CN214310568U - Liquid level detection system and in-vitro diagnostic apparatus - Google Patents

Abstract

The embodiment of the utility model discloses a liquid level detection system and an in-vitro diagnosis device, wherein the liquid level detection system comprises a liquid level detection module and a control module; the liquid level detection module comprises a signal generation circuit, a phase-locked loop circuit, a filter circuit and an operational amplifier circuit; the signal generating circuit is used for generating a reference signal and outputting the reference signal from an output end of the signal generating circuit; the phase-locked loop circuit is used for generating a liquid level detection signal according to the liquid level signal and the reference signal, and a second output end of the phase-locked loop circuit forms a feedback loop with a first output end of the phase-locked loop circuit through the filter circuit so as to adjust the liquid level detection signal; the control module is used for determining the liquid level state of the liquid to be detected according to the liquid level detection signal. Compared with the prior art, the embodiment of the utility model provides a technical scheme can be according to the liquid level signal that samples, through stable liquid level detected signal of phase-locked loop circuit output, effectively avoids because of detecting the phenomenon that unstable phenomenon leads to the testing result to have the error, and then has improved the accuracy that the liquid level detected.

Description

Liquid level detection system and in-vitro diagnostic apparatus

Technical Field

The embodiment of the utility model provides a relate to and detect technical field, especially relate to a liquid level detection system and external diagnostic equipment.

Background

At present, automatic detection instruments are increasingly popular with users due to the advantages of rapidness, high efficiency and the like.

The liquid level detection is an important function in an automatic detection instrument, but the liquid level detection is unstable in the prior art, so that the accuracy of a liquid level detection result is reduced.

SUMMERY OF THE UTILITY MODEL

An embodiment of the utility model provides a liquid level detection system and external diagnostic equipment to improve the accuracy that the liquid level detected.

In a first aspect, an embodiment of the present invention provides a liquid level detection system, include: the liquid level detection module and the control module; the liquid level detection module comprises a signal generation circuit, a phase-locked loop circuit, a filter circuit and an operational amplifier circuit;

the power end of the signal generating circuit is connected with a first power voltage, and the signal generating circuit is used for generating a reference signal and outputting the reference signal from the output end of the signal generating circuit; the power supply end of the phase-locked loop circuit is connected with a second power supply voltage, the input end of the phase-locked loop circuit is electrically connected with the output end of the signal generating circuit, the sampling end of the phase-locked loop circuit is used for collecting a liquid level signal, and the phase-locked loop circuit is used for generating a liquid level detection signal according to the liquid level signal and the reference signal and outputting the liquid level detection signal to the first input end of the filter circuit from the first output end of the phase-locked loop circuit;

a second input end of the filter circuit is electrically connected with a second output end of the phase-locked loop circuit, and the second output end of the phase-locked loop circuit forms a feedback loop with the first output end of the phase-locked loop circuit through the filter circuit so as to adjust the liquid level detection signal; the output end of the filter circuit is electrically connected with the input end of the operational amplifier circuit, the output end of the operational amplifier circuit is electrically connected with the control module, and the control module is used for determining the liquid level state of the liquid to be detected according to the liquid level detection signal.

Optionally, the signal generating circuit includes an oscillating circuit, a frequency dividing circuit and a first resistor, the oscillating circuit includes an oscillator, and the frequency dividing circuit includes a frequency divider;

the power supply end of the oscillator and the power supply end of the frequency divider are both connected to the first power supply voltage, the grounding end of the oscillator is grounded, and the output end of the oscillator outputs an oscillation signal; the input end of the frequency divider is electrically connected with the output end of the oscillator through the first resistor, and the output end of the frequency divider is electrically connected with the input end of the phase-locked loop circuit.

Optionally, the liquid level detection module further comprises an adjusting circuit, and the adjusting circuit comprises a digital potentiometer and a second resistor;

the power supply end of the digital potentiometer is connected to the first power supply voltage, the output end of the digital potentiometer is electrically connected with the control end of the phase-locked loop circuit through the second resistor, and the digital potentiometer is used for adjusting the static value of the phase-locked loop circuit.

Optionally, the filter circuit includes a third resistor, a fourth resistor, a first capacitor, a second capacitor, and a third capacitor;

the first end of the third resistor is electrically connected with the first output end of the phase-locked loop circuit, the second end of the third resistor is grounded through the first capacitor, and the second output end of the phase-locked loop circuit is electrically connected with the second end of the third resistor;

the first end of the fourth resistor is electrically connected with the first output end of the phase-locked loop circuit, the second end of the fourth resistor is grounded through the second capacitor, the first end of the third capacitor is electrically connected with the first output end of the phase-locked loop circuit, and the second end of the third capacitor is electrically connected with the input end of the operational amplifier circuit.

Optionally, the operational amplifier circuit includes a first operational amplifier, a second operational amplifier, a fifth resistor, a sixth resistor, and a fourth capacitor;

the non-inverting input end of the first operational amplifier is electrically connected with the output end of the filter circuit through the fifth resistor, the inverting input end of the first operational amplifier is grounded, the output end of the first operational amplifier is electrically connected with the non-inverting input end of the second operational amplifier through the sixth resistor, the inverting input end of the second operational amplifier is electrically connected with the output end of the second operational amplifier, the output end of the second operational amplifier is electrically connected with the control module, and the fourth capacitor is connected between the output end of the first operational amplifier and the inverting input end of the first operational amplifier.

Optionally, the phase-locked loop circuit includes a phase-locked loop control chip and a fifth capacitor;

the power end of the phase-locked loop control chip is connected with the first power voltage, the first sampling end of the phase-locked loop control chip is used for sampling the liquid level signal, the second sampling end of the phase-locked loop control chip is electrically connected with the first end of the fifth capacitor, the second end of the fifth capacitor is electrically connected with the first sampling end of the phase-locked loop control chip, the input end of the phase-locked loop control chip is electrically connected with the output end of the signal generating circuit, the first output end of the phase-locked loop control chip is electrically connected with the first input end of the filter circuit, and the second output end of the phase-locked loop control chip is electrically connected with the second input end of the filter circuit.

In a second aspect, an embodiment of the present invention further provides an in vitro diagnostic apparatus, which includes the liquid level detection system provided in any embodiment of the present invention, the in vitro diagnostic apparatus further includes a probe assembly, a liquid level detection plate and a mounting plate, the probe assembly includes a probe, a swab and a slider, and the probe is electrically connected to the liquid level detection system; the liquid level detection plate is fixedly connected with the mounting plate, and the liquid level detection system is arranged on the liquid level detection plate;

the swab set up in on the mounting panel, and be located the below of probe with the probe sets up relatively, the probe with slider fixed connection, the slider is used for driving through the slide rail the probe is in move in the swab.

Optionally, the swab comprises an inner bore, a liquid inlet and a liquid outlet, which are in communication with each other.

Optionally, the in vitro diagnostic apparatus further comprises a liquid path module, the liquid path module is respectively connected with the liquid inlet hole and the liquid outlet hole of the swab, and the liquid path module is used for cleaning the probe.

Optionally, the liquid path module includes a first switch valve, a second switch valve, a third switch valve, a fourth switch valve, a first pump, a second pump and a third pump;

the first switch valve is connected with a liquid suction end of the first pump, the first pump is used for pumping cleaning liquid through the first switch valve, one end of the second switch valve is connected with the liquid suction end of the first pump, the other end of the second switch valve is connected with the liquid suction end of the second pump, and a liquid discharge end of the second pump is connected with the inner wall of the probe;

one end of the third switch valve is connected with the liquid suction end of the first pump, the other end of the third switch valve is connected with the liquid inlet hole of the swab, and the liquid outlet hole of the swab is connected with the third pump through the fourth switch valve.

The embodiment of the utility model provides a technical scheme produces the reference signal through the signal generation circuit to with reference signal input to phase-locked loop circuit's first input, phase-locked loop circuit is according to received reference signal and the liquid level signal output liquid level detected signal who gathers, liquid level detected signal through the filtering, enlarge the back and input to control module, control module confirms the liquid level state of the liquid that awaits measuring according to received liquid level detected signal. Compared with the prior art, the embodiment of the utility model provides a technical scheme can be according to the liquid level signal that samples, through stable liquid level detected signal of phase-locked loop circuit output, effectively avoids because of detecting the phenomenon that unstable phenomenon leads to the testing result to have the error, and then has improved the accuracy that the liquid level detected.

Drawings

Fig. 1 is a schematic structural diagram of a liquid level detection system according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of another liquid level detection system according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of another liquid level detection system according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of another liquid level detection system according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of another liquid level detection system according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of an in vitro diagnostic apparatus according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of an in vitro diagnostic apparatus according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a liquid path module according to an embodiment of the present invention;

fig. 9 is a schematic cross-sectional view illustrating a swab according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Fig. 1 is a schematic structural diagram of a liquid level detection system provided in an embodiment of the present invention, and referring to fig. 1, the liquid level detection system provided in an embodiment of the present invention includes a liquid level detection module 10 and a control module 20; the liquid level detection module 10 comprises a signal generation circuit 110, a phase-locked loop circuit 120, a filter circuit 130 and an operational amplifier circuit 140; a power supply terminal A1 of the signal generating circuit 110 is connected to a first power supply voltage VDD1, and the signal generating circuit 110 is used for generating a reference signal VREF and outputting the reference signal VREF from an output terminal A2; a power supply terminal B1 of the phase-locked loop circuit 120 is connected to a second power supply voltage VDD2, an input terminal B2 of the phase-locked loop circuit 120 is electrically connected to an output terminal a2 of the signal generating circuit 110, a sampling terminal B3 of the phase-locked loop circuit 120 is used for acquiring a liquid level signal VCS, and the phase-locked loop circuit 120 is used for generating a liquid level detection signal VCKS according to the liquid level signal VCS and a reference signal VREF and outputting the liquid level detection signal VCKS from a first output terminal B4 to a first input terminal E1 of the filter circuit 130; the second input end E2 of the filter circuit 130 is electrically connected to the second output end B5 of the phase-locked loop circuit 120, and the second output end B5 of the phase-locked loop circuit 120 forms a feedback loop with the first output end B4 of the phase-locked loop circuit 120 through the filter circuit 130 to adjust the liquid level detection signal VCKS; the output end E3 of the filter circuit 130 is electrically connected to the input end F1 of the operational amplifier circuit 140, the output end F2 of the operational amplifier circuit 140 is electrically connected to the control module 20, and the control module 20 is configured to determine the liquid level state of the liquid to be detected according to the liquid level detection signal VCKS.

Specifically, the first power voltage VDD1 and the second power voltage VDD2 are both provided by a power module (not shown) to provide power voltages for the liquid level detection module 10 and the control module 20. The signal generating circuit 110 can automatically generate a reference signal VRFE and input the reference signal VREF to the input terminal B2 of the pll circuit 120, and the sampling terminal B3 of the pll circuit can collect a liquid level signal VCS of the liquid to be measured, wherein the liquid level signal VCS can be a pulse signal reflecting capacitance. For example, the sampling end B3 of the pll circuit 120 may be connected to a probe, the probe is used to contact with the liquid to be measured, and the probe is made of a metal material, and the probe can form a spatially distributed capacitance with a spatial environment, so that when the probe contacts with the liquid to be measured, the spatially distributed capacitance is increased, and the pulse width of the liquid level signal VCS becomes larger. The phase-locked loop circuit 120 compares the sampled liquid level signal VCS with the reference signal VREF generated by the signal generation circuit 110, the frequency of the reference signal VREF is used for synchronously adjusting the collected liquid level signal VCS, a feedback loop is formed by a first output end B4 and a second output end B5 of the phase-locked loop circuit 120, the output liquid level detection signal VCKS can be adjusted in a self-adaptive mode, so that the liquid level detection signal VCKS is a stable direct-current voltage signal, the adjusted output liquid level detection signal VCKS is output to the control module 20 after passing through the filter circuit 130 and the operational amplifier circuit 140, and the control module 20 determines the contact state of the probe and the liquid level of the liquid to be detected according to the received liquid level detection signal VCKS. For example, the control module 20 may determine the liquid level state of the liquid to be measured according to the magnitude relationship between the received liquid level detection signal VCKS and the preset voltage value. When the probe does not contact the liquid level of the liquid to be detected, the level value of the liquid level signal VCS is low, the phase-locked loop circuit 120 compares the reference signal VREF with the liquid level signal VCS and outputs a liquid level detection signal VCKS, at this time, the liquid level detection signal VCKS is smaller than a preset voltage value stored in the control module 20, and the control module 20 determines that the probe does not contact the liquid level of the liquid to be detected. When the probe touches the liquid surface of the liquid to be detected, the capacitance formed between the probe and the liquid is increased, so that the level value of the liquid level signal VCS is increased, the phase-locked loop circuit 120 compares the reference signal VREF with the liquid level signal VCS and then outputs a liquid level detection signal VCKS, at this time, the liquid level detection signal VCKS is greater than a preset voltage value stored in the control module 20, and the control module 20 determines that the probe touches the liquid level of the liquid to be detected. Since the level detection signal VCKS is a stable dc voltage signal output by the phase-locked loop circuit 120 after the comparison between the reference signal VREF and the level signal VCS, the accuracy of the control module 20 in determining the level of the liquid to be measured can be increased.

The embodiment of the utility model provides a technical scheme produces the reference signal through the signal generation circuit to with reference signal input to phase-locked loop circuit's first input, phase-locked loop circuit is according to received reference signal and the liquid level signal output liquid level detected signal who gathers, liquid level detected signal through the filtering, enlarge the back and input to control module, control module confirms the liquid level state of the liquid that awaits measuring according to received liquid level detected signal. Compared with the prior art, the embodiment of the utility model provides a technical scheme can be according to the liquid level signal that samples, through stable liquid level detected signal of phase-locked loop circuit output, effectively avoids because of detecting the phenomenon that unstable phenomenon leads to the testing result to have the error, and then has improved the accuracy that the liquid level detected.

Optionally, fig. 2 is a schematic structural diagram of another liquid level detection system according to an embodiment of the present invention, and with reference to fig. 2, on the basis of the foregoing technical solutions, the signal generating circuit 110 includes an oscillating circuit 111, a frequency dividing circuit 112 and a first resistor R1, the oscillating circuit 111 includes an oscillator U1, and the frequency dividing circuit 112 includes a frequency divider U2; a power supply terminal b of the oscillator U1 and a power supply terminal f of the frequency divider U2 are both connected to a first power supply voltage VDD1, a ground terminal c of the oscillator U1 is grounded, and an output terminal d of the oscillator U1 outputs an oscillation signal; the input terminal e of the frequency divider U2 is electrically connected to the output terminal d of the oscillator U1 through a first resistor R1, and the output terminal g of the frequency divider U2 is electrically connected to the input terminal B2 of the phase-locked loop circuit 120.

Specifically, the oscillator U1 and the frequency divider U2 are both in the form of a chip, the oscillator U1 may be a crystal oscillator, the oscillator U1 generates an oscillation signal under the action of the first power voltage VDD1, the frequency divider U2 divides the frequency of the received oscillation signal to obtain a reference signal VREF, and the divided reference signal VREF is input to the input terminal B2 of the phase-locked loop circuit 120. For example, the oscillator U1 generates an oscillating signal with a frequency of 6M, and the frequency divider U2 divides the oscillating signal of 6M by sixteen to reduce the input speed of the first input terminal B2 of the phase-locked loop circuit 120, so that the phase-locked loop circuit 102 and the control module can respond to the reference signal VREF better.

Optionally, fig. 3 is a schematic structural diagram of another liquid level detection system according to an embodiment of the present invention, and referring to fig. 3, on the basis of the foregoing technical solutions, the phase-locked loop circuit 120 includes a phase-locked loop control chip U4 and a fifth capacitor C5; a power end j of the phase-locked loop control chip U4 is connected to the first power voltage VDD1, a first sampling end n of the phase-locked loop control chip U4 is used for sampling the liquid level signal VCS, a second sampling end m of the phase-locked loop control chip U4 is electrically connected to a first end of the fifth capacitor C5, a second end of the fifth capacitor C5 is electrically connected to a first sampling end n of the phase-locked loop control chip U4, an input end k of the phase-locked loop control chip U4 is electrically connected to an output end a2 of the signal generation circuit 110, a first output end o1 of the phase-locked loop control chip U4 is connected to a first input end E1 of the filter circuit 130, and a second output end o2 of the phase-locked loop control chip U4 is electrically connected to a second input end E2 of the filter circuit 130.

Specifically, the phase-locked loop control chip U4 may be a CD4046, and the phase-locked loop control chip U4 is configured to convert the capacitance level signal VCS into a voltage level detection signal VCKS. The fifth capacitor C5 is connected between the first sampling terminal n and the second sampling terminal m of the pll control chip U4, wherein the fifth capacitor C5 is a parasitic capacitor of the pll control chip U4, and is used for configuring a quiescent operating point of the pll control chip U4.

Further, with continued reference to fig. 3, the liquid level detection module 10 further includes an adjustment circuit 150, the adjustment circuit 150 including a digital potentiometer U3 and a second resistor R2; the power supply terminal h of the digital potentiometer U3 is connected to a first power supply voltage VDD1, the output terminal i of the digital potentiometer is electrically connected to the control terminal B6 of the PLL circuit 120 through a second resistor R2, and the digital potentiometer U3 is used for adjusting the static value of the PLL circuit 120.

Specifically, the digital potentiometer U3 is connected to the control end p of the digital potentiometer U3 phase-locked loop control chip U4 through the second resistor R2, and is matched with the fifth capacitor C5, so that the function of adjusting the static working point of the phase-locked loop control chip U4 is achieved, and the accuracy of liquid level detection is improved beneficially by adjusting the static working point of the phase-locked loop control chip U4. Illustratively, the second power voltage VDD2 is 9V, the initial static operating point of the pll control chip U4 is 7V, when the probe touches the liquid level of the liquid to be measured, the level of the liquid level signal VCS is 8V, and the difference between the liquid level signal VCS and the static operating point of the pll control chip U4 is 1V, which is not beneficial to identifying the liquid level signal VCS; therefore, the static operating point of the phase-locked loop control chip U4 can be adjusted to 1V through the digital potentiometer U3, the difference between the liquid level signal and the static operating point of the phase-locked loop control chip U4 is 7V, the signal identification is facilitated, and the improvement of the sensitivity of the liquid level detection system is facilitated.

Optionally, fig. 4 is a schematic structural diagram of another liquid level detection system according to an embodiment of the present invention, where fig. 4 specifically shows specific structures of the filter circuit 130 and the operational amplifier circuit 140, and referring to fig. 3 and fig. 4, on the basis of the above technical solutions, the filter circuit 130 includes a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2, and a third capacitor C3; a first end of the third resistor R3 is electrically connected to the first output end B4 of the pll circuit 120, a second end of the third resistor R3 is grounded via the first capacitor C1, and the second output end B5 of the pll circuit 120 is electrically connected to the second end of the third resistor R3; a first end of the fourth resistor R4 is electrically connected to the first output terminal B4 of the pll circuit 120, a second end of the fourth resistor R4 is grounded via the second capacitor C2, a first end of the third capacitor C3 is electrically connected to the first output terminal B4 of the pll circuit 120, and a second end of the third capacitor C3 is electrically connected to the input terminal F1 of the op-amp circuit 140.

The operational amplifier circuit 140 includes a first operational amplifier OP1, a second operational amplifier OP2, a fifth resistor R5, a sixth resistor R6 and a fourth capacitor C4; the non-inverting input terminal of the first operational amplifier OP1 is electrically connected to the output terminal E3 of the filter circuit 130 through a fifth resistor R5, the inverting input terminal of the first operational amplifier OP1 is grounded, the output terminal of the first operational amplifier OP1 is electrically connected to the non-inverting input terminal of the second operational amplifier OP2 through a sixth resistor R6, the inverting input terminal of the second operational amplifier OP2 is electrically connected to the output terminal of the second operational amplifier OP2, the output terminal of the second operational amplifier OP2 is electrically connected to the control module 20, and the fourth capacitor C4 is connected between the output terminal of the first operational amplifier OP1 and the inverting input terminal of the first operational amplifier OP 1.

Specifically, the third resistor R3, the fourth resistor R4, the first capacitor C1, the second capacitor C2 and the third capacitor C3 form an RC filter network for filtering the liquid level detection signal VCKS. When the probe connected with the first sampling end n of the phase-locked loop control chip U4 does not touch the liquid level of the liquid to be detected, the liquid level signal VCS acquired by the phase-locked loop control chip U4 is 3.5V, and when the probe touches the liquid level of the liquid to be detected, the frequency of the acquired signal becomes lower due to the increase of the spatially distributed capacitance formed between the probe and the liquid to be detected, so the liquid level signal VCS becomes higher, for example, 8V, when the probe touches the liquid level, the liquid level signal VCS jumps from 3.5V to 8V, and the control module 20 recognizes that the liquid level signal VCS has 4.5V jump. Third electric capacity C3 connects the voltage of the one end of fifth resistance R5 then for 4.5V, first operational amplifier OP1 is used for the amplification function, amplifies 4.5V's liquid level detection signal VCKS, and second operational amplifier OP2 is as following the function, with the stability of guaranteeing liquid level detection signal VCKS, control module 20 confirms the liquid level that the probe touched the liquid that awaits measuring according to received liquid level detection signal VCKS, for prior art, the embodiment of the utility model provides a technical scheme can be fast, stable, accurate detection liquid level state of the liquid that awaits measuring.

Fig. 5 is a schematic structural diagram of another liquid level detection system provided by the embodiment of the present invention, and the circuit structure shown in fig. 5 specifically illustrates the working principle of the liquid level detection system provided by the embodiment of the present invention. The oscillator U1 is a crystal oscillator, and its pin a is connected to the first power voltage VDD1 through a seventh resistor R7, and in other embodiments, the pin a may be floating. The oscillator U1 generates an oscillation signal under the action of the first power voltage VDD1, the seventh capacitor C7 is configured to filter the oscillation signal, the oscillation signal is buffered by the first resistor R1 and then input to the frequency divider U2, the frequency divider U2 divides the frequency of the received oscillation signal to obtain a reference signal VREF, and the divided reference signal VREF is input to the input terminal B2 of the phase-locked loop circuit 120. The pll control chip U4 may be a CD4046, and the pll control chip U4 is configured to convert the capacitance level signal VCS into a voltage level detection signal VCKS. The fifth capacitor C5 is connected between the first sampling terminal n and the second sampling terminal m of the pll control chip U4, wherein the fifth capacitor C5 is a parasitic capacitor of the pll control chip U4, and is used for configuring a quiescent operating point of the pll control chip U4. The digital potentiometer U3 is connected to the control end p of the digital potentiometer U3 phase-locked loop control chip U4 through the second resistor R2 and is matched with the fifth capacitor C5, the function of adjusting the static working point of the phase-locked loop control chip U4 is achieved, and the improvement of the liquid level detection precision is facilitated by adjusting the static working point of the phase-locked loop control chip U4. Illustratively, the second power voltage VDD2 is 9V, the initial static operating point of the pll control chip U4 is 7V, when the probe touches the liquid level of the liquid to be measured, the level of the liquid level signal VCS is 8V, and the difference between the liquid level signal VCS and the static operating point of the pll control chip U4 is 1V, which is not beneficial to identifying the liquid level signal VCS; therefore, the static operating point of the phase-locked loop control chip U4 can be adjusted to 1V through the digital potentiometer U3, the difference between the liquid level signal and the static operating point of the phase-locked loop control chip U4 is 7V, the signal identification is facilitated, and the improvement of the sensitivity of the liquid level detection system is facilitated. The third resistor R3, the fourth resistor R4, the first capacitor C1, the second capacitor C2, the third capacitor C3 and the eighth capacitor C8 form an RC filter network for filtering the liquid level detection signal VCKS. When the probe connected with the first sampling end n of the phase-locked loop control chip U4 does not touch the liquid level of the liquid to be detected, the liquid level signal VCS acquired by the phase-locked loop control chip U4 is 3.5V, and when the probe touches the liquid level of the liquid to be detected, the frequency of the acquired signal becomes lower due to the increase of the spatially distributed capacitance formed between the probe and the liquid to be detected, so the liquid level signal VCS becomes higher, for example, 8V, when the probe touches the liquid level, the liquid level signal VCS jumps from 3.5V to 8V, and the control module 20 recognizes that the liquid level signal VCS has 4.5V jump. The voltage of one end of the third capacitor C3, which is connected with the fifth resistor R5, is 4.5V, the first operational amplifier OP1 and the peripheral accessory elements thereof jointly form an amplifying circuit for amplifying the 4.5V liquid level detection signal VCKS, the second operational amplifier OP2 and the sixth resistor R6 form a following circuit to ensure the stability of the liquid level detection signal VCKS, and the twelfth resistor, the thirteenth resistor, the voltage regulator tube D1 and the tenth capacitor jointly form an output circuit for outputting a stable direct current voltage signal (the liquid level detection signal VCKS). The operational amplifier circuit 140, the signal generating circuit 110, the phase-locked loop circuit 120, and the filter circuit 130 do not share the same ground network, which is beneficial to independent transmission between signals and prevents interference. Control module 20 confirms the liquid level that the probe touched the liquid that awaits measuring according to received liquid level detection signal VCKS, for prior art, the embodiment of the utility model provides a technical scheme can be quick, stable, accurate detection liquid level state of awaiting measuring liquid.

Optionally, the embodiment of the utility model provides an in vitro diagnostic equipment is still provided, include the utility model discloses the liquid level detecting system that arbitrary embodiment provided. Fig. 6 is a schematic structural diagram of an in vitro diagnostic apparatus provided by an embodiment of the present invention, the in vitro diagnostic apparatus provided by an embodiment of the present invention includes the liquid level detection system provided by any embodiment of the present invention, referring to fig. 6, on the basis of the above technical solutions, the in vitro diagnostic apparatus further includes a probe assembly, a liquid level detection plate 4 and a mounting plate 1, the probe assembly includes a probe 5, a swab 7 and a slider 2, the probe 5 is electrically connected with the liquid level detection system; the liquid level detection plate 4 is fixedly connected with the mounting plate 1, and the liquid level detection system is arranged on the liquid level detection plate 4; swab 7 sets up on mounting panel 1, and is located the below of probe 5 and sets up with probe 5 relatively, probe 5 and slider 2 fixed connection, and slider 2 is arranged in driving probe 5 through slide rail 3 and removes in swab 7.

Specifically, the embodiment of the utility model provides an in vitro diagnostic equipment can be automatic detection instrument, like medical external diagnostic instrument, arouses the cross contamination of the liquid that awaits measuring because of adnexed reagent or other liquid in order to reduce probe 5, needs the depth that the strict control probe inserted the liquid that awaits measuring to the liquid level of liquid that awaits measuring needs accurate detection. The liquid level detection system composed of the liquid level detection module 10 and the control module 20 is arranged on the liquid level detection plate 4, and the probe 5 is electrically connected with the sampling end B3 of the phase-locked loop circuit 120 in the liquid level detection module 10 through a lead. The mounting panel 1 is the supporting component of external diagnostic equipment, and the top of mounting panel 1 is provided with the lead screw motor, and probe 5 and slider 2 fixed connection, lead screw motor drive slider 2 reciprocate on slide rail 3 to make probe 5 can reciprocate. The swab 7 is provided at the bottom of the mounting plate 1 and is provided opposite to the probe 5 so that the probe 5 can penetrate the swab 7 to detect the liquid level of the liquid to be measured when moving up and down. When the probe 5 penetrates through the swab 7 and touches the liquid level of the liquid to be detected, the liquid level detection module 10 detects that the liquid level signal VCS jumps, the phase-locked loop circuit 120 generates a liquid level detection signal VCKS according to the liquid level signal VCS and the reference signal VREF, and the liquid level detection signal VCKS is filtered, amplified and then sent to the control module 20 for processing and analysis.

After the in-vitro diagnostic equipment detects a liquid to be detected, the probe 5 needs to be cleaned, but the cleaning solution for cleaning the probe 5 has different formulations, which causes different ion concentrations of the cleaning solution, so that the capacitance value of the probe to the ground is changed, and the accuracy of the liquid level detection result is affected. The embodiment of the utility model provides an external diagnostic equipment still includes the liquid way module for wash the probe. Fig. 7 is a schematic structural diagram of an in vitro diagnostic apparatus provided by the embodiment of the present invention, fig. 8 is a schematic structural diagram of a liquid path module provided by the embodiment of the present invention, fig. 9 is a schematic sectional structural diagram of a swab provided by the embodiment of the present invention, refer to fig. 5-9, and the embodiment of the present invention provides an in vitro diagnostic apparatus having the following concrete working principle:

before the liquid level detection of the liquid to be detected is performed, the probes 5 in the probe assembly 30 are cleaned by the liquid path module 40. Referring to fig. 8, the fluid circuit block 40 includes a first switching valve SV1, a second switching valve SV2, a third switching valve SV3, a fourth switching valve SV4, a first pump PL1, a second pump PL2, and a third pump PL 3; the first switch valve SV1 is connected with a liquid suction end of a first pump PL1, the first pump PL1 is used for pumping cleaning liquid through the first switch valve SV1, one end of a second switch valve SV2 is connected with a liquid suction end of the first pump PL1, the other end of the second switch valve SV2 is connected with a liquid suction end of the second pump PL2, and a liquid discharge end of the second pump PL2 is connected with the inner wall of the probe 5; one end of the third switch valve SV3 is connected to the suction end of the first pump PL1, the other end of the third switch valve SV3 is connected to the liquid inlet Q1 of the swab 7, and the liquid outlet Q2 of the swab 7 is connected to the third pump PL3 via the fourth switch valve SV 4. The first pump PL1 and the second pump PL2 are plunger pumps for pumping a fixed amount of the cleaning liquid, and the third pump PL3 is a gas-liquid mixing pump for sucking the waste liquid generated after the probe 5 is cleaned. The liquid path module 40 is connected with the swab 7 through a pipeline, as shown in fig. 9, the swab 7 comprises an inner hole Q3, a liquid inlet hole Q1 and a liquid outlet hole Q2 which are communicated with each other, and the probe 5 moves up and down in the inner hole Q3 of the swab 7 under the driving of the sliding block 2. Because probe 5 is used for absorbing the liquid to be measured to liquid level detection information feedback to liquid level detection module 10, consequently, probe 5 is the hollow structure including inner wall and outer wall, carries out the cleaning process to probe 5, opens first ooff valve SV1, and first pump machine PL1 absorbs quantitative washing liquid for use. When the inner wall of the probe 5 is cleaned, the first switch valve SV1 is closed, the second switch valve SV2 is opened, the first pump PL1 pushes liquid, the second pump PL2 sucks liquid, cleaning liquid in the first pump PL1 is fed into the inner hole of the probe 5, the probe 5 moves upwards to the liquid outlet hole Q2 of the swab 7, the cleaning liquid in the probe 5 flows into the inner hole Q3 of the swab 7, the fourth switch valve SV4 is opened, and the third pump PL3 extracts the cleaned waste liquid, so that the cleaning liquid does not remain on the inner wall of the swab, and the cleaning liquid is prevented from affecting the liquid level detection result.

When the outer wall of the probe 5 is cleaned, the first switch valve SV1 and the second switch valve SV2 are closed, the third switch valve SV3 is opened, the first pump PL1 pushes cleaning liquid into the liquid inlet hole Q1 of the swab, the probe 5 is controlled to move up and down in the swab 7, the effect of cleaning the outer wall of the probe 5 is achieved, meanwhile, the fourth switch valve SV4 is opened, and the third pump PL3 extracts the cleaned waste liquid, so that no cleaning liquid is left on the outer wall of the swab. Through the inter combination of liquid way module 40 and swab 7, wash the inner wall and the outer wall of probe 5, liquid way module 40 can also be with the waste liquid drainage after wasing simultaneously, prevents to remain the washing liquid on the probe 5, detects for the liquid level and provides good external environment, consequently, probe 5 can not form electric capacity through the liquid that awaits measuring and other impurity medium, has improved liquid level detection precision. For example, when the probe does not touch the liquid level of the liquid to be measured, the liquid level signal VCS collected by the phase-locked loop control chip U4 should be 3.5V, but due to impurities on the probe 5, the capacitance formed between the probe 5 and the environment is increased, and further the level amount of the liquid level signal VCS collected by the phase-locked loop control chip U4 is increased, for example, to 5V, when the probe touches the liquid level of the liquid to be measured, the liquid level signal VCS jumps from 5V to 8V, the jump amount is 3V, and is smaller than the jump amount from 3.5V to 8V, so the control module 20 determines that the probe 5 does not touch the liquid level at this time, and thus the depth of the probe 5 inserted into the liquid to be measured is large, and the liquid to be measured is cross-contaminated.

Therefore, the embodiment of the utility model provides a technical scheme can be high-efficient, quick, accurate, stable carry out the liquid level and detect, through the inter combination of liquid way module and swab, wash the inner wall and the outer wall of probe, liquid way module can also be with the waste liquid drainage after wasing simultaneously, prevents to remain the washing liquid on the probe, provides good external environment for the liquid level detects to, the probe can not form electric capacity through the liquid that awaits measuring and other impurity medium, has improved liquid level detection precision.

As another optional implementation manner of the embodiment of the present invention, with continuing reference to fig. 6, the in vitro diagnostic apparatus further includes an elastic sheet 6, the elastic sheet 6 is disposed on the mounting plate 1, and the swab 7 is fixedly mounted on the mounting plate 1 through the elastic sheet 6. Wherein, shell fragment 6 plays the effect of buffering swab 7, drives the in-process of 2 up-and-down motion of slider at the lead screw motor, makes swab 7 take place to shake through shell fragment 6 to the vibratory stress that release swab 7 received can effectually prevent that the washing liquid from remaining inside swab 7, thereby is favorable to improving the precision that the liquid level detected.

It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.

Claims (10)

1. A liquid level detection system, comprising: the liquid level detection module and the control module; the liquid level detection module comprises a signal generation circuit, a phase-locked loop circuit, a filter circuit and an operational amplifier circuit;

the power end of the signal generating circuit is connected with a first power voltage, and the signal generating circuit is used for generating a reference signal and outputting the reference signal from the output end of the signal generating circuit; the power supply end of the phase-locked loop circuit is connected with a second power supply voltage, the input end of the phase-locked loop circuit is electrically connected with the output end of the signal generating circuit, the sampling end of the phase-locked loop circuit is used for collecting a liquid level signal, and the phase-locked loop circuit is used for generating a liquid level detection signal according to the liquid level signal and the reference signal and outputting the liquid level detection signal to the first input end of the filter circuit from the first output end of the phase-locked loop circuit;

a second input end of the filter circuit is electrically connected with a second output end of the phase-locked loop circuit, and the second output end of the phase-locked loop circuit forms a feedback loop with the first output end of the phase-locked loop circuit through the filter circuit so as to adjust the liquid level detection signal; the output end of the filter circuit is electrically connected with the input end of the operational amplifier circuit, the output end of the operational amplifier circuit is electrically connected with the control module, and the control module is used for determining the liquid level state of the liquid to be detected according to the liquid level detection signal.

2. The fluid level detection system of claim 1, wherein the signal generation circuit comprises an oscillation circuit, a frequency dividing circuit, and a first resistor, the oscillation circuit comprising an oscillator, the frequency dividing circuit comprising a frequency divider;

the power supply end of the oscillator and the power supply end of the frequency divider are both connected to the first power supply voltage, the grounding end of the oscillator is grounded, and the output end of the oscillator outputs an oscillation signal; the input end of the frequency divider is electrically connected with the output end of the oscillator through the first resistor, and the output end of the frequency divider is electrically connected with the input end of the phase-locked loop circuit.

3. The fluid level detection system of claim 1, wherein the fluid level detection module further comprises an adjustment circuit comprising a digital potentiometer and a second resistor;

the power supply end of the digital potentiometer is connected to the first power supply voltage, the output end of the digital potentiometer is electrically connected with the control end of the phase-locked loop circuit through the second resistor, and the digital potentiometer is used for adjusting the static value of the phase-locked loop circuit.

4. The fluid level detection system of claim 1, wherein the filter circuit comprises a third resistor, a fourth resistor, a first capacitor, a second capacitor, and a third capacitor;

the first end of the third resistor is electrically connected with the first output end of the phase-locked loop circuit, the second end of the third resistor is grounded through the first capacitor, and the second output end of the phase-locked loop circuit is electrically connected with the second end of the third resistor;

the first end of the fourth resistor is electrically connected with the first output end of the phase-locked loop circuit, the second end of the fourth resistor is grounded through the second capacitor, the first end of the third capacitor is electrically connected with the first output end of the phase-locked loop circuit, and the second end of the third capacitor is electrically connected with the input end of the operational amplifier circuit.

5. The fluid level detection system of claim 1, wherein the op-amp circuit comprises a first operational amplifier, a second operational amplifier, a fifth resistor, a sixth resistor, and a fourth capacitor;

the non-inverting input end of the first operational amplifier is electrically connected with the output end of the filter circuit through the fifth resistor, the inverting input end of the first operational amplifier is grounded, the output end of the first operational amplifier is electrically connected with the non-inverting input end of the second operational amplifier through the sixth resistor, the inverting input end of the second operational amplifier is electrically connected with the output end of the second operational amplifier, the output end of the second operational amplifier is electrically connected with the control module, and the fourth capacitor is connected between the output end of the first operational amplifier and the inverting input end of the first operational amplifier.

6. The fluid level detection system of claim 1, wherein the phase locked loop circuit comprises a phase locked loop control chip and a fifth capacitor;

the power end of the phase-locked loop control chip is connected with the first power voltage, the first sampling end of the phase-locked loop control chip is used for sampling the liquid level signal, the second sampling end of the phase-locked loop control chip is electrically connected with the first end of the fifth capacitor, the second end of the fifth capacitor is electrically connected with the first sampling end of the phase-locked loop control chip, the input end of the phase-locked loop control chip is electrically connected with the output end of the signal generating circuit, the first output end of the phase-locked loop control chip is electrically connected with the first input end of the filter circuit, and the second output end of the phase-locked loop control chip is electrically connected with the second input end of the filter circuit.

7. An in vitro diagnostic apparatus comprising the liquid level detection system according to any one of claims 1 to 6;

the in-vitro diagnostic equipment also comprises a probe assembly, a liquid level detection plate and a mounting plate, wherein the probe assembly comprises a probe, a swab and a sliding block, and the probe is electrically connected with the liquid level detection system; the liquid level detection plate is fixedly connected with the mounting plate, and the liquid level detection system is arranged on the liquid level detection plate;

the swab set up in on the mounting panel, and be located the below of probe with the probe sets up relatively, the probe with slider fixed connection, the slider is used for driving through the slide rail the probe is in move in the swab.

8. The in vitro diagnostic apparatus of claim 7, wherein the swab comprises an inner bore, an inlet bore, and an outlet bore in communication with one another.

9. The in vitro diagnostic apparatus according to claim 8, further comprising a liquid path module connected to the liquid inlet and outlet holes of the swab, respectively, for cleaning the probe.

10. The in vitro diagnostic apparatus of claim 9, wherein the fluid circuit module comprises a first switch valve, a second switch valve, a third switch valve, a fourth switch valve, a first pump, a second pump, and a third pump;

the first switch valve is connected with a liquid suction end of the first pump, the first pump is used for pumping cleaning liquid through the first switch valve, one end of the second switch valve is connected with the liquid suction end of the first pump, the other end of the second switch valve is connected with the liquid suction end of the second pump, and a liquid discharge end of the second pump is connected with the inner wall of the probe;

one end of the third switch valve is connected with the liquid suction end of the first pump, the other end of the third switch valve is connected with the liquid inlet hole of the swab, and the liquid outlet hole of the swab is connected with the third pump through the fourth switch valve.

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