Magnetic bead concentration detection device

Abstract

The utility model discloses a magnetic bead concentration detection device which comprises a detection unit and a signal processing unit, the detection unit is provided with a first cavity, a sample pool and a second cavity which are sequentially communicated, the first cavity and the second cavity are located on two opposite sides of the sample pool, and the sample pool is used for placing a reaction cup for storing magnetic bead solution. A light source module and a first lens assembly are arranged in the first cavity, the first lens assembly enables emergent light of the light source module to enter the sample pool, a second lens assembly and a light receiving module are arranged in the second cavity, and the second lens assembly enables light passing through the sample pool to enter the light receiving module; the light source module and the light receiving module are respectively connected with the signal processing unit, and the signal processing unit can obtain the magnetic bead concentration of the magnetic bead solution by processing an electric signal according to the electric signal generated after the light receiving module receives light. Compared with an existing magnetic bead concentration detection method based on a magnetic field, the magnetic bead concentration detection device can improve the detection efficiency, reduce the workload of operators and is low in cost.

Description

Technical Field

[0001] The utility model relates to the field of optical instruments, in particular to a magnetic bead concentration detection device. Background Art

[0002] Magnetic beads are a new type of magnetic material developed in recent years. They have magnetic responsiveness (also known as superparamagnetism) and can be collected by an external magnetic field. After the magnetic field is removed, the magnetism of the magnetic beads disappears and they can be redispersed evenly in the solution. In addition, the magnetic beads can be endowed with surface functional groups such as hydroxyl, carboxyl, thiol and amino groups through copolymerization and surface modification. These groups can specifically bind to the target molecules.

[0003] The magnetic bead method can be combined with an automated workstation to achieve batch operation due to its simple operation, high specific binding efficiency, safety and non-toxicity, thereby greatly improving the separation efficiency of substances and the standardization of operations. Therefore, with the continuous increase in the market size of in vitro diagnostics (IVD), the immunodiagnostic market has a huge demand for immunomagnetic bead raw materials.

[0004] When using magnetic beads for immunoassays in the field of in vitro diagnosis, on the one hand, there are requirements for the concentration ratio between the magnetic beads and the components to be extracted in the liquid sample. Too high a concentration of magnetic beads is not conducive to sufficient contact between the magnetic beads and the sample, while too little concentration cannot completely extract the required substances. On the other hand, the immune complex formed by the magnetic beads and the test sample needs to be washed and then subjected to magnetic analysis, which will inevitably cause the loss of magnetic beads. The loss of magnetic beads may cause a decrease in the immunoassay signal value, which will inevitably affect the accuracy of the test data. Therefore, it is particularly important to detect the magnetic bead concentration of the sample.

[0005] The traditional method of detecting the concentration of magnetic beads is to use an optical or electron microscope. However, the number of magnetic beads that can be seen in the field of view of the microscope is limited. To make the results representative, a sufficient number of particles must be counted. This method not only increases the workload of operators, resulting in low detection efficiency, but also reduces the accuracy of magnetic bead concentration detection. At present, the following methods are mainly used to detect the relaxation time of magnetic bead suspensions based on the magnetic material properties of magnetic bead solutions. However, this magnetic field-based magnetic bead concentration detection method has the disadvantages of long detection time, slow speed, low efficiency, high detection cost, and cumbersome operation. Utility Model Content

[0006] The utility model aims to provide a magnetic bead concentration detection device, which can improve detection efficiency, reduce the workload of operators and has low cost.

[0007] To achieve the above-mentioned object, the utility model provides a magnetic bead concentration detection device, comprising a detection unit and a signal processing unit, wherein the detection unit is provided with a first cavity, a sample pool and a second cavity which are connected in sequence, wherein the first cavity and the second cavity are respectively located on opposite sides of the sample pool, and the sample pool is used to place a reaction cup storing a magnetic bead solution;

[0008] A light source module and a first lens assembly are arranged in the first cavity, and the first lens assembly is used to make the output light of the light source module incident on the sample pool. A second lens assembly and a light receiving module are arranged in the second cavity, and the second lens assembly is used to make the light passing through the sample pool incident on the light receiving module. The light source module and the light receiving module are respectively connected to the signal processing unit.

[0009] Optionally, a first groove is provided on a cavity wall of the first cavity away from one end of the sample pool, the light emitting element of the light source module is provided in the first groove, and the diameter of the first groove gradually increases toward the groove opening;

[0010] And / or, a second groove is arranged on the cavity wall of the second cavity away from the sample pool, the photoelectric receiving element of the light receiving module is arranged in the second groove and the diameter of the second groove gradually increases towards the groove opening.

[0011] Optionally, a first groove is provided on a cavity wall of the first cavity away from one end of the sample pool, the detection unit is further provided with a first cover plate, the light source module is provided on the first cover plate, and the light emitting element of the light source module is located in the first groove;

[0012] And / or, a second groove is provided on the cavity wall of the second cavity away from one end of the sample pool, the detection unit is further provided with a second cover plate, the light receiving module is provided on the second cover plate, and the photoelectric receiving element of the light receiving module is located in the second groove.

[0013] Optionally, the first lens assembly includes a first lens and a second lens, the first lens is used to collimate the output light of the light source module, and the second lens is used to focus the light passing through the first lens onto the sample pool;

[0014] And / or, the second lens assembly includes a third lens and a fourth lens, the third lens is used to collimate the light passing through the sample cell, and the fourth lens is used to focus the light passing through the third lens onto the light receiving module.

[0015] Optionally, a filter is further arranged in the second cavity, and the filter is a bandpass filter, a central wavelength of which is consistent with the peak wavelength of the light emitted by the light source module.

[0016] Optionally, the center of the light emitting element of the light source module, the center of the first lens assembly, the center of the bottom end of the reaction cup placed in the sample pool, the center of the second lens assembly and the center of the photoelectric receiving element of the light receiving module are on the same straight line.

[0017] Optionally, the top of the reaction cup is provided with a convex portion extending to the side, the sample pool is provided with a slot hole communicating with the outside, the outer port of the slot hole is provided with a groove, the reaction cup is extended into the slot hole so that the bottom end of the reaction cup is placed in the sample pool, and the convex portion of the reaction cup is located in the groove.

[0018] Optionally, the signal processing unit includes a digital voltage terminal, an analog voltage terminal, a first inductor, a third capacitor and a fourth capacitor, one end of the first inductor is connected to the digital voltage terminal, and the other end is connected to the analog voltage terminal, the third capacitor is connected between the digital voltage terminal and the ground terminal, the fourth capacitor is connected between the analog voltage terminal and the ground terminal, and the first inductor, the third capacitor and the fourth capacitor form a filtering circuit.

[0019] Optionally, the signal processing unit includes a signal conditioning module, the light receiving module includes a photoelectric receiving element and a first operational amplifier, one end of the photoelectric receiving element is connected to the ground end, and the other end is connected to the inverting input end of the first operational amplifier, and the signal conditioning module includes a second operational amplifier, and the non-inverting input end of the second operational amplifier is connected to the output end of the first operational amplifier.

[0020] Optionally, the first cavity, the sample pool and the second cavity of the detection unit are light-proof.

[0021] It can be known from the above technical scheme that a magnetic bead concentration detection device provided by the utility model includes a detection unit and a signal processing unit. The detection unit is provided with a first cavity, a sample pool and a second cavity connected in sequence. The first cavity and the second cavity are respectively located on opposite sides of the sample pool. The sample pool is used to place a reaction cup for storing a magnetic bead solution. A light source module and a first lens assembly are provided in the first cavity. The first lens assembly allows the emitted light of the light source module to be incident on the sample pool. A second lens assembly and a light receiving module are provided in the second cavity. The second lens assembly allows the light passing through the sample pool to be incident on the light receiving module. The light source module and the light receiving module are respectively connected to the signal processing unit. The emitted light of the light source module is incident on the magnetic bead solution in the sample pool through the first lens assembly, and the light transmitted through the magnetic bead solution is incident on the light receiving module through the second lens assembly. The signal processing unit can obtain the magnetic bead concentration of the magnetic bead solution by processing the electrical signal according to the electrical signal generated after the light receiving module receives the light. Compared with the existing magnetic bead concentration detection method based on the magnetic field, the use of this magnetic bead concentration detection device can improve the detection efficiency, reduce the workload of the operator, and has low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A schematic diagram of a magnetic bead concentration detection device provided in one embodiment of the utility model;

[0024] Figure 2 A schematic diagram of the optical path and circuit principle of a magnetic bead concentration detection device provided in one embodiment of the utility model;

[0025] Figure 3 A circuit diagram of a light source module of a magnetic bead concentration detection device provided in one embodiment of the utility model;

[0026] Figure 4 A circuit diagram of a light receiving module and a signal conditioning module of a magnetic bead concentration detection device provided in one embodiment of the utility model;

[0027] Figure 5 A schematic diagram of a single-point common ground for a digital power supply and an analog power supply of a signal processing unit of a magnetic bead concentration detection device provided by an embodiment of the utility model.

[0028] The reference numerals in the drawings of the specification include:

[0029] 101-first cover plate, 102-light source module, 103-first lens, 104-second lens, 105-sample pool, 106-third lens, 107-fourth lens, 108-filter, 109-light receiving module, 110-second cover plate, 111-second wiring harness, 112-first wiring harness, 113-signal processing unit, 114-first cavity, 115-second cavity, 116-reaction cup. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0031] The present embodiment provides a magnetic bead concentration detection device, comprising a detection unit and a signal processing unit, wherein the detection unit is provided with a first cavity, a sample pool and a second cavity which are connected in sequence, wherein the first cavity and the second cavity are respectively located on opposite sides of the sample pool, and the sample pool is used to place a reaction cup storing a magnetic bead solution;

[0032] A light source module and a first lens assembly are arranged in the first cavity, and the first lens assembly is used to make the output light of the light source module incident on the sample pool. A second lens assembly and a light receiving module are arranged in the second cavity, and the second lens assembly is used to make the light passing through the sample pool incident on the light receiving module. The light source module and the light receiving module are respectively connected to the signal processing unit.

[0033] The sample pool is a cavity structure, which can be used to place a reaction cup storing a magnetic bead solution. The first cavity and the second cavity are respectively located on opposite sides of the sample pool, and the three are connected, so that the output light of the light source module is incident on the sample pool through the first lens assembly, and can be irradiated to the magnetic bead solution, and the light transmitted through the magnetic bead solution is incident on the light receiving module through the second lens assembly. The signal processing unit can obtain the magnetic bead concentration of the magnetic bead solution by processing the electrical signal generated after the light receiving module receives the light. Compared with the existing magnetic bead concentration detection method based on the magnetic field, the magnetic bead concentration detection device can be used to place the reaction cup storing the magnetic bead solution in the sample pool for detection, which can improve the detection efficiency, reduce the workload of the operator, and has low cost.

[0034] For example, reference may be made to Figure 1 , Figure 1 A schematic diagram of a magnetic bead concentration detection device provided in an embodiment is shown in the figure. As shown in the figure, the detection unit is provided with a first cavity 114, a sample pool 105 and a second cavity 115, and the three are connected in sequence. The first cavity 114 and the second cavity 115 are respectively located on opposite sides of the sample pool 105. In some embodiments, the first cavity 114, the sample pool 105 and the second cavity 115 are all opaque, which can effectively avoid the influence of ambient light on the detection accuracy. The detection unit can be made of black opaque material to form a closed light-isolating device, and can be made of lightweight metal material to make the device light and easy to carry.

[0035] In some embodiments, a first groove is provided on the cavity wall of the first cavity 114 away from the sample pool 105, the light-emitting element of the light source module 102 is provided in the first groove and the diameter of the first groove gradually increases toward the groove, and the groove of the first groove is the groove of the first groove in the first cavity 114, so that the light emitted by the light-emitting element is concentrated and irradiated to the first lens assembly. The first groove can be funnel-shaped. In some embodiments, a first groove is provided on the cavity wall of the first cavity 114 away from the sample pool 105, and the detection unit is further provided with a first cover plate 101, the light source module 102 is provided on the first cover plate 101, and the light-emitting element of the light source module 102 is in the first groove. The first cover plate 101 is provided on the outside of the first cavity 114, and the first cover plate 101 can be provided with a hole for inserting the first wire harness 112, one end of the first wire harness 112 is connected to the signal processing unit 113, and the other end is inserted into the hole of the first cover plate 101 and connected to the light source module 102.

[0036] In some embodiments, a second groove is provided on the cavity wall of the second cavity 115 away from the sample pool 105, the photoelectric receiving element of the light receiving module 109 is provided in the second groove and the second groove gradually increases in diameter toward the notch, and the notch of the second groove is the notch of the second groove in the second cavity 115, so that the light passing through the second lens assembly can be concentrated and irradiated to the photoelectric receiving element. The second groove can be funnel-shaped. In some embodiments, a second groove is provided on the cavity wall of the second cavity 115 away from the sample pool 105, and the detection unit is further provided with a second cover plate 110, the light receiving module 109 is provided on the second cover plate 110, and the photoelectric receiving element of the light receiving module 109 is in the second groove. The second cover plate 110 is provided on the outside of the second cavity 115, and the second cover plate 110 can be provided with a hole for inserting the second wire harness 111, one end of the second wire harness 111 is connected to the signal processing unit 113, and the other end can be inserted into the hole of the second cover plate 110 and connected to the light receiving module 109.

[0037] In some embodiments, the first lens assembly may include a first lens 103 and a second lens 104, wherein the first lens 103 is used to collimate the light emitted by the light source module 102, and the second lens 104 is used to focus the light passing through the first lens 103 onto the sample pool 105. Figure 1 As shown, the first lens 103 is a plano-convex lens, and the second lens 104 is a plano-convex lens. The two plano-convex lenses are installed opposite to each other. The light emitted by the light-emitting component of the light source module 102 is concentrated on the first lens 103, refracted into parallel light by the first lens 103 and irradiated to the second lens 104. The parallel light is refracted by the second lens 104 and focused to irradiate the reaction cup 116 in the sample pool 105, and irradiates the magnetic bead solution in the reaction cup 116 in the sample pool 105.

[0038] In some embodiments, the second lens assembly includes a third lens 106 and a fourth lens 107, wherein the third lens 106 is used to collimate the light passing through the sample pool 105, and the fourth lens 107 is used to focus the light passing through the third lens 106 onto the light receiving module 109. Figure 1 As shown, the third lens 106 is a plano-convex lens, and the fourth lens 107 is a plano-convex lens. The two plano-convex lenses are installed opposite to each other, focusing the light irradiated on the magnetic bead solution in the reaction cup 116 in the sample pool 105, and transmitting to the third plano-convex lens 106 after passing through the magnetic bead solution. The light is refracted into parallel light by the third lens 106, and the parallel light is irradiated to the fourth lens 107. After being refracted by the fourth lens 107, it is focused and irradiated to the photoelectric receiving element of the light receiving module 109, and the photoelectric receiving element converts the light passing through the magnetic bead solution into an electrical signal. Any lens from the first lens 103 to the fourth lens 107 can be made of a high-transmittance material, and an anti-reflection film can be set on the surface. The light transmission wavelength range of the anti-reflection film includes the wavelength of the light emitted by the light source module 102, so as to ensure that the generated light source passes through the lens and improve the detection sensitivity. For example, the light transmission wavelength range of the anti-reflection film is: 350-700nm.

[0039] In some embodiments, a filter 108 is also provided in the second cavity 115, and the filter 108 is used to filter out stray light to prevent stray light from interfering with the light collected by the photoelectric receiving element through the magnetic bead solution. The filter 108 can be a bandpass filter, and its central wavelength is consistent with the peak wavelength of the light emitted by the light source module 102. The peak wavelength λ1 of the light emitted by the light source module 102 is consistent with the central wavelength λ2 of the filter 108. The filter 108 uses a narrow bandwidth range, such as λ2±10nm, which can reduce the influence of stray light on the accuracy of magnetic bead concentration detection. In some embodiments, the filter 108 can be arranged between the third lens 106 and the fourth lens 107, and the light is transmitted to the third lens 106 through the magnetic bead solution. The light is refracted into parallel light by the third lens 106, and the parallel light is filtered out by the filter 108. The parallel light is further irradiated to the fourth lens 107, and is refracted by the fourth lens 107 and focused to irradiate the photoelectric receiving element of the light receiving module 109.

[0040] The magnetic bead concentration detection device adopts a modular structure and a symmetrical layout. The structural parts on the left and right sides can be used interchangeably to meet the requirements of low cost and good maintainability.

[0041] In some embodiments, the center of the light emitting element of the light source module 102, the center of the first lens assembly, the center of the bottom end of the reaction cup 116 placed in the sample pool 105, the center of the second lens assembly, and the center of the photoelectric receiving element of the light receiving module 109 are on the same straight line. This arrangement can realize that the emitted light of the light emitting element is refracted by the first lens assembly and concentrated on the magnetic bead solution, ensuring sufficient illumination for concentration detection and improving detection sensitivity; at the same time, the transmitted light of the magnetic bead solution is refracted by the second lens assembly and concentrated on the photoelectric receiving element, ensuring that sufficient light is received and converted into electrical signals, thereby improving detection accuracy. Exemplary corresponding Figure 1 In the device shown, the center of the light-emitting element of the light source module 102, the center of the first lens 103, the center of the second lens 104, the center of the bottom of the reaction cup 116 of the sample pool 105, the center of the third lens 106, the center of the filter 108, the center of the fourth lens 107 and the center of the photoelectric receiving element of the light receiving module 109 are on the same horizontal line.

[0042] The sample pool 105 may be provided with a slot hole connected to the outside world, and the reaction cup 116 extends into the slot hole so that the bottom end of the reaction cup 116 is placed in the sample pool 105, so that the output light of the light source module 102 is incident on the sample pool 105, and can irradiate the magnetic bead solution in the reaction cup 116. In some embodiments, the top of the reaction cup 116 is provided with a convex portion extending to the side, and the sample pool 105 is provided with a slot hole connected to the outside world, and the outer end of the slot hole is provided with a groove, and the reaction cup 116 extends into the slot hole so that the bottom end of the reaction cup 116 is placed in the sample pool 105, and the convex portion of the reaction cup 116 is in the groove. In this way, the reaction cup 116 can be a T-shaped reaction cup, and the slot hole of the sample pool 105 can be T-shaped, and the shapes of the two match. Figure 1 In the device shown, convex parts extending to the side are respectively provided on both sides of the top of the reaction cup 116, so that the reaction cup 116 is a T-shaped reaction cup, and the convex parts on both sides of the top of the reaction cup 116 are stuck at the outer end of the slot hole, so that the bottom of the reaction cup 116 is just in the sample pool 105. If a groove is provided at the outer end of the slot hole of the sample pool 105, the convex parts on both sides of the top of the reaction cup 116 can be placed in the groove when the reaction cup 116 extends into the slot hole, and the two are matched. By setting the position of the slot hole and the height of the reaction cup 116, the center of the bottom of the reaction cup 116 can be placed in the same straight line with the center of the light emitting element of the light source module 102, the center of the first lens assembly, the center of the second lens assembly, and the center of the photoelectric receiving element of the light receiving module 109.

[0043] Furthermore, a flap can be provided at the outer end of the slot, and the flap can be opened and closed. When testing a sample, the flap is opened to place the reaction cup 116 storing the magnetic bead solution into the sample pool 105, and then the flap is closed. The flap is flexibly designed, which can facilitate the storage and taking of the magnetic bead solution of the test sample, and can also shield the magnetic bead solution from external light when testing the magnetic bead solution, so as to avoid affecting the accuracy of the detection of the magnetic bead solution.

[0044] For example, reference may be made to Figure 2 , Figure 2 The light path and circuit principle diagram of a magnetic bead concentration detection device provided in an embodiment. The light source module 102 provides a detection light source for the detection unit. In some embodiments, the light source module 102 may include a light emitting element and a constant current source, one end of the constant current source is connected to the voltage end, and the other end is connected to the light emitting element, for providing a working current to the light emitting element. For example, reference may be made to Figure 3 , Figure 3 A circuit diagram of a light source module of a magnetic bead concentration detection device provided in an embodiment, as shown in the figure, the input terminal IN of the constant current source U1 is connected to the voltage terminal, the output terminal OUT and the SET terminal are connected to the light-emitting element D1, and the first capacitor C1 and the second capacitor C2 are connected in parallel between the voltage terminal and the ground terminal, which are filter capacitors, and the second resistor R2 is connected between the output terminal OUT of the constant current source U1 and the light-emitting element D1, and the first resistor R1 is connected between the SET terminal of the constant current source U1 and the light-emitting element D1. The first resistor R1 and the second resistor R2 are constant current source configuration resistors. The voltage terminal provides a working voltage for the constant current source U1, and the voltage terminal can be a digital voltage terminal. The working current I provided by the constant current source U1 is 10uA*(R1 / R2).

[0045] The constant current source U1 can use the LT3902 constant current source to provide the working current for the light-emitting device D1. R1 and R2 use precision resistors. Compared with the constant voltage source to provide the working voltage, it can eliminate the influence of the working voltage fluctuation on the working current of the light-emitting device D1, and reduce the influence of the resistance temperature drift on the resistance value, thereby ensuring the stability of the light source and improving the stability and accuracy of the magnetic bead concentration detection. The light-emitting device D1 can use a high-brightness diode. Using a high-brightness diode as a light source generator can achieve good substitutability and maintainability, and reduce design costs.

[0046] The light receiving module 109 is used to receive light that passes through the magnetic bead solution and convert it into an electrical signal. In some embodiments, the light receiving module 109 includes a photoelectric receiving element and a first operational amplifier, wherein one end of the photoelectric receiving element is connected to the ground terminal, and the other end is connected to the inverting input terminal of the first operational amplifier. Figure 4 , Figure 4A circuit diagram of an optical receiving module and a signal conditioning module of a magnetic bead concentration detection device provided in an embodiment, as shown in the figure, the optical receiving module 109 includes a photoelectric receiving element D2 and a first operational amplifier U2, the positive electrode of the photoelectric receiving element D2 is connected to the ground terminal, and the negative electrode is connected to the inverting input terminal IN-pin of the first operational amplifier U2. One end of the fifth resistor R5 is connected to the reverse input terminal IN-pin of the first operational amplifier U2, and the other end is connected to the output terminal Vout pin of the first operational amplifier U2. The fifth resistor R5 is a feedback amplifier resistor, and its function is to amplify the current signal. The sixth capacitor C6 is connected in parallel with the fifth resistor R5, and its function is to filter, make the circuit more stable, avoid ringing, and affect the detection accuracy. One end of the fourth resistor R4 is connected to the in-phase input terminal IN+pin of the first operational amplifier U2, and the other end is connected to the ground terminal. The fourth resistor R4 is a compensation matching resistor, and its resistance value is consistent with that of the fifth resistor R5, so as to reduce the bias effect caused by the input current of the operational amplifier. The fifth capacitor C5 is connected in parallel with the fourth resistor R4, and its function is to filter, eliminate noise interference, reduce the output error of the operational amplifier, and improve accuracy. The first operational amplifier U2 can be connected to the analog voltage terminal A+5V and the analog ground terminal AGND. The first operational amplifier U2 can adopt a low-noise, wide-bandwidth voltage feedback type high-speed operational amplifier, and its application of low input bias current is very suitable for the photodiode preamplifier. The photoelectric receiving element D2 can adopt a PIN photodiode, which will generate current under light irradiation, and the current is converted into voltage through IV.

[0047] In some implementations, the signal processing unit 113 includes a signal conditioning module, the signal conditioning module includes a second operational amplifier, and the non-inverting input terminal of the second operational amplifier is connected to the output terminal of the first operational amplifier. Figure 4, one end of the sixth resistor R6 is connected to the output terminal Vout pin of the first operational amplifier U2, and the other end is connected to the in-phase input terminal IN+ pin of the second operational amplifier U3. One end of the seventh capacitor C7 is connected to the in-phase input terminal IN+ pin of the second operational amplifier U3, and the other end is grounded. The sixth resistor R6 and the seventh capacitor C7 form an RC filter circuit, and the output signal of the optical receiving module 109 is input to the second operational amplifier U3 through the sixth resistor R6 and the seventh capacitor C7. One end of the seventh resistor R7 is connected to the inverting input terminal IN- pin of the second operational amplifier U3, and the other end is connected to the ground terminal AGND, which is a bias resistor used to reduce the impact of the offset current on the output of the operational amplifier. One end of the eighth resistor R8 is connected to the inverting input terminal IN- pin of the second operational amplifier U3, and the other end is connected to the output terminal Vout pin of the second operational amplifier U3, which is a feedback resistor. The eighth capacitor C8 is connected in parallel with the eighth resistor R8, and its function is to filter, so that the circuit is more stable, and ringing phenomenon is avoided, which affects the detection accuracy. The second operational amplifier U3 can be connected to the analog voltage terminal A+5V and the analog ground terminal AGND. The second operational amplifier U3 can adopt a low-noise, high-precision voltage feedback operational amplifier, and its low-noise performance can be used as an ideal high-performance ADC buffer. The signal conditioning module used in this device can not only amplify the electrical signal corresponding to the magnetic bead solution, but also improve the circuit performance through the peripheral resistor and capacitor components to form balanced matching, filtering and other circuits, reduce the operational amplifier output error caused by noise interference, offset voltage, output ringing, etc. of the operational amplifier circuit, and improve accuracy.

[0048] For reference Figure 2 As shown, the signal processing unit 113 may include an AD acquisition module, which performs analog-to-digital conversion on the amplified electrical signal input from the ADC_IN terminal, and transmits it to the MCU for processing through the SPI communication method, and the MCU is a processor. The AD acquisition module can select a 16-bit, 250kSPS, successive approximation analog-to-digital converter (ADC), which is powered by a single power supply (VDD) of 2.7V to 5.25V, and an SPI serial interface. It integrates a low-noise, wide-bandwidth, and extremely short aperture delay sampling and holding circuit, which is suitable for the application of medical instruments and equipment. The MCU is the main control processor and the control and processing core of the signal processing unit 113. It processes the data collected by the AD acquisition module, sends it to the display module through the I2C communication method, displays the test results to the user, and uploads the test results to the PC through the RS232 communication method. The display module can adopt the I2C interface method, and can display the magnetic bead concentration test results to the user through the digital display method, and can reserve the LCD display interface to facilitate the later upgrade and expansion to meet the user's liquid crystal display needs. The LED digital tube display can not only satisfy the user's intuitive viewing of the magnetic bead concentration test results, but also reduce the design cost.

[0049] The signal processing unit 113 may also include a power supply module to provide a working voltage for the entire device. A DC24V adapter may be used as a working power supply, which is converted into a stable, low-ripple DC working voltage of 5V and 3.3V through a non-isolated DC-DC module. The 5V voltage provides a working voltage for the light source module 102, the light receiving module 109, the signal conditioning module, the AD acquisition module, and the display module, and the 3.3V provides a working voltage for the MCU and serial communication. This device has no high-power components, and a 48W adapter power supply can meet the application, reducing the design cost.

[0050] In some embodiments, the signal processing unit 113 includes a digital voltage terminal, an analog voltage terminal, a first inductor, a third capacitor, and a fourth capacitor, wherein one end of the first inductor is connected to the digital voltage terminal, and the other end is connected to the analog voltage terminal, the third capacitor is connected between the digital voltage terminal and the ground terminal, the fourth capacitor is connected between the analog voltage terminal and the ground terminal, and the first inductor, the third capacitor, and the fourth capacitor form a filter circuit. For example, reference may be made to Figure 5 , Figure 5 A schematic diagram of a signal processing unit of a magnetic bead concentration detection device provided in an embodiment, wherein the digital power supply and the analog power supply are separated and grounded at a single point, as shown in the figure, including a digital voltage terminal and an analog voltage terminal, and a π-shaped filter circuit is formed by a first inductor L1, a third capacitor C3 and a fourth capacitor C4. The third resistor R3 can be a 0Ω resistor to achieve a single-point common ground for the digital ground terminal GND and the analog ground terminal AGND. This design can isolate the analog part and the digital part of the detection circuit, avoid mutual interference between the digital and analog, and can also achieve circuit filtering, improve the stability of the digital and analog voltages, improve circuit performance, and reduce the impact of voltage fluctuations on detection accuracy.

[0051] The magnetic bead concentration detection device of this embodiment can be applied to the magnetic bead concentration detection in optical immunoassay. The magnetic bead concentration detection device of this embodiment adopts modular design, symmetrical structure, good airtightness, and sophisticated optical path structure. It does not require too many lenses and filters. Four lenses and filters can constitute the centralized transmission of optical signals and the wavelength requirements of the required detection optical signals. At the same time, there is no need to consider the influence of scattered light on the accuracy of magnetic bead concentration, and the design can match the sample pool placed in the T-shaped reaction cup, which is convenient for the rapid placement of sample magnetic beads, thereby realizing low cost, simple operation, high efficiency, rapid, reliable and accurate detection of magnetic bead concentration.

[0052] The magnetic bead concentration detection device of this embodiment has a modular structure and a symmetrical structure. It has a simple structure and is easy to design and implement. It does not require a complex optical path detection unit, which is convenient for mass production. The structural parts on the left and right sides are interchangeable, which is convenient for maintenance and replacement, and reduces the design cost. In addition, the sophisticated optical path design structure does not require too many lenses and filters to ensure sufficient light for magnetic bead concentration detection, thereby improving the detection sensitivity and accuracy, while reducing the use of high-cost optical components and reducing the design cost.

[0053] The above is a detailed introduction to the magnetic bead concentration detection device provided by the utility model. This article uses specific examples to illustrate the principles and implementation methods of the utility model. The description of the above embodiments is only used to help understand the method and core idea of ​​the utility model. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the utility model, the utility model can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the utility model.

Claims

1. A magnetic bead concentration detection device, characterized in that: It comprises a detection unit and a signal processing unit, wherein the detection unit is provided with a first cavity, a sample pool and a second cavity which are connected in sequence, the first cavity and the second cavity are respectively located at two opposite sides of the sample pool, and the sample pool is used to place a reaction cup storing a magnetic bead solution; A light source module and a first lens assembly are arranged in the first cavity, and the first lens assembly is used to make the output light of the light source module incident on the sample pool. A second lens assembly and a light receiving module are arranged in the second cavity, and the second lens assembly is used to make the light passing through the sample pool incident on the light receiving module. The light source module and the light receiving module are respectively connected to the signal processing unit.

2. The magnetic bead concentration detection device according to claim 1, characterized in that: A first groove is arranged on the cavity wall of the first cavity away from one end of the sample pool, the light emitting element of the light source module is arranged in the first groove and the diameter of the first groove gradually increases toward the groove opening; And / or, a second groove is arranged on the cavity wall of the second cavity away from the sample pool, the photoelectric receiving element of the light receiving module is arranged in the second groove and the diameter of the second groove gradually increases towards the groove opening.

3. The magnetic bead concentration detection device according to claim 1, characterized in that: A first groove is provided on the cavity wall of the first cavity away from one end of the sample pool, the detection unit is further provided with a first cover plate, the light source module is provided on the first cover plate, and the light emitting element of the light source module is located in the first groove; And / or, a second groove is provided on the cavity wall of the second cavity away from one end of the sample pool, the detection unit is further provided with a second cover plate, the light receiving module is provided on the second cover plate, and the photoelectric receiving element of the light receiving module is located in the second groove.

4. The magnetic bead concentration detection device according to claim 1, characterized in that: The first lens assembly includes a first lens and a second lens, the first lens is used to collimate the output light of the light source module, and the second lens is used to focus the light passing through the first lens onto the sample pool; And / or, the second lens assembly includes a third lens and a fourth lens, the third lens is used to collimate the light passing through the sample cell, and the fourth lens is used to focus the light passing through the third lens onto the light receiving module.

5. The magnetic bead concentration detection device according to claim 1, characterized in that: A filter is also arranged in the second cavity. The filter is a bandpass filter, and the center wavelength of the filter is consistent with the peak wavelength of the light emitted by the light source module.

6. The magnetic bead concentration detection device according to claim 1, characterized in that: The center of the light emitting element of the light source module, the center of the first lens assembly, the center of the bottom end of the reaction cup placed in the sample pool, the center of the second lens assembly and the center of the photoelectric receiving element of the light receiving module are on the same straight line.

7. The magnetic bead concentration detection device according to claim 1, characterized in that: The top of the reaction cup is provided with a convex portion extending to the side, the sample pool is provided with a slot hole communicating with the outside, the outer end of the slot hole is provided with a groove, the reaction cup is extended into the slot hole so that the bottom end of the reaction cup is placed in the sample pool, and the convex portion of the reaction cup is located in the groove.

8. The magnetic bead concentration detection device according to any one of claims 1 to 7, characterized in that: The signal processing unit includes a digital voltage terminal, an analog voltage terminal, a first inductor, a third capacitor and a fourth capacitor, one end of the first inductor is connected to the digital voltage terminal, and the other end is connected to the analog voltage terminal, the third capacitor is connected between the digital voltage terminal and the ground terminal, the fourth capacitor is connected between the analog voltage terminal and the ground terminal, and the first inductor, the third capacitor and the fourth capacitor form a filtering circuit.

9. The magnetic bead concentration detection device according to any one of claims 1 to 7, characterized in that: The signal processing unit includes a signal conditioning module, the light receiving module includes a photoelectric receiving element and a first operational amplifier, one end of the photoelectric receiving element is connected to the ground end, and the other end is connected to the inverting input end of the first operational amplifier, the signal conditioning module includes a second operational amplifier, and the non-inverting input end of the second operational amplifier is connected to the output end of the first operational amplifier.

10. The magnetic bead concentration detection device according to claim 1, characterized in that: The first cavity, the sample pool and the second cavity of the detection unit are light-proof.

Images