Automatic analysis device, diagnostic system, and diagnostic method

Abstract

An automatic analysis device is provided with: an ultrasonic transducer including a piezoelectric body and an electrode attached to the piezoelectric body; and a control device that performs fault diagnosis of the ultrasonic transducer, the control device defining and storing a normal range of electrical impedance unique to the ultrasonic transducer on the basis of a measured value of the electrical impedance obtained by applying a voltage to the electrode. The fault diagnosis of the ultrasonic transducer is performed by comparing the measured value of the electrical impedance obtained by applying a voltage to the electrode during the diagnosis with the normal range.

Description

Technical Field

[0001] This invention relates to an automatic analysis device with an ultrasonic transducer, a diagnostic system for determining whether the ultrasonic transducer of the automatic analysis device is normal or abnormal, and a diagnostic method. Background Technology

[0002] In automated analytical apparatus, samples and reagents are dispensed into a reaction unit, stirred, and allowed to react. Specific components in the sample are quantitatively analyzed based on the absorbance of the resulting liquid. Besides directly stirring the liquid within the reaction unit with a stirring rod, non-contact methods based on ultrasound are also used for stirring the samples and reagents. Ultrasonic non-contact stirring is useful for avoiding contamination between the sample and reagents and is employed in some automated analytical apparatuses. On the other hand, malfunctions of the ultrasonic transducer that generates ultrasound waves directly affect the accuracy and reproducibility of the component analysis.

[0003] In contrast, Patent Document 1 discloses a method for diagnosing faults in ultrasonic transducers based on the impedance spectrum of the ultrasonic transducer.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2022-177414 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In Patent Document 1, regarding impedance, a normal parent group is generated in advance from multiple normal ultrasonic transducers, and the normal range defined by the normal parent group is compared with the measured value during diagnosis, thereby performing fault diagnosis of the ultrasonic transducer.

[0009] However, the measured impedance of the ultrasonic transducer in the automatic analysis device varies due to factors other than faults. For example, even among corresponding ultrasonic transducers of the same type of automatic analysis device, the measured impedance can differ due to factors such as the length of the wiring connected to the electrodes, the retrieval path of the wiring, and individual differences between the ultrasonic transducers. Conventionally, including the technology in Patent Document 1, a normal range is defined for the ultrasonic transducer based on multiple data obtained from multiple automatic analysis devices, and this normal range is shared for fault diagnosis of ultrasonic transducers in multiple automatic analysis devices under management. However, as mentioned above, this normal range is a statistically obtained value that does not consider the influence of various factors such as wiring length on the measured impedance. Therefore, the inventors of this application conducted verification and found that, depending on the automatic analysis device, sometimes ultrasonic transducers diagnosed as normal are abnormal, and there is room for improvement in diagnostic accuracy. When an ultrasonic transducer is determined to be abnormal, unnecessary replacement of the ultrasonic transducer is performed, reducing the operating rate of the automatic analysis device, and potentially increasing the required replacement time and component costs beyond what is necessary.

[0010] The purpose of this invention is to provide an automatic analysis device, diagnostic system, and diagnostic method that can improve the reliability of fault diagnosis of ultrasonic transducers.

[0011] Methods for solving problems

[0012] To achieve the above objectives, the present invention provides an automatic analysis device comprising: an ultrasonic transducer including a piezoelectric element and electrodes mounted on the piezoelectric element; and a control device for diagnosing faults in the ultrasonic transducer, wherein the control device defines and stores a normal range of inherent impedance of the ultrasonic transducer based on a measured value of impedance obtained by applying voltage to the electrodes, and compares the measured value of impedance obtained by applying voltage to the electrodes during diagnosis with the normal range to diagnose faults in the ultrasonic transducer.

[0013] Invention Effects

[0014] According to the present invention, the reliability of fault diagnosis of the ultrasonic transducer in an automatic analysis device can be improved. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a diagnostic system according to one embodiment of the present invention.

[0016] Figure 2 This is a schematic diagram showing a cross-section of the ultrasonic stirring mechanism and its drive system in an automatic analysis device according to an embodiment of the present invention.

[0017] Figure 3This is a diagram illustrating the difference in impedance spectra between a normal ultrasonic transducer and a faulty ultrasonic transducer.

[0018] Figure 4 This is an explanatory diagram of the normal range for fault diagnosis of an ultrasonic transducer in one embodiment of the present invention.

[0019] Figure 5 This is an illustrative diagram illustrating fault diagnosis using an ultrasonic transducer within the normal range in one embodiment of the present invention.

[0020] Figure 6 This is a diagram illustrating the definition of the normal range of the impedance of an ultrasonic transducer implemented in one embodiment of the present invention and the timing of the diagnosis of the ultrasonic transducer.

[0021] Figure 7 This is a flowchart illustrating an example of a series of processing procedures of a control device involved in defining the normal range in one embodiment of the present invention.

[0022] Figure 8 This is a flowchart illustrating an example of a series of processing steps of a control device involved in fault diagnosis of an ultrasonic transducer according to an embodiment of the present invention.

[0023] Figure 9 This is an example of the diagnostic results of an ultrasonic transducer output by the control device to the display unit in one embodiment of the present invention.

[0024] Figure 10 This is an explanatory diagram of the normal range for fault diagnosis of the ultrasonic transducer in the modified example. Detailed Implementation

[0025] The embodiments of the present invention will be described below using the accompanying drawings. In the following description, the same or corresponding elements in each figure are labeled with the same reference numerals, and repeated descriptions are omitted where appropriate.

[0026] (Diagnostic System)

[0027] Figure 1 This is a schematic diagram of a diagnostic system according to one embodiment of the present invention. Figure 1 The diagnostic system 100 shown includes an ultrasonic transducer 203 equipped in an automated analysis device 101. Figure 2 The control device 116 is a computer equipped with a CPU and other arithmetic processing units, and storage devices such as RAM, ROM, HDD, and SSD. Figure 1In this embodiment, the automatic analysis device 101 with a control device 116 will be used as an example for explanation. Specifically, in this embodiment, the automatic analysis device 101 has a computer that also functions as the control device 116 of the diagnostic system 100; in other words, it also functions as the control device of the ultrasonic transducer 203 (…). Figure 2 The control device 116 for the diagnostic function of the diagnostic system 100. However, the control device 116 of the diagnostic system 100 may also be a computer (server, etc.) connected to the automatic analysis device 101 via a network such as a LAN or the Internet.

[0028] (Structure of the automatic analysis device)

[0029] Figure 1 The illustrated automatic analysis device 101 includes: a sample delivery line 105, a reaction tray 110, a reagent tray 107, a sample dispensing mechanism 104, a reagent dispensing mechanism 108, an ultrasonic stirring mechanism 114, a light source 111, an absorbance meter 112, a cleaning mechanism 118, a drive circuit 115, a selection unit 117, an input unit 119, a display unit 120, and a control device 116.

[0030] The sample transport line 105 is a device that moves the sample holder 103 to the sample dispensing mechanism 104. Multiple sample cups 102 are provided on the sample holder 103. Each sample cup 102 contains a sample such as blood or urine for analysis.

[0031] On the reaction plate 110, multiple reaction units 109 are arranged in a ring around the circumference. Specimens and reagents are dispensed into each reaction unit 109. Multiple reagent bottles 106 are provided on the reagent plate 107. The reagents mixed with the specimens are contained in the reagent bottles 106. A specimen dispensing mechanism 104 dispenses specimens from a sample cup 102 into the reaction units 109 on the reaction plate 110. A reagent dispensing mechanism 108 dispenses reagents from the reagent bottles 106 on the reagent plate 107 into the same reaction unit 109 on the reaction plate 110. An ultrasonic stirring mechanism 114 stirs the mixture of specimens and reagents dispensed into the reaction units 109 using ultrasonic waves 113, promoting the reaction between the specimens and reagents. The mixture of specimens and reagents is also called the reaction solution.

[0032] Light source 111 illuminates the reaction unit 109. Absorbance meter 112 disperses the light passing through the reaction liquid inside the reaction unit 109 and measures the absorbance. The measured absorbance is input to control device 116, where specific components contained in the sample are quantitatively analyzed. Cleaning mechanism 118 cleans the reaction unit 109 after the sample analysis is completed.

[0033] The drive circuit 115 applies a voltage to supply ultrasonic waves 113 to the ultrasonic stirring mechanism 114. The selection unit 117 selectively switches the circuit connection of the ultrasonic stirring mechanism 114 to either the drive circuit 115 or the control device 116. The input unit 119 is an external interface, allowing users or other operators to access the control device 116. The display unit 120 is a monitor that displays the operation screen of the control device 116, notifications output from the control device 116, alarms, etc.

[0034] (The operation of the automatic analysis device)

[0035] In the automated analysis device 101 with the above-described structure, the sample and reagent are dispensed from the sample cup 102 and reagent bottle 106 to the same reaction unit 109 via the sample dispensing mechanism 104 and reagent dispensing mechanism 108, respectively. The mixture of sample and reagent is stirred by the ultrasonic stirring mechanism 114. In this embodiment, since it is the object of the ultrasonic stirring mechanism 114, the mixture of sample and reagent is recorded as the stirred liquid. In this embodiment, the reaction disk 110 rotates counterclockwise when viewed from above. Due to the rotation of the reaction disk 110, the reaction unit 109 containing the stirred liquid is sequentially conveyed to the front of the ultrasonic stirring mechanism 114, and the stirred liquid is stirred and mixed by the ultrasonic stirring mechanism 114 in a non-contact manner. The reaction unit 109, which causes interference from the mixing of the stirred liquid, is conveyed between the light source 111 and the absorbance meter 112 by the rotation of the reaction disk 110, and the absorbance of the stirred liquid, i.e., the reaction liquid, is measured. The reaction unit 109, having completed the absorbance measurement of the stirred liquid, is transported to the cleaning mechanism 118 via the rotation of the reaction plate 110, where it is cleaned. In the reaction unit 109, which is used to clean up interference, other samples are dispensed from the sample cup 102 via the sample dispensing mechanism 104, repeating the above sequence. These sequential actions are performed in parallel for multiple samples.

[0036] (Ultrasonic stirring mechanism)

[0037] Figure 2 This is a schematic diagram showing the cross-section of the ultrasonic stirring mechanism 114 and its driving system. Figure 2 The cross-section of the ultrasonic stirring mechanism 114 shown is cut by a vertical plane passing through the rotation center of the reaction plate 110.

[0038] The ultrasonic stirring mechanism 114 comprises an ultrasonic transducer 203, a fixed platform 204, and a reflector 205. The ultrasonic transducer 203 is constructed by comprising a piezoelectric element 201 and multiple electrodes 202 mounted on the piezoelectric element 201. The electrodes 202 are arranged vertically and mounted on the piezoelectric element 201 in a manner that clamps the piezoelectric element 201. The fixed platform 204 supports the ultrasonic transducer 203, which is housed within the casing of the automatic analysis device 101. The reflector 205 is arranged opposite the ultrasonic transducer 203.

[0039] The automatic analysis device 101 has an annular reaction tank 206 containing a heat-insulating solvent 207. An ultrasonic stirring mechanism 114 is disposed inside the reaction tank 206. A reaction unit 109 containing a stirred liquid 208 is inserted into the reaction tank 206 and immersed in the heat-insulating solvent 207. It moves with the rotation of the reaction plate 110 and is transported between the ultrasonic transducer 203 and the reflector plate 205 to stir the stirred liquid 208.

[0040] The ultrasonic transducer 203 is connected to either the control device 116 or the drive circuit 115 via a selection unit 117. The selection unit 117 includes a circuit connection switching switch 209 and a segment switching switch 210. The circuit connection switching switch 209 switches the connection target of the ultrasonic transducer 203 to either the drive circuit 115 or the control device 116. Furthermore, the ultrasonic transducer 203 is divided into multiple segments 211 arranged vertically. Each segment 211 has at least one (one on each side in this embodiment) electrode 202 of the same shape on one or both sides of the piezoelectric element 201, which irradiates ultrasonic waves 113. The segment switching switch 210 selects the electrode 202 to which voltage is applied and selects the segment 211 to irradiate ultrasonic waves 113. Because the ultrasonic transducer 203 has this segmented structure, even if the liquid level of the stirred liquid 208 inside the reaction unit 109 varies depending on the analytical item, it is possible to select the segment of ultrasonic waves 113 that effectively agitate the stirred liquid 208. The circuit connection switching switch 209 and segment switching switch 210 can use, for example, relays or multiplexers.

[0041] The control device 116 includes: a measuring unit 213 for measuring electrical impedance spectra, and a device for using... Figure 4 Detailed definition of normal range section 214, usage Figure 7 The detailed description includes the storage unit 215 and the diagnostic unit 216 for diagnosing faults in the ultrasonic transducer 203. These measurement units 213, normal range definition units 214, storage units 215, and diagnostic units 216 are functions of the control device 116, which can be implemented by hardware elements such as circuits or by software elements such as programs.

[0042] (Ultrasonic stirring action)

[0043] When the ultrasonic transducer 203 is connected to the drive circuit 115 via the circuit connection switch 209 and the segment switch 210, and voltage is applied to the ultrasonic transducer 203 by the drive circuit 115, ultrasonic waves 113 are generated in the segment 211 connected to the drive circuit 115. The generated ultrasonic waves 113 propagate through the insulating solvent 207 and the stirred liquid 208 inside the reaction unit 109 to the reflector 205, are reflected by the reflector 205, and pass through the stirred liquid 208 inside the reaction unit 109 again. At this time, since an acoustic flow is generated in the propagation direction of the ultrasonic waves 113, a swirling flow 212 is generated in the stirred liquid 208 by the ultrasonic waves 113 passing from the ultrasonic transducer 203 through the stirred liquid 208 toward the reflector 205, and the ultrasonic waves 113 that are reflected by the reflector 205 and have their angle changed and pass through the stirred liquid 208. In this way, the swirling flow 212 is generated in the stirred liquid 208, thereby mixing the sample and reagents.

[0044] Furthermore, by using the segment switching switch 210 to select the segment 211 connected to the drive circuit 115, ultrasonic waves 113 can be emitted from any segment 211.

[0045] (Impedance measurement operation)

[0046] Fault diagnosis of the ultrasonic transducer 203 is performed by measuring the impedance spectrum of the ultrasonic transducer 203. Specifically, as described later, in the control device 116, based on the measured impedance value obtained by applying voltage to the electrode 202, a normal range of the inherent impedance of the ultrasonic transducer 203 is defined and stored in the storage unit 215, as described later. Furthermore, during subsequent diagnosis (e.g., before sample analysis), the control device 116 compares the measured impedance value obtained by applying voltage to the electrode 202 with the normal range to perform fault diagnosis of the ultrasonic transducer 203. The ultrasonic transducer 203 used for defining the normal range is the same individual as the ultrasonic transducer 203 used for fault diagnosis.

[0047] Regarding the impedance spectrum used for fault diagnosis, the ultrasonic transducer 203 is connected to the control device 116 via circuit connection switch 209 and segment switch 210. The measurement unit 213 of the control device 116 applies a voltage lower than the voltage applied by the drive circuit 115 to the ultrasonic transducer 203 for measurement. The impedance spectrum is obtained by scanning voltages of arbitrary frequencies and analyzing their electrical responses. During the impedance spectrum measurement, the frequency characteristics of the phase difference between voltage and current can also be measured. Voltages of arbitrary frequencies can be generated, for example, using a direct digital synthesizer.

[0048] In addition, similar to the ultrasonic stirring action, the impedance measurement action can also be performed by switching the segment 211 connected to the control device 116 using the segment switching switch 210, thereby measuring the impedance spectrum of each segment 211.

[0049] (Changes in electrical impedance)

[0050] Figure 3 This is a diagram illustrating the difference in impedance spectrum between a normal ultrasonic transducer 203 and a faulty ultrasonic transducer 203. Figure 3 The impedance spectrum represented by the solid line is the impedance spectrum 301 of a normal ultrasonic transducer 203. The impedance spectrum represented by the dashed line is the impedance spectrum 302 of a faulty ultrasonic transducer 203. The impedance spectrum of the ultrasonic transducer 203 reaches its minimum value (minimum impedance) at the resonant frequency. When a voltage is applied at the resonant frequency 303, the vibration displacement of the ultrasonic transducer 203 is large; therefore, the ultrasonic transducer 203 is generally used at frequencies near its resonant frequency. Figure 3 As shown, the resonant frequency 305 of the ultrasonic transducer 203 changes from the normal resonant frequency 303 when it malfunctions. Furthermore, compared to the minimum impedance 304 at the resonant frequency 303 of a normal ultrasonic transducer 203, the impedance 306 at the resonant frequency 305 of the malfunctioning ultrasonic transducer 203 is larger. Therefore, it is possible to set a normal range for the resonant frequency and the impedance at that resonant frequency, and to perform fault diagnosis of the ultrasonic transducer 203.

[0051] At this time, besides a malfunction of the ultrasonic transducer 203, the length and shape (wiring path) of the electrical wiring from the measuring unit 213 to the ultrasonic transducer 203, as well as other environmental factors, can also affect the measured impedance value. In particular, when the electrical wiring becomes longer, the measured impedance value decreases. Therefore, in diagnostic methods that compare the measured impedance value with a general normal range, it is impossible to determine whether the main reason for the measured impedance value being lower than the normal range is a malfunction of the ultrasonic transducer 203 or the length of its electrical wiring. Therefore, a method that defines a normal range excluding factors affecting the measured impedance value other than a malfunction of the ultrasonic transducer 203, and diagnoses a malfunction of the ultrasonic transducer 203 based on a comparison of this normal range with the measured impedance value at the time of diagnosis, is effective.

[0052] In this embodiment, fault diagnosis, excluding factors affecting the impedance measurement value other than a fault in the ultrasonic transducer 203, is achieved by defining the normal range in the normal range definition unit 214. Influencing factors are eliminated by defining the normal range and diagnosing faults within the same system. Here, "system" refers to the system involved in the impedance measurement, including the measurement unit 213, the ultrasonic transducer 203, and the electrical wiring connecting these measurement units 213 and the ultrasonic transducer 203. "Same system" means that the ultrasonic transducer 203 and its electrical wiring are the same entity when defining the normal range and during diagnosis. When the measurement unit 213 is implemented in hardware, it is preferable that the measurement unit 213 is also the same entity. When the measurement unit 213 is implemented in software, it is preferable to ensure the consistency of the program, etc. In this embodiment, factors excluded as influencing factors on the impedance measurement value of the ultrasonic transducer 203 include, for example, the individual differences between the ultrasonic transducer used in the impedance measurement during the normal range definition and the ultrasonic transducer used for fault diagnosis, the length of its electrical wiring, and the shape (wiring path) of the electrical wiring.

[0053] (An example of the definition of normal range)

[0054] Figure 4 This is an explanatory diagram of the normal range used in fault diagnosis of the ultrasonic transducer 203. The normal range is defined by the normal range definition unit 214 of the control device 116. First, a voltage is applied to a designated electrode 202 of a normal ultrasonic transducer 203 by the measuring unit 213, and the impedance spectrum 301 is measured for that electrode 202. The ultrasonic transducer 203 used in defining the normal range is in a normal state. Based on the measured value of the impedance spectrum 301 obtained from the normal ultrasonic transducer 203, the normal range of the impedance inherent in that designated electrode 202 of the ultrasonic transducer 203 is defined. The normal range is defined based on the characteristic quantities extracted from the impedance spectrum 301.

[0055] The characteristic quantities defining the normal range are the resonant frequency 303 of the ultrasonic transducer 203 and the minimum impedance 304 at that resonant frequency 303. Furthermore, at frequencies higher than the resonant frequency 303, the impedance on the impedance spectrum 301 is at its maximum. The frequency at which the impedance at the impedance spectrum 301 reaches its maximum value is called the anti-resonant frequency 401. In this embodiment, the anti-resonant frequency 401 of the normal ultrasonic transducer 203 and the maximum impedance 402 at the anti-resonant frequency 401 are used as the second characteristic quantity.

[0056] Furthermore, the control device 116 defines the normal range based on the deviation of the characteristic quantities (such as the resonant frequency 303) extracted as described later from the impedance spectrum obtained by multiple measurements using the electrode 202 via the normal range definition unit 214. For example, the following method can be used: the impedance is repeatedly measured a predetermined number of times N (e.g., 20 times), the standard deviation σ of the N characteristic quantities obtained in the repeated measurements is calculated, and the average value of the characteristic quantities ±3σ is set as the normal range. ±3σ is calculated for the resonant frequency 303, the minimum impedance 304, the anti-resonant frequency 401, and the maximum impedance 402, respectively.

[0057] exist Figure 4 On the graph shown with frequency and impedance as axes, the normal range includes a first normal range 403 defined as the range of the average value of the minimum impedance 304 ± 3σ and the range of the average value of the resonant frequency 303 corresponding to the minimum impedance 304 ± 3σ. Furthermore, in this embodiment, the normal range includes a second normal range 404 defined as the range of the average value of the maximum impedance 402 ± 3σ and the range of the average value of the anti-resonant frequency 401 corresponding to the maximum impedance 402 ± 3σ. In addition to these, as characteristic quantities defining the normal range, values ​​that characterize the waveform of the impedance spectrum, such as the difference between the resonant frequency 303 and the anti-resonant frequency 401, and the difference between the minimum impedance 304 and the maximum impedance 402, can also be used.

[0058] The normal ranges (first normal range 403, second normal range 404) defined by the normal range definition unit 214 as described above are stored in the storage unit 215.

[0059] (Other examples of the definition of normal range)

[0060] When the normal range is defined based on the deviation of multiple impedance measurements using the same electrode 202 as described above, the normal range becomes too narrow when the measurement reproducibility is high and the standard deviation σ becomes small, which may not adequately ensure the margin for fault diagnosis.

[0061] As described above, the ultrasonic transducer 203 has multiple electrodes 202 of the same shape. Utilizing a segmented structure, the control device 116 can define a normal range based on the deviation of characteristic quantities (such as resonant frequency 303) extracted from the impedance spectrum of each electrode 202, i.e., each segment 211. In this case, a normal range can be defined in a shorter time compared to repeated measurements along segment 211.

[0062] (Fault Diagnosis)

[0063] Figure 5This is an explanatory diagram for fault diagnosis of the ultrasonic transducer 203 using the normal range defined by the normal range definition unit 214. Following the definition of the normal range, as... Figure 5 As shown, during the diagnosis of the ultrasonic transducer 203, the control device 116 measures a new impedance spectrum 405 for the ultrasonic transducer 203 and compares the resonant frequency 406 and the impedance 407 at the resonant frequency 406 involved in the impedance spectrum 405 with the first normal range 403. Simultaneously, the control device 116 compares the anti-resonant frequency 408 and the impedance 409 at the anti-resonant frequency 408 involved in the impedance spectrum 405 with the second normal range 404. If the resonant frequency 406 and the impedance 407 converge to the first normal range 403, and the anti-resonant frequency 408 and the impedance 409 converge to the second normal range 404, the control device 116 diagnoses the ultrasonic transducer 203 as being in a normal state. Conversely, if the resonant frequency 406 and impedance 407 do not converge within the first normal range 403, or if the anti-resonant frequency 408 and impedance 409 do not converge within the second normal range 404, the control device 116 diagnoses the ultrasonic transducer 203 as being in a faulty state. Figure 5 In the example, the coordinates defined by the resonant frequency 406 and the impedance 407 deviate from the first normal range 403, and the ultrasonic transducer 203 involved in the impedance spectrum 405 is determined to be in a fault state.

[0064] (Definition of normal range and timing of fault diagnosis)

[0065] Figure 6 This diagram illustrates the definition of the normal range of the impedance of the ultrasonic transducer 203 and the timing of the diagnosis of the ultrasonic transducer 203. Regarding the application of the same ultrasonic transducer 203, the diagnostic stages are roughly divided into two phases: a first phase 501, defining the normal range for fault diagnosis based on the impedance spectrum of the ultrasonic transducer 203, and a second phase 502, implementing fault diagnosis of the ultrasonic transducer 203.

[0066] The first stage 501 is the timing at which the impedance of the ultrasonic transducer 203 installed in the automatic analysis device 101 is measured and the normal state of the ultrasonic transducer 203 is ensured. That is, the first stage 501 is the timing shortly after a new ultrasonic transducer 203 is installed in the automatic analysis device 101, for example, the timing before the ultrasonic transducer 203 is used for analyzing a sample. Examples of the first stage 501 include replacing the ultrasonic transducer 203 with a new ultrasonic transducer before the automatic analysis device 101 leaves the factory, before the start of use after delivery, and after the start of use. The normal range of the inherent impedance of the ultrasonic transducer 203 is defined based on the measured impedance value obtained at the timing when the normal state of the ultrasonic transducer 203 is estimated.

[0067] The second stage 502 is the timing for diagnosing the condition of the ultrasonic transducer 203 by analyzing the sample using the automatic analysis device 101. For example, the opportunity to diagnose a fault in the ultrasonic transducer 203 before analyzing the sample is an example of the second stage 502.

[0068] Whether the ultrasonic transducer 203 is in a normal or faulty state is determined by whether the characteristic quantity extracted from the impedance spectrum measured in the second stage 502 converges to or deviates from the normal range defined in the first stage 501. Here, the characteristic is that the impedances of the first stage 501 and the second stage 502 are measured and compared using the same system. This means that, both in defining the normal range and during diagnosis, the ultrasonic transducer 203 is the same entity, and the electrical wiring connecting the control device 116 and the ultrasonic transducer 203 is identical, and the measurement environment, such as wiring length and shape, is physically identical. Therefore, variations in the measured impedance value caused by differences in the measurement system, such as individual differences in the ultrasonic transducer 203, the length and shape of the electrical wiring, and factors other than faults in the ultrasonic transducer 203, will be suppressed.

[0069] like Figure 6 As shown, when the ultrasonic transducer 203 of the first system 503 malfunctions and is replaced with a new ultrasonic transducer, the system containing the new ultrasonic transducer 203 is classified as a second system 504, different from the first system 503. In this embodiment, whenever the system is changed in this way, the normal operating range inherent to each system is defined according to the system in the first stage 501. The fault diagnosis based on the normal operating range defined for the first system 503 applies only to the ultrasonic transducer 203 contained in the first system 503. Similarly, the fault diagnosis based on the normal operating range defined for the second system 504 applies only to the ultrasonic transducer 203 contained in the second system 504, and the fault diagnosis based on the normal operating range defined for the third system 505 applies only to the ultrasonic transducer 203 contained in the third system 505.

[0070] Furthermore, when the automatic analysis device 101 is equipped with multiple ultrasonic transducers 203, these multiple ultrasonic transducers 203 are processed as different systems, and normal ranges are defined independently for each of the multiple ultrasonic transducers 203.

[0071] (First-stage processing flow)

[0072] Figure 7This is a flowchart illustrating an example of a series of processing steps involving the control device 116 in defining the normal range implemented in the first stage. As described above, the first normal range 403 and the second normal range 404 are defined in the first stage 501, ensuring the normal state of the ultrasonic transducer 203. For example, the normal range is defined when the ultrasonic transducer 203 is installed in the automatic analysis device 101 at the manufacturing plant, when the automatic analysis device 101 is installed at a customer's location, or when the ultrasonic transducer 203 is replaced.

[0073] Step 101

[0074] When it begins Figure 7 During the process, in step S101, the circuit connection switching switch 209 of the selection unit 117 is controlled to connect the ultrasonic transducer 203 to itself, and the impedance spectrum 301 is measured by the measurement unit 213. At this time, regarding the impedance spectrum 301, the segment switching switch 210 is controlled to sequentially switch the segments 211 connected to the control device 116, and the measurement is performed multiple times according to segment 211.

[0075] Step S102

[0076] In the next step S102, the control device 116 extracts characteristic quantities under normal conditions from each segment 211 of the electrical impedance spectrum 301 measured in step S101.

[0077] Step S103

[0078] In step S103, the control device 116 compares the feature quantity extracted in step S102 with the initial determination range pre-stored in the storage unit 215 via the diagnostic unit 216. The initial determination range is the same as the normal range. Figure 4 The frequency and impedance range specified on the curve are preset values ​​that are empirically or theoretically set in advance to detect obvious abnormal conditions. Through this initial judgment, the assembly of the automatic analysis device 101, the measurement circuit including the measurement unit 213, and the control are checked for initial defects (such as connector detachment).

[0079] Step S104

[0080] In step S104, the control device 116 determines whether the feature quantity extracted in step S102 is within the initial determination range. If the feature quantity converges to the initial determination range, the process is transferred to the definition of the normal range in step S105. If the feature quantity deviates from the initial determination range, the process is transferred to step S107.

[0081] Step S105

[0082] When the process transitions from step S104 to step S105, the control device 116 defines, via the normal range definition unit 214, a first normal range 403 and a second normal range 404 for use in fault diagnosis of the ultrasonic transducer 203 (in this embodiment, segmented 211). These defined normal ranges are inherent to the system and are used in subsequent fault diagnoses (second stage 502) within the same system, provided the system is not updated due to replacement of the ultrasonic transducer 203, etc.

[0083] Step S106

[0084] In the next step S106, the control device 116 saves the normal range defined in step S105 to the storage unit 215, and the process ends. Figure 7 The process involves retrieving the normal range corresponding to the ultrasonic transducer 203 being diagnosed from the storage unit 215 during subsequent diagnostic testing of the transducer 203.

[0085] Step S107

[0086] When the process transitions from step S104 to step S107, the control device 116 outputs an alarm to the display unit 120 to notify of initial defects such as improper installation of the ultrasonic transducer 203, and the process ends. Figure 7 The process.

[0087] (Second-stage processing flow)

[0088] Figure 8 This is a flowchart illustrating an example of a series of processing steps by the control device 116 involved in the fault diagnosis of the ultrasonic transducer 203 implemented in the second stage. The second stage 502 is a scenario where the state of the ultrasonic transducer 203 is diagnosed during the analysis preparation actions performed when the automatic analysis device 101 is started and before the analysis of the sample begins. If the ultrasonic transducer 203 is diagnosed as faulty in the second stage 502, the automatic analysis device 101 avoids the consumption of the sample and reagents by not performing the sample analysis. Alternatively, if the automatic analysis device 101 has multiple ultrasonic stirring mechanisms 114, as a temporary measure, when one ultrasonic transducer 203 is diagnosed as faulty, the sequence of ultrasonic stirring mechanisms 114 that do not use the faulty ultrasonic transducer 203 is switched, and the analysis of the remaining ultrasonic transducers 203 begins. Similar to the definition of the normal range implemented in the first stage 501, the control device 116 also performs fault diagnosis according to the ultrasonic transducer 203 and segment 211.

[0089] Step S201

[0090] When it begins Figure 8During the process, the control device 116 measures the current impedance spectrum 405 of the ultrasonic transducer 203 of the diagnostic object in step S201.

[0091] Step S202

[0092] In the next step S202, the control device 116 extracts characteristic quantities from the current impedance spectrum 405 of the ultrasonic transducer 203 of the diagnostic object.

[0093] Step S203

[0094] In step S203, the control device 116 retrieves the normal range inherent to the ultrasonic transducer 203 of the diagnostic object from the storage unit 215 and compares the feature quantity extracted in step S202 with the normal range.

[0095] Step S204

[0096] In step S204, the control device 116 determines whether the feature quantity extracted in step S202 is within the normal range. If the feature quantity converges within the normal range, the process is transferred to step S205. If the feature quantity deviates from the normal range, the process is transferred to step S206.

[0097] Step S205

[0098] When the process transitions from step S204 to step S205, the control device 116 determines that the ultrasonic transducer 203 is normal, stores the characteristic quantity determined to be normal in the storage unit 215, and ends the process. Figure 8 The process continues with the operation of the automatic analysis device 101, transferring the process to the analysis of the specimen, etc.

[0099] Step S206

[0100] When the process transitions from step S204 to step S206, the control device 116 determines that the ultrasonic transducer 203 is in a fault state and saves the characteristic quantity determined to be in a fault state in the storage unit 215.

[0101] Step S207

[0102] In the next step S207, the control device 116 outputs a fault alarm to the output device (e.g., display unit 120) to notify the user that the ultrasonic transducer 203 is in a fault state.

[0103] Step S208

[0104] Furthermore, in step S208, the control device 116 displays the detailed results of the fault diagnosis on the display unit 120 to complete the process. Figure 8The process either stops the operation of the automatic analysis device 101 or switches to a sequence that does not use the faulty ultrasonic transducer 203 and continues the operation of the automatic analysis device 101.

[0105] (Display of fault diagnosis results)

[0106] Figure 9 This is an example of the diagnostic results of the ultrasonic transducer 203 output by the control device 116 to the display unit 120. Figure 9 The image shows an example of a fault diagnosis report 801 for the ultrasonic transducer 203, segmented by 211. In report 801, each segment 211, from No. 1 to No. 13, is displayed as either "OK" indicating a normal state or "NG" indicating a fault state. Additionally, in... Figure 9 The diagram illustrates an example where the automatic analysis device 101 is equipped with multiple ultrasonic transducers 203. The columns labeled "Element 1," "Element 2," ..., "Element 6" represent the diagnostic results of different ultrasonic transducers 203. The diagnostic results for each segment 211 are displayed when the ultrasonic transducer 203 is selected. Figure 9 In the example, segments No. 3-7 and 10-12 of "Component 3" were determined to be in a fault state. Additionally, as... Figure 9 As shown, the serial number (Ser) of the ultrasonic transducer 203 and the date (Date) of its installation on the automatic analysis device 101 can also be displayed for each ultrasonic transducer 203, and the elapsed time since the current normal range was defined can be known for each ultrasonic transducer 203.

[0107] (Effect)

[0108] (1) According to this embodiment, during fault diagnosis of the ultrasonic transducer 203, the measured value of the impedance of the ultrasonic transducer 203 is evaluated by comparing it with the inherent normal range obtained in advance from the ultrasonic transducer 203 itself, which is the object of diagnosis. Therefore, the variation in the measured value of the impedance caused by factors other than the fault of the ultrasonic transducer 203 is suppressed, and the variation in impedance from the defined normal range can be regarded as a variation mainly caused by the state change of the ultrasonic transducer 203. Therefore, the misdiagnosis of a normal ultrasonic transducer 203 being judged as abnormal can be suppressed, and the reliability of fault diagnosis of the ultrasonic transducer 203 can be improved. In addition, the unnecessary replacement work of the ultrasonic transducer 203 can be suppressed, the decrease in the operating rate of the automatic analysis device 101 can be suppressed, and the operation time and component costs required for unnecessary replacement of the ultrasonic transducer 203 can be suppressed.

[0109] Furthermore, since the normal range of the ultrasonic transducer 203 is defined using this ultrasonic transducer 203, it also has the following advantages: it eliminates the need for a series of prior preparations to measure the individual impedances by preparing multiple normal ultrasonic transducers in order to generate a normal master group for defining the normal range.

[0110] (2) The inherent normal range of each ultrasonic transducer 203 includes a first normal range 403 that defines the minimum impedance 304 of the ultrasonic transducer 203 and its corresponding resonant frequency 303 as characteristic quantities. Furthermore, in this embodiment, the inherent normal range of each ultrasonic transducer 203 includes a second normal range 404 that defines the maximum impedance 402 of the ultrasonic transducer 203 and its corresponding anti-resonant frequency 401 as characteristic quantities. For fault diagnosis unaffected by individual differences of the ultrasonic transducer 203, electrical wiring length, etc., the first normal range 403 can be used to evaluate the impedance during diagnosis. In addition, by evaluating the second normal range 404, it is possible to confirm the impedance-specific waveform that obtains the maximum impedance 402 at an anti-resonant frequency 401 that is higher than the resonant frequency 303. Although there are abnormalities in the ultrasonic transducer 203, it cannot be said that the possibility of the characteristic quantity accidentally converging to the first normal range 403 due to other abnormalities of the measurement system such as short circuits is completely non-existent. In contrast, in addition to the evaluation based on the first normal range 403, the impedance is also evaluated through the second normal range 404 at the anti-resonant frequency 401. This allows for more accurate detection of faults in the ultrasonic transducer 203 and further improves the reliability of fault diagnosis of the ultrasonic transducer 203.

[0111] (3) As described above, the control device 116 measures the impedance spectrum multiple times according to the ultrasonic transducer 203 and the segment 211, extracts characteristic quantities from the measured impedance spectrum, and defines a first normal range 403 and a second normal range 404 based on the deviation of these characteristic quantities. Thus, the size of the normal range, specifically the amplitude of the frequency and impedance value, can be set appropriately and inherently according to the ultrasonic transducer 203.

[0112] (4) In the case of an ultrasonic transducer 203 having multiple electrodes 202 of the same shape, the control device 116 can also define a first normal range 403 and a second normal range 404 based on the deviation of the characteristic quantity extracted from the impedance spectrum of each electrode 202 for the ultrasonic transducer 203. In this case, it is not necessary to measure the impedance multiple times, and the first normal range 403 and the second normal range 404 can be defined by one or fewer measurements.

[0113] (Variation example)

[0114] This invention is not limited to the embodiments described above and can include various modifications. For example, the embodiments described above are detailed embodiments for the purpose of easily understanding and illustrating the invention, and are not limited to having all the structures described. For example, a part of the structure can be replaced with other structures. In addition, for a part of the structure of the embodiments, other structures can be deleted or added.

[0115] For example, in the above embodiments, a normal range can be defined in stages to determine the deterioration of the ultrasonic transducer 203. Figure 10 An explanatory diagram showing the normal range used in fault diagnosis of the ultrasonic transducer 203 in this modified example. (See diagram below.) Figure 10 As shown, in this example, the first normal range 403 is divided into a first region A and a second region B, which includes the first region A. Specifically, the lower limit of the frequency of the first region A is above the lower limit of the frequency of the second region B, and the upper limit of the frequency of the first region A is below the upper limit of the frequency of the second region B. Furthermore, the lower limit of the impedance of the first region A is above the lower limit of the impedance of the second region B, and the upper limit of the impedance of the first region A is below the upper limit of the impedance of the second region B. And, in Figure 10 On the graph, the area of ​​the first region A is smaller than the area of ​​the second region B. As an example, it can be compared with... Figure 4 The first normal range 403 is similarly defined as the second region B based on the average value of the repeatedly measured characteristic quantity ±3σ, and the first region A based on the average value of the characteristic quantity ±2σ.

[0116] In this case, if the measured impedance value obtained by applying voltage to the electrodes 202 of the ultrasonic transducer 203 during fault diagnosis in the second stage 502 is within the range of the defined first region A, the control device 116 diagnoses these segments 211 as being in a normal state. Conversely, if the measured impedance value obtained by applying voltage to each electrode 202 during diagnosis is outside the range of the defined second region B, the control device 116 diagnoses these segments 211 as being in a fault state. Furthermore, if the measured impedance value obtained by applying voltage to each electrode 202 during diagnosis is outside the range of the first region A but within the range of the second region B, the control device 116 diagnoses these segments 211 as being in a deteriorated state. A deteriorated state is, for example, a state where a fault state has not yet been reached at the current time but deterioration has begun, and a state that may transition to a fault state within a specified period.

[0117] Furthermore, the phased definition of such normal range is not limited to the first normal range 403, but can also be applied to the second normal range 404.

[0118] Furthermore, while examples of defining a normal range or performing fault diagnosis via control device 116 have been described above, the essence of the invention lies in implementing a normal range system and fault diagnosis of the ultrasonic transducer 203 within the same system. Based on this, it is also possible to perform fault diagnosis of the ultrasonic transducer 203 by setting a predetermined normal range based on the measured impedance value in the first stage 501 without using control device 116, and then comparing the impedance measured in the subsequent second stage 502 with the normal range.

[0119] Explanation of reference numerals in the attached figures

[0120] 100… Diagnostic system, 101… Automatic analysis device, 116… Control device, 120… Display unit (output device), 201… Piezoelectric element, 202… Electrode, 203… Ultrasonic transducer, 301… Impedance spectrum, 303… Resonant frequency (frequency corresponding to minimum impedance), 304… Minimum impedance, 401… Anti-resonant frequency (frequency corresponding to maximum impedance), 402… Maximum impedance, 403… First normal range (normal range), 404… Second normal range (normal range), 501… First stage (timing for estimating the normal state of the ultrasonic transducer), A… First region, B… Second region.

Claims

1. An automatic analysis device, comprising: An ultrasonic transducer comprising a piezoelectric element and electrodes mounted on the piezoelectric element; A control device that performs fault diagnosis on the ultrasonic transducer. Its features are, The control device defines and stores the normal range of the inherent impedance of the ultrasonic transducer based on the measured impedance value obtained by applying voltage to the electrode. During diagnosis, the measured impedance value obtained by applying voltage to the electrode is compared with the normal range to perform fault diagnosis of the ultrasonic transducer.

2. The automatic analysis device according to claim 1, characterized in that, The ultrasonic transducer used in the definition of the normal range is the same as the ultrasonic transducer used for the fault diagnosis.

3. The automatic analysis device according to claim 1, characterized in that, The normal range is defined based on the feature quantities extracted from the electrical impedance spectrum.

4. The automatic analysis device according to claim 3, characterized in that, The normal range includes defining the minimum value of the impedance and the frequency corresponding to the minimum value as a first normal range of the characteristic quantity.

5. The automatic analysis device according to claim 4, characterized in that, The normal range includes a second normal range that defines the maximum value of the impedance and the frequency corresponding to the maximum value as the characteristic quantity.

6. The automatic analysis device according to claim 3, characterized in that, The control device defines the normal range based on the deviation of the characteristic quantity extracted from each impedance spectrum obtained by using the electrode through multiple measurements.

7. The automatic analysis device according to claim 3, characterized in that, The ultrasonic transducer has multiple electrodes of the same shape. The control device defines the normal range based on the deviation of a characteristic quantity extracted from the impedance spectrum of each electrode.

8. The automatic analysis device according to claim 1, characterized in that, The normal range of the inherent impedance of the ultrasonic transducer is defined based on the measured impedance values ​​obtained at a time when the normal state of the ultrasonic transducer is estimated.

9. The automatic analysis device according to claim 1, characterized in that, The normal range is divided into a first region and a second region that includes the first region. If the measured impedance obtained by applying voltage to the electrode during diagnosis is within the range of the first region, the control device diagnoses the ultrasonic transducer as being in a normal state. If the measured impedance obtained by applying voltage to the electrode during diagnosis is outside the range of the second region, the control device diagnoses the ultrasonic transducer as being in a fault state. If the measured impedance obtained by applying voltage to the electrode during diagnosis is outside the range of the first region but within the range of the second region, the control device diagnoses the ultrasonic transducer as being in a deteriorated state.

10. The automatic analysis device according to claim 1, characterized in that, If the control device diagnoses a fault in the ultrasonic transducer, it will send an alarm to the output device.

11. A diagnostic system having a control device for diagnosing faults in an ultrasonic transducer, the ultrasonic transducer comprising a piezoelectric element and electrodes mounted on the piezoelectric element, and equipped with an automatic analysis device. Its features are, The control device defines and stores the normal range of the inherent impedance of the ultrasonic transducer based on the measured impedance value obtained by applying voltage to the electrode. During diagnosis, the measured impedance value obtained by applying voltage to the electrode is compared with the normal range to perform fault diagnosis of the ultrasonic transducer.

12. The diagnostic system according to claim 11, characterized in that, The control device is equipped with the automatic analysis device.

13. A diagnostic method for fault diagnosis of an ultrasonic transducer, the ultrasonic transducer comprising a piezoelectric element and electrodes mounted on the piezoelectric element, and equipped with an automatic analysis device. Its features are, Based on the measured impedance values ​​obtained by applying voltage to the electrodes, the normal range of the inherent impedance of the ultrasonic transducer is defined. The fault diagnosis of the ultrasonic transducer is performed by comparing the measured value of the impedance obtained by applying voltage to the electrode during diagnosis with the normal range.

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