Sample sampling method

Abstract

Disclosed is a sample sampling method, comprising the following steps: acquiring a first number of steps when a pipette triggers an empty suction alarm signal; comparing the first number of steps with a second number of steps and a third number of steps; on the basis of the comparison result of the number of steps of descending, treating a blood film or / and bubble by using different methods; and performing a sampling operation on a sample in which the blood film or / and bubble has been treated. According to the present invention, the first number of steps of the pipette descending when the blood film or / and bubble appears can be determined on the basis of the empty suction alarm signal. Since the amount of the sample in a test tube corresponding to a blood film or / and a bubble appearing at different positions is different, according to the present invention, the first number of steps is compared with the second number of steps and the third number of steps, and, on the basis of the comparison result, different treatment methods are used for blood films or / and bubbles at different positions, thereby automatically treating blood films or / and bubbles in the sample, avoiding the phenomenon of invalid empty suction, and improving the accuracy of sample sampling.

Description

A sample sampling method Technical Field

[0001] This invention relates to the field of in vitro diagnostic technology, and more specifically to a sample collection method. Background Technology

[0002] In the application of sample analysis and testing instruments, pipettes are needed to automatically sample samples from test tubes. During the sampling process, a pressure sensor on the pipette detects the pressure change in its chamber to determine whether the pipette has descended to the specified liquid level. Then, a specified volume of sample is drawn and injected into the reaction vessel. The sampling accuracy directly affects the subsequent measurement results.

[0003] In practice, it was found that whole blood in a test tube will produce a blood film and / or air bubbles after being shaken. When the pipette comes into contact with the blood film and / or air bubbles during its descent, the liquid level detection based on pressure changes will trigger an alarm signal in advance. The pipette will start to aspirate before reaching the designated liquid level, resulting in a sample volume that is less than expected or even empty aspiration, which seriously affects the progress of subsequent tasks and reduces the sampling accuracy. Technical issues

[0004] This invention discloses a sample collection method to solve the problem that blood films or air bubbles in samples affect the sampling accuracy in the prior art. Technical solutions

[0005] A sample collection method includes the following steps:

[0006] Obtain the first step number when the pipette triggers the empty aspiration alarm signal;

[0007] Compare the number of the first step with the number of the second step and the number of the third step;

[0008] Different methods are used to treat the blood film and / or air bubbles based on the comparison results of the number of descent steps;

[0009] Sampling operations are performed on samples after blood film and / or bubble treatment;

[0010] Specifically, the initial position of the pipette in standby mode is set as the origin, and the initial position of the pipette descending into the test tube to begin liquid level detection is set as the first position; the upper limit position of the sample volume in the test tube is set as the second position, and the lower limit position is set as the third position; the number of steps for the pipette to descend from the origin to the second position is set as the second step, and the number of steps for the pipette to descend to the third position is set as the third step; the number of steps relative to the origin for the position where the pipette triggers the empty suction alarm signal when descending from the first position to perform liquid level detection is set as the first step.

[0011] Furthermore, based on the comparison results of the number of descent steps, different methods are used to treat the blood film and / or bubbles, including the following steps:

[0012] When the number of steps in the first step is less than the number of steps in the third step, the blood film and / or air bubbles are broken using a pipette.

[0013] When the number of steps in the first step is greater than the number of steps in the third step, control the pipette to descend below the blood film and / or air bubbles, avoiding the blood film and / or air bubbles.

[0014] Furthermore, when the number of steps in the first step is less than the number of steps in the third step, the blood film and / or air bubbles are broken using a pipette, including the following steps:

[0015] When the number of steps in the first step is greater than the number of steps in the second step but less than the number of steps in the third step, the pipette is moved up and down to break the blood film and / or air bubbles.

[0016] When the number of steps in the first step is less than the number of steps in the second step, the pipette is moved up and down after the empty aspiration operation to break the blood film and / or air bubbles.

[0017] Furthermore, the distance between the lowest position of the pipette during the membrane breaking operation and the first position is not greater than the length of the sampling device on the pipette.

[0018] Furthermore, the number of steps required for the pipette to descend to its lowest position is greater than the number of steps required for the third step.

[0019] Furthermore, the highest position the pipette can move up and down during the membrane breaking operation is set according to the overall sampling time allocated for the detection items.

[0020] Furthermore, the total time for the membrane breaking operation and the air suction operation does not exceed the overall sampling time.

[0021] Furthermore, sampling is performed on the blood film and / or the sample after bubble treatment, including the following steps:

[0022] If the number of steps in the first step is less than the number of steps in the third step, the sample is resampled. If the empty aspiration alarm signal is not triggered during the descent of the pipette, the sample sampling is completed.

[0023] When the number of steps in the first step is greater than the number of steps in the third step, the pipette is lowered and a liquid level detection operation is performed. Once the actual sample is detected, the sample collection is completed.

[0024] Furthermore, the method for determining when to trigger the air intake alarm signal includes the following steps:

[0025] Obtain the first pressure value of the pipette at the initial detection position on the liquid surface;

[0026] Obtain the second pressure value generated by the pipette during its descent;

[0027] Determine whether the difference between the second pressure value and the first pressure value is greater than the first threshold. If it is, perform the sampling action.

[0028] Obtain the third pressure value inside the pipette after the sampling action is performed;

[0029] Determine whether the difference between the third pressure value and the first pressure value is less than the second threshold. If it is less, trigger the air suction alarm signal.

[0030] Furthermore, the first position is set according to the height of the test tube. Beneficial effects

[0031] This invention determines the first step of pipette descent when blood film and / or air bubbles appear based on the empty aspiration alarm signal. This indicates the specific location of the blood film and / or air bubbles in the test tube. Since different locations correspond to different sample volumes in the test tube, this invention compares the first step with the second and third steps. Based on the comparison results, different processing methods are applied to blood film and / or air bubbles at different locations, thereby automatically processing the blood film and / or air bubbles in the sample, avoiding ineffective empty aspiration, and improving sample sampling accuracy. Attached Figure Description

[0032] Figure 1 is a flowchart of the sample collection method of the present invention;

[0033] Figure 2 is a schematic diagram of sample collection according to the present invention. Detailed Implementation

[0034] The technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0035] As shown in Figure 1, this invention discloses a sample collection method, comprising the following steps:

[0036] The initial position of the pipette in standby mode is set as the origin; the initial position where the pipette descends into the test tube to begin liquid level detection is set as the first position; the upper limit position of the sample volume in the test tube is set as the second position, and the lower limit position is set as the third position; the number of steps for the pipette to descend from the origin to the second position is set as the second step number H1, and the number of steps to the third position is set as the third step number H0; the number of steps relative to the origin from which the pipette triggers the empty aspiration alarm signal when descending from the first position to perform liquid level detection is set as the first step number Hx.

[0037] Obtain the first step number when the pipette triggers the empty aspiration alarm signal;

[0038] Compare the number of the first step with the number of the second step and the number of the third step;

[0039] Different methods are used to treat the blood film and / or air bubbles based on the comparison results of the number of descent steps;

[0040] Sampling operations are performed on samples after blood film and / or bubble treatment.

[0041] This invention determines the first step of pipette descent when blood film and / or air bubbles appear based on the empty aspiration alarm signal. This indicates the specific location of the blood film and / or air bubbles in the test tube. Since different locations correspond to different sample volumes in the test tube, this invention compares the first step with the second and third steps. Based on the comparison results, different processing methods are applied to blood film and / or air bubbles at different locations, thereby automatically processing the blood film and / or air bubbles in the sample, avoiding ineffective empty aspiration, and improving sample sampling accuracy.

[0042] It is understood that in this invention, the first position is the highest position in the test tube where blood film and / or bubbles can appear. The first position can be specifically set according to the height of the test tube. Since blood film and / or bubbles may appear at any position above the sample volume, the height of the first position is greater than that of the second position.

[0043] Specifically, based on the comparison results of the descent steps, different methods are used to treat the blood film and / or bubbles, including the following steps:

[0044] When the number of steps in the first step is less than the number of steps in the third step, the blood film and / or air bubbles are broken using a pipette.

[0045] When the number of steps in the first step is greater than the number of steps in the third step, control the pipette to descend below the blood film and / or air bubbles, avoiding the blood film and / or air bubbles.

[0046] It is understood that when the number of steps in the first step is greater than the number of steps in the third step, the pipette passes through the blood film and / or air bubbles during the descent of the pipette. That is, the method of handling the blood film and / or air bubbles in this invention includes not only direct manipulation of the blood film and / or air bubbles to destroy them, but also indirect manipulation through the blood film and / or air bubbles to avoid them. In other words, all methods that can prevent the blood film and / or air bubbles from affecting sample collection are included within the protection scope of this invention.

[0047] Furthermore, when the number of steps in the first step is less than the number of steps in the third step, the blood film and / or air bubbles are broken using a pipette, including the following steps:

[0048] When the number of steps in the first step is greater than the number of steps in the second step but less than the number of steps in the third step, the pipette is moved up and down to break the blood film and / or air bubbles.

[0049] When the number of steps in the first step is less than the number of steps in the second step, the pipette is moved up and down after the empty aspiration operation to break the blood film and / or air bubbles.

[0050] During the pipette membrane breaking operation, the distance between the lowest position and the first position of the vertical movement should not exceed the length of the sampling device on the pipette.

[0051] Understandably, existing pipette structures generally consist of two parts: a drive mechanism, such as a pipette pump, and a sampling device, such as a tip or sampling needle. When the blood film and / or air bubbles appear between the first and second positions, setting the lowest position can prevent the pipette from descending too far and contaminating the pipette pump structure above the tip or sampling needle. Furthermore, the empty aspiration operation before the membrane breaking operation can remove some of the blood film and / or air bubbles, causing the position of the blood film and / or air bubbles to descend, thus further preventing contamination of the pipette pump structure above the tip or sampling needle. At the same time, when the number of the first step is less than the number of the third step, in order to ensure that membrane breaking operations can be performed for different sample volumes, it is understandable that the number of steps H2 in which the pipette descends to the lowest position should be greater than the number of steps H0 in the third step.

[0052] Furthermore, the highest position and number of times the pipette is moved up and down during the membrane breaking operation are set according to the overall sampling time allocated for the test items.

[0053] Specifically, the total time for membrane breaking and air suction operations should not exceed the overall sampling time.

[0054] It is understandable that when the sample analyzer is taking samples, the sampling time for different test items is a fixed value, i.e., the overall sampling time. After the pipette triggers the empty aspiration alarm signal, the time for membrane breaking and empty aspiration operations should not be too long, otherwise it will affect the sampling operations of subsequent test items.

[0055] When the number of steps in the first step is greater than the number of steps in the second step but less than the number of steps in the third step, the sample aspiration detection time during the descent is too long due to the excessive number of steps in the pipette descent. This results in insufficient time for subsequent actions to perform the dry aspiration operation, so it is omitted and the membrane breaking operation is performed directly. When the number of steps in the first step is greater than the number of steps in the third step, the same applies. The sample aspiration detection time during the descent is too long due to the excessive number of steps in the pipette descent. This results in insufficient remaining time for subsequent actions to perform the dry aspiration operation and the membrane breaking operation. At this time, the descent height of the pipette is already within the minimum sample volume. Therefore, it is sufficient to directly descend a few steps to reach the actual sample position.

[0056] Furthermore, sampling is performed on the blood film and / or the sample after bubble treatment, including the following steps:

[0057] If the number of steps in the first step is less than the number of steps in the third step, the sample is resampled. If the empty aspiration alarm signal is not triggered during the descent of the pipette, the sample sampling is completed.

[0058] When the number of steps in the first step is greater than the number of steps in the third step, the pipette is lowered and a liquid level detection operation is performed. Once the actual sample is detected, the sample collection is completed.

[0059] This invention employs different sampling methods depending on the position of the first step descent. For steps less than the third step, the time spent on membrane breaking and empty aspiration operations is too long, leaving insufficient time within a single sampling period to allow the pipette to descend directly and perform liquid level detection sampling. Therefore, a resampling operation is performed to complete the entire sampling process. If the empty aspiration alarm signal is not triggered during the resampling operation, the sample is successfully collected; otherwise, the sampling operation for this task is abandoned. For steps greater than the third step, since the pipette is close to the actual sample, the sampling operation is performed by directly lowering the pipette at the empty aspiration position and activating liquid level detection. To avoid the above process timeout, this invention sets the pipette to descend twice and perform liquid level detection. If the actual sample is not detected in either of the two descents, the sampling operation for this task is abandoned.

[0060] Furthermore, the method for determining when to trigger the air intake alarm signal is as follows:

[0061] Obtain the first pressure value of the pipette at the initial detection position on the liquid surface;

[0062] Obtain the second pressure value generated by the pipette during its descent;

[0063] Determine whether the difference between the second pressure value and the first pressure value is greater than the first threshold. If it is, perform the sampling action.

[0064] Obtain the third pressure value inside the pipette after the sampling action is performed;

[0065] Determine whether the difference between the third pressure value and the first pressure value is less than the second threshold. If it is less, trigger the air suction alarm signal.

[0066] Understandably, when the pipette descends to the initial position for liquid level detection, the aspiration action is initiated and the pipette descends to perform the liquid level detection operation. Simultaneously, the pressure value inside the pipette is read in real time, i.e., the second pressure value. Therefore, the second pressure value is the real-time pressure value inside the pipette. When the difference between the second pressure value and the first pressure value is greater than the first threshold, it indicates that the pipette has touched the sample. However, at this point, it is impossible to determine whether there is blood film and / or air bubbles in the sample. Therefore, the aspiration action needs to be performed, and the third pressure value generated after aspiration is completed is read. When the difference between the third pressure value and the first pressure value is less than the second threshold, it indicates that blood film and / or air bubbles have been aspirated; if it is greater than the second threshold, it indicates that a real sample has been aspirated.

[0067] Understandably, since the initial position of the liquid level detection is far from the actual sample, the pressure here is basically the pressure value generated by the pipette drawing air. When the pipette draws blood film and / or air bubbles, or the actual sample, the second pressure value generated by the pipette drawing liquid will be greater than the first pressure value. Therefore, the first threshold is used to determine whether the pipette has touched the sample. Since the pressure value generated by the pipette drawing the actual sample is greater than the pressure value generated by the pipette drawing blood film and / or air bubbles, the second threshold is used to determine whether the pipette drew blood film and / or air bubbles or the actual sample.

[0068] To better understand and illustrate the method of the present invention, the following detailed description of the method of the present invention is provided through specific embodiments. As shown in Figure 2, it is a schematic diagram of a sample taking process according to the present invention.

[0069] 1) Hx < H1: After the empty aspiration alarm signal is triggered, the pipette performs an empty aspiration operation at position Hx. After filling the volume, the pipette moves up and down twice to perform a membrane breaking operation. In this embodiment, the lowest position of the membrane breaking operation is set to 90 steps above Zmax (Zmax is the number of steps the pipette takes from the origin to the bottom), and the highest position is 70 steps above the lowest position. After the membrane breaking operation is completed, the pipette returns to a safe height and performs the sampling operation again by liquid level detection. If the empty aspiration alarm signal is not triggered during the resampling operation, the sample sampling is completed; otherwise, the current sampling task will not be executed.

[0070] The safety height refers to the height at which the pipette descends from the origin and moves horizontally without interfering with other structures. It can be understood that since there is a certain distance between the origin and the height at which the pipette can interfere with other structures when moving horizontally, the safety height can be set differently within this distance depending on the specific characteristics of different sample analyzers.

[0071] 2) H1 < Hx < H0: After the empty aspiration alarm signal is triggered, the pipette moves up and down twice to perform the membrane breaking operation. The lowest and highest positions of the membrane breaking operation are the same as the set values ​​when Hx < H1. After the membrane breaking operation is completed, the pipette returns to the safe height and the sampling operation is performed again by liquid level detection. If the empty aspiration alarm signal is not triggered during the re-sampling operation, the sample sampling is completed; otherwise, the current sampling task will not be executed.

[0072] 3) Hx > H0: When a low-level blood film and / or air bubble is detected, in this embodiment, the pipette steps 18 steps to perform aspiration and determines whether there is empty aspiration. If not, the pipette steps 3 steps to perform sampling. If so, the pipette continues to step 18 steps to perform aspiration and determines whether there is empty aspiration. If not, the pipette steps 3 steps to perform sampling. Otherwise, the sampling task will not be executed.

[0073] Traditional sample collection methods do not automatically handle blood films and / or air bubbles in test tubes. When blood films and / or air bubbles in the test tube affect the pipette's liquid level detection position, an alarm will sound indicating no sample was detected. In such cases, the blood films and / or air bubbles must be manually punctured, which is time-consuming and labor-intensive, significantly impacting task efficiency. This invention eliminates the need for manual handling of blood films and / or air bubbles in test tubes, reducing operator workload and time, and improving work efficiency and automation. Furthermore, this invention automatically identifies and handles blood films and / or air bubbles in test tubes, minimizing their impact on sampling accuracy and improving detection efficiency and accuracy.

[0074] This invention uses a pressure sensor on a pipette to detect the liquid level. After sampling, the pressure sensor detects whether the difference between the pressure value and the initial pressure value is greater than a threshold to determine whether there is a blood film or / and air bubbles. When an alarm is triggered to detect the presence of blood film or / and air bubbles, different methods are used to deal with the blood film or / and air bubbles according to the location of the liquid level detection, so as to avoid the influence of blood film or / and air bubbles on the sample sampling accuracy.

[0075] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. A sample collection method, characterized in that, Includes the following steps: Obtain the first step number when the pipette triggers the empty aspiration alarm signal; Compare the number of the first step with the number of the second step and the number of the third step; Different methods are used to treat the blood film and / or air bubbles based on the comparison results of the number of descent steps; Sampling operations are performed on samples after blood film and / or bubble treatment; Specifically, the initial position of the pipette in standby mode is set as the origin, and the initial position of the pipette descending into the test tube to begin liquid level detection is set as the first position; the upper limit position of the sample volume in the test tube is set as the second position, and the lower limit position is set as the third position; the number of steps for the pipette to descend from the origin to the second position is set as the second step, and the number of steps for the pipette to descend to the third position is set as the third step; the number of steps relative to the origin for the position where the pipette triggers the empty suction alarm signal when descending from the first position to perform liquid level detection is set as the first step.

2. The sample collection method according to claim 1, characterized in that, Based on the comparison of the number of descent steps, different methods are used to treat the blood film and / or air bubbles, including the following steps: When the number of steps in the first step is less than the number of steps in the third step, the blood film and / or air bubbles are broken using a pipette. When the number of steps in the first step is greater than the number of steps in the third step, control the pipette to descend below the blood film and / or air bubbles, avoiding the blood film and / or air bubbles.

3. The sample collection method according to claim 2, characterized in that, When the number of steps in the first step is less than the number of steps in the third step, the blood film and / or air bubbles are broken using a pipette, including the following steps: When the number of steps in the first step is greater than the number of steps in the second step but less than the number of steps in the third step, the pipette is moved up and down to break the blood film and / or air bubbles. When the number of steps in the first step is less than the number of steps in the second step, the pipette is moved up and down after the empty aspiration operation to break the blood film and / or air bubbles.

4. The sample collection method according to claim 3, characterized in that, During the membrane breaking operation, the distance between the lowest position and the first position of the pipette during vertical movement is not greater than the length of the sampling device on the pipette.

5. The sample collection method according to claim 3, characterized in that, The number of steps required for the pipette to descend to its lowest position is greater than the number of steps required for the third step.

6. The sample collection method according to claim 3, characterized in that, The highest position the pipette can move up and down during the membrane breaking operation is set according to the overall sampling time allocated for the test items.

7. The sample collection method according to claim 6, characterized in that, The total time for the membrane breaking and air suction operations shall not exceed the overall sampling time.

8. The sample collection method according to claim 2, characterized in that, Sampling procedures for samples treated with blood film and / or air bubbles include the following steps: If the number of steps in the first step is less than the number of steps in the third step, the sample is resampled. If the empty aspiration alarm signal is not triggered during the descent of the pipette, the sample sampling is completed. When the number of steps in the first step is greater than the number of steps in the third step, the pipette is lowered and a liquid level detection operation is performed. Once the actual sample is detected, the sample collection is completed.

9. The sample collection method according to claim 1, characterized in that, The method for determining whether an air intake alarm signal is triggered includes the following steps: Obtain the first pressure value of the pipette at the initial detection position on the liquid surface; Obtain the second pressure value generated by the pipette during its descent; Determine whether the difference between the second pressure value and the first pressure value is greater than the first threshold. If it is, perform the sampling action. Obtain the third pressure value inside the pipette after the sampling action is performed; Determine whether the difference between the third pressure value and the first pressure value is less than the second threshold. If it is less, trigger the air suction alarm signal.

10. The sample collection method according to any one of claims 1-9, characterized in that, The first position is set according to the height of the test tube.

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