Needle blocking detection device for full-automatic chemiluminescence immunoassay analyzer

Abstract

The utility model discloses a needle blocking detection device for a full-automatic chemiluminescence immunoassay analyzer, which comprises an upper fixing plate and a lower fixing plate which are combined into a whole through a connecting piece, a detection circuit board is arranged on the upper plate surface of the lower fixed plate, a plurality of single-channel capacitive detection circuits are distributed on the detection circuit board, and upper polar plates of induction capacitors Cj of the plurality of single-channel capacitive detection circuits are respectively positioned on the upper plate surface of the detection circuit board; a conductive contact is arranged at the position of an upper pole plate of each induction capacitor Cj, a liquid conveying pipeline is arranged between each conductive contact and the upper fixing plate, and a lower pole plate of the induction capacitor Cj of the single-channel capacitive detection circuit is connected with a grounding end through the upper fixing plate. According to the utility model, the capacitance value of the liquid in the transfusion pipeline is collected through the induction capacitor Cj, whether the needle is blocked is judged, and the color, the light transmittance, the material and even scratches of the transfusion pipeline are not limited.

Description

Technical Field

[0001] This utility model relates to a fully automated chemiluminescence immunoassay analyzer, and more particularly to a needle blockage detection device for a fully automated chemiluminescence immunoassay analyzer. Background Technology

[0002] In fully automated chemiluminescence immunoassay analyzers, the magnetic bead cleaning unit and substrate dispensing unit play crucial roles in the detection process. These units require their respective injection or aspiration needles to perform sample aspiration and dispensing operations in the reaction vessel. Current fully automated chemiluminescence immunoassay analyzers require dozens of injection and aspiration needles, and this number increases exponentially with the increase in instrument analysis speed. Each needle corresponds to a separate tubing, and injection and aspiration needles are often designed in pairs, performing multiple injection and aspiration operations on the sample and reactants in the reaction vessel according to a specific sequence. If the injection needle is not cleaned for a long time or if impurities are present in the tubing, it can become clogged, reducing the amount of residual liquid in the reaction vessel and potentially leading to misinterpretations. Conversely, if crystals or impurities enter the inner wall of one aspiration needle, it can become clogged, preventing timely aspiration of liquid from the reaction vessel. When the other injection needle subsequently adds liquid to the reaction vessel, the liquid will overflow into the machine, ultimately leading to abnormal results and, in severe cases, machine damage. Therefore, accurately detecting needle blockage is of paramount importance.

[0003] Currently, existing immunoassay analyzers often use ultrasonic or photoelectric sensors inserted into the tubing to detect needle blockage and thus determine whether the needle is blocked. However, practical applications revealed shortcomings in both methods. Firstly, while ultrasonic sensors are highly sensitive and can detect water flow in pipelines, assembly requires a tight seal between the pipeline and the ultrasonic sensor, with no gaps or movement. Furthermore, the pipeline in contact with the sensor must be free of scratches, bends, or other minor abnormalities; otherwise, false alarms will occur. This approach places excessive demands on assembly processes, making it unsuitable for mass production. Secondly, photoelectric sensors detect differences in light intensity received by air and liquid flowing through the pipeline, determining whether the liquid is flowing normally and thus whether the needle is blocked. However, in practical applications, slow-moving liquid droplets may remain in the air column within the pipeline. When these droplets pass through the detection area, they continuously trigger the sensor, leading to false alarms. Additionally, since the substrates used in immunoassay analyzers need to be stored away from light, using photoelectric sensors would require transparent pipelines. This would expose some substrates to visible light for extended periods, causing characteristic failure and abnormal detection results. Summary of the Invention

[0004] In view of this, the present invention provides a needle blockage detection device for a fully automated chemiluminescence immunoassay analyzer.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] The needle blockage detection device for a fully automated chemiluminescence immunoassay analyzer described in this utility model includes an upper fixing plate and a lower fixing plate, which are connected as a whole by a connector. A detection circuit board is disposed on the upper surface of the lower fixing plate. The detection circuit board is provided with a plurality of single-channel capacitive detection circuits. The upper plates of the sensing capacitors Cj of the plurality of single-channel capacitive detection circuits are respectively located on the upper surface of the detection circuit board. A conductive contact is disposed at the position of the upper plate of each sensing capacitor Cj. An infusion pipe is disposed between each conductive contact and the upper fixing plate. The lower plate of the sensing capacitor Cj of the single-channel capacitive detection circuit is connected to the ground terminal through the upper fixing plate. The upper plate of the sensing capacitor Cj is disposed on the upper surface of the detection circuit board in the form of a solder pad.

[0007] Optionally, the single-channel capacitive detection circuit includes a comparator U1. The inverting input of the comparator U1 is connected to the ground terminal via the sensing capacitor Cj, and is connected to the output terminal OUT of the comparator U1 via resistor R1. The non-inverting input of the comparator U1 is connected to the ground terminal via a parallel circuit consisting of a voltage divider resistor R3 and a filter capacitor C1, and is connected to the power supply Vcc via a voltage divider resistor R2 and to the output terminal OUT of the comparator U1 via resistor R4.

[0008] Alternatively, the conductive contact may be a conductive sponge or a conductive spring, which serves as a buffer and improves the reliable contact between the conductive contact and the infusion pipeline.

[0009] Alternatively, an arc-shaped groove is provided on the lower surface of the upper fixing plate along each of the infusion pipes to enhance the positioning between the lower surface of the upper fixing plate and the infusion pipes.

[0010] This invention uses the sensing capacitor Cj to collect the capacitance value of the liquid in the infusion pipeline and determine whether a needle blockage has occurred. There are no restrictions on the color, light transmittance, material, or even scratches of the infusion pipeline. The color and material of the infusion pipeline can be designed according to the characteristics of the liquid itself to keep the liquid's own characteristics from being disturbed by external factors. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of this utility model.

[0012] Figure 2 This is a circuit diagram of the single-channel capacitive detection circuit described in this utility model. Detailed Implementation

[0013] The embodiments of this utility model will be described in detail below with reference to the accompanying drawings. These embodiments are implemented based on the technical solution of this utility model and provide detailed implementation methods and specific operation processes. However, the protection scope of this utility model is not limited to the following embodiments.

[0014] It should be noted that in the description of this utility model, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0015] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0016] like Figure 1 As shown, the needle blockage detection device for a fully automated chemiluminescence immunoassay analyzer described in this utility model includes an upper fixing plate 1.1 and a lower fixing plate 1.2. The upper and lower fixing plates are combined into one unit by a connector 1.3 and connected to the fully automated chemiluminescence immunoassay analyzer through a connecting hole 1.4. Therefore, it will not move with the up and down movement of the aspiration and injection needles, thus eliminating the detection error caused by the movement of the infusion tubing.

[0017] like Figure 1 , 2 As shown, a detection circuit board 2 is provided on the upper surface of the lower fixed plate 1.2. Several single-channel capacitive detection circuits are arranged on the detection circuit board 2. The upper plates of the sensing capacitors Cj of the several single-channel capacitive detection circuits are all set on the upper surface of the detection circuit board 2 in the form of pads 2.1. A conductive contact 3 is provided at the position of the upper plate (pad 2.1) of each sensing capacitor Cj. An infusion pipe 4 is provided between each conductive contact 3 and the upper fixed plate 1.1. The lower plate of the sensing capacitor Cj of each single-channel capacitive detection circuit is connected to the ground terminal GND through the upper fixed plate 1.1.

[0018] Beneficially or exemplaryly, such as Figure 2As shown, the single-channel capacitive detection circuit includes a comparator U1. The inverting input of the comparator U1 is connected to the ground terminal GND via the sensing capacitor Cj, and is connected to the output terminal OUT of the comparator U1 via the resistor R1. The non-inverting input of the comparator U1 is connected to the ground terminal via a parallel circuit consisting of a voltage divider resistor R3 and a filter capacitor C1, and is connected to the power supply Vcc via a voltage divider resistor R2 and to the output terminal OUT of the comparator U1 via a resistor R4.

[0019] Beneficially or exemplaryly, such as Figure 1 As shown, the conductive contact 3 is a conductive sponge or a conductive spring, which plays a buffering role and improves the reliable contact between the conductive contact and the infusion pipeline, avoiding interference with the detection capacitance value caused by gap changes due to pipeline movement or assembly errors.

[0020] One end of the conductive sponge or conductive spring is connected to the upper electrode (pad 2.1) of the sensing capacitor Cj, and the other end is in contact with the infusion pipeline. It is used to directly conduct the capacitance value sensed in the infusion pipeline 4 to the upper electrode (pad 2.1) of the capacitor Cj. It also serves as the medium for direct contact between the infusion pipeline 4 and the upper electrode (pad 2.1) of the sensing capacitor Cj, ensuring reliable electrical contact between the upper electrode (pad 2.1) of the sensing capacitor Cj and the outer wall of the infusion pipeline 4 even under mass assembly and transportation shaking, thereby reducing capacitance detection error. At the same time, the diameter of the conductive sponge or conductive spring can be adjusted according to the wall thickness or material of the infusion pipeline 4 to adjust the sensitivity of capacitance detection.

[0021] Advantageously or exemplary, an arc-shaped groove is provided on the lower plate surface of the upper fixing plate 1.1 along each infusion pipe 4 to enhance the positioning between the lower plate surface of the upper fixing plate 1.1 and the infusion pipe 4.

[0022] The working principle of this utility model is briefly described as follows:

[0023] After power-on, the voltage across the sensing capacitor Cj is 0, and the voltage at the inverting input of comparator U1 is also 0. Since there is a voltage divider circuit composed of resistors R2 and R3 at the non-inverting input of U1, comparator U1 will output a high level. At this time, the output of comparator U1 will charge the sensing capacitor Cj through resistor R1, and simultaneously raise the voltage at the non-inverting input of comparator U1 through resistor R4. As the sensing capacitor Cj charges, the voltage gradually increases, meaning the voltage at the inverting input of comparator U1 continuously increases. When the voltage at the inverting input of comparator U1 exceeds the voltage at the non-inverting input, it outputs a low level, causing the inverting input of comparator U1 to discharge. Simultaneously, the effect of resistor R4 will decrease the voltage at the non-inverting input of comparator U1. As the voltage at the inverting input gradually decreases until it falls below the voltage at the non-inverting input, the output of U1 will return to a high level. Therefore, the output of circuit U1 will continuously oscillate and output PWM. When the value of the sensing capacitor Cj changes, it directly affects the frequency of the PWM output at the comparator U1. To facilitate the analysis of the relationship between the value of the sensing capacitor Cj and the PWM frequency fpwm, assuming that the resistors R2, R3, and R4 are all equal, the following relationship is obtained:

[0024] ;

[0025] According to the above formula, the output frequency can be adjusted by changing the resistance value of resistor R1. Selecting a suitable resistance value allows for matching and acquisition of the pipeline status under different liquid velocities. The output signal of comparator U1 is directly connected to the pin of the main control chip. Measuring the number of pulses at a fixed time interval or the width of each pulse indirectly yields the current capacitance value. Since this is only used to determine the presence or absence of liquid in the infusion pipeline in practical applications, what is needed is not the absolute value of the capacitance, but rather the relative change, i.e., the change in the number of pulses or the pulse width.

[0026] The above is a discrete component capacitance acquisition circuit scheme. In addition, there are schemes that use specific capacitance detection chips to achieve the same function.

[0027] Finally, it should be emphasized that the above description is merely a preferred embodiment of this utility model and is not intended to limit this utility model. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still make modifications to the technical solutions described in the foregoing embodiments without creative effort, or make equivalent substitutions for some of the technical features. Therefore, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A needle-clogging detection device for a fully automated chemiluminescence immunoassay analyzer, characterized in that: The device includes an upper fixed plate and a lower fixed plate, which are connected as a whole by a connector. A detection circuit board is provided on the upper surface of the lower fixed plate. The detection circuit board is equipped with several single-channel capacitive detection circuits. The upper plates of the sensing capacitors Cj of the several single-channel capacitive detection circuits are respectively located on the upper surface of the detection circuit board. A conductive contact is provided at the position of the upper plate of each sensing capacitor Cj. An infusion pipe is provided between each conductive contact and the upper fixed plate. The lower plate of the sensing capacitor Cj of the single-channel capacitive detection circuit is connected to the ground terminal through the upper fixed plate.

2. The needle blockage detection device for a fully automated chemiluminescence immunoassay analyzer according to claim 1, characterized in that: The single-channel capacitive detection circuit includes a comparator U1. The inverting input of the comparator U1 is connected to the ground terminal via the sensing capacitor Cj, and is connected to the output terminal OUT of the comparator U1 via resistor R1. The non-inverting input of the comparator U1 is connected to the ground terminal via a parallel circuit consisting of a voltage divider resistor R3 and a filter capacitor C1, and is connected to the power supply Vcc via a voltage divider resistor R2 and to the output terminal OUT of the comparator U1 via resistor R4.

3. The needle blockage detection device for a fully automated chemiluminescence immunoassay analyzer according to claim 1 or 2, characterized in that: The conductive contact is a conductive sponge or a conductive spring.

4. The needle blockage detection device for a fully automated chemiluminescence immunoassay analyzer according to claim 1 or 2, characterized in that: An arc-shaped groove is provided along the lower surface of the upper fixing plate for each of the infusion pipes.

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