Automatic positioning method for blood collection needle based on multi-parameter fusion

Abstract

This invention relates to the field of blood collection technology, and provides an automatic blood collection needle positioning method based on multi-parameter fusion. The method includes: collecting blood flow activity characteristic parameters of the target body's blood collection area within a historical period, analyzing the blood flow activity characteristic values ​​to determine whether the blood flow effectiveness within the target body's blood collection area meets the standard; when the blood flow effectiveness within the target body's blood collection area meets the standard, collecting tissue elasticity characteristic parameters of the blood vessel segment within the target body's blood collection area, analyzing the tissue elasticity characteristic values ​​to determine whether the blood collection needle positioning reliability meets the standard; when the blood collection needle positioning reliability does not meet the standard, determining a processing strategy to determine the adjustment range of the blood flow activity characteristic threshold. This invention improves the efficiency of automatic blood collection needle positioning.

Description

Technical Field

[0001] This application relates to the field of blood collection technology, and in particular to an automatic positioning method for blood collection needles based on multi-parameter fusion. Background Technology

[0002] Automated blood collection and assisted puncture localization technology has broad application prospects in clinical nursing and laboratory fields. Currently, existing automated localization methods usually rely on single-modality sensors for detection. Some existing technologies use ultrasound imaging equipment to acquire images of the target body's blood vessels and use image recognition algorithms to determine the location and diameter of the blood vessels, thereby guiding the blood collection needle to be inserted. Other technologies use Doppler flowmeters to detect blood flow signals within the blood vessels to confirm their activity. For subjects in special physiological states such as shock, severe dehydration, or hypotension, their peripheral veins are often collapsed and blood perfusion is extremely weak or even stagnant. In such cases, relying solely on blood flow signal detection will make it difficult to effectively distinguish between low-flow vessels with puncture value and completely occluded vessels, which can easily lead to misjudgment of the blood sampling area. At the same time, existing methods generally ignore the decisive influence of vascular physical characteristics on puncture efficiency. When the subject has vascular sclerosis, loose skin, or large vascular slippage, even if the vessel location is accurately identified and there is blood flow, the automatic needle insertion process may cause vascular slippage, penetration of the vessel wall, or difficulty in puncture due to poor elastic strain rate of the vessel wall or abnormal elastic coefficient of the skin, which may lead to puncture failure or secondary damage such as hematoma.

[0003] Chinese Patent Publication No. CN113017625A discloses a control method and device for a blood collection robot. The control method includes: acquiring an image of a blood vessel region to be punctured; identifying multiple blood vessels within the region based on the acquired image; acquiring the geometric parameters of the multiple blood vessels; determining the target blood vessel based on the geometric parameters; locating the puncture needle insertion point on the target blood vessel; acquiring the angle information of the target blood vessel and the three-dimensional spatial coordinates of the puncture needle insertion point; planning the needle insertion path and angle based on the three-dimensional spatial coordinates; and controlling the robotic arm of the blood collection robot to move its distal end, the blood collection needle, towards the puncture needle insertion point according to the needle insertion path and angle, and then puncturing the target blood vessel. This invention can intelligently acquire the three-dimensional spatial positioning of the needle insertion point based on image recognition technology, thereby controlling the blood collection robot to accurately puncture the target blood vessel, achieving fully automated, unmanned blood collection, effectively avoiding puncture errors, reducing patient pain, and lowering labor costs.

[0004] Chinese Patent Publication No. CN119818157A discloses an automated venous and arterial puncture control method for achieving high-precision puncture through precise control. The method includes: after determining the start of automated venous and arterial puncture control, acquiring vascular ultrasound images; establishing a venous and arterial vessel detection model based on a lightweight deep network and target detection algorithm for the target vessel ultrasound image data; using the vessel detection model to detect and locate the vessel; acquiring images of the vessel to be detected and located in real time, and obtaining the vessel location and category based on the trained vessel detection model; confirming the target vessel location based on vessel location and classification, with the target vessel location being the puncture target location; planning the puncture path based on the target vessel location, including venous puncture path planning and arterial puncture path planning; and converting the path and control parameters based on the puncture path planning. The method also discloses a device and system that have low requirements for the working environment, can adapt to dynamic environments, are easy to promote, reduce puncture difficulty and labor intensity, and are portable. Summary of the Invention

[0005] To address this, the present invention provides an automatic positioning method for blood collection needles based on multi-parameter fusion, which overcomes the problem in the prior art where, under low perfusion conditions such as shock and hypotension, weak or stagnant blood flow, or the risk of vascular slippage or hardening, the blood collection needle cannot effectively assess vascular activity and is difficult to achieve stable puncture in segments with poor elasticity, thus leading to a decrease in the positioning efficiency of blood collection needles under special conditions.

[0006] To achieve the above objectives, the present invention provides an automatic blood collection needle positioning method based on multi-parameter fusion, comprising:

[0007] Collect blood flow activity characteristic parameters of the target body's blood collection area within a historical period;

[0008] Analyze the blood flow activity characteristic values ​​based on the aforementioned blood flow activity characteristic parameters;

[0009] Based on the comparison between the blood flow activity characteristic value and the predetermined blood flow activity characteristic threshold, it is determined whether the blood flow effectiveness in the target body's blood collection area meets the standard.

[0010] In response to the fact that the blood flow effectiveness in the target body's blood collection area meets the standard, tissue elasticity characteristic parameters of the vascular segment in the target body's blood collection area are collected;

[0011] Analyze the tissue elasticity characteristic values ​​based on the aforementioned tissue elasticity characteristic parameters;

[0012] The reliability of the blood collection needle positioning is determined based on the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold.

[0013] In response to the failure of the blood collection needle positioning reliability to meet the standard, the adjustment range of the blood flow activity characteristic characterization threshold is determined based on the difference between the tissue elasticity characteristic characterization value and the predetermined tissue elasticity characteristic characterization threshold.

[0014] The blood flow activity characteristic parameters include local blood flow perfusion signal value, tissue impedance change rate, and puncture failure resistance difference value;

[0015] The tissue elasticity characteristic parameters include the skin elastic coefficient and the ultrasound elastic strain rate of the blood vessel wall.

[0016] Furthermore, the process of analyzing the blood flow activity characteristic values ​​using the blood flow activity characteristic parameters includes:

[0017] Collect local blood perfusion signal values, tissue impedance change rate, and puncture failure resistance difference values ​​of the target body's blood collection area during historical periods;

[0018] The ratio of the local blood perfusion signal value to the predetermined local blood perfusion signal threshold is determined as the first limiting characterization parameter;

[0019] The ratio of the rate of change of tissue impedance to a predetermined threshold for the rate of change of tissue impedance is determined as the second limiting characterization parameter.

[0020] The ratio of the difference in puncture resistance to the predetermined threshold for the difference in puncture resistance is determined as the third limiting characterization parameter.

[0021] The summation of the first, second, and third limiting characterization parameters is determined as the blood flow activity characteristic characterization value.

[0022] Furthermore, the process of determining whether the blood flow effectiveness within the target body's blood collection area meets the standard by comparing the blood flow activity characteristic value with the predetermined blood flow activity characteristic threshold includes:

[0023] The results of comparing the extracted blood flow activity feature values ​​with the predetermined blood flow activity feature thresholds are obtained.

[0024] If the blood flow activity characteristic value is greater than the predetermined blood flow activity characteristic threshold, then the blood flow effectiveness in the target body's blood collection area is determined to meet the standard.

[0025] Furthermore, the process of determining whether the blood flow effectiveness in the target body's blood collection area does not meet the standard by comparing the blood flow activity characteristic value with the predetermined blood flow activity characteristic threshold includes:

[0026] The results of comparing the extracted blood flow activity feature values ​​with the predetermined blood flow activity feature thresholds are obtained.

[0027] If the blood flow activity characteristic characterization value is less than or equal to the predetermined blood flow activity characteristic characterization threshold, then the blood flow effectiveness in the target body's blood collection area is determined to be non-compliant with the standard.

[0028] Furthermore, the process of analyzing the tissue elasticity characteristic values ​​using the tissue elasticity characteristic parameters includes:

[0029] Collect the skin elasticity coefficient and the ultrasonic elastic strain rate of the blood vessel wall in the target body's blood collection area during the historical period;

[0030] The ratio of the skin elastic coefficient to a predetermined skin elastic coefficient threshold is determined as the first tissue-defined characterization parameter.

[0031] The ratio of the ultrasonic elastic strain rate of the blood vessel wall to a predetermined ultrasonic elastic strain rate threshold of the blood vessel wall is determined as the second tissue-defined characterization parameter.

[0032] The summation of the first tissue-defined characterization parameter and the second tissue-defined characterization parameter is determined as the tissue elasticity characteristic characterization value.

[0033] Furthermore, the process of determining whether the blood collection needle positioning reliability meets the standard by comparing the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold includes:

[0034] The result of calculating the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold;

[0035] If the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold is greater than the predetermined difference threshold, then the reliability of the blood collection needle positioning is determined to meet the standard.

[0036] Furthermore, the process of determining that the blood collection needle positioning reliability does not meet the standard based on the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold includes:

[0037] The result of calculating the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold;

[0038] If the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold is less than or equal to the predetermined difference threshold, then the reliability of the blood collection needle positioning is determined to be non-compliant with the standard.

[0039] Furthermore, the process of determining the processing strategy based on the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold includes:

[0040] The result of calculating the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold;

[0041] If the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold is less than or equal to the predetermined difference threshold, then the adjustment range of the blood flow activity characteristic threshold is determined.

[0042] Furthermore, the process of determining the adjustment range of the blood flow activity characteristic characterization threshold includes:

[0043] The result of calculating the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold;

[0044] The adjustment range of the blood flow activity characteristic threshold is positively correlated with the difference result.

[0045] Furthermore, the process following the determination of the adjustment range of the blood flow activity characteristic characterization threshold includes:

[0046] The predetermined blood flow activity characteristic characterization threshold is updated based on the adjustment amplitude to form the updated blood flow activity characteristic characterization threshold.

[0047] Return to the steps of blood flow activity characteristic parameters of the target body's blood collection area within the historical collection period, and re-evaluate blood flow effectiveness based on the updated blood flow activity characteristic characterization threshold to find blood collection areas that meet the updated criteria.

[0048] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention provides an automatic blood collection needle positioning method based on multi-parameter fusion. By collecting local blood perfusion signal values, tissue impedance change rate, and puncture failure resistance difference values ​​of the target body's blood collection area within a historical period, it analyzes blood flow activity characteristic values, enabling accurate prediction of vascular filling and vascular patency in the blood collection area. Based on the comparison results of the blood flow activity characteristic values ​​with predetermined blood flow activity characteristic thresholds, it determines whether the blood flow effectiveness in the target body's blood collection area meets the standard. When the blood flow effectiveness in the target body's blood collection area meets the standard, the skin elasticity of the vascular segment in the target body's blood collection area is collected. By analyzing the coefficients and ultrasonic elastic strain rate of the blood vessel wall, the tissue elasticity characteristic values ​​can be fully reflected, effectively identifying factors affecting positioning accuracy and puncture safety, such as skin laxity, hardening, easy slippage of blood vessels, and fragile blood vessel walls. This further improves the rationality and stability of the automatic positioning path planning of the blood collection needle. The difference between the tissue elasticity characteristic value and a predetermined tissue elasticity characteristic threshold is used to determine whether the blood collection needle positioning reliability meets the standard. When the blood collection needle positioning reliability does not meet the standard, the adjustment range of the blood flow activity characteristic threshold is determined based on the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold. This achieves adaptive correction of blood flow judgment conditions based on tissue mechanical properties, adapting to targets of different ages, skin types, physiological states, and pathological conditions. This improves the generalization and environmental adaptability of the automatic positioning method, which is beneficial for improving the efficiency of one-time puncture in automated blood collection, reducing the risk of tissue damage and blood vessel puncture, and enhancing the safety and intelligence level of blood collection operations.

[0049] In particular, this invention collects local blood perfusion signal values, tissue impedance change rate, and puncture failure resistance difference, and calculates their ratios to their respective predetermined thresholds to generate limited characterization parameters, which are then summed to obtain blood flow activity characteristic characterization values. By comparing these values ​​with predetermined blood flow activity characteristic characterization thresholds, the invention can accurately determine whether the blood flow effectiveness of the target body's blood collection area meets the standards. This overcomes the limitation of single blood flow signal detection in distinguishing between puncturable and unused blood vessels under low perfusion conditions, significantly improving the accuracy of identifying blood vessel segments with blood collection value. This provides a reliable basis for the subsequent automatic positioning of blood collection needles, thereby reducing the risk of misselecting invalid blood collection areas from the source and ensuring the accuracy and efficiency of blood collection needle positioning.

[0050] In particular, this invention collects the skin elasticity coefficient and the ultrasonic elastic strain rate of the blood vessel wall, and calculates their ratios to their respective predetermined thresholds to generate tissue-defined characterization parameters, which are then summed to obtain the tissue elasticity characteristic characterization value. By calculating the difference between this characterization value and the predetermined tissue elasticity characteristic characterization threshold, and comparing it with the predetermined difference threshold, the reliability of the automatic positioning method for blood collection needles can be accurately determined to meet the standards. By incorporating physical characteristics such as vascular slippage and hardening degree into the quantitative analysis, this invention overcomes the defect of existing technologies that ignore the influence of vascular physical state on the puncture process. It provides a reliable predictive basis for puncture stability for automatic positioning of blood collection needles, thereby effectively avoiding risks such as slippage, penetration difficulties, or vessel wall damage caused by poor vascular elasticity, and significantly improving the stability and safety of the automatic positioning method in the actual puncture process.

[0051] In particular, this invention achieves dynamic compensation for puncture difficulty based on vascular elasticity by adjusting the blood flow activity threshold based on the positive correlation difference between tissue elasticity and a predetermined threshold when the reliability of automatic positioning does not meet the standard, and re-evaluating blood flow effectiveness based on the updated threshold to locate a better blood collection area. This significantly improves the adaptive capability and optimization efficiency of the automatic positioning method for blood collection needles under complex vascular conditions, and further ensures the efficiency of automatic positioning of blood collection needles. Attached Figure Description

[0052] Figure 1 This is a flowchart illustrating the steps of the automatic blood collection needle positioning method based on multi-parameter fusion in an embodiment of the present invention.

[0053] Figure 2 This is a flowchart illustrating the steps involved in analyzing blood flow activity characteristic values ​​according to an embodiment of the present invention.

[0054] Figure 3 This is a logic diagram for determining whether the effectiveness of blood flow within the target body's blood collection area meets the standards in an embodiment of the present invention;

[0055] Figure 4 This is a logic diagram for determining whether the reliability of blood collection needle positioning meets the standard in an embodiment of the present invention. Detailed Implementation

[0056] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0057] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0058] Please see Figure 1The diagram shows the steps of an automatic blood collection needle positioning method based on multi-parameter fusion according to an embodiment of the present invention. The present invention provides an automatic blood collection needle positioning method based on multi-parameter fusion, comprising:

[0059] Step S1: Collect blood flow activity characteristic parameters of the target body's blood collection area within the historical period;

[0060] Step S2: Analyze the blood flow activity characteristic values ​​based on the blood flow activity characteristic parameters;

[0061] Step S3: Based on the comparison results between the blood flow activity feature characterization value and the predetermined blood flow activity feature characterization threshold, determine whether the blood flow effectiveness in the target body's blood collection area meets the standard;

[0062] Step S4: In response to the blood flow effectiveness meeting the standard in the target body's blood collection area, collect the tissue elasticity characteristic parameters of the vascular segment in the target body's blood collection area; analyze the tissue elasticity characteristic value based on the tissue elasticity characteristic parameters;

[0063] Step S5: Determine whether the reliability of the blood collection needle positioning meets the standard based on the difference between the tissue elasticity characteristic characterization value and the predetermined tissue elasticity characteristic characterization threshold.

[0064] Step S6: In response to the blood collection needle positioning reliability not meeting the standard, the adjustment range of the blood flow activity characteristic characterization threshold is determined based on the difference between the tissue elasticity characteristic characterization value and the predetermined tissue elasticity characteristic characterization threshold.

[0065] It is understandable that the local blood flow perfusion signal value refers to the integral of the peak value of the real-time blood flow intensity signal over time within the acquisition period divided by the acquisition period duration; it is a quantitative indicator reflecting the microcirculation perfusion level of the area to be blood collected, and is usually collected by a Doppler flowmeter; the larger the value, the richer the local tissue blood flow and the higher the vascular filling.

[0066] It is understandable that the rate of change of tissue impedance refers to the absolute value of the difference between the maximum and minimum impedance values ​​during the collection period divided by the baseline impedance value; the rate of change of tissue impedance in the blood collection area over time obtained by the four-electrode method; the blood resistivity is lower than that of the surrounding tissue, and the greater the rate of change of impedance, the more obvious the blood flow fluctuation and the stronger the vascular activity.

[0067] It is understandable that the difference between the resistance before and after puncture refers to the peak resistance before puncturing the blood vessel wall minus the trough resistance after puncturing the blood vessel lumen. A micro-force sensor is used to monitor the change in resistance at the moment the puncture needle punctures the blood vessel wall. When the needle enters the blood vessel lumen, the resistance drops sharply. The larger this difference is, the more obvious the blood vessel lumen is, and the clearer the feeling of puncture failure is.

[0068] It is understandable that the skin elasticity coefficient refers to the ratio of applied stress to strain, where applied stress is the applied force divided by the contact area, and strain is the skin deformation divided by the initial skin thickness. It is a parameter that reflects the skin's ability to resist deformation in the area to be punctured. It is usually obtained through a suction cup skin elasticity measuring instrument. The lower the coefficient, the looser the skin, and the easier it is for blood vessels to slide during puncture.

[0069] It is understandable that the ultrasound elastic strain rate of the blood vessel wall refers to the change in displacement of the blood vessel wall before and after pressure is applied, divided by the initial thickness of the blood vessel wall; it is the strain ratio of the blood vessel wall under external pressure, measured using ultrasound elastography technology; the lower the strain rate, the harder the blood vessel wall, making it easier to rupture or difficult to penetrate during puncture.

[0070] Specifically, the historical cycle refers to the target body's dynamic case cycle. The historical cycle in the example is [3 days, 14 days], and the example is preferably 7 days.

[0071] In this embodiment, by collecting local blood perfusion signal values, tissue impedance change rate, and puncture failure resistance difference values ​​of the target body's blood collection area within a historical period, the blood flow activity characteristic values ​​can be analyzed, enabling accurate prediction of vascular filling and patency in the blood collection area. Based on the comparison between the blood flow activity characteristic values ​​and predetermined blood flow activity characteristic thresholds, it is determined whether the blood flow effectiveness within the target body's blood collection area meets the standard. When the blood flow effectiveness within the target body's blood collection area meets the standard, the skin elasticity coefficient and ultrasonic elastic strain rate of the vascular segment within the target body's blood collection area are collected to analyze the tissue. The elastic characteristic value fully reflects the mechanical properties of the skin and blood vessel walls, effectively identifying factors affecting positioning accuracy and puncture safety, such as skin laxity, hardening, easy slippage of blood vessels, and fragile blood vessel walls. This further improves the rationality and stability of the automatic positioning path planning for blood collection needles. The difference between the tissue elastic characteristic value and a predetermined tissue elastic characteristic threshold determines whether the blood collection needle positioning reliability meets the standard. When the blood collection needle positioning reliability does not meet the standard, the adjustment range of the blood flow activity characteristic threshold is determined based on the difference between the tissue elastic characteristic value and the predetermined tissue elastic characteristic threshold. This achieves adaptive correction of blood flow judgment conditions based on tissue mechanical properties, adapting to targets of different ages, skin types, physiological states, and pathological conditions. This improves the generalization and environmental adaptability of the automatic positioning method, helps improve the efficiency of one-time puncture in automated blood collection, reduces the risk of tissue damage and blood vessel puncture, and enhances the safety and intelligence level of blood collection operations.

[0072] Please see Figure 2 The diagram shows a flowchart illustrating the steps involved in analyzing blood flow activity characteristic values ​​according to an embodiment of the present invention. The process of analyzing blood flow activity characteristic values ​​based on blood flow activity characteristic parameters according to the present invention includes:

[0073] Step S21: Collect local blood perfusion signal values, tissue impedance change rate, and puncture failure resistance difference values ​​of the target body's blood collection area within the historical period;

[0074] Step S22: The ratio of the local blood perfusion signal value to the predetermined local blood perfusion signal threshold is determined as the first limiting characterization parameter; the ratio of the tissue impedance change rate to the predetermined tissue impedance change rate threshold is determined as the second limiting characterization parameter; the ratio of the puncture failure resistance difference to the predetermined puncture failure resistance difference threshold is determined as the third limiting characterization parameter.

[0075] Step S23: The first limited characterization parameter, the second limited characterization parameter and the third limited characterization parameter are summed to determine the blood flow activity characteristic characterization value.

[0076] In this embodiment, the blood flow activity characteristic parameters are acquired using multi-mode sensing technology. The local blood flow perfusion signal value is obtained by continuously acquiring the blood flow intensity signal through a laser Doppler probe attached to the skin surface. The tissue impedance change rate is obtained by applying a weak current to the area to be blood collected using a four-electrode method, and calculating the percentage of impedance fluctuation within one cycle by measuring the voltage change between the electrodes. The puncture failure resistance difference value is obtained by integrating a micro-force sensor into the blood collection needle handle, which captures the peak resistance and valley resistance before and after puncturing the blood vessel wall in real time with high-frequency sampling during automatic needle insertion, and quantifies the puncture failure sensation by calculating the difference.

[0077] In this embodiment, the determination of the local blood perfusion signal threshold, the tissue impedance change rate threshold, and the puncture failure resistance difference threshold are all based on clinical pre-experiment data and statistical analysis. The local blood perfusion signal threshold is determined by measuring the blood perfusion value of the blood collection area in healthy individuals and combining it with receiver operating characteristic (ROC) curve analysis to determine the optimal cutoff value. The tissue impedance change rate threshold is set based on the typical range of local tissue impedance extracted from the literature review and the baseline change rate of impedance with cardiac cycle fluctuations under normal blood flow conditions. The puncture failure resistance difference threshold is determined by collecting puncture resistance curves under different vascular conditions through in vitro tissue simulation experiments or clinical pre-experiments, statistically analyzing the resistance difference distribution before and after puncturing the vessel wall, and using ROC curve analysis to determine the minimum difference that can clearly distinguish the intravascular and extravascular states as the threshold. The local blood perfusion signal threshold, tissue impedance change rate threshold, and puncture failure resistance difference threshold are stored in the system as preset initial benchmarks to provide a basis for evaluating blood flow effectiveness.

[0078] Please see Figure 3 As shown, this is a logic diagram for determining whether the blood flow effectiveness within the target body's blood collection area meets the standard, according to an embodiment of the present invention. The process of determining whether the blood flow effectiveness within the target body's blood collection area meets the standard based on the comparison result of the blood flow activity feature characterization value and the predetermined blood flow activity feature characterization threshold includes:

[0079] The results of comparing the extracted blood flow activity feature values ​​with the predetermined blood flow activity feature thresholds are obtained.

[0080] If the blood flow activity characteristic characterization value is greater than the predetermined blood flow activity characteristic characterization threshold, then the blood flow effectiveness in the target body's blood collection area is determined to meet the standard.

[0081] If the blood flow activity characteristic characterization value is less than or equal to the predetermined blood flow activity characteristic characterization threshold, then the blood flow effectiveness in the target body's blood collection area is determined to be non-compliant with the standard.

[0082] In this embodiment, the predetermined blood flow activity characteristic characterization threshold is obtained in advance. All blood flow activity characteristic characterization values ​​of the target body's blood collection area are collected within one historical period, and their average value is calculated and determined as the blood flow activity characteristic characterization threshold. It is selected within the range [3.05, 3.25], and preferably 3.15 in this embodiment.

[0083] In this embodiment, by collecting local blood perfusion signal values, tissue impedance change rate, and puncture failure resistance difference, and calculating their ratios to their respective predetermined thresholds to generate limited characterization parameters, the blood flow activity characteristic characterization values ​​are obtained by summing them. By comparing these values ​​with the predetermined blood flow activity characteristic characterization thresholds, it is possible to accurately determine whether the blood flow effectiveness of the target body's blood collection area meets the standards. This overcomes the limitation of single blood flow signal detection in distinguishing between puncturable and unused blood vessels under low perfusion conditions, significantly improving the identification accuracy of blood collection value vessel segments. This provides a reliable basis for the subsequent automatic positioning of blood collection needles, thereby reducing the risk of misselecting invalid blood collection areas from the source and ensuring the accuracy and efficiency of blood collection needle positioning.

[0084] Specifically, the process of analyzing the tissue elasticity characteristic values ​​using the tissue elasticity characteristic parameters includes:

[0085] Collect the skin elasticity coefficient and the ultrasonic elastic strain rate of the blood vessel wall in the target body's blood collection area during the historical period;

[0086] The ratio of the skin elastic coefficient to a predetermined skin elastic coefficient threshold is determined as the first tissue-defined characterization parameter.

[0087] The ratio of the ultrasonic elastic strain rate of the blood vessel wall to a predetermined ultrasonic elastic strain rate threshold of the blood vessel wall is determined as the second tissue-defined characterization parameter.

[0088] The summation of the first tissue-defined characterization parameter and the second tissue-defined characterization parameter is determined as the tissue elasticity characteristic characterization value.

[0089] In this embodiment, the acquisition of skin elasticity coefficient adopts the principle of mechanical testing. A constant pressure or negative pressure is applied to the skin through a probe attached to the area to be blood collected. The deformation of the skin after being subjected to force is monitored in real time using a built-in displacement sensor. The ratio of stress to strain is calculated to quantify the skin's ability to resist deformation. The ultrasonic elastic strain rate of the blood vessel wall uses ultrasonic elastography technology. A linear array probe is placed on the skin surface directly above the blood vessel to collect radio frequency signals of the blood vessel wall under external pressure or natural pulsation. By tracking the amount of tissue displacement change and calculating its ratio to the initial thickness of the blood vessel wall, a strain rate value reflecting the stiffness of the blood vessel is obtained.

[0090] In this embodiment, the skin elastic coefficient threshold is typically obtained based on a statistical survey of healthy individuals. Measurement data from healthy subjects in the area to be punctured are collected, and the normal range is determined through statistical analysis as an initial benchmark. The vascular wall ultrasonic elastic strain rate threshold is derived from in vitro or in vivo tissue elastic modulus measurement studies. Based on the differences in elasticity values ​​of different components such as lipids, fibrous tissues, and calcified tissues, a cutoff value with high sensitivity and specificity is selected by plotting the subject working characteristic curve to distinguish between soft vascular walls suitable for puncture and hard lesion vascular walls unsuitable for puncture. The skin elastic coefficient threshold and the vascular wall ultrasonic elastic strain rate threshold are stored in the system as preset initial parameters to provide a benchmark reference for subsequent dynamic adaptive adjustment.

[0091] Please see Figure 4 As shown, this is a logic diagram for determining whether the reliability of blood collection needle positioning meets the standard in an embodiment of the present invention. The process of determining whether the reliability of blood collection needle positioning meets the standard based on the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold includes:

[0092] The result of calculating the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold;

[0093] If the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold is greater than the predetermined difference threshold, then the reliability of the blood collection needle positioning is determined to meet the standard.

[0094] If the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold is less than or equal to the predetermined difference threshold, then the reliability of the blood collection needle positioning is determined to be non-compliant with the standard.

[0095] In this embodiment, the predetermined tissue elasticity characteristic characterization threshold is obtained in advance. All tissue elasticity characteristic characterization values ​​of the target body's blood collection area are collected within one historical period, and their average value is calculated to determine the tissue elasticity characteristic characterization threshold. The threshold is selected within the range [2.05, 2.25], and is preferably 2.15 in this embodiment.

[0096] In this embodiment, the predetermined difference threshold is obtained in advance. The difference between all tissue elasticity feature values ​​of the target body's blood collection area within one historical period and the predetermined tissue elasticity feature threshold is calculated, and the average value is calculated. The difference threshold is selected within the range [0.05, 0.25], and is preferably 0.15 in this embodiment.

[0097] In this embodiment, the skin elastic coefficient and the ultrasonic elastic strain rate of the blood vessel wall are collected, and their ratios to their respective predetermined thresholds are calculated to generate tissue-defined characterization parameters. These parameters are then summed to obtain the tissue elastic characteristic characterization value. By calculating the difference between this characterization value and the predetermined tissue elastic characteristic characterization threshold and comparing it with the predetermined difference threshold, the reliability of the automatic positioning method for blood collection needles can be accurately determined. This incorporates physical characteristics such as vascular slippage and hardening degree into the quantitative analysis, overcoming the shortcomings of existing technologies that ignore the influence of vascular physical state on the puncture process. It provides a reliable predictive basis for puncture stability for automatic positioning of blood collection needles, thereby effectively avoiding risks such as slippage, penetration difficulties, or vessel wall damage caused by poor vascular elasticity, and significantly improving the stability and safety of the automatic positioning method in the actual puncture process.

[0098] Specifically, the process of determining the processing strategy based on the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold includes:

[0099] The result of calculating the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold;

[0100] If the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold is greater than or equal to the predetermined difference threshold, then the adjustment range of the blood flow activity characteristic threshold is determined.

[0101] In this embodiment, by establishing a dynamic compensation mechanism based on tissue elasticity difference, the quantitative correlation between vascular physical properties and blood flow screening standards is realized: when the difference between the tissue elasticity characteristic value and the predetermined threshold reaches the preset standard, the system uses the difference as a quantitative basis to directly determine the upward adjustment range of the blood flow activity characteristic threshold.

[0102] Specifically, the process of determining the adjustment range of the blood flow activity characteristic characterization threshold includes:

[0103] The result of calculating the difference between the tissue elasticity characteristic value and the predetermined tissue elasticity characteristic threshold;

[0104] The adjustment range of the blood flow activity characteristic threshold is positively correlated with the difference result.

[0105] In this embodiment, the positive correlation between the adjustment range and the tissue elasticity difference enables differentiated and precise adjustment of the blood flow activity characteristic characterization threshold. The system dynamically determines the upward adjustment range of the blood flow activity characteristic characterization threshold based on the degree to which the tissue elasticity deviates from the predetermined threshold. The worse the elasticity, the greater the compensation force; when the elasticity is close to normal, it is finely adjusted or not adjusted at all.

[0106] Specifically, the process following the determination of the adjustment range of the blood flow activity characteristic characterization threshold includes:

[0107] The predetermined blood flow activity characteristic characterization threshold is updated based on the adjustment amplitude to form the updated blood flow activity characteristic characterization threshold.

[0108] Return to the steps of blood flow activity characteristic parameters of the target body's blood collection area within the historical collection period, and re-evaluate blood flow effectiveness based on the updated blood flow activity characteristic characterization threshold to find blood collection areas that meet the updated criteria.

[0109] In this embodiment, when the reliability of automatic positioning does not meet the standard, the blood flow activity threshold is increased based on the positive correlation difference between tissue elasticity and a predetermined threshold, and the blood flow effectiveness is reassessed based on the updated threshold to locate a better blood collection area. This achieves dynamic compensation for puncture difficulty based on vascular elasticity, significantly improves the adaptive capability and optimization efficiency of the automatic positioning method for blood collection needles under complex vascular conditions, and further ensures the efficiency of automatic positioning of blood collection needles.

[0110] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to the specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A multi-parameter fusion-based automatic positioning method for a blood collection needle, characterized in that, Comprising: Collecting blood flow activity characteristic parameters of the target body blood collection area in the historical period; Analyzing blood flow activity characteristic representation values based on the blood flow activity characteristic parameters; Determining whether the blood flow effectiveness in the target body blood collection area meets the standard based on the comparison result of the blood flow activity characteristic representation values and the predetermined blood flow activity characteristic representation threshold value; In response to the blood flow effectiveness in the target body blood collection area meeting the standard, collecting tissue elasticity characteristic parameters of the blood vessel segment in the target body blood collection area; Analyzing tissue elasticity characteristic representation values based on the tissue elasticity characteristic parameters; Determining whether the blood collection needle positioning reliability meets the standard based on the difference result of the tissue elasticity characteristic representation values and the predetermined tissue elasticity characteristic representation threshold value; In response to the blood collection needle positioning reliability not meeting the standard, determining the adjustment range of the blood flow activity characteristic representation threshold value based on the difference result of the tissue elasticity characteristic representation values and the predetermined tissue elasticity characteristic representation threshold value. The blood flow activity characteristic parameters include local blood perfusion signal values, tissue impedance change rates, and puncture failure resistance difference values. The tissue elasticity characteristic parameters include skin elasticity coefficients and blood vessel wall ultrasonic elasticity strain rates.

2. The multi-parameter fusion-based automatic positioning method of a blood taking needle according to claim 1, characterized in that, The process of analyzing blood flow activity characteristic representation values based on the blood flow activity characteristic parameters includes: Collecting local blood perfusion signal values, tissue impedance change rates, and puncture failure resistance difference values of the target body blood collection area in the historical period; Calculating the ratio of the local blood perfusion signal values to the predetermined local blood perfusion signal threshold value to determine the first limited representation parameter; Calculating the ratio of the tissue impedance change rate to the predetermined tissue impedance change rate threshold value to determine the second limited representation parameter; Calculating the ratio of the puncture failure resistance difference value to the predetermined puncture failure resistance difference value threshold value to determine the third limited representation parameter; Summing the first, second, and third limited representation parameters to determine the blood flow activity characteristic representation value.

3. The multi-parameter fusion-based automatic positioning method of a blood taking needle according to claim 2, characterized in that, The process of determining whether the blood flow effectiveness in the target body blood collection area meets the standard based on the comparison result of the blood flow activity characteristic representation values and the predetermined blood flow activity characteristic representation threshold value includes: Extracting the comparison result of the blood flow activity characteristic representation values and the predetermined blood flow activity characteristic representation threshold value; If the blood flow activity characteristic representation value is greater than the predetermined blood flow activity characteristic representation threshold value, it is determined that the blood flow effectiveness in the target body blood collection area meets the standard.

4. The multi-parameter fusion-based automatic positioning method of a blood taking needle according to claim 3, characterized in that, The process of determining whether the blood flow effectiveness in the target body blood collection area meets the standard based on the comparison result of the blood flow activity characteristic representation values and the predetermined blood flow activity characteristic representation threshold value includes: Extracting the comparison result of the blood flow activity characteristic representation values and the predetermined blood flow activity characteristic representation threshold value; If the blood flow activity characteristic representation value is less than or equal to the predetermined blood flow activity characteristic representation threshold value, it is determined that the blood flow effectiveness in the target body blood collection area does not meet the standard.

5. The multi-parameter fusion-based automatic positioning method of a blood taking needle according to claim 4, characterized in that, The process of analyzing tissue elasticity characteristic representation values based on the tissue elasticity characteristic parameters includes: Collecting skin elasticity coefficients and blood vessel wall ultrasonic elasticity strain rates of the target body blood collection area in the historical period; Calculating the ratio of the skin elasticity coefficient to the predetermined skin elasticity coefficient threshold value to determine the first tissue limited representation parameter; The ratio of the calculated vascular wall ultrasonic elastic strain rate and a predetermined vascular wall ultrasonic elastic strain rate threshold is determined as a second tissue limited characterization parameter; The first tissue limited characterization parameter and the second tissue limited characterization parameter are summed to determine the tissue elasticity characteristic characterization value.

6. The multi-parameter fusion-based automatic positioning method of a blood taking needle according to claim 5, characterized in that, The process of determining whether the blood taking needle positioning reliability meets the standard based on the difference between the tissue elasticity characteristic characterization value and the predetermined tissue elasticity characteristic characterization threshold value includes: Calculating the difference between the tissue elasticity characteristic characterization value and the predetermined tissue elasticity characteristic characterization threshold value; If the difference between the tissue elasticity characteristic characterization value and the predetermined tissue elasticity characteristic characterization threshold value is greater than a predetermined difference threshold value, it is determined that the blood taking needle positioning reliability meets the standard.

7. The multi-parameter fusion-based automatic positioning method of a blood taking needle according to claim 6, characterized in that, The process of determining whether the blood taking needle positioning reliability does not meet the standard based on the difference between the tissue elasticity characteristic characterization value and the predetermined tissue elasticity characteristic characterization threshold value includes: Calculating the difference between the tissue elasticity characteristic characterization value and the predetermined tissue elasticity characteristic characterization threshold value; If the difference between the tissue elasticity characteristic characterization value and the predetermined tissue elasticity characteristic characterization threshold value is less than or equal to a predetermined difference threshold value, it is determined that the blood taking needle positioning reliability does not meet the standard.

8. The multi-parameter fusion-based automatic positioning method of a blood taking needle according to claim 7, characterized in that, The process of determining the processing strategy based on the difference between the tissue elasticity characteristic characterization value and the predetermined tissue elasticity characteristic characterization threshold value includes: Calculating the difference between the tissue elasticity characteristic characterization value and the predetermined tissue elasticity characteristic characterization threshold value; If the difference between the tissue elasticity characteristic characterization value and the predetermined tissue elasticity characteristic characterization threshold value is less than or equal to a predetermined difference threshold value, the adjustment range of the blood flow activity characteristic characterization threshold value is determined.

9. The multi-parameter fusion-based automatic positioning method of a blood taking needle according to claim 8, characterized in that, The process based on the determination of the adjustment range of the blood flow activity characteristic characterization threshold value includes: Calculating the difference between the tissue elasticity characteristic characterization value and the predetermined tissue elasticity characteristic characterization threshold value; The adjustment range of the blood flow activity characteristic characterization threshold value is positively correlated with the difference result.

10. The multi-parameter fusion-based automatic positioning method of a blood taking needle according to claim 9, characterized in that, The process after the determination of the adjustment range of the blood flow activity characteristic characterization threshold value includes: Based on the adjustment range, the predetermined blood flow activity characteristic characterization threshold value is updated to form an updated blood flow activity characteristic characterization threshold value; Returning to the step of collecting the blood flow activity characteristic parameters of the target body blood taking area in the historical period, and re-evaluating the blood flow effectiveness based on the updated blood flow activity characteristic characterization threshold value to find a blood taking area that meets the updated standard.

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