The example workcoil 600 may be selectively designed based on, for example, spatial constraints relative to the induction heater control station 210 of the diagnostic instrument 202, the size of one or more workpieces to be heated by the workcoil 600, etc. In some examples, variables such as the cross-sectional shape of the wire, the metal type of the wire, the number of turns of the wire, the spacing between the turns, the height of the workcoil 600, the diameter of the workcoil 600, the shape of the workcoil 600, the resistance of the workcoil 600, etc. are selectively selected based on one or more intended uses of the workcoil 600.

[0088] As illustrated in FIG. 6, the example work coil 600 includes an opening 612. In operation, a work piece (e.g., work piece 214 of FIG. 2) is disposed within the opening 612 and is heated by a magnetic field generated by the work coil 600 when a current flows through the example work coil 600 of FIG. 6. The work piece does not touch, or is substantially not touching, the example work coil 600 during heating, but the example work coil 600 is exposed to biological and / or chemical substances on the work piece. Also, in examples where the work piece is washed during heating, the example work coil 600 is exposed to a cleaning fluid (e.g., fluid 218 of FIG. 2). In some examples, at least a portion of the cleaning fluid and / or biological / chemical substances may transfer to the work coil 600. Exposure to the cleaning fluid and / or biological / chemical substances may corrode the work coil 600, which may damage the work coil 600.

[0089] To prevent corrosion, the example workcoil 600 includes one or more coatings 614 applied to the housing 602. The coatings 614 may include, for example, surface treatment chemicals such as Chemtetall™ Oaktite® and / or ceramic coatings (e.g., ceramic coatings made by Cerakote™). Thus, the example workcoil 600 of FIG. 6 includes protection against corrosion to increase the operational life of the workcoil 600 and improve the reliability of the workcoil 600 in light of exposure to biological and / or chemical agents.

[0090] As disclosed above, the example induction heater control station 210 of FIG. 2 generates heat to clean a workpiece, such as an aspiration and dispensing device. In some examples, this heat may result in overheating of one or more components of the induction heater control station 210. The example induction heater control station 210 manages heat generated by the work coil (e.g., work coil 308, 600 of FIGS. 3 and 6), one or more printed circuit boards (e.g., heater board 300, tank circuit board 302 of FIG. 3), and / or other electrical components of the printed circuit boards (e.g., capacitor 306, frequency control circuit 316 of FIG. 3) through one or more thermal management techniques. The thermal management techniques employed by the induction heater control station 210, for example, substantially reduce the risk that the work coil will short out electrical components of the printed circuit boards and / or that waste heat will damage electrical components of the printed circuit boards.

[0091] For example, FIG. 7 illustrates an example tank circuit board 700 (e.g., tank circuit board 302 of FIG. 3) including an electromagnetic interference (EMI) shield 702 and a heat sink 704. The EMI shield 702 includes a thermally conductive material (e.g., metal) that substantially surrounds a work coil 706 (e.g., work coils 308, 600 of FIG. 2, FIG. 6). In some examples, the EMI shield 702 is coated with a coating including, for example, Teflon™. In some examples, the EMI of the induction heater 212 of FIG. 2, for example, may exceed limits or regulations imposed by an organization such as the Underwriters Laboratories and / or a governmental agency such as the European Union. The example EMI shield 702 substantially reduces the EMI of the induction heater 212 to comply with one or more standards for regulatory approval (e.g., CE compliance).

[0092] The example heat sink 704 of FIG. 7 substantially reduces overheating of the work coil 706 and / or the tank circuit board 700 by directing waste heat away from the work coil 706 and / or the tank circuit board 700. In the example of FIG. 7, thermal energy is conducted through the conductors of the work coil 706, such as the Litz wire 604 of FIG. 6 (and, in some examples, the magnetic wire 606 of the sense coil of FIG. 6), as well as through one or more copper vias formed, for example, in the tank circuit board 700. The thermal energy is transferred to the heat sink 704. In some examples, thermal energy from the work coil 706 is also transferred to the heat sink through the thermally conductive material of the EMI shield 702. The example heat sink 704 transfers heat, for example, from the tank circuit board 700 to the surrounding environment. In some examples, the heat sink transfers heat to the interior of the diagnostic instrument (e.g., the diagnostic instrument 202 of FIG. 2) in which the induction heater control station 210 is installed.

[0093] In some examples, the induction heater controller 226 of the example induction heater control station 210 of FIG. 2 reduces the duty cycle of the induction heater 212 (e.g., via the drive manager 332 and / or the performance manager 340 of FIG. 2) to manage the generation of waste heat. For example, the induction heater 212 may be activated to generate heat at a first temperature (e.g., based on the temperature profiles 342, 500 of FIGS. 3 and 5) at a first power setting (e.g., wattage) for a first predefined time period, such as 4 seconds. The induction heater 212 may also be activated to generate heat at a second temperature at a second power setting (e.g., wattage) higher than the first temperature for a second predefined time period, such as 2 seconds. A first temperature generated over a first (e.g., longer) time period and a second temperature generated over a second (e.g., shorter) time period may both be used to heat the workpiece, but the lower temperature heat generated over the first (e.g., longer) time period may take longer to dissipate. In the example of Figure 7, the induction heater controller 226 commands the induction heater 212 to generate heat for the shorter second time period to dissipate the heat more quickly. In this manner, the induction heater controller 226 reduces the duty cycle of the induction heater to more efficiently manage waste heat.

[0094] In this manner, the thermal management techniques employed by the induction heater control station 210 substantially reduce the risk of overheating electrical components such as coils, capacitors, etc., thus improving the performance of the induction heater control station 210. Additionally, the reduction in EMI shielding 702, heat sink 704, and / or duty cycle substantially reduces the need for other mechanical modes of controlling and / or removing heat from the induction heater control station 210, thereby simplifying design considerations.

[0095] Figure 8 is a top perspective view of the example tank circuit board 700 of Figure 7 including a work coil 706 disposed within a wash cup 800 (e.g., wash cup 216 of Figure 2). Figure 9 is a cross-sectional view of the example wash cup 800 and work coil 706 taken along line 1-1 of Figure 8 including a workpiece 900 (e.g., workpiece 214 of Figure 2) disposed within the work coil 706. For purposes of illustration, the example EMI shield 702 of Figure 7 is not shown in Figures 8 or 9.

[0096] As disclosed above, in some examples, the workcoil 706 is at least partially disposed within a washing cup 800 to facilitate cleaning of the workpiece 900, e.g., before, during, and / or after inductive heating of the workpiece 900 by the workcoil 706, to aid in removing biological and / or chemicals on the workpiece 900. The washing cup 800 collects a washing fluid (e.g., fluid 218 of FIG. 2) used to rinse the workpiece 900. The example washing cup 800 may include one or more openings or areas to accommodate and / or removably secure the workcoil 706, an electrical cable coupled to the workcoil 706, or the like, proximate to or substantially within the washing cup 800.

[0097] As illustrated in FIG. 9 , a first portion 902 of the workpiece 900 is disposed within and heated by the workcoil 706. A second portion 904 of the workpiece 900 is disposed within the wash cup 800, and a third portion 906 of the workpiece 900 is not disposed within the wash cup 800. The workpiece 900 may be selectively moved relative to the workcoil 706, for example, by the robot arm 221 of FIG. 2, which may hold the third portion 906 of the workpiece 900. As disclosed above, the induction heater control station 210 selectively adjusts the heat generated by the workcoil 706 based on a temperature profile (e.g., temperature profiles 342, 500) to heat the first, second, and / or third portions 902, 904, 906 of the workpiece 900 based on different characteristics of the respective portions, such as coating thickness, cross-sectional shape, diameter, etc.

[0098] Before, during, and / or after heating of the workpiece 900, a cleaning buffer is flowed over one or more surfaces of the workpiece 900 to wash away biological and / or chemical residues on the workpiece 900. In some examples, the cleaning buffer is flowed over the exterior and / or interior surfaces of the workpiece 900.

[0099] In some examples, a phase change (e.g., from liquid to vapor or gas) occurs to a cleaning buffer used to clean the workpiece during heating of the workpiece due to heat generated by the work coil 706. For example, the pump 246 of the example system 200 of FIG. 2 establishes an increased pressure to move a fluid (e.g., a liquid such as fluid 218 of FIG. 2) through the workpiece 900, which may be, for example, a probe having an opening extending along the length of the probe for receiving the fluid. The fluid flow rate provided by the pump 246 may be a substantially constant flow rate or a time-dependent flow rate. The increased pressure increases the saturation temperature of the fluid moving through the workpiece 900. As a result of the heat generated by the work coil 706 during induction heating, the temperature of the material of at least a portion of the workpiece 900 (e.g., the portion surrounded by the work coil 706) increases due to exposure to the heat of the workpiece 900. The heat generated by the work coil 706 is transferred, for example, through a wall of the workpiece 900 (e.g., the probe). Heat is transferred to the fluid flowing through the workpiece 900. As the workpiece 900 is exposed to heat over time, the temperature of the fluid may rise high enough to reach the saturation temperature of the fluid. When the fluid reaches its saturation temperature, a phase change of the fluid passing through the probe may occur. For example, a fluid passing through a portion of the workpiece 900 disposed within the work coil 706 may undergo a phase change and become a saturated liquid-vapor mixture due to the transfer of heat from the work coil through the wall of the workpiece 900 to the fluid. As the fluid flows downstream or past the region of the workpiece 900 disposed within the work coil 706, the temperature of the fluid drops below the saturation temperature. As a result, the vapor in the liquid-vapor mixture liquefies back to the liquid phase. In this manner, the phase change of the fluid may be temporally based on the flow of the fluid to the work coil 706.

[0100] When the phase change begins, bubbles form in the fluid moving through the workpiece 900 (e.g., the probe). Bubbles may form at or near the portion of the workpiece 900 disposed within the work coil 706. Bubbles may form temporarily within the heated portion of the workpiece 900 surrounded by the work coil. The formation, movement, and collapse of bubbles locally alters the movement of the fluid through the workpiece 900. The change in fluid movement due to the bubbles alters the magnitude and direction of the shear stress in the fluid. Some induction heating examples disclosed herein produce the formation, movement, and collapse of multiple bubbles, which result in multiple (e.g., temporary) spikes in shear stress and changes in shear stress direction in the fluid, which facilitate and / or enhance the cleaning of the workpiece 900. Thus, in some examples disclosed herein, the cleaning of the workpiece 900 involves a combination of elevated temperature and elevated liquid shear stress. In some examples, the pump 246 of FIG. 2 creates a pulsatile flow rate, which results in repeated drops in pressure to promote phase changes and / or bubble effects.

[0101] As an example, pump 246 of FIG. 2 may dispense fluid (e.g., liquid) at an average of 1.6 mL / s, which may create an average pressure difference of 30 psig at the portion of the workpiece 900 within the work coil 706. An example fluid may include a wash buffer that contains mostly water. Thus, the wash buffer properties may approximate those of pure water. Assuming a 1 atm environment, the saturation temperature of water under these conditions is 134° C. The outer surface temperature of a portion of the workpiece 900 (e.g., first portion 217 of workpiece 214 of FIG. 2) after preheating for 0.5 seconds at 270 W with a flow rate of 1.6 mL / s may be measured to be, for example, 160° C. Thus, the inner surface temperature of the workpiece 900 (e.g., defining the opening in the probe) is 154° C. In this way, the inner surface of the workpiece 900, and therefore the layer of fluid at the inner surface, exceeds the saturation temperature of the water (and therefore the cleaning buffer), which allows the fluid to undergo a phase change.

[0102] The example wash cup 800 of Figures 8 and 9 may be made of a material that can withstand the heat generated by the work coil 706, such as Isoplast™ plastic. The shape, size, and / or other design factors of the wash cup 800 may vary from those illustrated in Figures 8 and 9. For example, the design of the wash cup 800 may be selected based on the diagnostic instrument with which the wash cup 800 will be used, the size of the workpiece or workpieces to be cleaned, etc.

[0103] 2-9 , one or more of the elements, processes, and / or devices illustrated in FIGURES 2-9 may be combined, divided, rearranged, omitted, deleted, and / or implemented in any other manner. Additionally, the example diagnostic instrument 202, example processors 204, 227, example power supply 206, example display 208, example GUI 209, example timer 211, example induction heater control station 210, example induction heater 212, example power drive unit 220, example induction heater controller 226, example heater board 300, example tank circuit board 302, example capacitor 306, example work coil 308, example sense coil 312, example frequency control circuit 316, example coil temperature sensor 318, example temperature monitor 322, example current monitor 324, example voltage monitor 326, example voltage monitor 328, example voltage monitor 329, example voltage monitor 330, example voltage monitor 331, example voltage monitor 332, example voltage monitor 333, example voltage monitor 334, example voltage monitor 335, example voltage monitor 336, example voltage monitor 337, example voltage monitor 338, example voltage monitor 339, example voltage monitor 340, example voltage monitor 341, example voltage monitor 342, example voltage monitor 343, example voltage monitor 344, example voltage monitor 345, example voltage monitor 346, example voltage monitor 347, example voltage monitor 348, example voltage monitor 349, example voltage monitor 350, example voltage monitor 351, example voltage monitor 352, example voltage monitor 353, example voltage monitor 354, example voltage monitor 355, example voltage monitor 356, example voltage monitor 357, example voltage monitor 358, example voltage monitor 359, example voltage monitor 360, example voltage monitor 361, example voltage monitor 362, example voltage monitor 363, example 2-9 , the example system 200 of FIGS. 2-9 may be implemented in hardware, software, firmware, and / or any combination of hardware, software, and / or firmware.Thus, for example, an example diagnostic instrument 202, example processors 204, 227, example power supply 206, example display 208, example GUI 209, example timer 211, example induction heater control station 210, example induction heater 212, example power drive unit 220, example induction heater controller 226, example heater board 300, example tank circuit board 302, example capacitor 306, example work coil 308, example sense coil 312, example frequency control circuit 316, example coil temperature sensor 318, example temperature monitor 322, example current monitor 324, example voltage monitor 326, example fixed frequency clock 328, example power supply 206, example power supply 208, example power supply 209, example power supply 210, example power supply 212 ... 330, example drive manager 332, example database 336, example frequency manager 338, example performance manager 340, example fault monitor 344, example communicator 346, example variable DC power supply 400, example switched RF current driver 408, example signal scaler 410, and / or, more generally, any of the example systems 200 of FIGS. 2-9 may be implemented with one or more analog or digital circuits, logic circuits, programmable processors, application specific integrated circuits (ASICs), programmable logic devices (PLDs), and / or field programmable logic devices (FPLDs).When reading any of the apparatus and system claims of this patent to cover pure software and / or firmware implementations, one may also read the example diagnostic instrument 202, example processors 204, 227, example power supply 206, example display 208, example GUI 209, example timer 211, example induction heater control station 210, example induction heater 212, example power drive unit 220, example induction heater controller 226, example heater board 300, example tank circuit board 302, example capacitor 306, example work coil 308, example sense coil 312, example frequency control circuit 316, example coil temperature sensor 318, example temperature monitor 322, example current monitor 324, example power supply 326, example power supply 328, example power supply 329, example power supply 330, example power supply 331, example power supply 332, example power supply 333, example power supply 334, example power supply 335, example power supply 336, example power supply 337, example power supply 338, example power supply 339, example power supply 340, example power supply 341, example power supply 342, example power supply 343, example power supply 344, example power supply 345, example power supply 346, example power supply 347, example power supply 348, example power supply 349, example power supply 350, example power supply 351, example power supply 352, example power supply 353, example power supply 354, example power supply 355, example power supply 356, example power supply 357, example power supply 358, example power supply 359, example power supply 360, example power supply 361, example power supply 362, example power supply 363, example power supply 364, example power supply 365, example power supply 366, example power supply At least one of the example systems 200 of Figures 2-9 is expressly defined herein to include a tangible computer-readable storage device or storage disk, such as a memory, a digital versatile disk (DVD), a compact disk (CD), a Blu-ray disk, etc., that stores software and / or firmware. Furthermore, the example systems 200 of Figures 2-9 may include one or more elements, processes, and / or devices in addition to or instead of those illustrated in Figures 2-9 and / or may include two or more of any or all of the illustrated elements, processes, and devices.

[0104] Flowcharts representing example machine-readable instructions for implementing the example system 200 of FIGS. 2-9 are shown in FIGS. 10 and 11. In these examples, the machine-readable instructions include a program for execution by a processor, such as the processor 227 shown in the example processor platform 1200 discussed below in connection with FIG. 12. The program may be embodied in software stored on a tangible computer-readable storage medium, such as a CD-ROM, a floppy disk, a hard drive, a digital versatile disk (DVD), a Blu-ray disk, or a memory associated with the processor 227, although the entire program and / or portions thereof may alternatively be executed by devices other than the processor 227 and / or may be embodied in firmware or dedicated hardware. Furthermore, although the example program is described with reference to the flowcharts illustrated in FIGS. 10 and 11, many other ways of implementing the example system 200 may alternatively be used. For example, the order of execution of the blocks may be changed and / or some of the described blocks may be changed, deleted, or combined.

[0105] As mentioned above, the example processes of Figures 10 and 11 may be implemented using coded instructions (e.g., computer and / or machine readable instructions) stored on a tangible computer-readable storage medium, such as a hard disk drive, flash memory, read-only memory (ROM), compact disk (CD), digital versatile disk (DVD), cache, random access memory (RAM), and / or any other storage device or storage disk, on which information is stored for any duration (e.g., long term, permanently, for a short moment, temporarily for buffering, and / or for caching information). As used herein, the term tangible computer-readable storage medium is expressly defined to include any type of computer-readable storage device and / or storage disk, and to exclude propagating signals, and to exclude transmission media. As used herein, "tangible computer-readable storage medium" and "tangible machine-readable storage medium" are used interchangeably. Additionally or alternatively, the example processes of Figures 10 and 11 may be implemented using coded instructions (e.g., computer and / or machine readable instructions) stored on a non-transitory computer and / or machine readable medium, such as a hard disk drive, flash memory, read-only memory, compact disk, digital versatile disk, cache, random access memory, and / or any other storage device or storage disk, where information is stored for any duration (e.g., long term, permanently, for a short moment, temporarily for buffering, and / or for caching information). As used herein, the term non-transitory computer readable medium is expressly defined to include any type of computer readable storage device and / or storage disk, and to exclude propagating signals, and to exclude transmission media. As used herein, the phrase "at least," when used as a transition term in the preamble of a claim, is open ended in the same manner that the term "comprising" is open ended.

[0106] Figure 10 depicts an example flow diagram illustrating an example method 1000 for resonating a tank circuit of an inductive heater, such as the tank circuit 304 of the inductive heater 212 of Figures 2 and 3, at a resonant frequency during a thermal cycle of the inductive heater. The example method 1000 may be implemented, for example, by the inductive heater controller 226 (e.g., processor 227) of Figures 2 and 3, the frequency control circuit 316 of Figures 3 and 4, etc.

[0107] The example method 1000 includes setting the variable DC power supply to a first power setting at the start of a thermal cycle (block 1002). The start of a thermal cycle may include when a workpiece, such as the workpiece 214 of FIG. 2, is placed in proximity to a work coil for heating. In some examples, the start of a thermal cycle is determined based on one or more user inputs to the induction heater controller 226. The drive manager 332 of the example induction heater controller 226 of FIG. 3 can send instructions 234 to the power drive unit 220 to set the variable DC power supply 400 of FIG. 4 to a low power setting to substantially limit energy loss in the tank circuit 304, regardless of whether the tank circuit 304 is resonating at its resonant frequency.

[0108] The example method 1000 includes enabling a fixed frequency clock (block 1004). For example, the fixed frequency clock 330 may be enabled by the example frequency manager 338 of the example induction heater controller 226 of FIG. 3. Enabling the fixed frequency clock 330 generates a fixed frequency signal 402 that goes to the SYNC input pin 406 of the switched RF current driver 408. The example switched RF current driver 408 drives the tank circuit 304 to oscillate at a fixed frequency.

[0109] The example method 1000 includes detecting a sense signal (block 1006). For example, when a current flows through the work coil 308 of FIG. 3, the work coil 308 generates a magnetic field (e.g., magnetic field 106 of FIG. 1). The example sense coil 312 of FIG. 3 detects the magnetic field and generates a sense signal 314. The sense signal 314 may be detected by the example signal scaler 410 of the frequency control circuit 316 of FIG. 4.

[0110] If the sense signal 314 is not detected, the example method 1000 continues with the current provided to the tank circuit 304 driving the tank circuit 304 to resonate at a fixed frequency (e.g., block 1004). If the signal scaler 410 detects the sense signal 314, the example method 1000 continues with switching to drive the tank circuit 304 to resonate at its resonant frequency with the scaled sense signal (block 1008).

[0111] For example, the signal scaler 410 generates the scaled sense signal 412 by scaling (e.g., voltage scaling) the sense signal 314 to the SYNC input pin 406. The signal scaler 410 applies a delay to the sense signal 314 to optimize synchronization of the current provided to the tank circuit 304 and the current 401 already flowing in the tank circuit 304. In the example method 1000, the frequency manager 338 instructs the frequency control circuit 316 to switch a switch (e.g., the SPDT switch 404 of FIG. 4 ) to use the scaled sense signal 412 to drive the switched RF current driver 408 instead of the fixed frequency signal 402.

[0112] The example method 1000 includes setting the variable DC power supply to a second power setting (block 1010). For example, the drive manager 332 of the example induction heater controller 226 of FIG. 3 can send instructions 234 to the power drive unit 220 to set the variable DC power supply 400 of FIG. 4 to a high power setting (compared to the low setting set in block 1002).

[0113] The example method 1000 continues to allow the tank circuit 304 to resonate at its resonant frequency until a determination is made that the thermal cycle is completed (block 1012). In some examples, the example method 1000 adjusts the current provided to the tank circuit 304 based on the sense signal 314 generated during inductive heating of the workpiece 214 to allow the tank circuit 304 to continue to resonate at its resonant frequency despite load variations on the work coil 308 due to the workpiece 214.

[0114] In some examples, the induction heater controller 226 determines that the thermal cycle is to end based on a current signal 325 received from a current monitor 324 indicating a change in current flow in the work coil 308. In some examples, a change in current flow in the work coil 308 may indicate that the workpiece 214, or a portion thereof, has moved out of the magnetic field. In some examples, the induction heater controller 226 determines that the thermal cycle is to end based on one or more user inputs.

[0115] If the thermal cycle is to end, the example method 1000 includes setting the variable DC power supply (e.g., via the drive manager 332) to a first (e.g., low) power setting (block 1014). After a delay, the example method 1000 includes turning off the variable DC power supply (block 1016).

[0116] The example method 1000 of FIG. 10 includes determining whether a sense signal is detected (block 1018). For example, after the variable DC power supply is turned off, the energy in the tank circuit 304 dissipates over time and the sense coil 312 no longer generates a sense signal 314 that is recognized by the signal scaler 410. If the sense signal 314 is no longer detected, the example method 1000 includes switching the SYNC input pin 406 of the switched RF current drive circuit 408 to be driven by the fixed frequency clock 330 (e.g., via the drive manager 332) (block 1020). After a period of time, the example method 1000 includes disabling the fixed frequency clock 330 to terminate the thermal cycle of the induction heater 212 (block 1022).

[0117] Figure 11 depicts an example flow diagram illustrating an example method 1100 for inductively heating a workpiece, such as the workpiece 214, 502 of Figures 2 and 5, with an induction heater, such as the induction heater 212 of Figure 2. The example method 1100 may be implemented, for example, by the induction heater controller 226 (e.g., processor 227) of Figures 2 and 3.

[0118] 11 begins at the start of a thermal cycle, which may be determined, for example, by a user input to the induction heater controller 226. The user input to begin a thermal cycle causes the drive manager 332 to, for example, command the power drive unit 220 to provide current to the tank circuit 304 of the example induction heater 212.

[0119] An example method 1100 includes identifying a temperature profile of a portion of a workpiece to be heated (block 1102). For example, the performance manager 340 of the induction heater controller 226 may identify a temperature profile 342, 500 stored in the database 336 of FIG. 3. The example temperature profile 342, 500 includes one or more heating settings for the induction heater 212 for the portion 217, 219, 504, 506 of the workpiece 214, 502 to be heated. In some examples, the performance manager 340 identifies the temperature profile 342, 500 of the portion based on one or more user inputs that define, for example, the characteristics 215 (e.g., size, coating thickness) of the portion 217, 219, 504, 506 to be heated. In other examples, the performance manager 340 identifies the temperature profile 342 based on a position of the workpiece 214, 502 relative to the induction heater 212 (e.g., based on movement by the robotic arm 221 of the diagnostic instrument 202). In other examples, the performance manager 340 identifies the temperature profile 342, 500 based on changes in current and / or voltage in the induction heater 212 detected by the current monitor 324 and / or voltage monitor 326, respectively. In some such examples, a change, such as a drop in current, may indicate that a different portion 217, 219, 504, 506 of the workpiece 214, 502 is disposed in proximity to the work coil 308 for heating.

[0120] The example method 1100 includes adjusting a resonant frequency in a tank circuit of the induction heater (block 1104). Adjusting the resonant frequency of the tank circuit may be performed substantially as disclosed above with respect to the example method 1000 of FIG. 10. For example, as disclosed above, the induction heater controller 226 and the frequency control circuit 316 enable the tank circuit 304 to resonate at its resonant frequency during generation of a magnetic field by the work coil 308 based on a sensing signal 314 generated by the sense coil 312. Oscillation of the tank circuit 304 at its resonant frequency provides efficient transfer of heat to the workpiece 214, 502.

[0121] The example method 1100 includes heating the portions of the workpiece based on the temperature profile (block 1106). For example, the induction heater 212 of Figures 2-4 may heat the portions 217, 219, 504, 506 of the workpiece 214, 502 for a predefined period of time at one or more heating settings based on the temperature profile 342, 500. In some examples, the induction heater controller 226 generates instructions 234 to adjust the current and / or power provided to the tank circuit 304 and / or the voltage generated in the tank circuit 304 to achieve the heating settings of the temperature profile 342, 500 of the portions 217, 219, 504, 506 to be heated.

[0122] The example method 1100 includes monitoring one or more conditions in the induction heater (block 1108). For example, the example fault monitor 344 analyzes the temperature data 323 received from the temperature monitor 322, the current data 325 received from the current monitor 324, and / or the voltage data 327 received from the voltage monitor 326 of FIG. 3. Based on this analysis, the example fault monitor 344 detects whether any of the components of the induction heater 212 have failed and / or predicts that any of the components are likely to fail. For example, the fault monitor 344 identifies conditions that may result in, for example, overheating of the work coil 308, a short circuit of one or more components of the frequency control circuit 316, etc. In some examples, the fault monitor 344 compares the data 323, 325, 327 to reference data 334 stored in the database 336 of FIG. 3 regarding, for example, threshold currents and / or voltages of the tank circuit 304. The fault monitor 344 tracks performance data obtained from the induction heaters 212 to identify and / or predict one or more faults in the induction heater control station 210 .

[0123] The example method 1100 includes generating one or more induction status updates (block 1110). For example, if the fault monitor 344 predicts that the work coil 308 is likely to overheat, the fault monitor 344 may generate one or more instructions 346 to stop operation of the induction heater 212. In some examples, the fault monitor 344 instructs the power drive unit 220 to adjust the current provided to the induction heater 212 taking into account the fault prediction and / or performance tracking by the fault monitor 344. In some examples, the fault monitor 344 generates present / ready data 240 and / or pass / fail data 242 for display via the GUI 209 of the example diagnostic instrument 202 based on the prediction.

[0124] The example method 1100 includes determining whether another portion of the workpiece is to be heated (block 1112). If another portion of the work coil is to be heated, the example method 1100 returns to identifying the temperature profile 342, 500 of the other portion to be heated (e.g., block 1102). The example method 1100 adjusts the resonant frequency in the tank circuit based on the change to the resonant frequency due to the load variation in the tank circuit to efficiently heat the portion of the workpiece (e.g., blocks 1104, 1106). The load variation may result from the introduction of another portion into the tank circuit that has one or more different characteristics than the portion previously heated by the induction heater. If another portion of the workpiece is not to be heated, the example method 1100 ends.

[0125] Figure 12 is a block diagram of an example processor platform 1200 capable of executing the instructions of Figures 10 and 11 to implement the example system 200 of Figures 2 through 9. The processor platform 1200 may be, for example, a server, a personal computer, a mobile device (e.g., a mobile phone, a smartphone, a tablet such as an iPad®), a personal digital assistant (PDA), an Internet appliance, a medical diagnostic instrument 202, or any other type of computing device.

[0126] The illustrated example processor platform 1200 includes a processor 227. The illustrated example processor 227 is hardware. For example, the processor 227 may be implemented by one or more integrated circuits, logic circuits, microprocessors, or controllers from any desired family or manufacturer.

[0127] The processor 227 of the illustrated example includes a local memory 1213 (e.g., a cache). The processor 227 of the illustrated example is in communication with a main memory, including a volatile memory 1214 and a non-volatile memory 1216, via a bus 1218. The volatile memory 1214 may be implemented by synchronous dynamic random access memory (SDRAM), dynamic random access memory (DRAM), RAMBUS dynamic random access memory (RDRAM), and / or any other type of random access memory device. The non-volatile memory 1216 may be implemented by flash memory and / or any other desired type of memory device. Access to the main memory 1214, 1216 is controlled by a memory controller.

[0128] The processor platform 1200 of the illustrated example also includes an interface circuit 1220. The interface circuit 1220 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.

[0129] In the illustrated example, one or more input devices 1222 are connected to the interface circuit 1220. The input devices 1222 allow a user to input data and commands to the processor 227. The input devices may be realized by, for example, audio sensors, microphones, cameras (still or video), keyboards, buttons, mice, touch screens, track pads, track balls, isopoints, voice recognition systems, and / or medical diagnostic instruments 202.

[0130] One or more output devices 1224 are also connected to the interface circuit 1220 of the illustrated example. The output device 1224 may be realized, for example, by a display device (e.g., a light emitting diode (LED), an organic light emitting diode (OLED), a liquid crystal display, a cathode ray tube display (CRT), a touch screen, a tactile output device, a printer, and / or a speaker), the power drive unit 220, the frequency control circuit 316, the induction heater 212. The interface circuit 1220 of the illustrated example therefore typically includes a graphics driver card, a graphics driver chip, or a graphics driver processor.

[0131] The interface circuitry 1220 of the illustrated example also includes communications devices such as transmitters, receivers, transceivers, modems, and / or network interface cards to facilitate the exchange of data with external machines (e.g., computing devices of any type) over a network 1226 (e.g., an Ethernet connection, a digital subscriber line (DSL), a telephone line, a coaxial cable, a cellular telephone system, etc.).

[0132] The processor platform 1200 of the illustrated example also includes one or more mass storage devices 1228 for storing software and / or data. Examples of such mass storage devices 1228 include floppy disk drives, hard drive disks, compact disk drives, Blu-ray disk drives, RAID systems, and digital versatile disks.

[0133] Encoded instructions 1232 for implementing the example methods of Figures 10 and 11 may be stored in mass storage device 1228, in volatile memory 1214, in non-volatile memory 1216, and / or on a removable tangible computer-readable storage medium such as a CD or DVD.

[0134] From the foregoing, it will be appreciated that the above systems, methods, and apparatus provide control and monitoring of the performance of an induction heater to reduce biological carryover from one or more workpieces (e.g., probes) through induction heating. Examples disclosed herein account for manufacturing variations and / or aging of the electrical components of the induction heater by allowing the tank circuit to resonate at its resonant frequency rather than a fixed frequency. Additionally, examples disclosed herein dynamically respond to load variations on the induction heater due to, for example, the introduction of a workpiece into the induction heater, the positioning of the workpiece relative to the induction heater, and the characteristics of different portions of the workpiece to be heated. Some such examples adjust the current provided to the tank circuit of the induction heater to respond to changes in the resonant frequency of the tank circuit as a result of the presence of a workpiece. Some disclosed examples provide improved reliability of the induction heater through waste heat management techniques that reduce the risk of overheating and / or through predictive failure analysis. Examples disclosed herein can be implemented with diagnostic instruments (e.g., chemical analyzers) to provide a system for efficiently analyzing samples and conveniently cleaning tools used to perform the analysis without the need for a separate cleaning instrument.

[0135] Although certain example methods, apparatus, and articles of manufacture are disclosed herein, the scope of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus, and articles of manufacture that fairly fall within the scope of the claims of this patent.

Claims

1. 1. A system comprising: an induction heater including a work coil and a sense coil; a drive unit for supplying a current to the work coil to generate an electromagnetic field, the sense coil detecting the electromagnetic field and outputting a feedback signal, the feedback signal indicative of a change in the electromagnetic field due to movement of the workpiece relative to the work coil from a first position to a second position, where at the first position a first portion of the workpiece is exposed to the electromagnetic field and where at the second position a second portion of the workpiece is exposed to the electromagnetic field; a controller operably coupled to the drive unit, the controller causing the drive unit to adjust an amount of current provided to or a voltage generated by the induction heater for a second portion of the workpiece in response to changes in the electromagnetic field due to movement of the workpiece; A system comprising:

2. The system of claim 1 , wherein the controller causes the drive unit to adjust the current or voltage based on a temperature profile of the workpiece exposed to the electromagnetic field.

3. The system of claim 2 , wherein the temperature profile includes a first temperature profile in a first portion of the workpiece and a second temperature profile in a second portion of the workpiece.

4. The system of claim 1 or 2, wherein the controller induces a frequency that causes a circuit including the work coil and the sense coil to oscillate based on the feedback signal.

5. 5. The system of claim 4, further comprising a fixed frequency clock, the controller selectively disabling the fixed frequency clock to cause the circuit to switch from the fixed frequency to oscillating at the resonant frequency based on the feedback signal.

6. 10. The system of claim 1, wherein the controller causes the drive unit to adjust an amount of current supplied to the induction heater or a voltage generated at the induction heater such that a characteristic of the biological sample carried by the second portion of the workpiece exposed to the electromagnetic field is adjusted.

7. The system of claim 1 or 2, wherein the sense coil is wound around the work coil.

8. At least one computer-readable storage medium containing instructions, the instructions causing a processor circuit to at least: determining a temperature to be output by the induction heater to modify a property of the biological specimen based on a signal output by a sense coil of a tank circuit of the induction heater, the signal being indicative of a change in resonant frequency of the tank circuit from a first position to a second position due to movement of the workpiece relative to the tank circuit; At least one computer-readable storage medium that causes the drive unit to control an amount of current supplied to or a voltage generated at the induction heater based on temperature in response to changes in the resonant frequency of the tank circuit.

9. The temperature is a first temperature, and the instructions, when executed, cause the processor circuit to: detecting a change in the signal between a first time and a second time; In response to detecting the change, determining a second temperature output by the inductive heater to modify a property of the biological sample; 10. The at least one computer-readable storage medium of claim 8, further comprising: a drive unit configured to control an amount of current supplied to the induction heater or a voltage generated at the induction heater based on the second temperature.

10. 10. At least one computer-readable storage medium according to claim 8, wherein the instructions, when executed, cause the drive unit to control a power level of a power source in communication with the induction heater.

11. An apparatus comprising: At least one memory; With orders, a processor circuit, the processor circuit comprising: causing the drive unit to supply a first amount of current to the induction heater to generate an electromagnetic field in a work coil of the induction heater to modify a property of a material exposed to the electromagnetic field, the material being carried by a first portion of the workpiece; causing the drive unit to detect a change in the electromagnetic field due to movement of the workpiece relative to the work coil from a first position to a second position based on a feedback signal output by a sense coil of the induction heater, where at the first position a first portion of the workpiece is exposed to the electromagnetic field, and at the second position a second portion of the workpiece is exposed to the electromagnetic field, the second portion of the workpiece carrying material; The apparatus executes instructions to cause the drive unit to provide an amount of second current to the induction heater in response to changes in the electromagnetic field due to movement of the workpiece to adjust a property of a material exposed to the electromagnetic field.

12. 12. The apparatus of claim 11, wherein the processor circuit causes the drive unit to modify an amount of electrical current provided based on an amount of heat generated by the induction heater.

13. The apparatus of claim 11 , wherein the processor circuitry causes the drive unit to adjust the current based on a temperature profile of the material exposed to the electromagnetic field.

14. 12. The apparatus of claim 11, wherein the processor circuitry generates a frequency at which the circuitry including the work coil and the sense coil oscillates based on the feedback signal.

15. The apparatus of any one of claims 11 to 14, wherein the material comprises a human biological sample.

16. 1. A method of controlling an induction heating system, the method comprising: determining a temperature output by the induction heater to modify a property of the biological specimen based on a signal output by a sense coil of a tank circuit of the induction heater, the signal being indicative of a change in resonant frequency of the tank circuit in response to a change in position of the workpiece relative to the tank circuit from a first position to a second position; having a drive unit control an amount of current provided to or a voltage generated by the induction heater based on the temperature in response to a change in resonant frequency due to a change in position of the workpiece; The method includes:

17. 17. The method of claim 16, further comprising causing the tank circuit to switch from oscillating at a fixed frequency to oscillating at a resonant frequency by controlling a switch.

18. the change in position is a first change in position, and the method comprises: detecting a change in the signal in response to a second change in position of the workpiece relative to the tank circuit from the second position to a third position; causing a drive unit to control an amount of current provided to or a voltage generated by the induction heater in response to the detection; 20. The method of claim 16, further comprising:

19. Detecting a change in the signal between a first time and a second time; In response to detecting the change, determining a second temperature output by the inductive heater to modify a property of the biological sample; causing the drive unit to control an amount of current supplied to or a voltage generated at the induction heater based on the second temperature; 20. The method of claim 16, further comprising:

20. An apparatus comprising: generating means for generating an electromagnetic field; supplying means for supplying the generating means with a current that generates an electromagnetic field; a detection means for detecting the electromagnetic field, the detection means outputting a feedback signal indicative of detection of the electromagnetic field, the feedback signal indicative of a change in the electromagnetic field due to movement of the workpiece relative to the electromagnetic field from a first position to a second position, where at the first position a first portion of the workpiece is exposed to the electromagnetic field and where at the second position a second portion of the workpiece is exposed to the electromagnetic field; processing means for causing the supplying means to adjust the amount of current supplied to the generating means for a second portion of the workpiece in response to changes in the electromagnetic field due to movement of the workpiece; An apparatus comprising:

21. 21. The apparatus of claim 20, wherein the processing means causes the supplying means to adjust the current to a temperature profile of the workpiece exposed to the electromagnetic field.

22. 22. The apparatus of claim 21, wherein the temperature profile includes a first temperature profile in a first portion of the workpiece and a second temperature profile in a second portion of the workpiece.

23. 22. Apparatus according to claim 20 or 21, wherein the processing means causes the generating means to adjust the amount of electrical current provided such that a property of the biological sample carried by the second portion of the workpiece exposed to the electromagnetic field is adjusted.

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