WO2018068338A1

WO2018068338A1 - Tester for micromechanical properties of biological soft tissue

Info

Publication number: WO2018068338A1
Application number: PCT/CN2016/102403
Authority: WO
Inventors: 冯原; 赵雪峰; 孙立宁; 黄珑
Original assignee: 苏州大学张家港工业技术研究院
Priority date: 2016-10-13
Filing date: 2016-10-18
Publication date: 2018-04-19
Also published as: CN106370519B; CN106370519A

Abstract

A tester for micromechanical properties of a biological soft tissue, comprising: a support, the support being provided thereon with a sample test platform (21), a pressure test head (22) facing the sample test platform (21) and a drive mechanism driving the pressure test head (22) to move towards/away from the sample test platform (21); a miniature force testing assembly, the miniature force testing assembly comprising a first conduit (31), a first piston (32) actively connected to the first conduit (31) and supporting the sample test platform (21), a second conduit (33), a second piston (34) actively connected to the second conduit (33), a pressure-amplifying platform (35) connected to the second piston (34), and a force sensor (36) for testing the force of the pressure-amplifying platform (35), the first conduit (31) and the second conduit (33) being connected by means of a hose, and the cross-sectional area of the sample test platform (21) being smaller than the cross-sectional area of the pressure-amplifying platform (35). A micro force is amplified using the principle of hydraulic amplification, and a micro displacement is amplified using the principle of lever amplification so as to test the micro force and the micro deformation of a biological soft tissue.

Description

Biological soft tissue micromechanical property tester

Technical field

The invention relates to the field of biomechanics of soft tissues, in particular to a biosoft tissue micromechanical property tester.

Background technique

The biomechanical study of soft tissue covers a very broad range, including almost all tissue systems except the bones in the human body. These tissue systems specifically include skin, cartilage, connective tissue, muscles, and internal organs. The broad range of biological soft tissue studies requires a complete mechanical performance test including compression, stretching, torsion, shearing, indentation, and fatigue testing.

A major goal of soft tissue research is to characterize the mechanical properties of biological tissues to better design computational models that better understand various medical conditions, such as internal organ damage and traumatic brain injury during motor vehicle accidents. Changes in the properties of materials in the brain, etc. Soft tissue research also analyzes the material behavior of biological tissues under different mechanical loads in human body, such as the effect of mechanical load on fiber structure adjustment. As data is provided for better computational models, this information is essential for the development of biological tissue engineering that is compatible with the mechanical properties and structure of the native tissue.

The mechanical properties of biological tissues are important in the research and development of tissue engineering and medical devices. Current major biomechanical properties testing includes extrusion testing, tensile testing, and shear testing. For anisotropic tissue testing, extrusion testing and tensile testing are the main test methods. Among them, the extrusion test has lower requirements for biological tissue fixation, flexible testing and wide application.

At present, the test instruments for the mechanical properties of biological tissues are Bose 5500 series, Instron 5900, CSM bioindenter series, TestResource 100 series, although the basic functions of the products can be tested. However, it is difficult to test for small deformation and stress, and it is impossible to carry out tests on samples of 5 mm or less, and the cost is high.

In view of the above shortcomings, the designer actively researches and innovates in order to create a new type of biological soft tissue micromechanical property tester, which makes it more industrially valuable.

Summary of the invention

In order to solve the above technical problems, an object of the present invention is to provide a biosoft tissue micromechanical property tester capable of testing micro-miniature forces and micro-displacements.

The biosoft tissue micromechanical property tester of the present invention comprises a support, and the support is provided

a sample test stand, a pressure test head facing the sample test stand, and a drive mechanism driving the pressure test head toward/toward the sample test stand;

a micro force test assembly comprising a first conduit, a first piston movably coupled to the first conduit and supporting the sample test station, a second conduit, a second piston operatively coupled to the second conduit And an amplifying pressure platform connected to the second piston and a force sensor for performing force test on the amplifying pressure platform, wherein the first conduit and the second conduit are connected by a hose, and the cross-sectional area of the sample testing platform is smaller than that of the amplifying pressure platform Cross-sectional area.

Further, the support further includes a micro-displacement measuring assembly including a lever that moves with one end of the pressure test head, a support rod of the support lever, and a displacement test slide that is moved by the lever and a displacement sensor for performing a displacement test on the displacement test slider, wherein a distance between the end of the lever that moves with the pressure test head and the strut is smaller than a distance between the displacement test slug and the strut .

Further, the micro-displacement measuring assembly further includes a rail slot defining a linear movement of the displacement test slider, the lever is provided with a sliding slot along a length thereof, and one end of the displacement test slider and the sliding slot The sliding connection and the other end are slidably connected to the rail groove.

Further, the lever is further provided with an adjusting groove along a length thereof, and an end of the strut is rotatably connected to the adjusting groove.

Further, the driving structure is a linear motor, and an output end of the linear motor is connected to the pressure testing head through a connecting rod.

Further, the lever is connected to the connecting rod with the end of the pressure test head moving.

Further, the distance between the force sensor and the amplification pressure table can be adjusted.

Further, a hydraulic port is disposed on a bottom of each of the first conduit and the second conduit, and two ends of the hose are respectively connected to the two hydraulic ports.

Further, the XYZ mobile platform supporting the first conduit is further disposed on the support, the XYZ mobile platform includes an X mobile platform connected to the support, and an XY mobile platform slidably connected to the X mobile platform. a Y mobile platform sliding along the XY mobile platform, a Z platform bottom plate connected to the Y mobile platform, a first Z-direction platform vertically connected to the Z platform bottom plate, a second Z-direction platform sliding longitudinally along the first Z-direction platform, and a first a Z-platform top plate connected to the first conduit and connected to the first conduit, further comprising a first driving component for driving the XY mobile platform to move in the X direction on the X mobile platform, and driving the Y mobile platform on the XY mobile platform A second drive assembly that moves in the Y direction drives a third drive assembly that moves the second Z-direction platform in the Z-direction on the first Z-direction platform.

Further, the first driving component includes a first spiral bracket connected to the X moving platform, a first stopper connected to the XY moving platform, and the first spiral barrel bracket can be connected to the first a first screw abutting the stopper, a first threaded tube screwed to the first screw and connected to the first screw holder, and a first spiral barrel screwed to the end of the first screw; the second drive assembly includes a second screw bracket connected to the XY moving platform, a second stopper connected to the Y moving platform, a second screw disposed on the second spiral bracket and capable of abutting the second stopper, and a second Screw screwed and second screw a second threaded tube connected to the drum holder, a second spiral barrel screwed to the second screw end; the third driving assembly includes a knob bracket connected to the Z platform bottom plate, and the second Z-direction platform a third screw that is rotatably coupled to the knob bracket, a third screw barrel bracket that is coupled to the second Z-direction platform, and a third screw that is coupled to the third screw barrel and that is coupled to the third screw a third threaded tube connected to the third spiral barrel bracket, and a third spiral barrel screwed to the end of the third screw, the knob includes a knob rod, a knob ring sleeved on the knob rod, and the knob ring is on the outer circumference A first vertical knob arm and a second knob arm are connected, and the ends of the first knob arm and the second knob arm are respectively provided with contacts facing the knob bracket and the third screw.

With the above solution, the present invention has at least the following advantages:

1. Use the principle of hydraulic amplification to amplify the small force, so that the micro-micro force of the biological soft tissue can be tested;

2. The micro-displacement is amplified by the principle of lever amplification, so that the micro-deformation of the biological soft tissue can be tested;

3. The XYZ mobile platform has high adjustment accuracy and can accurately adjust the initial position of the sample test bench.

The above description is only an overview of the technical solutions of the present invention, and the technical means of the present invention can be more clearly understood and can be implemented in accordance with the contents of the specification. Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

DRAWINGS

Figure 1 is a schematic view of the structure of the present invention;

2 is a schematic perspective view showing the XYZ mobile platform of the present invention;

Fig. 3 is a schematic structural view of a knob of the present invention.

detailed description

The specific embodiments of the present invention are further described in detail below with reference to the drawings and embodiments. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

Referring to FIG. 1 to FIG. 3, a biosoft tissue micro-mechanical characteristic tester according to a preferred embodiment of the present invention includes a support, and the support comprises a horizontal bottom plate 11 and a vertical plate 12 vertically connected to the bottom plate 11, and the bottom plate An XYZ moving platform 50 is disposed on the XYZ moving platform 50. The first duct 31 is movably connected with a first piston 32 slidable relative to the longitudinal direction thereof. The first piston 32 is connected with a sample testing table 21 through The first piston 32 supports the sample test table 21; the bottom plate 11 is further provided with a second conduit 33, the second conduit 33 is movably connected with a second piston 34 slidable relative to the longitudinal direction thereof, and the second piston 34 is connected with an amplifying pressure table 35 The second piston 34 supports the amplifying pressure platform 35; the bottom of the first conduit 31 and the second conduit 33 are respectively provided with a hydraulic port 37, and the two hydraulic ports 37 are connected through the hose to connect the first conduit 31 with the second conduit 33. The vertical plate 12 is provided with a linear motor 23, the linear motor 23 is connected to a connecting rod 24, the connecting rod is connected to a pressure test head 22, the end of the pressure test head 22 is facing the sample test stand 21; and the riser 12 is also provided with Can be connected to the amplification pressure table 35 The force sensor 36. In the present invention, the first duct 31, the first piston 32, the second duct 33, the second piston 34, the amplifying pressure table 35, and the force sensor 36 for stress testing the amplifying pressure table 35 constitute a micro force test assembly for biological soft tissue. That is, the hydraulic force amplification principle is used to amplify the minute force, thereby testing the micro-miniature force of the biological soft tissue. In order to enable hydraulic amplification, the cross-sectional area of the sample test stand 21 in the present invention is smaller than the cross-sectional area of the magnifying pressure table 35.

When the small force of the sample is measured, the sample is placed on the sample test stand 21, and after the linear motor 23 drives the pressure test head 22 to press the sample, the sample test stand 21 is pressed to pressurize the first piston 32 to generate a pressure. Since the first conduit 31 communicates with the second conduit 33, the pressure is transmitted to the second piston 34 by the liquid, and the liquid is at the same pressure because the cross-sectional area of the amplification pressure table 35 is larger than the cross-sectional area of the sample test table 21, and the corresponding conduction pressure Being amplified, that is, by amplifying the pressure table 35, the pressure received by the sample is performed. Zooming in; since the force sensor 36 is in contact with the amplifying pressure table 35, the force sensor 36 measures the pressure received by the amplifying pressure table 35, and after conversion, the pressure received by the sample is obtained, thereby detecting the mechanical properties of the sample.

Since it is necessary to ensure that the force sensor 26 is in contact with the amplifying pressure table 35, the pressure of the amplifying pressure table 35 can be measured. Therefore, the distance between the force sensor 36 and the amplifying pressure table 35 can be adjusted in the present invention, by adjusting the position of the force sensor 36, The force sensor 26 is brought into contact with the amplification pressure stage 35. Specifically, the force sensor 36 is mounted on the force sensor fixing plate 13, and a waist groove 14 is formed on the vertical plate 12, and the force sensor fixing plate 13 is mounted on the riser 12 through the waist groove 14 by bolts, thereby The position of the force sensor fixing plate 13 on the riser 12 can be adjusted, so that the adjustment force sensor 26 comes into contact with the amplification pressure table 35.

In the present invention, the link 24 connected to the pressure test head 22 is further connected with a lever 41. One end of the lever 41 is connected to the connecting rod 24, and the other end is suspended, and a strut 42 is disposed on the riser 12, and the strut 42 is provided. Rotatingly connected with the lever 41 for supporting the lever 41, one end of the lever 41 can be moved with the pressure test head 22; the lever 41 is also rotatably connected with the displacement test slide 43 and is provided with a positive displacement test slide on the riser 12 The displacement sensor 44 of the plug 43 measures the displacement of the displacement test slider 43. In the present invention, the lever 41, the strut 42, the displacement test slider 43, and the displacement sensor 44 for performing displacement test on the displacement test slider constitute a micro-displacement measuring component, that is, the micro-displacement is amplified by the principle of lever amplification, thereby applying biological soft tissue The tiny deformations are tested. In order to enable lever magnification, the distance between the end of the lever 41 that moves with the pressure test head 22 and the strut 42 in the present invention is smaller than the distance between the displacement test spool 43 and the strut 42.

In order to limit the displacement test slider 43 to move linearly under the driving of the lever 41, the present invention further provides a rail groove 45 for linearly sliding the displacement test slider 43 on the riser, and the rail groove 45 is longitudinally disposed. Since the lever 41 is rotated by the pressure test head 22 around the support rod 41, and the end of the lever 41 is longitudinally moved with the pressure test head 22, the displacement test slide 43 is moved longitudinally along the guide rail groove 45 by the lever 41. In order to convert the curved path of the curve into a linear moving track, the present invention is provided with a sliding groove along the longitudinal direction of the lever 41, and one end of the displacement test sliding plug 43 is slidably connected with the sliding groove, and the other end is slidably connected with the guiding groove 45. An adjustment groove is further provided on the lever 41 along its length to rotationally connect the end of the strut 42 with the adjustment groove. By sliding the displacement test spool 43 and the strut 42 in the chute and the adjusting groove, respectively, the end portion of the lever 41 and the displacement test slider are longitudinally moved during the rotation of the lever 41, accurately reflecting the sample being pressed. After the micro deformation.

When measuring the small displacement of the sample, the sample is placed on the sample test stand 21, and after the linear motor 23 drives the pressure test head 22 to press the sample, the longitudinal movement of the pressure test head 22 drives the lever 41 to rotate, so that the displacement test slider 43 Moving along the rail groove 45, the distance between the end of the lever 41 moving with the pressure test head 22 and the strut 42 is smaller than the distance between the displacement test spool 43 and the strut 42, and therefore, the displacement test spool 43 is moved. The displacement is greater than the distance moved by the pressure test head 22, thereby amplifying the small displacement of the pressure test head 22, and the amplified displacement is measured by the displacement sensor 44. After conversion, the small deformation amount of the sample can be obtained, thereby detecting the mechanics of the sample. characteristic.

The initial position of the sample test station 21 in the present invention is adjusted by the XYZ moving platform 50. Specifically, the XYZ mobile platform 50 includes an X mobile platform 51 connected to the bottom plate 11, an XY moving platform 52 slidably connected to the X moving platform 51, a Y moving platform 53 sliding along the XY moving platform 52, and a Y moving platform 53. a Z platform bottom plate 54, a first Z-direction platform 55 vertically connected to the Z platform bottom plate 54, a second Z-direction platform 56 longitudinally sliding along the first Z-direction platform 55, and a second Z-direction platform 56 connected to the first conduit The 31-connected Z-platform top plate 57 further includes a first drive assembly that drives the XY moving platform 52 to move in the X-direction on the X-moving platform 51, and a second drive that drives the Y-moving platform 53 to move in the Y-direction on the XY moving platform 52. The assembly drives a third drive assembly that moves the second Z-direction platform 56 in the Z-direction on the first Z-direction platform 55.

Specifically, the first driving component includes a first spiral bracket 61 connected to the X moving platform 51, a first stopper 62 connected to the XY moving platform 52, a first screw 63 disposed on the first spiral cylinder bracket 61 and capable of abutting against the first gear 62, and the first screw 63 and the first spiral cylinder a first threaded tube 64 connected to the bracket 61, a first spiral barrel 65 screwed to the end of the first screw 63; the second driving assembly includes a second spiral barrel bracket connected to the XY moving platform 52, and connected to the Y moving platform 53 a second stopper, a second screw 73 disposed on the second spiral cylinder bracket to be abutted against the second stopper, a second threaded tube screwed to the second screw 73 and connected to the second spiral cylinder bracket, and a second screw barrel 75 screwed to the second screw end; the third drive assembly includes a knob bracket 81 coupled to the Z platform bottom plate 54, a knob 82 rotatably coupled to the second Z-direction platform 56 and capable of abutting the knob bracket 81, a third screw holder 83 connected to the second Z-direction platform 56, a third screw 84 that is disposed on the third screw holder 83 and that can abut against the knob 82, is screwed to the third screw 84, and is coupled to the third screw barrel a third threaded tube 85 connected to the bracket 83 and a third spiral barrel 86 screwed to the end of the third screw 84 The knob 82 includes a knob lever 91 and a knob ring 92 sleeved on the knob lever 91. The first knob arm 93 and the second knob arm 94 are connected to the outer circumference of the knob ring 92. The first knob arm 93 and the first knob arm The ends of the two knob arms 94 are respectively provided with contacts facing the knob bracket 81 and the third screw 84, and the knob 82 is rotatably connected to the second Z-direction platform 56 through the knob lever 91.

In order to make the XY moving platform 52 slide relative to the X moving platform 51, the Y moving platform 53 can slide relative to the XY moving platform 52, and the second Z-direction platform 56 can slide relative to the first Z-direction platform 55, the present invention is on the XY moving platform 52. A sliding slot is respectively disposed on the upper and lower surfaces, and the two sliding slots are orthogonally arranged, and a slider 58 is disposed between the XY moving platform 52 and the X moving platform 51, and between the Y moving platform 53 and the XY moving platform 52; A longitudinal chute is also provided on the deck of the first Z-direction platform 55 toward the second Z-direction platform 56, and a slider 58 is disposed between the first Z-direction platform 55 and the second Z-direction platform 56.

When the initial position of the sample test table 21 is adjusted, the horizontal position and the longitudinal height of the top plate 87 of the Z platform can be adjusted. Specifically, the first spiral cylinder 65 is rotated to drive the first threaded tube 64 to rotate, so that the first The screw 63 moves toward the first stopper 62 and abuts against the first stopper 62, and is resisted by the first stopper 62. The XY moving platform 52 moves in the X direction on the X moving platform 51, thereby driving the Z platform top plate 57 along the X. Similarly, the second spiral barrel 75 is rotated to drive the second threaded tube to rotate, so that the second screw 73 moves toward the second stopper and abuts against the second stopper, and is resisted by the second stopper, and the Y movement platform 53 moves in the Y direction on the XY moving platform 52, thereby driving the Z platform top plate 57 to move in the Y direction; rotating the third spiral barrel 86 to drive the third threaded tube 85 to rotate, so that the third screw 84 moves toward the knob 82, and The contact 95 on the first knob arm 93 of the knob 82 is in contact, and under the action of the third screw 84, the knob 82 is rotated around the knob lever 91, so that the contact 95 on the second knob arm 94 is in contact with the knob bracket 81. With the resisting action of the knob bracket 81, the second Z-direction platform 56 moves in the Z direction on the first Z-direction platform 55, thereby driving the Z-platform top plate 57 to move in the Z direction, that is, the initial position adjustment of the sample testing table 21 is realized. The invention utilizes the screw to adjust the spatial position of the top plate of the Z platform, and the adjustment precision is high, and the micro adjustment can be realized.

For data acquisition and processing, the data acquisition and processing integrated application programming interface is performed, and the force and displacement signals of the test acquisition can be displayed in real time, and numerical analysis and processing are performed for different material models. The data acquisition board adopts PCI-1706 to realize the synchronous acquisition of force and displacement signals. The post-processing uses the high elasticity model to analyze and interpolate the signals to realize the integrated integration of data acquisition and processing.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. It should be noted that those skilled in the art can make some improvements without departing from the technical principles of the present invention. And modifications and variations are also considered to be within the scope of the invention.

Claims

A biosoft tissue micromechanical property tester, comprising: a support, the support is provided

a sample test stand, a pressure test head facing the sample test stand, and a drive mechanism driving the pressure test head toward/toward the sample test stand;

a micro force test assembly comprising a first conduit, a first piston movably coupled to the first conduit and supporting the sample test station, a second conduit, a second piston operatively coupled to the second conduit And an amplifying pressure platform connected to the second piston and a force sensor for performing force test on the amplifying pressure platform, wherein the first conduit and the second conduit are connected by a hose, and the cross-sectional area of the sample testing platform is smaller than that of the amplifying pressure platform Cross-sectional area.
The biosoft tissue micromechanical property tester according to claim 1, wherein the support further comprises a micro-displacement measuring component, wherein the micro-displacement measuring component comprises a lever that moves with one end of the pressure test head, a struts supporting the lever, a displacement test slider driven by the lever, and a displacement sensor for performing a displacement test on the displacement test slider, the distance between the end of the lever moving with the pressure test head and the struts Less than the distance between the displacement test spool and the strut.
The biosoft tissue micromechanical property tester according to claim 2, wherein the micro-displacement measuring assembly further comprises a guide groove defining a linear movement of the displacement test slider, the lever being provided with a slide along its length. a slot, one end of the displacement test slider is slidably connected to the sliding slot, and the other end is slidably connected to the rail slot.
The biosoft tissue micromechanical property tester according to claim 3, wherein the lever is further provided with an adjustment groove along a length thereof, and an end of the strut is rotatably connected to the adjustment groove.
The biosoft tissue micromechanical property tester according to claim 2, wherein the driving structure is a linear motor, and an output end of the linear motor is connected to the pressure test head through a connecting rod.
The biosoft tissue micromechanical property tester according to claim 5, wherein: The lever is coupled to the link with the end of the pressure test head moving.
The biosoft tissue micromechanical property tester according to claim 1, wherein a distance between the force sensor and the amplification pressure stage is adjustable.
The biosoft tissue micromechanical property tester according to claim 1, wherein the bottoms of the first conduit and the second conduit are each provided with a hydraulic port, and the two ends of the hose are respectively connected to the two hydraulic ports.
The biosoft tissue micromechanical property tester according to any one of claims 1-8, wherein the support is further provided with an XYZ mobile platform supporting the first conduit, and the XYZ mobile platform includes The X mobile platform connected by the support, the XY mobile platform slidably connected to the X mobile platform, the Y mobile platform sliding along the XY mobile platform, the Z platform bottom plate connected to the Y mobile platform, and the first vertical connection with the Z platform bottom plate a Z-direction platform, a second Z-direction platform longitudinally sliding along the first Z-direction platform, a Z-platform top plate connected to the second Z-direction platform and connected to the first conduit, and further comprising driving the XY mobile platform to move in the X a first driving component moving along the X direction on the platform, a second driving component driving the Y moving platform moving in the Y direction on the XY moving platform, and a driving the second Z-direction platform moving along the Z direction on the first Z-direction platform Three drive components.
The biosoft tissue micromechanical property tester according to claim 9, wherein the first driving component comprises a first spiral cylinder bracket connected to the X moving platform, and a first connection with the XY moving platform. a stopper, a first screw that is disposed on the first spiral cylinder bracket to be able to abut the first stopper, a first threaded pipe that is screwed to the first screw and connected to the first spiral cylinder bracket, and the first screw end a first spiral barrel; the second drive assembly includes a second spiral barrel bracket coupled to the XY moving platform, a second stop coupled to the Y moving platform, and a second spiral barrel bracket a second screw capable of abutting against the second block, a second threaded tube screwed to the second screw and connected to the second screw holder, and a second spiral barrel screwed to the second screw end; Three drive components include and a knob bracket connected to the bottom plate of the Z platform, a knob rotatably connected to the second Z-direction platform and capable of abutting the knob bracket, a third spiral barrel bracket connected to the second Z-direction platform, and a third spiral barrel bracket a third screw capable of abutting against the knob, a third threaded tube screwed to the third screw and connected to the third screw holder, and a third spiral barrel screwed to the third screw end, the knob including the knob a knob ring sleeved on the knob shaft, the first knob arm and the second knob arm being perpendicular to the outer circumference of the knob ring, and the ends of the first knob arm and the second knob arm are respectively provided respectively A contact toward the knob bracket and the third screw.