A syringe piston eccentricity detection device and method for a syringe pump

Abstract

A syringe piston eccentricity detection device and method for a syringe pump, wherein the syringe piston eccentricity detection device comprises: an eccentricity detection body having a ring-shaped opening, a plurality of probes being arranged inside the ring-shaped opening; a pressure sensor or a displacement sensor being arranged inside the eccentricity detection body, a proximal end of each probe being connected to the pressure sensor or the displacement sensor, and a distal end of each probe extending towards the center of the ring-shaped opening; the eccentricity detection body being connected to a barrel of a syringe; a signal acquisition unit being connected to the pressure sensor or the displacement sensor, and being configured to acquire pressure data or displacement data of the pressure sensor or the displacement sensor; a judgment module being configured to judge whether the piston has occurred eccentricity according to the pressure data or the displacement data acquired by the signal acquisition unit; the judgment module being configured to judge that the piston has occurred eccentricity when at least one of the pressure data or the displacement data has changed; and the pressure sensor being a pressure-sensitive resistor.

Description

TECHNICAL FIELD

[0001] The present application relates to the injection technical field, especially to a syringe piston eccentricity detection device and method for an injection pump. BACKGROUND

[0002] The injection pump is driven by a motor to drive a lead screw, and the lead screw drives a push rod of a syringe. A piston is sleeved on the front end of the push rod. The piston extrudes liquid medicine to realize injection of the liquid medicine. When the lead screw is eccentric or the motor fails, the push rod in the syringe will be eccentric, the eccentricity of the push rod drives the eccentricity of the piston, and finally the unstable and inaccurate liquid output of the syringe is caused. The inaccurate liquid output will greatly affect the health status of the patient. How to timely find the above technical problems has become a technical problem to be solved in the industry. SUMMARY

[0003] In order to solve the defects of the prior art, the purpose of the present application is to provide a syringe piston eccentricity detection device and method for an injection pump, which can accurately judge the syringe piston eccentricity phenomenon.

[0004] To achieve the above purpose, the present application provides a syringe piston eccentricity detection device for an injection pump, comprising:

[0005] The eccentricity detection body has a ring-shaped opening, and a plurality of probes are arranged on the inner side of the ring-shaped opening. A plurality of pressure sensors or displacement sensors are arranged in the eccentricity detection body. The proximal end of each probe is connected to the pressure sensor or the displacement sensor, and the distal end of the probe extends towards the center of the ring-shaped opening.

[0006] The eccentricity detection body has a docking portion connected to the empty barrel of the syringe.

[0007] The signal acquisition unit is connected to the pressure sensor or the displacement sensor, and is used to acquire pressure data or displacement data of the pressure sensor or the displacement sensor.

[0008] The judgment module is used to judge whether the piston is eccentric according to the pressure data or the displacement data acquired by the signal acquisition unit.

[0009] The judgment module is set to judge that the piston is eccentric when at least one pressure data or displacement data changes.

[0010] The pressure sensor is a pressure-sensitive resistor.

[0011] The docking portion has a fixed structure.

[0012] Preferably, the extension lines of the distal ends of each probe intersect at the center of the ring-shaped opening.

[0013] Preferably, the probes include four, and the included angle of the extensions of any two adjacent probes is a right angle.

[0014] To achieve the above object, the injection pump injector piston eccentricity detection method provided by the embodiment of the present application adopts the injection pump injector piston eccentricity detection device, and comprises the following steps:

[0015] The eccentricity detection ring body is sleeved on the push rod of the injector and fixed on the empty barrel of the injector, so that the end portions of the plurality of probes are in contact with the central axis of the push rod;

[0016] The voltage value of each pressure-sensitive resistor or the displacement data of the displacement sensor when the piston is not eccentric is acquired;

[0017] When the voltage value of any pressure-sensitive resistor or the displacement data of any displacement sensor changes, it is judged that the piston is eccentric.

[0018] Preferably,

[0019] The four pressure-sensitive resistors are respectively distributed in the four extension directions of the coordinate axes, and the data changes of each pressure-sensitive resistor are acquired multiple times within a preset period and recorded;

[0020] Within a preset period, the total number of different eccentric directions on the same coordinate axis is subtracted to set the eccentric coordinate point of the piston within the preset period;

[0021] The straight line extension direction from the coordinate circle point to the eccentric coordinate point is the eccentric direction of the piston.

[0022] Preferably, the voltage value corresponding to the pressure-sensitive resistor is acquired to be smaller once within a preset period, and it is judged that the piston is eccentric once in the corresponding direction;

[0023] The difference between the number of times that the voltage values of the two pressure-sensitive resistors in different directions on the same axis decrease is the eccentric coordinate of the corresponding axis of the piston within the preset period;

[0024] The eccentric coordinates on the two coordinate axes together constitute the eccentric coordinate point of the piston.

[0025] Preferably, the offset length dimension of the piston on the longitudinal coordinate axis is:

[0026] ;

[0027] The difference between the total number of different eccentric directions on the longitudinal coordinate axis;

[0028] The offset length dimension of the piston on the transverse coordinate axis is:

[0029] ;

[0030] The difference between the total number of different eccentric directions on the horizontal coordinate axis;

[0031] N is the number of detections within a preset period.

[0032] Preferably, the eccentricity of the piston within a preset period is obtained according to the eccentric coordinate point, when the eccentricity is less than a first threshold value, it is judged that the piston does not occur fault offset;

[0033] When the eccentricity is not less than the first threshold value, it is judged that the piston occurs fault offset.

[0034] Preferably, the calculation formula of the eccentricity is:

[0035] ,

[0036] The difference between the total number of different eccentric directions on the vertical coordinate axis;

[0037] The difference between the total number of different eccentric directions on the horizontal coordinate axis;

[0038] N is the number of detections within a preset period.

[0039] In order to achieve the above purpose, the injector provided by the embodiment of the application comprises the injector piston eccentricity detection device for the injection pump, and further comprises: an empty cylinder, a push rod matched in the empty cylinder, a piston arranged at one end of the push rod facing the empty cylinder, and a push rod seat arranged at one end of the push rod away from the empty cylinder.

[0040] The push rod is arranged in the annular opening of the injector piston eccentricity detection device for the injection pump.

[0041] The injector piston eccentricity detection device for the injection pump is fixed on the end of the empty cylinder facing the push rod seat.

[0042] The above technical solution can accurately judge the eccentricity of the injector piston, and can accurately calculate the offset direction, offset angle and offset size of the injector piston. Through the setting of the first threshold value of the eccentricity, the misjudgment phenomenon is avoided, the equipment fault is accurately processed, and the accuracy of the liquid volume of the injector is improved.

[0043] Other features and advantages of the present application will be described in the following description, and some will become apparent from the description, or will be understood by those skilled in the art through implementation of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0044] The accompanying drawings are intended to provide a further understanding of the present application, and constitute a part of the specification, and together with the embodiments of the present application, are used to explain the present application, and do not constitute a limitation on the present application. In the drawings:

[0045] Figure 1Structure schematic diagram of the syringe piston eccentricity detection device for the injection pump according to the embodiment of the present application;

[0046] Figure 2 Structure schematic diagram of the syringe piston eccentricity detection device for the injection pump according to the embodiment of the present application when the device is set on the piston;

[0047] Figure 3 Structure schematic diagram of the syringe piston eccentricity detection device for the injection pump according to the embodiment of the present application when the device is set on the piston;

[0048] Figure 4 Structure schematic diagram of the push rod according to the embodiment of the present application;

[0049] Figure 5 Flow chart of the syringe piston eccentricity detection method for the injection pump according to the embodiment of the present application;

[0050] Figure 6 Coordinate system schematic diagram constituted by four spring probes;

[0051] Figure 7 Structure schematic diagram of the syringe according to the embodiment of the present application.

[0052] Reference signs:

[0053] 101 - eccentricity detection ring body; 102 - probe; 103 - pressure sensitive resistor; 104 - push rod; 105 - center shaft; 106 - piston; 107 - push rod seat; 108 - limiting part; 109 - empty cylinder; 110 - butt joint part. DETAILED DESCRIPTION

[0054] The preferred embodiments of the present application will be described herein below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are merely intended to illustrate and explain the present application, and should not be interpreted as limiting the present application. The preferred embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0055] Embodiments of the present application will be described in more detail by referring to the accompanying drawings. Although certain embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms, and should not be interpreted as being limited to the embodiments set forth herein, but rather these embodiments are provided to more thoroughly and completely understand the present application. It should be understood that the drawings and embodiments of the present application are merely for exemplary purposes, and are not intended to limit the scope of protection of the present application.

[0056] As used herein, the term "includes" and its variants are to be read to be analogous to "comprises," or "comprising." The term "based on" is to be read as "based, at least in part, on." The term "one embodiment" means "at least one embodiment." The term "another embodiment" means "at least one additional embodiment." The term "some embodiments" means "at least some embodiments." Related definitions will be given in the description below.

[0057] It should be noted that the terms "first", "second", and the like in the present application can be mentioned only for distinguishing different devices, components or parts, and not for limiting the order or interdependence of the functions performed by these devices, components or parts.

[0058] It should be noted that the modification of "one" or "multiple" mentioned in the present application is illustrative and not restrictive, and those skilled in the art should understand that unless otherwise explicitly indicated in the context, it should be understood as "one or more". "Multiple" should be understood as two or more.

[0059] The syringe piston eccentricity detection device for injection pump of the present application comprises:

[0060] The eccentricity detection body 101 has an annular opening, and a plurality of probes 102 are arranged on the inner side of the annular opening;

[0061] A plurality of pressure sensors or displacement sensors are arranged in the eccentricity detection body 101, and the proximal end of each probe 102 is connected to the pressure sensor or displacement sensor, and the distal end of the probe 102 extends towards the center of the annular opening;

[0062] The eccentricity detection body 101 has a docking portion connected to the empty barrel 109 of the syringe;

[0063] The signal acquisition unit is connected to the pressure sensor or displacement sensor, and is used to acquire the pressure data or displacement data of the pressure sensor or displacement sensor;

[0064] The judgment module is used to judge whether the piston 106 has occurred eccentricity according to the pressure data or displacement data acquired by the signal acquisition unit;

[0065] The judgment module is set to judge that the piston 106 has occurred eccentricity when at least one pressure data or displacement data changes;

[0066] The pressure sensor is a pressure sensitive resistor 103;

[0067] The docking portion 110 has a fixed structure.

[0068] For the purpose, technical solutions and advantages of the present application to be clearer, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0069] Embodiment 1

[0070] Figure 1 For the structure schematic diagram of the syringe piston eccentricity detection device for injection pump according to the embodiment of the present application, Figure 2 For the structure schematic diagram of the syringe piston eccentricity detection device for injection pump according to the embodiment of the present application when it is sleeved on the piston, Figure 3 For the structure schematic diagram of the syringe piston eccentricity detection device for injection pump according to the embodiment of the present application when it is sleeved on the piston, Figure 4 For the structure schematic diagram of the push rod according to the embodiment of the present application, Figure 7 For the structure schematic diagram of the syringe according to the embodiment of the present application, as shown in Figures 1-4 and Figure 7 The syringe piston eccentricity detection device for injection pump according to the embodiment of the present application comprises an eccentricity detection ring body 101, which is annular.

[0071] In an exemplary embodiment, the syringe piston eccentricity detection device for injection pump according to the embodiment of the present application is used for the syringe on the injection pump, and is usually arranged at the end of the syringe away from the needle; since the syringe comprises a barrel 109 and a push rod, and the end of the push rod facing the barrel 109 is provided with a piston and the end away from the barrel 109 is provided with a push rod seat, it can be understood that the syringe piston eccentricity detection device for injection pump according to the embodiment of the present application is sleeved on the push rod and fixed at the end of the barrel 109 facing the push rod seat, as shown in Figure 7 .

[0072] In an exemplary embodiment, the syringe piston eccentricity detection device for injection pump according to the embodiment of the present application, since the eccentricity detection body has an annular opening, the annular opening is sleeved on the push rod 104 of the syringe in use, and the detection of whether the piston 106 is eccentric is realized by the fitting detection of the central axis 105 of the push rod 104.

[0073] In an exemplary embodiment, the annular opening of the eccentricity detection body 101 is usually a circular annular opening.

[0074] In one exemplary embodiment, the eccentricity detection body 101 is provided with a plurality of probes 102. The distal end of each probe 102 protrudes out of the eccentricity detection body 101 and extends toward the center of the eccentricity detection body 101. The extension lines of the distal ends of each probe 102 converge at the center of the eccentricity detection body 101, that is, the distal ends of all probes 102 extend toward the center of the annular opening. The proximal end of each probe 102 is disposed within the eccentricity detection body 101. This can be understood as the distal ends of the plurality of probes 102 protruding toward the center point of the eccentricity detection ring body 101 and the distal ends of the probes 102 not being connected. Figure 1 , Figure 2 as well as Figure 3 As shown.

[0075] In one exemplary embodiment, a plurality of pressure sensors or displacement sensors are provided within the eccentricity detection body 101.

[0076] In one exemplary embodiment, the proximal end of each probe is connected to a pressure sensor or a displacement sensor.

[0077] In one exemplary embodiment, the pressure sensor is a pressure-sensitive resistor 103, which is connected to the proximal end of the probe 102.

[0078] In one exemplary embodiment, probe 102 is matched with varistor 103 as needed.

[0079] In one exemplary embodiment, the probe 102 corresponds one-to-one with the varistor 103, that is, each probe 102 is matched with a varistor 103 near its proximal end; in the embodiments of this application, there are four probes 102 and four varistor 103.

[0080] In one exemplary embodiment, the probe 102 is a metal probe as needed; the distal end of the probe 102 is not a sharp needle-like structure, but a spherical protrusion or a hemispherical structure.

[0081] In one exemplary embodiment, each probe 102 is the same size.

[0082] In one exemplary embodiment, probe 102 is a spring probe, the size and stress of which are matched to the central axis 105 of push rod 104.

[0083] In one exemplary embodiment, the syringe piston eccentricity detection device for the syringe pump of this application further includes a signal acquisition unit.

[0084] In one exemplary embodiment, when a displacement sensor is provided inside the eccentricity detection body 101, the signal acquisition unit is connected to the displacement sensor and is used for the displacement data of the displacement sensor.

[0085] In an exemplary embodiment, when the eccentricity detection body 101 is provided with a pressure sensor, the signal acquisition unit is connected with the pressure-sensitive resistor 103, for acquiring the pressure data of the pressure-sensitive resistor 103, i.e. the voltage signal; because the pressure-sensitive resistor has a smaller resistance when it is pressed, the voltage is also smaller, and the application utilizes the characteristic that the voltage of the pressure-sensitive resistor changes with the change of the pressure.

[0086] In an exemplary embodiment, the syringe piston eccentricity detection device for the syringe pump of the application further comprises a judgment module.

[0087] In an exemplary embodiment, the judgment module is used to judge whether the piston has occurred eccentricity according to the pressure data or the displacement data acquired by the signal acquisition unit, for example, judging whether the piston 106 has occurred eccentricity according to the voltage signal of the pressure-sensitive resistor 103.

[0088] In an exemplary embodiment, when the voltage signal of the at least one pressure-sensitive resistor changes, it is judged that the push rod 104 has occurred eccentricity, i.e. the piston 106 has occurred eccentricity.

[0089] In an exemplary embodiment, when the judgment module acquires the displacement data, for example, the displacement data of the at least one displacement sensor changes, it is judged that the push rod 104 has occurred eccentricity, i.e. the piston 106 has occurred eccentricity.

[0090] In an exemplary embodiment, the four probes 102 in the application are oppositely arranged, and the included angle of the extension lines of any two adjacent probes 102 is a right angle; it can be understood that each two oppositely arranged probes 102 form a line, and the other two oppositely arranged probes 102 also form a line, and the two lines are perpendicular to each other.

[0091] In an exemplary embodiment, the number of probes 102 can be set according to needs, but when there are four probes 102, the needs of use can be met; the number of probes 102 can exceed four according to needs.

[0092] In an exemplary embodiment, the distal ends of the probes 102 are not connected to each other.

[0093] In an exemplary embodiment, the eccentricity detection body 101 has a docking portion connected with the barrel 109 of the syringe, and the docking portion has a fixing structure; it can be understood that the eccentricity detection body 101 of the application is fixed on the barrel 109 through the fixing structure; the fixing structure can be adhesive connection, screw fixing, clamping, threaded connection and other fixing modes.

[0094] Embodiment 2

[0095] Figure 5 Figure 1 is a flow chart of the syringe piston eccentricity detection method according to the embodiment of the present application. Figure 6 Figure 2 is a schematic diagram of the coordinate system formed by the four spring probes. The following will be described in detail in combination with Figures 5-6 The syringe piston eccentricity detection method according to the embodiment of the present application will be described in detail.

[0096] In an exemplary embodiment, the syringe piston eccentricity detection method according to the embodiment of the present application is detected by the syringe piston eccentricity detection device according to the above embodiment.

[0097] First, in step 201, the eccentricity detection ring body is sleeved on the push rod of the syringe and fixed on the barrel of the syringe, so that the end of each probe is in contact with the central axis of the push rod.

[0098] In an exemplary embodiment, the eccentricity detection ring body 101 is sleeved on the push rod 104, i.e. the push rod is placed in the annular opening, and is fixedly arranged at one end of the barrel facing the push rod seat.

[0099] In an exemplary embodiment, the distal end of each probe 102 is in contact with the central axis 105 of the push rod 104.

[0100] In step 202, the voltage value of each pressure-sensitive resistor or the displacement data of the displacement sensor when the piston is not eccentric is obtained.

[0101] In an exemplary embodiment, when the pressure-sensitive resistor is arranged in the eccentricity detection ring body 101, the voltage value signal of each pressure-sensitive resistor 103 when the central axis 105 of the push rod 104 is not eccentric is obtained, and is recorded as the standard signal or standard voltage of the corresponding pressure-sensitive resistor 103 of each probe 102.

[0102] In an exemplary embodiment, the voltage value of each pressure-sensitive resistor is obtained and recorded multiple times within a preset period, and the voltage value of each pressure-sensitive resistor can also be obtained in real time as needed.

[0103] In an exemplary embodiment, when the displacement sensor is arranged in the eccentricity detection ring body 101, the displacement data of each displacement sensor when the central axis 105 of the push rod 104 is not eccentric is obtained, and is recorded as the corresponding displacement data or displacement reference data of the corresponding displacement sensor of each probe 102.

[0104] In step 203, when the voltage value of any pressure-sensitive resistor or the displacement data of any displacement sensor changes, it is determined that the piston is eccentric.

[0105] In an exemplary embodiment, when displacement sensors are arranged in the eccentricity detection ring body 101, the piston is determined to be eccentric when the displacement data of any displacement sensor changes.

[0106] In an exemplary embodiment, when pressure sensitive resistors are arranged in the eccentricity detection ring body 101, four spring probes constitute a coordinate system, and the four pressure sensitive resistors are respectively distributed in the four extension directions of the coordinate axes.

[0107] In an exemplary embodiment, the total number of different eccentric directions on the same coordinate axis in a period is subtracted to set the eccentric coordinate point of the piston 106 in the preset period.

[0108] In an exemplary embodiment, the straight line extension direction from the coordinate circle point to the eccentric coordinate point is the eccentric direction of the piston 106.

[0109] In an exemplary embodiment, the voltage value corresponding to the pressure sensitive resistor 103 is obtained once smaller in the preset period, and the piston 106 is determined to be eccentric once in the corresponding direction.

[0110] In an exemplary embodiment, the difference between the number of times that the voltage values of the two pressure sensitive resistors 103 in different directions on the same axis decrease is the eccentric coordinate of the piston 106 on the corresponding axis in the preset period.

[0111] In an exemplary embodiment, the eccentric coordinates on the two coordinate axes together constitute the eccentric coordinate point of the piston 106, that is, the coordinate point of the piston 106 in the coordinate system.

[0112] In an exemplary embodiment, the four spring probes are respectively named A, B, C, and D, as shown in Figure 6 , spring probe A and spring probe B constitute the longitudinal coordinate of the coordinate system, and spring probe C and spring probe D constitute the horizontal coordinate of the coordinate system.

[0113] In an exemplary embodiment, the voltage values of the four spring probes when the center axis 105 of the push rod 104 is not eccentric are respectively recorded as , the voltage values obtained in the preset period are respectively recorded as ´ , and the differences are respectively calculated as

[0114] ,

[0115] ,

[0116] ,

[0117] ;

[0118] Since the spring probe A and the spring probe B are in a straight line, when the ordinate deviates, that is, the pressing force of the spring probe A and the spring probe B changes, taking the deviation in the direction of the spring probe A as an example, since the pressing force on the spring probe A increases, the voltage value of the corresponding pressure-sensitive resistor 103 becomes smaller, at this time is negative, the pressing force on the spring probe B becomes smaller, is positive, at this time, the count is added by 1, that is, the deviation in the direction of the spring probe A is recorded once; conversely, the count is added by 1, that is, the deviation in the direction of the spring probe B is recorded once.

[0119] In an exemplary embodiment, by the same principle, the same is true for the abscissa composed of the spring probe C and the spring probe D, and the number of deviations in the abscissa is accumulated in a preset period respectively After the multiple accumulations in a preset period are completed, the total number of deviations in the abscissa and the ordinate is calculated respectively, and the calculation method is as follows:

[0120] ,

[0121] ;

[0122] That is, the total number of deviations and the deviation direction in the abscissa and the ordinate in the preset period are calculated respectively.

[0123] In an exemplary embodiment, taking the number of deviations in the abscissa as an example, which does not occur in a period, the deviation only occurs in the ordinate, the spring probe A deviates 5 times, and the spring probe B deviates 3 times, then the total number of deviations in the ordinate is 5-3=2 times at this time, and the 2 times are deviations in the direction of the spring probe A, at this time, the coordinates on the coordinate system are (0, 2); it can be understood that according to and the specific coordinate point of the point in the coordinate system can be determined, that is, , ).

[0124] In an exemplary embodiment, the extension direction of the straight line from the coordinate circle point (0, 0) to the eccentric coordinate point ( , ) is the eccentric direction of the piston 106, as shown in Figure 6 .

[0125] In an exemplary embodiment, the angle of the deviation of the point is determined according to the line connecting the point ( , ) and the circle point, that is, the angle Figure 6 shown in .

[0126] In an exemplary embodiment, the offset length of the piston 106 on the longitudinal coordinate axis is:

[0127] ;

[0128] is the difference between the total number of different eccentric directions on the longitudinal coordinate axis;

[0129] n is the number of detections within a preset period.

[0130] In an exemplary embodiment, the offset length of the piston 106 on the transverse coordinate axis is:

[0131] ;

[0132] is the difference between the total number of different eccentric directions on the transverse coordinate axis;

[0133] n is the number of detections within a preset period.

[0134] In an exemplary embodiment, the eccentricity of the piston 106 within a preset period is obtained according to the eccentric coordinate point, and when the eccentricity is less than a first threshold value, it is determined that the piston 106 does not occur a fault offset.

[0135] When the eccentricity is not less than the first threshold value, it is determined that the piston 106 occurs a fault offset.

[0136] In an exemplary embodiment, the calculation formula of the eccentricity is:

[0137] ,

[0138] is the difference between the total number of different eccentric directions on the longitudinal coordinate axis;

[0139] is the difference between the total number of different eccentric directions on the transverse coordinate axis;

[0140] n is the number of detections within a preset period.

[0141] In an exemplary embodiment, as needed, the first threshold value of the eccentricity is 20%, that is, when the eccentricity is less than 20%, it is determined that the piston 106 does not occur a fault offset; and when the eccentricity is greater than or equal to 20%, it is determined that the current offset of the piston 106 is caused by a fault.

[0142] Embodiment 3

[0143] Figure 7 is a schematic diagram of the injector structure of the embodiment of the present application, and now the injector structure of the embodiment of the present application will be described in detail. Figure 7 The injector structure of the embodiment of the present application will be described in detail.

[0144] The syringe of the embodiment of the application comprises the syringe piston eccentricity detection device for the syringe pump in the above embodiment.

[0145] In an exemplary embodiment, the syringe of the embodiment of the application is used for the syringe pump.

[0146] In an exemplary embodiment, the syringe of the embodiment of the application comprises a barrel 109, a push rod 104, a piston 106 arranged at the front end of the push rod 104, and a push rod seat 107 arranged at the rear end of the push rod 104. The push rod seat 107 is movably connected with the push rod 104, i.e. the push rod seat 107 is detachable. As shown in the figure, the push rod 104 is provided with a limiting part 108 at the end facing the push rod seat 107. The limiting part 108 is spaced from the end of the push rod 104 for mounting the push rod seat 107, and the limiting part 108 also limits the depth dimension of the push rod 104 inserted into the push rod seat 107. Figure 4

[0147] In an exemplary embodiment, when the syringe piston eccentricity detection device for the syringe pump is mounted, the push rod seat 107 is first detached from the push rod 104, and then the push rod seat 107 is mounted on the push rod 104 after the syringe piston eccentricity detection device for the syringe pump is sleeved.

[0148] In an exemplary embodiment, after the syringe piston eccentricity detection device for the syringe pump is sleeved on the push rod 104, it needs to be fixed on the end of the barrel 109 facing the push rod seat 107, i.e. the eccentricity detection ring body 101 is fixed on the end of the barrel 109 facing the push rod seat 107, as shown in the figure. Figure 7

[0149] In an exemplary embodiment, the fixing structure can be adhesive connection, screw fixing, clamping, threaded connection, etc.

[0150] Those skilled in the art can understand that the above is only the preferred embodiment of the application and is not used to limit the application, although the application has been described in detail with reference to the foregoing embodiments, and those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or make equivalent replacement for part of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application shall be included in the protection scope of the application.​​

Claims

1. An eccentricity detection method applicable to an eccentricity detection device for syringe pistons in injection pumps, characterized in that, The syringe piston eccentricity detection device for the syringe pump includes: An eccentricity detection body has an annular opening, and multiple probes are arranged inside the annular opening. Multiple pressure sensors or displacement sensors are arranged inside the eccentricity detection body. The proximal end of each probe is connected to the pressure sensor or the displacement sensor, and the distal end of each probe extends toward the center of the annular opening. The eccentricity detection body has a docking part that connects to the empty cylinder of the syringe; a signal acquisition unit, which is connected to the pressure sensor or displacement sensor, for acquiring pressure data of the pressure sensor or displacement data of the displacement sensor. The judgment module is used to determine whether the piston has become eccentric based on the pressure data or displacement data acquired by the signal acquisition unit; the judgment module is configured to determine that the piston has become eccentric when at least one of the pressure data or displacement data changes. The pressure sensor is a piezoresistive sensor; The docking part has a fixed structure; The probes include four, and the angle between the extensions of any two adjacent probes is a right angle; The eccentricity detection method applicable to the syringe piston eccentricity detection device for injection pumps includes: The eccentricity detection ring body is sleeved on the plunger of the syringe and fixed to the empty barrel of the syringe, so that the ends of multiple probes are in contact with the central axis of the plunger. Obtain the voltage value of each pressure-sensitive resistor or the displacement data of the displacement sensor when the piston is not eccentric; When the voltage value of any of the pressure-sensitive resistors or the displacement data of any of the displacement sensors changes, it is determined that the piston has become eccentric. The four varistors are respectively distributed in the four extension directions of the coordinate axis, and the data changes of each varistor are acquired and recorded multiple times within a preset period; Within a preset period, the total number of different eccentric directions on the same coordinate axis is subtracted and set as the eccentric coordinate point of the piston within the preset period. The direction of the straight line extending from the coordinate dot to the eccentric coordinate point is the eccentric direction of the piston; If the voltage value corresponding to the varistor decreases once within the preset period, it is determined that the piston deviates once in the corresponding direction. The difference in the number of times the voltage values ​​of two varistors in different directions on the same axis decrease is the eccentric coordinate of the piston on the corresponding axis within the preset period; The eccentric coordinates on the two coordinate axes together constitute the eccentric coordinate point of the piston.

2. The eccentricity detection method for a syringe piston eccentricity detection device applicable to a syringe pump as described in claim 1, characterized in that, The offset length of the piston on the vertical axis is: ； This represents the difference in the total number of different eccentric directions on the vertical axis; The offset length of the piston on the horizontal axis is: ； This represents the difference in the total number of different eccentric directions on the horizontal axis; n represents the number of times the test is performed within a preset period.

3. The eccentricity detection method for a syringe piston eccentricity detection device applicable to a syringe pump as described in claim 1, characterized in that, The eccentricity of the piston within the preset period is obtained based on the eccentric coordinate point. When the eccentricity is less than the first threshold, it is determined that the piston has not experienced a faulty offset. When the eccentricity is not less than the first threshold, it is determined that the piston has malfunctioned and shifted.

4. The eccentricity detection method for a syringe piston eccentricity detection device applicable to a syringe pump as described in claim 3, characterized in that, The formula for calculating the eccentricity is: ， This represents the difference in the total number of different eccentric directions on the vertical axis; This represents the difference in the total number of different eccentric directions on the horizontal axis; n represents the number of times the test is performed within a preset period.

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