阅读说明：本技术 一种基于超声医学影像的射血分数校准方法及专用设备 (Ejection fraction calibration method based on ultrasonic medical image and special equipment ) 是由 李成伟 刘文丽 陆舒洁 张鹏 孙劼 万国庆 张璞 于 2021-06-22 设计创作，主要内容包括：本发明是有关于一种基于超声医学影像的射血分数校准方法及专用设备,使用具有生物组织等效特性的材料制成人体动态心脏模型,通过高精度激光位移传感器精确测量并给出不同心率值下沿着左心室短轴切面方向且左心室外侧位置的位移量标准值；然后利用超声医学影像设备测量并给出该位置位移量的测量值,位移量标准值减去测量值获得修正值,建立心率值与位移量修正值的对照表,然后将该对照表、人体动态心脏模型左心室舒张态的心横径长度标准值和测得值内置于超声医学影像设备中,用于校准射血分数测量结果。通过本发明的校准方法及专用设备,可以提升超声医学影像设备射血分数测量结果的准确性,提升心力衰竭等临床疾病诊断结果的有效性。(The invention relates to a method for calibrating ejection fraction based on ultrasonic medical images and special equipment, wherein a human dynamic heart model is made of a material with biological tissue equivalent characteristics, and a displacement standard value along the direction of a left ventricle short axis section and at the position outside a left ventricle under different heart rate values is accurately measured and given through a high-precision laser displacement sensor; then, an ultrasonic medical imaging device is used for measuring and giving out a measured value of the position displacement, the measured value is subtracted from the displacement standard value to obtain a corrected value, a comparison table of a heart rate value and the displacement corrected value is established, and then the comparison table, the human dynamic heart model left ventricle diastolic heart transverse diameter length standard value and the measured value are built in the ultrasonic medical imaging device and used for calibrating the ejection fraction measurement result. By the calibration method and the special equipment, the accuracy of the ejection fraction measurement result of the ultrasonic medical imaging equipment can be improved, and the effectiveness of the diagnosis result of clinical diseases such as heart failure and the like can be improved.)

1. An ejection fraction calibration method based on ultrasonic medical images is characterized by comprising the following steps:

step 1: manufacturing a human dynamic heart model;

step 2: installing a human dynamic heart model in an acrylic water tank;

and step 3: installing a mechanical motion control mechanism and connecting the human dynamic heart model installed on the acrylic water tank with the mechanical motion control mechanism;

and 4, step 4: starting a mechanical motion control mechanism to drive the human dynamic heart model to generate regular reciprocating motion;

and 5: calibrating the displacement of the outer position of the left ventricle along the direction of the short axis section of the left ventricle, determining the position of a laser displacement sensor (16) by using an adjustable lifting bracket (20) without injecting water in an acrylic water tank, and measuring a standard value of the displacement of the position by the laser displacement sensor (16);

step 6: acquiring an echocardiogram, filling water in an acrylic water tank until the dynamic heart model of the human body is submerged, then acquiring the echocardiogram, and measuring the measurement value of the displacement by using an M-Teich method after the echocardiogram is acquired;

and 7: and for the heart rate value not in the comparison table, obtaining the displacement correction value corresponding to the heart rate value by adopting a linear interpolation mode.

2. The method for calibrating ejection fraction based on ultrasound medical image of claim 1, wherein the step 1 comprises:

step 1-1: drawing a three-dimensional numerical model based on an open-source human dynamic heart model, and regulating the geometric dimension of the three-dimensional numerical model by combining with real human heart data to enable the three-dimensional numerical model to present a real human physiological anatomical structure;

step 1-2: adjusting the elastic modulus of a myocardial material used for preparing the human dynamic heart model, wherein the myocardial material is made of three-component silicon-based rubber, the hardness of the myocardial material of the prepared human dynamic heart model is measured by using a Shore hardness meter, the elastic modulus is calculated according to a conversion formula of the hardness and the elastic modulus, and the elastic modulus of the myocardial material of the human dynamic heart model is equivalent to the elastic modulus of a real human myocardial tissue by adjusting the proportion of the three components; the elastic modulus of the myocardial material is 1.86-2.37 MPa, and the material is equivalent to the real myocardial tissue of a human body in terms of mechanical properties;

step 1-3: manufacturing a human dynamic heart model, performing 3D printing according to the three-dimensional numerical model in the step 1-1 to obtain the human dynamic heart model, performing reverse molding on the printed human dynamic heart model, and preparing the human dynamic heart model by using the mold and the myocardial material of the human dynamic heart model in the step 1-2; in order to facilitate various work in the subsequent steps, the model is divided into an upper part and a lower part in the process of back molding of the human dynamic heart model, all the subsequent steps are operated on the lower half part, and the upper part and the lower part are bonded together by using the same myocardial material in the step 1-2 after all the steps are finished to form the complete human dynamic heart model; the prepared human dynamic heart model comprises a left atrium, a left ventricle, a right atrium and a right ventricle;

step 1-4: determining an ultrasonic imaging position, based on the requirement of an M-Teich method ultrasonic cardiac imaging ejection fraction measuring method, forming a small hole at the outer side of a left ventricle along the direction of a short axis section of the left ventricle, and bonding a hard rubber leather tube (3) with the inner diameter not less than 1mm in a human dynamic heart model; in the left ventricle, according to the size of the heart transverse diameter of the human dynamic heart model, a hard rubber leather tube (3) is penetrated to be sleeved with a spring (2), one end of the spring (2) is propped against the wall of the left ventricle, and the other end of the spring (2) is propped against the ventricular septum; a channel is obliquely dug on the chamber interval and used for bonding and fixing the hard rubber leather tube (3) on the chamber interval, and the diameter of the channel is smaller than the inner diameter of the spring (2);

step 1-5: determining a positioning point mark, bonding a cylindrical acrylic gasket (1) with the diameter larger than 5mm and the thickness smaller than 0.5mm on the outer side of the small hole in the step 1-4, drilling a through hole with the diameter of 0.5mm in the center of the circle of the acrylic gasket (1), and simultaneously drilling 2 through holes with the diameter of 0.5mm on the same diameter at a position 1mm away from the center of the circle of the acrylic gasket (1) by taking the center of the circle of the acrylic gasket (1) as a symmetrical point; marking symmetrical positioning point marks x on the other diameter perpendicular to the connecting line of the group of symmetrical through holes, wherein the distance between the two positioning point marks x and the circle center of the acrylic gasket (1) is 1.5mm, and the two positioning point marks x are used for calibrating the displacement of the acrylic gasket (1) by a subsequent laser displacement sensor (16); two No. 2 nylon wires (4) with the wire diameter of 0.23cm penetrate out of the hard rubber leather tube (3) in the step 1-4, penetrate through a circle center through hole of the acrylic gasket (1), respectively penetrate out of two symmetrical through holes on the acrylic gasket (1), and then penetrate back into the hard rubber leather tube (3); the thread end of the nylon thread (4) extends out of the other end of the opening of the hard rubber tube (3) by 10 cm; the lower end of the acrylic gasket (1) threaded with the nylon thread (4) is bonded on the outer wall of the left ventricle;

step 1-6: and (3) placing the human dynamic heart model bonded with the acrylic gasket (1) on an object stage of an optical projector, and measuring the transverse cardiac diameter length of the left ventricle along the short axis of the left ventricle and in the direction vertical to the upper surface of the acrylic gasket (1) to be used as the standard value of the transverse cardiac diameter length of the diastolic state of the left ventricle in the M-Teich method ultrasonic cardiac imaging ejection fraction measuring method.

3. The ejection fraction calibration method based on the ultrasonic medical image as claimed in any one of claims 1-2, wherein the specific step of step 2 is to use the equivalent material of the myocardium made of the same material in step 1-2 to make the inferior vena cava simulated blood vessel (5) and the pulmonary vein simulated blood vessel (6), the two simulated blood vessels are respectively adhered to the corresponding positions of the dynamic heart model of the human body, the hard rubber leather tube (3) and the nylon wire (4) inside the hard rubber leather tube are penetrated out from the inferior vena cava simulated blood vessel (5), then the whole dynamic heart model of the human body is respectively fixed on the left side plate and the front side plate of the acrylic water tank through the inferior vena cava simulated blood vessel (5) and the pulmonary vein simulated blood vessel (6), so that the surface of the acrylic gasket (1) is parallel to the right side plate (7) of the acrylic water tank and the distance from the right side plate (7) is 5-7 cm, to mimic the position of the heart in the human thorax.

4. The ejection fraction calibration method based on the ultrasonic medical image is characterized in that the outer wall of a first acrylic tube (9-1) arranged at the center of a left side plate of an acrylic water tank is bonded with the left side plate of the acrylic water tank, a rubber sealing cover is bonded to a tube opening of the first acrylic tube (9-1) positioned at the outer side of the acrylic water tank, a small hole is drilled in the middle of the rubber sealing cover, so that a hard rubber tube (3) and a nylon wire (4) penetrate out of the acrylic water tank, and a lower vena cava simulation blood vessel (5) is sleeved on the tube opening of the first acrylic tube (9-1) positioned at the inner side of the acrylic water tank and is bonded by glue; the outer wall of a second acrylic pipe (9-2) which is 10cm away from a water tank bottom plate and 8cm away from a left side plate of the water tank is bonded with the front panel of the acrylic water tank from the front side plate of the acrylic water tank, a pulmonary vein simulation blood vessel (6) is sleeved on the second acrylic pipe (9-2) and is positioned on the pipe orifice of the inner side of the acrylic water tank and is bonded with glue, the length of the second acrylic pipe (9-2) in the acrylic water tank is 2-3 cm, the length of the second acrylic pipe outside the acrylic water tank is 2-3 cm, an acrylic pipe cover (10) is screwed with the second acrylic pipe (9-2) through threads, and therefore the leakage of the acrylic water tank after water is filled is prevented.

5. The ejection fraction calibration method based on ultrasonic medical images as claimed in any one of claims 1-2, wherein the specific step of step 3 is to connect the control host (17) of the mechanical motion control mechanism with the computer (18) and the air pump piston system or the laser displacement sensor (16) through the control signal transmission line (15) and realize real-time communication; the nylon wire (4) is fixed at the front end of a push-pull rod of a pneumatic piston (11) in the air pump piston system, and the initial state of the push-pull rod of the pneumatic piston (11) is defined as the state when the push-pull rod is completely contracted into the pneumatic piston (11); the relative position of the pneumatic piston (11) and the acrylic water tank is moved, so that the left ventricle wall is in a diastole state when the push-pull rod is pushed out to the maximum length; when an image is acquired, a fixing device (13) of the air pump piston system is fixed on the experiment table through a fixing clamp body, so that the fixing device (13) and the acrylic water tank are prevented from generating relative displacement; the fixing device (13) is properly lifted, and a push-pull rod of the pneumatic piston (11) and the nylon wire (4) are ensured to be on the same straight line parallel to the table top of the experiment table.

6. The ejection fraction calibration method based on ultrasound medical images as claimed in any one of claims 1-2, wherein the specific step of step 4 is that the acrylic pad (1) on the outer wall of the left ventricle drives the dynamic human heart model to generate regular reciprocating motion under the traction of the nylon thread (4), wherein the contraction force of the left ventricle is provided by the push-pull rod of the pneumatic piston (11) returning to the initial state, at this time, the contraction of the left ventricle of the dynamic human heart model causes the spring (2) to be deformed by the compression of the left ventricle wall and the ventricular septum; the diastolic force for the left ventricular wall of the dynamic heart model of the human body to return to the diastolic state is provided by a compressed spring (2).

7. The ejection fraction calibration method based on ultrasound medical images as claimed in any one of claims 1-2, wherein the specific step of step 5 is to determine the position of the laser displacement sensor (16) by using the fixed support (20) capable of being lifted, and when the displacement at the position outside the left ventricle is calibrated along the direction of the short axis tangent plane of the left ventricle, the standard value of the displacement at the position outside the left ventricle is measured every 5 heart rate values for heart rate values between 40-150 times/min; during measurement, water is not added into the acrylic water tank, the right side plate (7) is taken down at the same time, a preset heart rate value is set to enable the left ventricle wall to generate regular reciprocating motion, the height and the position of the laser displacement sensor (16) are adjusted, laser points used for distance measurement of the laser displacement sensor (16) are projected on the acrylic gasket (1), the displacement quantity of two positioning point marks X which are symmetrical left and right on the acrylic gasket (1) is measured respectively, each positioning point measures 10 times of displacement quantity, an average value is taken as the displacement quantity measurement result of the position, and finally the average value of the displacement quantity measurement results of the two positioning points is taken as the standard value of the displacement quantity at the position outside the left ventricle along the short axis section direction of the left ventricle; each heart rate value set during the motion of the human dynamic heart model corresponds to the switching rate of the electromagnetic valve (12) of the air pump piston system, and because the change of the switching rate of the electromagnetic valve (12) of the air pump piston system may cause incomplete contraction motion of the push-pull rod of the pneumatic piston (11), the displacement amount along the direction of the short axis section of the left ventricle and at the position outside the left ventricle can be changed along with the change of the heart rate value, and each heart rate value corresponds to a standard value of the displacement amount.

8. The method according to claim 7, wherein the step 6 comprises the following steps: keeping the heart rate value of claim 7 unchanged, inserting the right side plate (7) back into the groove of the acrylic water tank, filling water into the acrylic water tank until the dynamic heart model of the human body is submerged, and then obtaining an ultrasonic cardiogram image; when obtaining an echocardiogram, fixing a probe of an ultrasonic imaging device on a fixed support (20), wherein the height of the probe is consistent with the height of a laser sensor (16) when a standard value of the dynamic heart displacement of a human body is marked in claim 7; then, a couplant is smeared on a plastic film (7-1) of a right side plate (7) of the acrylic water tank, and a fixed support (20) is moved, so that a probe of ultrasonic imaging equipment is attached to the plastic film (7-1), and an ultrasonic cardiogram image is obtained at the angle of a short-axis section of a left ventricle; because the acoustic characteristics of the acrylic gasket (1) and the left ventricle of the human dynamic heart model are different, and the reflecting effect of the acrylic gasket (1) on ultrasound is stronger, the image brightness of the acrylic gasket (1) in an ultrasonic cardiogram image is higher, when a probe of an ultrasonic imaging device is basically coplanar with the short-axis section of the left ventricle, the acrylic gasket (1) can present a bright rectangle with unchanged shape and changed position on the ultrasonic cardiogram image, and the short-axis section of the left ventricle is searched by the aid of the difference between the acrylic gasket (1) and the ultrasonic cardiogram image of the left ventricle of the human dynamic heart model; under the condition that the left ventricle of the human dynamic heart model is in a diastolic state, obtaining an ultrasonic cardiogram at the angle of a short-axis section of the left ventricle, repeatedly measuring for 10 times, and taking the average value of 10 measurement results as the measured value of the transverse diameter length of the diastolic state of the left ventricle.

9. A special apparatus for implementing the ejection fraction calibration method based on ultrasound medical image of claims 1-8, wherein: the device comprises a human dynamic heart model, an acrylic water tank, a mechanical motion control mechanism, a support (20) capable of being adjusted to lift and a laser displacement sensor (16), wherein the human dynamic heart model is arranged in the acrylic water tank and connected with the mechanical motion control mechanism, and the laser displacement sensor (16) is connected with the mechanical motion control mechanism through a control signal transmission line (15) and realizes real-time communication.

10. The special device for the ejection fraction calibration method based on the ultrasonic medical image according to claim 9, wherein: the human dynamic heart model is made of three-component silicon-based rubber, the hardness of a myocardial material of the human dynamic heart model for preparation is measured by using a Shore hardness meter, the elastic modulus is calculated according to a conversion formula of the hardness and the elastic modulus, and the elastic modulus of the prepared myocardial material is equivalent to the elastic modulus of a real human myocardial tissue by adjusting the proportion of the three components;

the human body dynamic heart model is manufactured by combining real human body heart data and adjusting the geometric dimension of the three-dimensional numerical model, and comprises a left atrium, a left ventricle, a right atrium and a right ventricle;

based on the requirement of an M-Teich method echocardiography ejection fraction measuring method, a small hole is arranged along the direction of a short axis section of a left ventricle and at the position outside the left ventricle, and a hard rubber leather tube (3) with the inner diameter not less than 1mm is adhered inside a human dynamic heart model; in the left ventricle, according to the size of the heart transverse diameter of the human dynamic heart model, a spring (2) is sleeved through a hard rubber leather tube (3), one end of the spring (2) is propped against the wall of the left ventricle, and the other end of the spring (2) is propped against the ventricular septum; a channel is obliquely dug on the chamber partition and used for bonding and fixing the hard rubber leather tube (3) on the chamber partition, and the diameter of the channel is smaller than the inner diameter of the spring (2);

a cylindrical acrylic gasket (1) with the diameter larger than 5mm and the thickness smaller than 0.5mm is bonded on the outer side of the small hole, a through hole with the diameter of 0.5mm is drilled in the center of the circle center of the acrylic gasket (1), meanwhile, the circle center of the acrylic gasket (1) is taken as a symmetrical point, and 2 through holes with the diameter of 0.5mm are drilled in the position which is 1mm away from the circle center of the acrylic gasket (1) on the same diameter; marking symmetrical positioning point marks x on the other diameter perpendicular to the connecting line of the group of symmetrical through holes, wherein the distance between the two positioning point marks x and the center of the acrylic gasket (1) is 1.5mm, and the two positioning point marks x are used for calibrating the displacement of the acrylic gasket (1) by a subsequent laser displacement sensor (16);

two No. 2 nylon wires (4) with the wire diameter of 0.23cm penetrate out of the hard rubber leather tube (3), penetrate through a circle center through hole of the acrylic gasket (1), respectively penetrate out of two symmetrical through holes on the acrylic gasket (1), and then penetrate back into the hard rubber leather tube (3); the thread end of the nylon thread (4) extends out of the other end of the opening of the hard rubber tube (3) by 10 cm; the lower end of the acrylic gasket (1) threaded with the nylon thread (4) is bonded on the outer wall of the left ventricle.

11. The special equipment for the ejection fraction calibration method based on the ultrasonic medical image is characterized in that the human dynamic heart model further comprises an inferior vena cava simulated blood vessel (5) and a pulmonary vein simulated blood vessel (6), the inferior vena cava simulated blood vessel (5) and the pulmonary vein simulated blood vessel (6) are made of the same material as the human dynamic heart model and are respectively adhered to corresponding positions of the human dynamic heart model, the hard rubber tube (3) and the nylon wire (4) inside the hard rubber tube (3) penetrate out of the inferior vena cava simulated blood vessel (5), then the whole human dynamic heart model is fixed on the left side plate and the front side plate of the acrylic water tank through the inferior vena cava simulated blood vessel (5) and the pulmonary vein simulated blood vessel (6), so that the surface of the acrylic gasket (1) and the right side plate (7) of the acrylic water tank are kept parallel, and the distance from the right side plate (7) is 5-7 cm, to mimic the position of the heart in the human thorax.

12. The special equipment for the ejection fraction calibration method based on the ultrasonic medical image is characterized in that the acrylic water tank consists of a detachable right side plate (7) and a water tank (8) without an upper cover plate, the right side plate (7) and the water tank (8) without the upper cover plate are both made of acrylic plates, the length of the whole acrylic water tank is 15-20 cm, the width of the whole acrylic water tank is 20-25 cm, the depth of the whole acrylic water tank is 20-25 cm, and the thickness of each acrylic plate is 2 cm;

the right side plate (7) consists of a plastic film (7-1) and a right side plate main body (7-2), the length and width of the plastic film (7-1) are both 10-15 cm, and the thickness of the plastic film is less than 0.5mm, and after the outer side of the plastic film (7-1) is coated with a coupling agent, an ultrasonic imaging probe can receive ultrasonic reflection signals of a human dynamic heart model in an acrylic water tank;

the outer side of the plastic film (7-1) is provided with a right side plate main body (7-2), and the left side edge, the right side edge and the lower edge of the right side plate (7) are etched to form a convex structure; the width of the protruding part of the convex structure is 1cm, the height of the protruding part is 1cm, and the width of both sides of the protruding part is 0.5 cm; the surface of the convex structure is bonded with a rubber sealing strip with the thickness of 0.5 mm; the front side plate, the rear side plate and the bottom plate which are connected with the right side plate (7) of the water tank (8) without the upper cover are all etched to form concave empty grooves corresponding to the convex shapes, and when the right side plate (7) is inserted into the corresponding empty grooves, water in the acrylic water tank cannot seep out from the joint of the right side plate (7) and the water tank (8) without the upper cover due to the expansion effect of the rubber sealing strip.

13. The special equipment for the ejection fraction calibration method based on the ultrasonic medical image is characterized by further comprising a first acrylic tube (9-1) and a second acrylic tube (9-2), wherein the outer wall of the first acrylic tube (9-1) arranged in the center of the left side plate of the acrylic water tank is bonded with the left side plate of the acrylic water tank, a rubber sealing cover is bonded to a tube opening of the first acrylic tube (9-1) positioned on the outer side of the acrylic water tank, a small hole is drilled in the middle of the rubber sealing cover, so that the hard rubber tube (3) and the nylon wire (4) penetrate out of the acrylic water tank, and the inferior vena cava simulation blood vessel (5) is sleeved on the tube opening of the first acrylic tube (9-1) positioned on the inner side of the acrylic water tank and is bonded by glue;

the outer wall of a second acrylic pipe (9-2) which is 10cm away from a water tank bottom plate and 8cm away from a left side plate of the water tank is bonded with the front panel of the acrylic water tank on the front side panel of the acrylic water tank, a pulmonary vein simulation blood vessel (6) is sleeved on a pipe orifice of the second acrylic pipe (9-2) which is positioned on the inner side of the acrylic water tank and is bonded with glue, the length of the second acrylic pipe (9-2) in the acrylic water tank is 2-3 cm, the length of the second acrylic pipe in the outer part of the acrylic water tank is 2-3 cm, and an acrylic pipe cover (10) is screwed with the second acrylic pipe (9-2) through threads so as to prevent the acrylic water tank from leaking after water is poured.

14. The special device for the ejection fraction calibration method based on the ultrasonic medical image according to claim 9, wherein: the mechanical motion control mechanism consists of a computer (18), a control host (17) and an air pump piston system, wherein the control host (17) is respectively connected with the computer (18) and the air pump piston system or the laser displacement sensor (16) through a control signal transmission line (15) and is communicated in real time;

the air pump piston system consists of four parts, and comprises an electromagnetic valve (12), a pneumatic piston (11), an air compressor (19) containing an air tank and a fixing device (13), wherein the electromagnetic valve (12) and the pneumatic piston (11) are arranged on the fixing device (13), the air compressor (19) is communicated with the electromagnetic valve (12) through an air pipe (14), the electromagnetic valve (12) is communicated with the pneumatic piston (11) through the air pipe (14), and the air compressor (19) is used for providing air flow with stable pressure within a period of time; the electromagnetic valve (12) is used for controlling the on-off state of air flow, when the electromagnetic valve (12) is closed, the air flow provided by the air compressor (19) is input into the pneumatic piston (11) through the electromagnetic valve (12), so that the push-pull rod of the pneumatic piston (11) is pushed out to the maximum position, and when the electromagnetic valve (12) is opened, the air flow is cut off; the length of a push-pull rod of the pneumatic piston (11) is 20mm, and the nylon wire (4) is fixed at the front end of the push-pull rod of the pneumatic piston (11);

wherein the computer (18) is provided with data acquisition and motion control software for adjusting the switching rate of the electromagnetic valve (12) and receiving and processing the displacement measurement result.

15. The special device for calibrating ejection fraction based on ultrasound medical image according to claim 9, wherein: the lifting-adjustable support (20) consists of an upright rod (20-1), a spring clamp (20-2), a fastening screw (20-3), a shelf (20-4) and a base (20-5), wherein the upright rod (20-1) is 20-25 cm high, the upright rod is fixed on the base (20-5) through threads at the bottom of the upright rod (20-1), and a screw hole is formed in the base (20-5) at a corresponding position; the spring clamp (20-2) is sleeved on the vertical rod (20-1), and the position of a laser displacement sensor (16) or a probe of ultrasonic imaging equipment is determined by using the adjustable lifting support (20); after the position of a probe of the laser displacement sensor (16) or the ultrasonic imaging equipment is determined, a spring clamp (20-2) is used for clamping and fixing; the fastening screw (20-3) is used for adjusting the height of the shelf (20-4), the shelf (20-4) is fixed when the fastening screw (20-3) is screwed, and the position of the shelf (20-4) can be adjusted up and down when the fastening screw (20-3) is unscrewed.

Technical Field

The invention relates to a medical image calibration method in the field of medical images, in particular to an ejection fraction calibration method based on ultrasonic medical images and special equipment.

Background

The prevention of cardiovascular disease is currently divided into four stages: zero-order prevention is to evade lifestyle that may cause cardiovascular disease from a lifestyle and mental health perspective; primary prevention is to correct an unhealthy lifestyle of a person at risk of the disease; the secondary prevention is to generally screen and treat the cardiovascular disease susceptible population with hypertension, hyperglycemia and hyperlipidemia, so as to realize early discovery, early diagnosis and early treatment; the third stage prevention is preventive medication for cardiovascular diseases, such as dosing aspirin and other drugs.

Of the four-stage preventive measures described above, secondary prevention is an important link in the discovery and diagnosis of cardiovascular diseases. Chronic diseases such as hypertension, hyperlipidemia and the like can be diagnosed in the form of blood drawing assay; for cardiovascular diseases with altered physicochemical properties, such as heart failure, medical images are important diagnostic criteria. Among all medical images, ultrasound medical images have the characteristics of real-time performance, simplicity, convenience and the like, and become an important means for clinically diagnosing diseases such as heart failure and the like. Among cardiac ultrasound measurement indices, ejection fraction is one of the important indicators for judging the type of heart failure. The ejection fraction is the percentage of stroke volume in the end-diastolic volume of the ventricles, with a normal value of 50% to 70%. It can represent the systolic function of the heart and is an important index for the color ultrasound examination of the heart, and the value of the left ventricle is generally measured. The formula for calculating ejection fraction is: EF ═ EDV-ES + 100%/EDV, where EF is ejection fraction; EDV is ventricular end-diastolic volume; ES is the end ventricular systolic volume. As can be seen from the equation, ejection fraction is an index of volume ratio, reflecting the ejection function of the ventricles from a volume perspective. If the ejection fraction is less than 50%, the myocardial contractile force is considered to be reduced, and the cardiac contractile function is considered to be decreased.

The heart color ultrasound image is used to measure ejection fraction, and the following three methods are most common. First, 3D measurement method. And (3) automatically outlining and respectively calculating the volume of the contraction phase and the diastole phase of the left ventricle by using the self-contained software of the ultrasonic imaging equipment, and then calculating the EF value. Second, two-dimensional-simpson biplane method. Drawing the endocardial boundary on the section of the standard four chambers and two chambers of the apex, respectively calculating the areas of contraction and relaxation states, and then calculating the EF value. Third, the M-Teich method. The EF value is calculated by representing the volume of the left ventricle at the end-diastolic (EDD) and end-systolic (ESD) dimensions under the guidance of the parasternal left ventricular short-axis slice.

Among the three methods, the M-type-Teich method is most convenient and fast to apply, has the widest range and has the longest history. The traditional M-Teich method utilizes extremely high sampling frequency to obtain a curve of the change of the section image position of the specific position of the myocardial wall along with time, and extracts the displacement of the specific position from the curve to calculate the ejection fraction. When the traditional M-type Teich method is used for acquiring images, a sampling line is required to be perpendicular to the myocardial intima of the wall of a measured target, and the repeatability and the accuracy of operation are low, so that the improved Teich methods such as an anatomical M-type method and an all-round M-type method are derived in recent research, but the ejection fraction is calculated according to the displacement extracted from the images on the basis of the basic principle.

Whatever the M-Teich method used for the measurement and calculation of the ejection fraction, it has the following disadvantages: firstly, the selection of the measurement position depends on the selection of the experience of a doctor, and the repeatability is low; secondly, the ejection fraction measurement can be influenced by the change of the blood content of the myocardium, so that the measurement result is inaccurate; thirdly, without a special calibration technology, the accuracy of the displacement measurement result cannot be evaluated and analyzed, and the accuracy and effectiveness of the ejection fraction calculation result cannot be evaluated.

In view of the above-mentioned defects of the prior M-Teich method for measuring and calculating ejection fraction, the inventor has made extensive research and design, and after repeated trial and improvement, finally created the invention with practical value.

Disclosure of Invention

The invention aims to overcome the defects of the existing method for measuring the ejection fraction by using a heart color ultrasound image, provides a new ejection fraction calibration method based on an ultrasonic medical image and special equipment, and aims to solve the technical problem of accurate measurement position and high practicability.

Another objective of the present invention is to overcome the defects of the existing method for measuring ejection fraction by using heart color ultrasound images, and to provide an ejection fraction calibration method and a special device based on ultrasound medical images with a novel structure, which are not affected by the change of the blood content of the myocardium itself, so as to ensure accurate measurement results, and are more practical.

The invention also aims to overcome the defects of the existing method for measuring ejection fraction by using heart color ultrasound images, and provides a new ejection fraction calibration method and special equipment based on ultrasonic medical images, so that the technical problem to be solved is to provide the special calibration technology, accurately evaluate and analyze the accuracy and effectiveness of the ejection fraction calculation result, improve the measurement repeatability of the ultrasonic cardiac displacement of the dynamic heart model of the human body, and be more practical.

The purpose of the invention and the technical problem to be solved are realized by adopting the following technical scheme. According to the invention, the ejection fraction calibration method based on the ultrasonic medical image comprises the following steps:

step 1: manufacturing a human dynamic heart model;

step 2: installing a human dynamic heart model in an acrylic water tank;

and step 3: installing a mechanical motion control mechanism and connecting the human dynamic heart model installed on the acrylic water tank with the mechanical motion control mechanism;

and 4, step 4: starting a mechanical motion control mechanism to drive the human dynamic heart model to generate regular reciprocating motion;

and 5: calibrating the displacement of the outer position of the left ventricle along the direction of the short axis section of the left ventricle, determining the position of the laser displacement sensor by using an adjustable lifting support without injecting water into an acrylic water tank, and measuring a standard value of the displacement at the outer position by using the laser displacement sensor;

step 6: acquiring an echocardiogram, filling water in an acrylic water tank until the dynamic heart model of the human body is submerged, then acquiring the echocardiogram, and measuring the measurement value of the displacement by using an M-Teich method after the echocardiogram is acquired;

and 7: and for the heart rate value between 40 and 150 times/minute, measuring the displacement correction value corresponding to the heart rate value every 5 times/minute, embedding a comparison table of the measured heart rate value and the displacement correction value and the standard value and the measured value of the left ventricular diastolic heart transverse diameter length into the ultrasonic equipment, namely, the heart rate value can be used for correcting the ejection fraction calculation result based on the ultrasonic medical image in the future, and for the numerical value not in the comparison table, obtaining the correction value of the heart rate value by adopting a linear interpolation mode.

The object of the present invention and the technical problems solved thereby can be further achieved by the following technical measures.

Further, step 1 comprises:

step 1-1: drawing a three-dimensional numerical model based on an open-source human dynamic heart model, and regulating the geometric dimension of the three-dimensional numerical model by combining with real human heart data to enable the three-dimensional numerical model to present a real human physiological anatomical structure;

step 1-2: adjusting the elastic modulus of a myocardial material used for preparing the human dynamic heart model, wherein the myocardial material is made of three-component silicon-based rubber, the hardness of the myocardial material of the prepared human dynamic heart model is measured by using a Shore hardness meter, the elastic modulus is calculated according to a conversion formula of the hardness and the elastic modulus, and the elastic modulus of the myocardial material of the human dynamic heart model is equivalent to the elastic modulus of a real human myocardial tissue by adjusting the proportion of the three components; the elastic modulus of the myocardial material is 1.86-2.37 MPa, and the material is equivalent to the real myocardial tissue of a human body in terms of mechanical properties;

step 1-3: manufacturing a human dynamic heart model, performing 3D printing on the human dynamic heart model according to the three-dimensional numerical model in the step 1-1, performing reverse molding on the printed human dynamic heart model, and preparing the human dynamic heart model by using the mold and the myocardial material of the human dynamic heart model in the step 1-2; in order to facilitate various work in the subsequent steps, the model is divided into an upper part and a lower part in the process of back molding of the human dynamic heart model, all the subsequent steps are operated on the lower half part, and the upper part and the lower part are bonded together by using the same myocardial material in the step 1-2 after all the steps are finished to form the complete human dynamic heart model; the prepared human dynamic heart model comprises a left atrium, a left ventricle, a right atrium and a right ventricle;

step 1-4: determining an ultrasonic imaging position, based on the requirement of an M-Teich method ultrasonic cardiac imaging ejection fraction measuring method, forming a small hole at the outer side of a left ventricle along the direction of a short axis section of the left ventricle, and bonding a hard rubber tube with the inner diameter not less than 1mm in the dynamic heart model of the human body; in the left ventricle, a spring is sleeved and connected through a hard rubber leather tube according to the size of the transverse diameter of the heart of the human dynamic heart model, one end of the spring is propped against the wall of the left ventricle, and the other end of the spring is propped against the ventricular septum; a channel is obliquely dug on the chamber partition and used for bonding and fixing the hard rubber leather tube on the chamber partition, and the diameter of the channel is smaller than the inner diameter of the spring 2;

step 1-5: determining a positioning point mark, bonding a cylindrical acrylic gasket with the diameter more than 5mm and the thickness less than 0.5mm on the outer side of the small hole in the step 1-4, drilling a through hole with the diameter of 0.5mm in the center of the circle of the acrylic gasket, and drilling 2 through holes with the diameter of 0.5mm on the same diameter at a position 1mm away from the center of the circle of the acrylic gasket by taking the center of the circle of the acrylic gasket as a symmetrical point; marking symmetrical positioning point marks x on the other diameter perpendicular to the connecting line of the group of symmetrical through holes, wherein the distance between the two positioning point marks x and the circle center of the acrylic gasket is 1.5mm, and the two positioning point marks x are used for calibrating the displacement of the acrylic gasket by a subsequent laser displacement sensor 16; two No. 2 nylon wires with the wire diameter of 0.23cm penetrate out of the hard rubber leather tube in the step 1-4, penetrate through the circle center through hole of the acrylic gasket, respectively penetrate out of two symmetrical through holes on the acrylic gasket, and then penetrate back into the hard rubber leather tube; the thread end of the nylon thread extends out of the other end of the orifice of the hard rubber tube by 10 cm; bonding the lower end of the acrylic gasket penetrated with the nylon thread on the outer wall of the left ventricle;

step 1-6: and placing the human dynamic heart model bonded with the acrylic gasket on an object stage of an optical projector, and measuring the transverse cardiac diameter length of the left ventricle along the short axis of the left ventricle and in the direction vertical to the upper surface of the acrylic gasket to be used as the standard value of the transverse cardiac diameter length of the diastolic state of the left ventricle in the M-Teich method ultrasonic cardiac imaging ejection fraction measuring method.

Further, the specific step of step 2 is to adopt the equivalent myocardial material with the same material in step 1-2 to make inferior vena cava simulated blood vessels and pulmonary vein simulated blood vessels, the two simulated blood vessels are respectively adhered at corresponding positions of the dynamic heart model of the human body, the nylon wires in the hard rubber leather tube and the hard rubber leather tube penetrate out of the inferior vena cava simulated blood vessels, then the whole dynamic heart model of the human body is respectively fixed on the left side plate and the front side plate of the acrylic water tank through the inferior vena cava simulated blood vessels and the pulmonary vein simulated blood vessels, so that the surface of the acrylic gasket is parallel to the right side plate of the acrylic water tank, and the distance from the surface to the right side plate is 5-7 cm, thereby simulating the position of the heart in the thoracic cavity of the human body.

Further, the outer wall of a first acrylic tube arranged in the center of a left side panel of the acrylic water tank is bonded with the left side panel of the acrylic water tank, a rubber sealing cover is bonded to a tube opening of the first acrylic tube positioned on the outer side of the acrylic water tank, a small hole is drilled in the middle of the rubber sealing cover, so that a hard rubber tube and a nylon wire penetrate out of the acrylic water tank, and an inferior vena cava simulation blood vessel is sleeved on the tube opening of the first acrylic tube positioned on the inner side of the acrylic water tank and bonded by glue;

the front side board of ya keli water tank is apart from last distance water tank bottom plate 10cm, the outer wall of the second ya keli pipe apart from 8cm of water tank left side board bonds together with the front panel of ya keli water tank, pulmonary vein simulation blood vessel cup joints on the mouth of pipe that the second ya keli pipe is located ya keli water tank inboard and bonds with glue, the second ya keli pipe is 2 ~ 3cm at the inside partial length of ya keli water tank, be 2 ~ 3cm at the outside partial length of ya keli water tank, the yakeli tube cap screws through screw thread and the outside yakeli pipe of second, in order to prevent the yakeli water tank seepage after watering.

Further, the step 3 is to connect the control host of the mechanical motion control mechanism with the computer and the air pump piston system or the laser displacement sensor through the control signal transmission line to realize real-time communication; fixing a nylon wire at the front end of a push-pull rod of a pneumatic piston in the air pump piston system, wherein the initial state of the push-pull rod of the pneumatic piston is defined as the state when the push-pull rod of the pneumatic piston is completely contracted into the pneumatic piston; moving the relative position of the pneumatic piston and the acrylic water tank to ensure that the left ventricle wall is in a diastole state when the push-pull rod is pushed to the maximum length; when an image is acquired, a fixing device of the air pump piston system is fixed on the experiment table through a fixing clamp body, so that the fixing device and the acrylic water tank are prevented from generating relative displacement; the fixing device is properly heightened to ensure that the push-pull rod of the pneumatic piston and the nylon wire are on the same straight line parallel to the table top of the experiment table.

Further, the method is characterized in that the concrete step 4 is that an acrylic gasket on the outer wall of the left ventricle drives the human dynamic heart model to generate regular reciprocating motion under the traction of a nylon wire, wherein the contraction force of the left ventricle is provided by a push-pull rod of a pneumatic piston when the push-pull rod is restored to an initial state, and at the moment, the contraction of the left ventricle of the human dynamic heart model causes a spring to be compressed by the wall of the left ventricle and the interval of the ventricle to generate deformation; the diastolic force to return the left ventricular wall of the dynamic heart model of the human body to the diastolic state is provided by the compressed spring.

Further, the specific step of the step 5 is to determine the position of the laser displacement sensor by using a liftable fixed support, and when the displacement at the position outside the left ventricle is calibrated along the direction of the short axis section of the left ventricle, for heart rate values of 40-150 times/minute, the standard value of the displacement at the position outside the left ventricle is measured every 5 times/minute of heart rate values; during measurement, water is not added into an acrylic water tank, a right side plate is taken down at the same time, a preset heart rate value is set to enable a left ventricle wall to generate regular reciprocating motion, the height and the position of a laser displacement sensor are adjusted, laser points used for ranging by the laser displacement sensor are projected on an acrylic gasket, displacement of two positioning point marks multiplied by the number is measured on the acrylic gasket in bilateral symmetry respectively, 10-time displacement measurement is carried out on each positioning point, an average value is taken as a displacement measurement result of the position, and finally the average value of the displacement measurement results of the two positioning points is taken as a standard value of the displacement at the position of the outer side of a left ventricle along the short axis section direction of the left ventricle; each heart rate value set during the motion of the human dynamic heart model corresponds to the switching rate of the electromagnetic valve of the air pump piston system, and because the change of the switching rate of the electromagnetic valve of the air pump piston system may cause incomplete contraction motion of the push-pull rod of the pneumatic piston, the displacement at the position outside the short-axis section of the left ventricle changes along with the change of the heart rate value, each heart rate value corresponds to a standard value of the displacement.

Further, the step 6 comprises the following specific steps: keeping the switching rate of the electromagnetic valve in the step 5 unchanged, inserting the right side plate back into the groove of the acrylic water tank, filling water into the acrylic water tank until the human dynamic heart model is submerged, and then obtaining an ultrasonic cardiogram image; when the ultrasonic cardiogram is obtained, a probe of the ultrasonic imaging equipment is fixed on the fixed support, and the height of the probe is consistent with the height of the laser sensor when the standard value of the human body dynamic heart displacement is calibrated; then smearing a coupling agent on a plastic film of a right side plate of the acrylic water tank, moving the fixed support to enable a probe of the ultrasonic imaging equipment to be attached to the plastic film, and acquiring an ultrasonic cardiogram image at an angle of a short-axis section of the left ventricle; because the acoustic characteristics of the acrylic gasket are different from those of the left ventricle of the human body dynamic heart model, the reflecting effect of the acrylic gasket on the ultrasound is stronger, so that the image brightness of the acrylic gasket in the ultrasonic cardiogram is higher, when a probe of the ultrasonic imaging equipment is basically coplanar with the short-axis section of the left ventricle, the acrylic gasket can present a bright rectangle with unchanged shape and changed position on the ultrasonic cardiogram, and the short-axis section of the left ventricle is searched in an auxiliary way by utilizing the difference between the acrylic gasket and the ultrasonic cardiogram of the left ventricle of the human body dynamic heart model; under the condition that the left ventricle of the human dynamic heart model is in a diastolic state, obtaining an ultrasonic cardiogram image at the angle of a short-axis section of the left ventricle, repeatedly measuring for 10 times, and taking the average value as the measured value of the heart transverse diameter length of the diastolic state of the left ventricle.

The purpose of the invention and the technical problem to be solved are realized by adopting the following technical scheme. The invention provides special equipment adopting an ejection fraction calibration method based on ultrasonic medical images, which is characterized by comprising the following steps: the device comprises a human dynamic heart model, an acrylic water tank, a mechanical motion control mechanism, a support capable of being adjusted to lift and a laser displacement sensor, wherein the human dynamic heart model is arranged in the acrylic water tank and is connected with the mechanical motion control mechanism, and the laser displacement sensor is connected with the mechanical motion control mechanism through a control signal transmission line and realizes real-time communication.

The object of the present invention and the technical problems solved thereby can be further achieved by the following technical measures.

Further, the human dynamic heart model is made of three-component silicon-based rubber, the hardness of a myocardial material of the human dynamic heart model for preparation is measured by using a Shore hardness tester, the elastic modulus is calculated according to a conversion formula of the hardness and the elastic modulus, and the elastic modulus of the prepared myocardial material is equivalent to the elastic modulus of a real human myocardial tissue by adjusting the proportion of the three components;

the human body dynamic heart model is manufactured by combining real human body heart data and adjusting the geometric dimension of the three-dimensional numerical model, and comprises a left atrium, a left ventricle, a right atrium and a right ventricle;

based on the requirement of an M-Teich method echocardiography ejection fraction measuring method, a small hole is arranged along the direction of a short axis section of a left ventricle and at the position outside the left ventricle, and a hard rubber leather tube with the inner diameter not less than 1mm is adhered inside a human dynamic heart model; in the left ventricle, a spring is sleeved and connected through a hard rubber leather tube according to the size of the transverse diameter of the heart of the human dynamic heart model, one end of the spring is propped against the wall of the left ventricle, and the other end of the spring is propped against the ventricular septum; a channel is obliquely dug on the chamber partition and used for bonding and fixing the hard rubber leather tube on the chamber partition, and the diameter of the channel is smaller than the inner diameter of the spring;

a cylindrical acrylic gasket with the diameter larger than 5mm and the thickness smaller than 0.5mm is bonded on the outer side of the small hole, a through hole with the diameter of 0.5mm is drilled in the center of the circle center of the acrylic gasket, meanwhile, the circle center of the acrylic gasket is taken as a symmetrical point, and 2 through holes with the diameter of 0.5mm are drilled in the same diameter at a position 1mm away from the circle center of the acrylic gasket; marking symmetrical positioning point marks x on the other diameter perpendicular to the connecting line of the group of symmetrical through holes, wherein the distance between the two positioning point marks x and the circle center of the acrylic gasket is 1.5mm, and the two positioning point marks x are used as a subsequent laser displacement sensor to calibrate the displacement of the acrylic gasket;

two No. 2 nylon wires with the wire diameter of 0.23cm penetrate out of the hard rubber leather tube, penetrate through the center through hole of the acrylic gasket, respectively penetrate out of two symmetrical through holes on the acrylic gasket, and then penetrate back into the hard rubber leather tube; the thread end of the nylon thread extends out of the other end of the orifice of the hard rubber tube by 10 cm; the lower end of the acrylic gasket penetrated with the nylon thread is bonded on the outer wall of the left ventricle.

Furthermore, the human dynamic heart model also comprises an inferior vena cava simulation blood vessel and a pulmonary vein simulation blood vessel, the inferior vena cava simulation blood vessel and the pulmonary vein simulation blood vessel are made of the same material as the human dynamic heart model and are respectively bonded at the corresponding positions of the human dynamic heart model, a nylon wire inside the hard rubber tube and the hard rubber tube penetrates out of the inferior vena cava simulation blood vessel, and then the whole human dynamic heart model is fixed on the left side plate and the front side plate of the acrylic water tank through the inferior vena cava simulation blood vessel and the pulmonary vein simulation blood vessel, so that the surface of the acrylic gasket is parallel to the right side plate of the acrylic water tank, and the distance from the surface to the right side plate is 5-7 cm, and the position of the heart in the human thoracic cavity is simulated.

Further, the acrylic water tank consists of a detachable right side plate and a water tank without an upper cover plate, the right side plate and the water tank without the upper cover plate are both made of acrylic plates, the length of the whole acrylic water tank is 15-20 cm, the width of the whole acrylic water tank is 20-25 cm, the depth of the whole acrylic water tank is 20-25 cm, and the thickness of each acrylic plate is 2 cm;

the right side plate consists of a plastic film and a right side plate main body, the length and width of the plastic film are both 10-15 cm, the thickness of the plastic film is less than 0.5mm, and after the couplant is coated on the outer side of the plastic film, the ultrasonic imaging probe can receive ultrasonic reflection signals of a human dynamic heart model in the acrylic water tank;

the outer side of the plastic film is provided with a right side plate main body, and the left side edge, the right side edge and the lower edge of the right side plate are etched to form a convex structure; the width of the protruding part of the convex structure is 1cm, the height of the protruding part is 1cm, and the width of both sides of the protruding part is 0.5 cm; the surface of the convex structure is bonded with a rubber sealing strip with the thickness of 0.5 mm; the front side plate, the rear side plate and the bottom plate which are connected with the right side plate of the water tank without the upper cover are all etched with concave empty grooves corresponding to the convex shapes, and when the right side plate is inserted into the corresponding empty grooves, water in the acrylic water tank cannot seep out from the joint of the right side plate and the water tank without the upper cover due to the expansion effect of the rubber sealing strip.

The artificial blood vessel is characterized by further comprising a first acrylic tube and a second acrylic tube, wherein the outer wall of the first acrylic tube arranged at the center of a left panel of the acrylic water tank is bonded with a left panel of the acrylic water tank, the first acrylic tube is a rubber sealing cover bonded with a pipe orifice positioned on the outer side of the acrylic water tank, a small hole is drilled in the middle of the rubber sealing cover, so that the hard rubber tube and a nylon wire penetrate out of the acrylic water tank, and a lower vena cava simulation blood vessel is sleeved on the pipe orifice positioned on the inner side of the acrylic water tank of the first acrylic tube and is bonded with glue;

the front side board of ya keli water tank is apart from last distance water tank bottom plate 10cm, the outer wall of the second ya keli pipe apart from 8cm of water tank left side board bonds together with the front panel of ya keli water tank, pulmonary vein simulation blood vessel cup joints on the mouth of pipe that the second ya keli pipe is located ya keli water tank inboard and bonds with glue, the second ya keli pipe is 2 ~ 3cm at the inside partial length of ya keli water tank, be 2 ~ 3cm at the outside partial length of ya keli water tank, the yakeli tube cap screws through screw thread and second yakeli pipe, in order to prevent the yakeli water tank from watering back seepage.

Further, the mechanical motion control mechanism consists of a computer, a control host and an air pump piston system, wherein the control host is respectively connected with the computer and the air pump piston system or the laser displacement sensor through a control signal transmission line and is communicated in real time;

the air pump piston system consists of 4 parts and comprises an electromagnetic valve, a pneumatic piston, an air compressor containing an air tank and a fixing device, wherein the electromagnetic valve and the pneumatic piston are arranged on the fixing device; the electromagnetic valve is used for controlling the on-off state of air flow, when the electromagnetic valve is closed, the air flow provided by the air compressor is input into the pneumatic piston through the electromagnetic valve, so that the push-pull rod of the pneumatic piston is pushed out to the maximum position, and when the electromagnetic valve is opened, the air flow is cut off; the length of the push-pull rod of the pneumatic piston is 20mm, and a nylon wire is fixed at the front end of the push-pull rod of the pneumatic piston;

data acquisition and motion control software is installed in the computer and used for adjusting the switching rate of the electromagnetic valve and receiving and processing the displacement measurement result.

Furthermore, the lifting-adjustable support consists of an upright rod, a spring clamp, a fastening screw, a shelf and a base, wherein the height of the upright rod is 20-25 cm, the upright rod is fixed on the base through threads at the bottom of the upright rod, and a screw hole is formed in the base at a corresponding position; the spring jacket is arranged on the upright rod, and the position of a probe of a laser displacement sensor or ultrasonic imaging equipment is determined by using the adjustable lifting bracket; after the position of a probe of a laser displacement sensor or ultrasonic imaging equipment is determined, clamping and fixing the probe by using a spring clamp; the fastening screw is used for adjusting the height of the shelf, the shelf is fixed when the fastening screw is screwed, and the position of the shelf can be adjusted up and down when the fastening screw is unscrewed.

Compared with the prior art, the invention has obvious advantages and beneficial effects. It has at least the following advantages:

1. the invention adopts three components of silicon-based materials to make the human dynamic heart model, and has good equivalence of the elastic modulus of the real human myocardial tissue; meanwhile, as the three-component silicon-based material does not absorb or seep water, the internal water content of the human dynamic heart model made of the three-component silicon-based material is kept stable, the myocardial material does not generate blood extrusion effect when the human dynamic heart model moves, and compared with the blood fraction measurement result of ultrasonic medical image shooting of the real human heart, the three-component silicon-based material can reduce the deviation of the blood fraction measurement result caused by the myocardial blood extrusion effect;

2. the human body dynamic heart model is made based on the three-dimensional data of the real human body heart structure, and has good structure equivalent characteristics; selecting the position same as the clinical ejection fraction measurement, namely setting a measurement point at the position outside the left ventricle along the direction of the short axis section of the left ventricle, wherein the measured displacement is the data of the position required by the clinic;

3. the acrylic gasket with the diameter less than 5mm is bonded at the set measuring point to form a flat measuring position and mark a positioning point, so that the measuring point when the laser displacement sensor carries out the displacement calibration of the human dynamic heart model is accurately positioned, and the measuring repeatability of a standard value is improved;

4. the left ventricle short axis section of the human dynamic heart model is difficult to obtain, and the clinical search of the left ventricle short axis section is usually based on the personal experience of the doctor. According to the invention, the acrylic gasket is bonded on the outer wall of the left ventricle at the position of the short-axis section of the left ventricle, the acoustic property of the acrylic gasket is different from that of the left ventricle of the human dynamic heart model, and the reflecting effect of the acrylic gasket on ultrasound is stronger, so that the image brightness of the acrylic gasket in an ultrasound image is higher, when a probe of an ultrasound imaging device is basically coplanar with the short-axis section of the left ventricle, the acrylic gasket presents a bright rectangle with an unchanged shape and a changed position on the ultrasound image, so that the acrylic gasket can be used for assisting in finding the short-axis section of the left ventricle, the positioning difficulty of the short-axis section of the left ventricle during the acquisition of the ultrasound image is reduced, and the measurement repeatability of the short-axis section displacement of the left ventricle of the human dynamic heart model is improved;

5. because the change of the switching rate of the electromagnetic valve of the air pump piston system can cause incomplete contraction movement of the push-pull rod of the pneumatic piston, the position displacement of the outer side of the left ventricle can change along with the change of the heart rate value, and the situation also accords with the actual situation that the movement of the left ventricle of the real heart of a human body is accelerated along with the heart rate and the contraction movement is incomplete; therefore, each heart rate value corresponds to a standard value of displacement; for the heart rate values between (40-150) times/minute, measuring the displacement correction value corresponding to the heart rate value every 5 times/minute, establishing a comparison table of the heart rate value and the displacement correction value, and for the numerical values which are not in the comparison table, obtaining the displacement correction value corresponding to the heart rate value by adopting a linear interpolation mode;

6. the comparison table of the heart rate value and the displacement correction value is arranged in the ultrasonic medical imaging equipment and used for calibrating the displacement measurement result used in the ejection fraction calculation, so that the accuracy of the ejection fraction calculation is improved, and the effectiveness of evaluating diseases such as heart failure by using the ejection fraction is improved.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following preferred embodiments are described in detail with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic illustration of the heart of the present invention.

Fig. 2 is a schematic top view of fig. 1.

Fig. 3 is a schematic top view of an acrylic water tank.

Fig. 4 is a right side view of the acrylic water tank right side plate.

FIG. 5 is a schematic view of the connection between the air pump piston system and the acrylic water tank according to the present invention.

Fig. 6 is a schematic view of the fixing bracket of the present invention.

Wherein:

1: acrylic gasket 2: spring

3: hard rubber hose 4: nylon wire

5: inferior vena cava mimic blood vessel 6: pulmonary vein simulated blood vessel

7: right side plate

7-1: plastic film 7-2: right side plate main body

8: water tank without upper cover

9: acrylic tube

9-1: first acrylic tube

9-2: second acrylic tube

10: acrylic pipe cover

11: the pneumatic piston 12: electromagnetic valve

13: the fixing device 14: trachea

15: control signal transmission line 16: laser displacement sensor

17: the control host 18: computer with a display

19: air compressor

20: adjustable lifting support

20-1: 20-2 of vertical rod: spring clip

20-3: fastening screws 20-4: shelf board

20-5: base seat

Detailed Description

To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, the following detailed description of the specific embodiments, methods, steps, structures, features and effects of the ejection fraction calibration method based on ultrasound medical images and the special equipment thereof according to the present invention are provided with the accompanying drawings and preferred embodiments.

Referring to fig. 1-6, a method for calibrating ejection fraction based on ultrasound medical images according to a preferred embodiment of the present invention mainly includes the following steps: as shown with reference to figures 1 and 2,

step 1: manufacturing a human dynamic heart model:

step 1-1: and drawing a three-dimensional numerical model based on the open-source human dynamic heart model. Regulating the geometric dimension of the three-dimensional numerical model by combining with the real human heart data to enable the three-dimensional numerical model to present a real human physiological anatomical structure; because the human ventricular myocardium wall is thicker, in order to reduce the resistance caused by the elasticity of the myocardial material during exercise, the thickness of the left ventricle and the right ventricle myocardium wall is reduced to 5 mm;

step 1-2: the elastic modulus of the myocardial material used for preparing the human dynamic heart model is adjusted. The myocardial material is made of three-component silicon-based rubber, the hardness of the myocardial material of the prepared human dynamic heart model is measured by using a Shore hardness meter, the elastic modulus is calculated according to a conversion formula of the hardness and the elastic modulus, and the elastic modulus of the myocardial material of the human dynamic heart model is equivalent to the elastic modulus of a real human myocardial tissue by adjusting the proportion of the three components.

The existing experimental conditions can not be used for directly detecting the elastic modulus, the Shore Hardness (HA) of the myocardial material is firstly measured, and the elastic modulus corresponding to the material is calculated by converting the Shore hardness and the elastic modulus according to a formula (1):

E＝(15.75+2.15HA)/(100-HA) (1)

wherein: e is the modulus of elasticity, in units: MPa;

HA is Shore hardness;

the elastic modulus of the myocardial material of the embodiment is 1.86-2.37 MPa, and the myocardial material can be approximately equivalent to a human body real myocardial tissue in terms of mechanical properties.

Step 1-3: and manufacturing a human dynamic heart model. 3D printing a human dynamic heart model according to the three-dimensional numerical model in the step 1-1, then performing reverse molding on the printed human dynamic heart model, and preparing the human dynamic heart model by using the mold and the myocardial material of the human dynamic heart model in the step 1-2; in order to facilitate various work in the subsequent steps, the model is divided into an upper part and a lower part in the process of back molding of the human dynamic heart model, all the subsequent steps are operated on the lower half part, and the upper part and the lower part are bonded together by using the same myocardial material in the step 1-2 after all the steps are finished to form the complete human dynamic heart model; the prepared human dynamic heart model comprises a left atrium, a left ventricle, a right atrium and a right ventricle;

step 1-4: an ultrasound imaging location is determined. Based on the requirement of an M-Teich method echocardiography ejection fraction measuring method, a small hole with the diameter of 1mm is arranged in the direction of a short axis section of a left ventricle and at the outer side of the left ventricle, and a hard rubber leather tube 3 with the inner diameter not less than 1mm is adhered inside a human dynamic heart model (as shown in figure 1); in the left ventricle, according to the size of the transverse diameter of the heart of the human dynamic heart model, a spring 2 with the length of 40mm, the wire diameter of 1mm and the outer ring diameter of 8mm penetrates through a hard rubber leather tube 3 to be sleeved, one end of the spring 2 is propped against the wall of the left ventricle, and the other end of the spring 2 is propped against the ventricular septum; a channel is obliquely dug on the chamber partition and used for bonding and fixing the hard rubber leather tube 3 on the chamber partition, and the diameter of the channel is smaller than the inner diameter of the spring 2;

step 1-5: and determining a positioning point mark. Bonding a cylindrical acrylic gasket 1 with the diameter larger than 5mm and the thickness smaller than 0.5mm on the outer side of the small hole in the step 1-4, drilling a through hole with the diameter of 0.5mm in the center of the circle of the acrylic gasket 1, and drilling 2 through holes with the diameter of 0.5mm on the same diameter at a position 1mm away from the center of the circle of the acrylic gasket 1 by taking the center of the circle of the acrylic gasket 1 as a symmetrical point; marking symmetrical positioning point marks x on the other diameter perpendicular to the connecting line of the group of symmetrical through holes, wherein the distance between the two positioning point marks x and the circle center of the acrylic gasket 1 is 1.5mm, and the two positioning point marks x are used for calibrating the displacement of the acrylic gasket 1 by a subsequent laser displacement sensor 16; two No. 2 nylon wires 4 with the wire diameter of 0.23cm penetrate out of the hard rubber leather tube 3 in the step 1-4, penetrate through a through hole in the center of the circle of the acrylic gasket 1, respectively penetrate out of two symmetrical through holes in the acrylic gasket 1, and then penetrate back into the hard rubber leather tube 3; the thread end of the nylon thread 4 extends out of the other end of the orifice of the hard rubber tube 3 by 10 cm; the lower end of the acrylic gasket 1 threaded with the nylon thread 4 is bonded on the outer wall of the left ventricle.

Step 1-6: and (3) placing the human dynamic heart model bonded with the acrylic gasket 1 on an object stage of an optical projector, and measuring the transverse cardiac diameter length of the left ventricle along the short axis of the left ventricle and in the direction vertical to the upper surface of the acrylic gasket 1 to be used as the standard value of the transverse cardiac diameter length of the diastolic state of the left ventricle in the M-Teich method ultrasonic cardiac imaging ejection fraction measuring method.

Step 2: the human dynamic heart model is arranged in an acrylic water tank. See fig. 3 and 4. The inferior vena cava simulated blood vessel 5 and the pulmonary vein simulated blood vessel 6 are made of the silicon rubber which is made of the same material and is made of the same myocardial equivalent material in the step 1-2, the thickness of the blood vessel wall of the inferior vena cava simulated blood vessel 5 and the pulmonary vein simulated blood vessel 6 is 2mm, the inner diameter of the blood vessel is 2.8cm, and the length can be determined according to actual conditions.

Two simulation blood vessels are respectively bonded at corresponding positions of a human dynamic heart model, a hard rubber leather tube 3 and a nylon wire 4 inside the hard rubber leather tube 3 penetrate out of a lower vena cava simulation blood vessel 5, then the whole human dynamic heart model is respectively fixed on a left side plate and a front panel of an acrylic water tank through the lower vena cava simulation blood vessel 5 and a pulmonary vein simulation blood vessel 6, so that the surface of the acrylic gasket 1 is parallel to a right side plate 7 of the acrylic water tank, the distance from the right side plate 7 is 5-7 cm, and the position of a heart in a human chest is simulated.

The outer wall of a first acrylic tube 9-1 arranged at the center of a left panel of the acrylic water tank is bonded with the left panel of the acrylic water tank, a rubber sealing cover is bonded at a tube opening of the first acrylic tube 9-1 positioned at the outer side of the acrylic water tank, a small hole is drilled in the middle of the rubber sealing cover, so that a hard rubber tube 3 and a nylon wire 4 penetrate out of the acrylic water tank, and a lower vena cava simulation blood vessel 5 is sleeved on the tube opening of the first acrylic tube 9-1 positioned at the inner side of the acrylic water tank and is bonded by glue;

the outer wall of a second acrylic pipe 9-2 which is 10cm away from a water tank bottom plate and 8cm away from a left side plate of the water tank on the distance of a front side plate of the acrylic water tank is bonded with the front panel of the acrylic water tank, a pulmonary vein simulation blood vessel 6 is sleeved on a pipe orifice of the second acrylic pipe 9-2 which is positioned on the inner side of the acrylic water tank and is bonded by glue, the internal part of the second acrylic pipe 9-2 in the acrylic water tank is 2-3 cm long, the external part of the acrylic water tank is 2-3 cm long, and an acrylic pipe cover 10 is screwed with the second external acrylic pipe 9-2 through threads so as to prevent the acrylic water tank from leaking after being filled with water.

And step 3: and installing a mechanical motion control mechanism and connecting the human dynamic heart model installed on the acrylic water tank with the mechanical motion control mechanism. The method comprises the following specific steps:

a control host 17 of the mechanical motion control mechanism is connected with a computer 18 and an air pump piston system or a laser displacement sensor 16 through a control signal transmission line 15 to realize real-time communication; fixing a nylon wire 4 at the front end of a push-pull rod of a pneumatic piston 11 in the air pump piston system, wherein the initial state of the push-pull rod of the pneumatic piston 11 is defined as the state when the push-pull rod is completely contracted into the pneumatic piston 11; moving the relative position of the pneumatic piston 11 and the acrylic water tank to ensure that the left ventricle wall is in a diastole state when the push-pull rod is pushed out to the maximum length; when an image is acquired, the fixing device 13 of the air pump piston system is fixed on the experiment table through the fixing clamp body, so that the fixing device and the acrylic water tank are prevented from generating relative displacement; the fixing device 13 is properly heightened to ensure that the push-pull rod of the pneumatic piston 11 and the nylon wire 4 are on the same straight line parallel to the table top of the experiment table.

And 4, step 4: and starting the mechanical motion control mechanism to drive the human dynamic heart model to generate regular reciprocating motion.

The acrylic gasket 1 on the outer wall of the left ventricle under the traction of the nylon wire 4 drives the dynamic human heart model to generate regular reciprocating motion, wherein the contraction force of the left ventricle is provided by a push-pull rod of the pneumatic piston 11 when the left ventricle is restored to an initial state, and at the moment, the contraction of the left ventricle of the dynamic human heart model leads the spring 2 to be compressed by the wall of the left ventricle and the ventricular septum to generate deformation; the diastolic force to return the left ventricular wall of the dynamic heart model of the human body to the diastolic state is provided by the compressed spring 2.

And 5: the displacement of the position outside the left ventricle is calibrated along the direction of the short-axis section of the left ventricle, water is not injected into the acrylic water tank, the position of the laser displacement sensor 16 is determined by using the support 20 capable of adjusting lifting, and the standard value of the displacement at the position outside the short-axis section of the left ventricle is measured by the laser displacement sensor 16.

The method comprises the specific steps that the position of a laser displacement sensor 16 is determined by utilizing a liftable fixed support 20, and when the displacement at the outer position of a left ventricle is calibrated along the direction of a short-axis section of the left ventricle, the standard value of the displacement at the outer position of the left ventricle is measured once every 5 heart rate values for 40-150 heart rate/min; during measurement, water is not added into the acrylic water tank, the right side plate 7 is taken down, a preset heart rate value is set to enable the left ventricle wall to generate regular reciprocating motion, the height and the position of the laser displacement sensor 16 are adjusted, laser points used for distance measurement of the laser displacement sensor 16 are projected on the acrylic gasket 1, the distance between the acrylic gasket 1 and the center of the acrylic gasket 1 is measured by 1.5mm, the displacement of the two positioning points which are symmetrical left and right is marked by X (shown in figure 3), each positioning point measures 10 times, the average value of the displacement measurement results is taken as the displacement measurement result of the position, and finally the average value of the displacement measurement results of the two positioning points is taken as the standard value of the displacement of the left ventricle in the short axis section direction and the position outside the left ventricle; each heart rate value set when the human dynamic heart model moves corresponds to the switching rate of the electromagnetic valve 12 of the air pump piston system, and because the change of the switching rate of the electromagnetic valve 12 of the air pump piston system may cause incomplete contraction movement of the push-pull rod of the pneumatic piston 11, the displacement at the outer position of the left ventricle short axis section changes along with the change of the heart rate value, so each heart rate value corresponds to a standard value of the displacement.

Step 6: and acquiring an echocardiogram, filling water in an acrylic water tank until the dynamic heart model of the human body is submerged, then acquiring the echocardiogram, and measuring the measured value of the displacement by using an M-Teich method after acquiring the echocardiogram.

Keeping the switching rate of the electromagnetic valve unchanged, inserting the right side plate 7 back into the groove of the acrylic water tank, filling water into the acrylic water tank until the human dynamic heart model is submerged, and then obtaining an ultrasonic cardiogram image; when obtaining an ultrasonic cardiogram, fixing a probe of ultrasonic imaging equipment on a fixed support 20, wherein the height of the probe is consistent with the height of the laser sensor 16 when calibrating a standard value of the human body dynamic heart displacement; then, coating a couplant on a plastic film 7-1 of a right side plate 7 of the acrylic water tank, moving the fixed support 20 to enable a probe of the ultrasonic imaging equipment to be attached to the plastic film 7-1, and acquiring an ultrasonic cardiogram image at the angle of a short-axis section of the left ventricle; because the acoustic characteristics of the acrylic gasket 1 are different from those of the left ventricle of the human dynamic heart model, and the reflecting effect of the acrylic gasket 1 on ultrasound is stronger, the image brightness of the acrylic gasket 1 in an ultrasound image is higher, when a probe of an ultrasound imaging device is basically coplanar with the short-axis section of the left ventricle, the acrylic gasket 1 presents a bright rectangle with an unchanged shape and a changed position on the ultrasound image, and the short-axis section of the left ventricle is searched by the aid of the difference between the ultrasound images of the acrylic gasket 1 and the left ventricle of the human dynamic heart model. Under the condition that the left ventricle of the human dynamic heart model is in a diastolic state, obtaining an ultrasonic cardiogram image at the angle of a short-axis section of the left ventricle, repeatedly measuring for 10 times, and taking the average value as the measured value of the heart transverse diameter length of the diastolic state of the left ventricle.

And 7: and (5) correcting the measurement result of the ultrasonic cardiac motion displacement. Subtracting the measured value from the standard value to obtain a corrected value of the ultrasonic cardiac motion displacement measurement result in the left ventricle outer side position in the left ventricle short axis section direction, measuring the displacement correction value corresponding to the heart rate value every 5 times/minute for the heart rate value between 40-150 times/minute, embedding the comparison table of the measured heart rate value and the displacement correction value and the standard value of the left ventricle diastolic heart transverse diameter length and the measured value into the ultrasonic equipment, so that the ultrasonic cardiac motion displacement measurement result can be used for correcting the ultrasonic cardiac motion displacement measurement result in the future, and obtaining the corrected value of the heart rate value in a linear interpolation mode for the numerical value not in the comparison table.

Referring to fig. 1 to 6, a special apparatus for an ejection fraction calibration method based on ultrasound medical images according to a preferred embodiment of the present invention includes a dynamic heart model of a human body, an acrylic water tank, a mechanical motion control mechanism, a lifting adjustable bracket 20 and a laser displacement sensor 16, wherein the dynamic heart model of the human body is disposed in the acrylic water tank and connected to the mechanical motion control mechanism, and the laser displacement sensor 16 is connected to the mechanical motion control mechanism through a control signal transmission line 15 to implement real-time communication.

Referring to fig. 1 and 2, the human dynamic heart model is made of three-component silicon-based rubber, the hardness of the myocardial material of the human dynamic heart model for preparation is measured by using a shore durometer, the elastic modulus is calculated according to a conversion formula of the hardness and the elastic modulus, and the elastic modulus of the prepared myocardial material is equivalent to the elastic modulus of a real human myocardial tissue by adjusting the proportion of the three components;

the human body dynamic heart model is manufactured by combining real human body heart data and adjusting the geometric dimension of the three-dimensional numerical model, and comprises a left atrium, a left ventricle, a right atrium and a right ventricle;

based on the requirement of an M-Teich method echocardiography ejection fraction measuring method, a small hole is arranged along the direction of a short axis section of a left ventricle and at the outer side of the left ventricle, and a hard rubber leather tube 3 with the inner diameter not less than 1mm is adhered inside a human dynamic heart model; in the left ventricle, according to the size of the transverse diameter of the heart of the human dynamic heart model, a spring 2 is sleeved and connected with the hard rubber leather tube 3, one end of the spring 2 is propped against the wall of the left ventricle, and the other end of the spring is propped against the ventricular septum; a channel is obliquely dug on the chamber partition and used for bonding and fixing the hard rubber leather tube 3 on the chamber partition, and the diameter of the channel is smaller than the inner diameter of the spring 2;

referring to fig. 1 and 2, a cylindrical acrylic gasket 1 with a diameter greater than 5mm and a thickness less than 0.5mm is bonded to the outer side of the small hole, a through hole with a diameter of 0.5mm is drilled in the center of the circle of the acrylic gasket 1, and meanwhile, 2 through holes with a diameter of 0.5mm are drilled in the same diameter at a position 1mm away from the center of the circle of the acrylic gasket 1 by taking the center of the circle of the acrylic gasket 1 as a symmetry point; marking symmetrical positioning point marks x on the other diameter perpendicular to the connecting line of the group of symmetrical through holes, wherein the distance between the two positioning point marks x and the circle center of the acrylic gasket 1 is 1.5mm, and the two positioning point marks x are used for calibrating the displacement of the acrylic gasket 1 by a subsequent laser displacement sensor 16; two No. 2 nylon wires with the wire diameter of 0.23cm penetrate out of the hard rubber leather tube 3, penetrate through a through hole in the center of the circle of the acrylic gasket 1, respectively penetrate out of two symmetrical through holes in the acrylic gasket 1, and then penetrate back into the hard rubber leather tube 3; the thread end of the nylon thread 4 extends out of the other end of the orifice of the hard rubber tube 3 by 10 cm; the lower end of the acrylic gasket 1 penetrated with the nylon thread 4 is bonded on the outer wall of the left ventricle.

Referring to fig. 3, the human dynamic heart model further comprises an inferior vena cava simulated blood vessel 5 and a pulmonary vein simulated blood vessel 6, the inferior vena cava simulated blood vessel 5 and the pulmonary vein simulated blood vessel 6 are made of the same material as the human dynamic heart model and are respectively bonded with the corresponding positions of the human dynamic heart model, the nylon wires 4 inside the hard rubber leather tube 3 and the hard rubber leather tube 3 penetrate out of the inferior vena cava simulated blood vessel 5, and then the whole human dynamic heart model is fixed on a left side plate and a front side plate of the acrylic water tank through the inferior vena cava simulated blood vessel 5 and the pulmonary vein simulated blood vessel 6, so that the surface of the acrylic gasket 1 is parallel to the right side plate 7 of the acrylic water tank, and the distance from the right side plate 7 is 5-7 cm, and the heart can be simulated at the position in the human thoracic cavity.

Referring to fig. 3, 4 and 5, the acrylic water tank is composed of a detachable right side plate 7 and a water tank 8 without an upper cover plate, the right side plate 7 and the water tank 8 without an upper cover are both made of acrylic plates, the whole length of the acrylic water tank is 15-20 cm, the width of the acrylic water tank is 20-25 cm, the depth of the acrylic water tank is 20-25 cm, the thickness of the acrylic plates is 2cm, the whole length of the water tank 8 without an upper cover is 15cm, the width of the water tank is 20cm, the depth of the water tank is 20cm, and the thickness of the acrylic plates is 2 cm.

Referring to fig. 4, the right side plate 7 is composed of a plastic film 7-1 and a right side plate main body 7-2, the length and width of the plastic film 7-1 are both 10-15 cm, and the thickness is less than 0.5mm, in this embodiment, the length and width of the plastic film 7-1 are both 10cm, and the thickness is 0.1 mm. After the couplant is coated on the outer side of the plastic film 7-1, the ultrasonic imaging probe can receive ultrasonic reflection signals of a human dynamic heart model in the acrylic water tank;

the outer side of the plastic film 7-1 is provided with a right side plate main body 7-2, and the left side edge, the right side edge and the lower edge of the right side plate 7 are etched to form a convex structure; the width of the protruding part of the convex structure is 1cm, the height of the protruding part is 1cm, and the width of both sides of the protruding part is 0.5 cm; the surface of the convex structure is bonded with a rubber sealing strip with the thickness of 0.5 mm; the concave empty groove corresponding to the convex shape is etched on the front side plate, the rear side plate and the bottom plate which are connected with the right side plate 7 of the water tank 8 without the upper cover, and when the right side plate 7 is inserted into the corresponding empty groove, water in the water tank 8 without the upper cover cannot seep out from the joint of the right side plate 7 and the water tank 8 without the upper cover due to the expansion effect of the rubber sealing strip.

Referring to fig. 3, the acrylic water tank further comprises a first acrylic pipe 9-1 and a second acrylic pipe 9-2, the outer wall of the first acrylic pipe 9-1 arranged at the center of the left panel of the acrylic water tank is bonded with the left panel of the acrylic water tank, a pipe orifice of the first acrylic pipe positioned at the outer side of the acrylic water tank is bonded with a rubber sealing cover, a small hole is drilled in the middle of the rubber sealing cover, so that a hard rubber pipe 3 and a nylon wire 4 penetrate out of the acrylic water tank, and a lower vena cava simulated blood vessel 5 is sleeved on the pipe orifice of the first acrylic pipe 9-1 positioned at the inner side of the acrylic water tank and is bonded by glue;

the outer wall of a second acrylic pipe 9-2 which is 10cm away from a water tank bottom plate and 8cm away from a left side plate of the water tank on the distance of a front side plate of the acrylic water tank is bonded with the front panel of the acrylic water tank, a pulmonary vein simulation blood vessel 6 is sleeved on a pipe orifice of the second acrylic pipe 9-2 which is positioned on the inner side of the acrylic water tank and is bonded by glue, the internal part of the second acrylic pipe 9-2 in the acrylic water tank is 2-3 cm long, the external part of the acrylic water tank is 2-3 cm long, and an acrylic pipe cover 10 is screwed with the second external acrylic pipe 9-2 through threads so as to prevent the acrylic water tank from leaking after being filled with water.

In the embodiment, the outer diameter of a first acrylic pipe 9-1 arranged at the central position on the left side plate of an uncovered water tank 8 is 3cm, the length of the first acrylic pipe 9-1 is 6cm, the wall thickness of the first acrylic pipe 9-1 is 0.5cm, the inner part of the first acrylic pipe 9-1 in the uncovered water tank 8 is 2cm, the outer part of the uncovered water tank 8 is 2cm, a rubber sealing cover with the thickness of 0.5cm is adhered to the pipe orifice of the first acrylic pipe 9-1 outside the uncovered water tank 8, a small hole is drilled in the middle of the rubber sealing cover, so that a hard rubber pipe 3 and a nylon wire 4 can conveniently penetrate out of the uncovered water tank 8, a second acrylic pipe 9-2 is arranged on the front panel of the uncovered water tank 8 at a position which is 10cm away from the bottom plate of the uncovered water tank 8 and 8cm away from the left side plate of the uncovered water tank 8, and the outer diameter of the second acrylic pipe 9-2 is 3cm, The length of the second acrylic pipe 9-2 is 6cm, the wall thickness of the second acrylic pipe is 0.5cm, the outer wall of the second acrylic pipe 9-2 is bonded with the left side plate of the uncovered water tank 8, the length of the part of the acrylic pipe inside the uncovered water tank 8 is 2cm, the length of the part of the acrylic pipe outside the uncovered water tank 8 is 2cm, the inner wall of the pipe orifice of the second acrylic pipe 9-2 outside the uncovered water tank 8 is provided with threads, and the acrylic pipe cover 10 with the threads can be screwed into the second acrylic pipe 9-2 to prevent the leakage of the uncovered water tank 8 after water is filled.

Referring to fig. 5, the mechanical motion control mechanism is composed of a computer 18, a control host 17 and an air pump piston system;

wherein, the computer 18 is provided with data acquisition and motion control software for adjusting the switching rate of the electromagnetic valve 12 and receiving and processing the displacement measurement result; the control host 17 is respectively connected with the computer 18 and the air pump piston system or the laser displacement sensor 16 through the control signal transmission line 15 and communicates in real time.

The air pump piston system consists of four parts, including an electromagnetic valve 12, a pneumatic piston 11, an air compressor 19 containing an air tank and a fixing device 13, wherein the electromagnetic valve 12 and the pneumatic piston 11 are installed on the fixing device 13, the air compressor 19 is communicated with the electromagnetic valve 12 through an air pipe 14, the electromagnetic valve 12 is communicated with the pneumatic piston 11 through the air pipe 14, and the air compressor 19 is used for providing air flow with stable pressure within a period of time; the electromagnetic valve 12 is used for controlling the on-off state of the air flow, when the electromagnetic valve 12 is closed, the air flow provided by the air compressor 19 is input into the pneumatic piston 11 through the electromagnetic valve 12, so that the push-pull rod of the pneumatic piston 11 is pushed out to the maximum position, and when the electromagnetic valve 12 is opened, the air flow is cut off; the length of the push-pull rod of the pneumatic piston 11 is 20mm, and the nylon wire 4 is fixed at the front end of the push-pull rod of the pneumatic piston 11.

Referring to fig. 6, the position of the laser displacement sensor 16 is determined using an adjustable lift bracket 20. The fixing support 20 consists of an upright rod 20-1, a spring clamp 20-2, a fastening screw 20-3, a shelf 20-4 and a base 20-5, wherein the upright rod 20-1 is 20-25 cm high and is fixed on the base 20-5 through a thread at the bottom of the upright rod 20-2, and a screw hole is formed in the corresponding position on the base 20-5; the spring clamp 20-2 is sleeved on the upright rod 20-1, and the position of the laser displacement sensor 16 or the probe of the ultrasonic imaging equipment is determined by using the support 20 capable of adjusting lifting; after the position of the probe of the laser displacement sensor 16 or the ultrasonic imaging equipment is determined, the probe is clamped and fixed by a spring clamp 20-2; the fastening screw 20-3 is used for adjusting the height of the shelf 20-4, the shelf 20-4 is fixed when the fastening screw 20-3 is screwed, and the position of the shelf 20-4 can be adjusted up and down when the fastening screw 20-3 is unscrewed.

The specific test method of the invention is to obtain the standard value X of the heart transverse diameter length in the diastolic state of the left ventricle according to the steps₁And the measured value X₂And the comparison table of the heart rate value and the displacement correction value is embedded into the ultrasonic equipment. Acquiring the heart rate value H of the patient through the ultrasonic image during any one ultrasonic cardiogram ejection fraction measurement_rSearching the comparison table of the heart rate value and the correction value of the displacement amount, and finding out the H in the table_rClosest heart rate value H₁And its corresponding displacement correction value Y₁Heart rate value H₂And its corresponding displacement correction value Y₂In which H is₁＜H_r＜H₂. (H) is found by linear fitting₁，Y₁)、(H₂，Y₂) The corresponding straight line equation is as follows:

Y＝aH+b (2)

wherein a and b are constants;

a＝(Y₂-Y₁)/(H₂-H₁)；

b＝(Y₁H₂-Y₂H₁)/(H₂-H₁)；

h is to be_rSubstituting into formula (2), and obtaining corresponding displacement correction value Y by linear interpolation_r. After the calculation is finished, the transverse cardiac diameter size X of the diastolic state of the left ventricle of the patient is measured by using an M-Teich method echocardiography ejection fraction measuring method₃And a transverse heart diameter dimension X in a contracted state₄Using a correction factor X₁/X₂Correcting the measured value X₃、X₄The formula is corrected to obtain X in the formulas (3) and (4)₃、X₄Corresponding correction result X₅、X₆，

X₅＝X₃·X₁/X₂ (3)

X₆＝X₄·X₁/X₂ (4)

Using corrected transverse cardiac dimension X in diastolic state of the left ventricle₅And a transverse heart diameter dimension X in a contracted state₆And a displacement correction value Y_rThe calibrated ejection fraction measurement result EF can be obtained by calculation according to equation (5).

EF＝(X₅-X₆+Y_r)/X₅ (5)

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.