Experimental device for promoting bone mass transfer through low-intensity pulsed ultrasound

Abstract

The invention discloses an experimental device for promoting bone mass transfer through low-intensity pulsed ultrasound. The experimental device comprises a bone environment simulation mechanism, a low-intensity pulsed ultrasound generation mechanism and a simulated liquid perfusion mechanism which are arranged on a base. The bone environment simulation mechanism comprises a closed bin, the top side of the closed bin is provided with a load bolt, and the bottom end is sequentially connected with a pressure spring, a pressure sensor and a sliding plate; the top face of one end of the sliding plate abuts against a cam arranged on a motor output shaft, and the bottom face of the other end is connected with a periodic load spring. The simulated liquid perfusion mechanism is respectively connected with the liquid injection hole and the liquid outlet hole of the closed bin through pipelines so as to circularly pump the body fluid simulated liquid into the closed bin; the low-intensity pulse ultrasonic generating mechanism comprises piezoelectric ceramics, and an oscilloscope and a signal generator which are connected with the piezoelectric ceramics; the experimental device can accurately simulate the bone block environment of a human body in different motion states, and is matched with low-intensity pulse ultrasound to effectively obtain the promotion effect on the bone mass transfer process, so that reliable experimental data is provided for the promotion research of the bone mass transfer process.

Description

Technical Field

[0001] The invention relates to the technical field of medical device testing, and in particular to an experimental device for promoting bone mass transfer by low-intensity pulsed ultrasound. Background Art

[0002] Low-intensity pulsed ultrasound is a device that uses sound waves to promote bone integration and bone healing. The mechanical effect of ultrasonic vibration helps to treat connective tissue damage, promote fracture healing, and combat osteoporosis. This micro-medical device has the characteristics of low power and non-invasiveness, and its clinical application is gradually expanding. After the artificial prosthesis is implanted in the body, the bone mass transfer system at the prosthesis interface is destroyed, affecting the bone integration effect and easily causing postoperative complications. As a result, the probability of secondary revision surgery due to prosthetic healing increases. Experimental studies have found that low-intensity pulsed ultrasound can promote the bone mass transfer process. Therefore, it is of great significance to quantitatively study the effect of ultrasound radiation parameters on bone mass transfer.

[0003] Although the current existing equipment can simulate the circulation environment of body fluids in the human body, its ultrasonic loading capacity is still insufficient when deeply exploring the promoting effect of low-intensity pulsed ultrasound on bone mass transfer, especially when simulating the human body in different physiological states (such as micro-overload, walking, etc.), its loading effect is difficult to be satisfactory. Based on this, it is necessary to improve the existing simulation equipment in view of the defects of the existing technology, so as to accurately simulate the human body in walking and micro-overload state by efficiently loading low-intensity pulsed ultrasound in bone mass transfer, so as to conduct in-depth research on the promoting effect of low-intensity pulsed ultrasound on bone mass transfer. Summary of the invention

[0004] The purpose of the present invention is to provide an experimental device that solves the above-mentioned prior art problems and realizes low-intensity pulsed ultrasound to promote bone mass transfer, which accurately simulates the human body in walking and micro-overload states.

[0005] To this end, the technical solution of the present invention is as follows:

[0006] An experimental device for promoting bone mass transfer by low-intensity pulsed ultrasound, comprising a bone environment simulation mechanism, a low-intensity pulsed ultrasound generating mechanism and a simulation liquid perfusion mechanism arranged on a base;

[0007] The bone environment simulation mechanism includes a closed chamber with an opening at the bottom; a load bolt is vertically penetrated in the center of the top surface of the closed chamber, and the bottom end of the load bolt located in the closed chamber is connected to a pressure spring, and the bottom end of the pressure spring is fixed to the center of the top surface of a horizontally arranged slide through a pressure sensor; a group of opposite side panels of the closed chamber are symmetrically provided with injection holes and liquid outlet holes, and a motor is fixed on the outer wall above the side panel with the injection holes, the motor is arranged in a manner that its output shaft is horizontally penetrated into the closed chamber, and a cam is fixed at the end of the output shaft; the large-size end of the cam is initially arranged downward and abuts against one end plate surface of the slide; a periodic load spring is arranged below the other end of the slide, which is arranged vertically, and its two ends are respectively fixed to the slide and the closed chamber;

[0008] The low-intensity pulsed ultrasound generating mechanism comprises a piezoelectric ceramic placement block, an oscilloscope and a signal generator; the piezoelectric ceramic placement block is fixed on a base, and an anti-overflow groove which can be tightly fitted with the bottom end of a closed chamber is provided on the top surface of the piezoelectric ceramic placement block to close the bottom opening of the closed chamber; a groove is provided on the top surface of the piezoelectric ceramic placement block, a piezoelectric ceramic is provided at the bottom of the groove, and a bone block bracket is provided on the groove wall above the piezoelectric ceramic, so that the bone block samples are arranged at intervals above the piezoelectric ceramic and can be against the center of the bottom surface of the slide; the piezoelectric ceramic is respectively connected to the signal generator and the oscilloscope through wires; the simulated liquid perfusion mechanism is respectively connected to the injection hole and the liquid outlet hole through pipelines to pump body fluid simulation liquid into the closed chamber.

[0009] Furthermore, two screw holes are symmetrically opened on another group of opposite side panels of the closed bin to respectively threadably assemble adjusting bolts, and the two adjusting bolts are horizontally inserted into the side panels of the closed bin, and the length of the ends of the adjusting bolts extending into the closed bin is adjusted by cooperating with the threads of the screw holes on the side panels; a first bone block sample clamping plate and a second bone block sample clamping plate are also symmetrically arranged in the closed bin, and the top sides of the two are respectively vertically fixed on the end surfaces of the two adjusting bolts located in the closed bin, and the bottom sides of the two are located on both sides of the bone block sample, so that the two bone block sample clamping plates can be adjusted to clamp on both sides of the bone block sample through the two adjusting bolts.

[0010] Furthermore, the first bone block sample clamping plate and the second bone block sample clamping plate include a vertical plate and a pressure block, the upper side of one side of the vertical plate is fixed to the end surface of the adjusting bolt located in the sealing chamber, and the pressure block is fixed to the lower side of the other side of the vertical plate; a buffer layer is also provided on the contact surface between the pressure block and the bone block sample.

[0011] Furthermore, a pressure gauge is installed on a side panel of the closed chamber to monitor the hydraulic pressure in the closed chamber in real time.

[0012] Furthermore, the simulated liquid perfusion mechanism includes a perfusion rack fixed on a horizontal platform, on which a culture medium bottle and a peristaltic pump are fixed; wherein, the culture medium bottle is an open bottle body for containing body fluid simulated liquid, and is provided with a liquid inlet end and a liquid outlet end; the liquid inlet end of the injection tube in the peristaltic pump is connected to the liquid outlet end of the culture medium bottle, and the liquid outlet end injection hole of the injection tube extends into the closed chamber; the liquid outlet hole of the closed chamber is connected to one end of the reflux pipe, and the other end of the reflux pipe is connected to the liquid inlet end of the culture medium bottle, so that the body fluid simulated liquid can flow back from the closed chamber through the reflux pipe to the culture medium bottle; a throttle valve is also provided on the reflux pipe.

[0013] Furthermore, the bone block support is composed of four identical clamping columns evenly distributed on the groove wall along the circumferential direction. The four clamping columns are vertically fixed on the groove wall to form a clamping hole with an inner diameter adapted to the outer diameter of the bottom end of the bone block sample, so that the bottom end of the bone block sample is inserted and clamped between the four clamping columns.

[0014] Furthermore, sealing layers are provided between the injection hole and the injection pipe of the sealing chamber, between the liquid outlet and the reflux pipe, between the shaft hole on the side panel and the output shaft of the motor, between the adjusted load bolt and the matching screw hole, and between the adjusted adjusting bolt and the matching screw hole.

[0015] Compared with the prior art, the experimental device for promoting bone mass transfer by low-intensity pulsed ultrasound has a reasonable structural design and is simple to operate. Through the mutual coordination among the bone environment simulation mechanism, the simulated fluid perfusion mechanism and the low-intensity pulsed ultrasound generating mechanism in its structural design, it can accurately simulate the bone environment of the human body under different motion states, and cooperate with low-intensity pulsed ultrasound to effectively obtain its promoting effect on the bone mass transfer process, providing reliable experimental data for low-intensity pulsed ultrasound to promote the bone mass transfer process and quantitatively study the effect of ultrasound radiation parameters on bone mass transfer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the experimental device for promoting bone mass transfer by low-intensity pulsed ultrasound of the present invention;

[0017] Figure 2 A side perspective view of a bone environment simulation mechanism of an experimental device for promoting bone mass transfer using low-intensity pulsed ultrasound according to the present invention;

[0018] Figure 3 Another side perspective view of the bone environment simulation mechanism of the experimental device for promoting bone mass transfer with low-intensity pulsed ultrasound of the present invention;

[0019] Figure 4 The schematic diagram of the structure of the piezoelectric ceramic placement block of the experimental device for promoting bone mass transfer by low-intensity pulsed ultrasound of the present invention. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the following embodiments are by no means intended to limit the present invention in any way.

[0021] See also Figure 1 to Figure 4 The experimental device for promoting bone mass transfer by low-intensity pulsed ultrasound comprises a bone environment simulation mechanism, a simulation liquid perfusion mechanism and a low-intensity pulsed ultrasound generating mechanism arranged on a base 13 .

[0022] The base 13 includes a horizontal platform, on which a bone environment simulation mechanism, a simulated fluid perfusion mechanism and a low-intensity pulsed ultrasound generating mechanism are arranged; an inverted L-shaped bracket is arranged on one side of the horizontal platform; the inverted L-shaped bracket is composed of a vertically connected vertical plate and a horizontal plate, wherein the bottom end of the vertical plate is fixed on the horizontal platform, and the horizontal plate is arranged toward the center of the horizontal platform.

[0023] See also Figure 2 and Figure 3 The bone environment simulation mechanism includes a closed chamber 2, which is a cubic chamber body surrounded by a top plate and four side plates and has an opening at the bottom; a group of opposite side plates of the closed chamber 2 are symmetrically provided with injection holes 24 and outlet holes 22, and both are opened on the lower side of the side plates.

[0024] A screw hole is vertically opened at the center of the top plate of the closed chamber 2, and a load bolt 14 is assembled in the inner thread of the screw hole; the load bolt 14 is partially inserted in the closed chamber 2 and cooperates with the thread of the screw hole on the top plate to adjust the length of the lower side of the load bolt 14 extending into the closed chamber 2; a pressure spring 15 is vertically arranged below the load bolt 14, and the top end of the pressure spring 15 is connected to the bottom end of the load bolt 14, and the bottom end is connected to a pressure sensor 19; a rectangular slide plate 20 is horizontally arranged below the pressure sensor 19, and the pressure sensor 19 is centrally fixed on the top surface of the slide plate 20, so that the load bolt 14, the pressure spring 15 and the pressure sensor 19 are centrally arranged.

[0025] A motor 12 for simulating the step frequency is arranged on the upper side of the side panel with the injection hole 24, and the motor 12 is fixed on the outer wall of the side panel, and its output shaft 25 is horizontally penetrated to the inner side of the closed chamber 2 through the shaft hole provided in the side panel, and a cam 26 is fixed on the shaft end of the output shaft 25 so as to utilize the motor 12 to drive the cam 26 to rotate; in the initial state, the large-size end of the cam 26 is arranged facing forward and abuts against the top surface of one end of the skateboard 20; since the cam 26 is a teardrop-shaped structure with a large-size end at one end and a small-size end at the other end, when the motor 12 drives the cam 26 to rotate, the small-size end of the cam 26 will apply a downward thrust to the skateboard 20 due to the pressure on the top surface of one end of the skateboard 20 for each rotation of the cam 26, thereby causing the skateboard 20 to be reciprocated and flipped downward under the rotation of the cam 26.

[0026] A periodic load spring 21 is arranged below the other end of the slide plate 20. The periodic load spring 21 is arranged vertically, and its top end is fixed on the bottom surface of the other end of the slide plate 20; a spring fixing plate is arranged below the periodic load spring 21, and it is fixed horizontally on the side plate of the sealing chamber 2, so that the bottom end of the periodic load spring 21 is fixed on the spring fixing plate, so that every time the small-sized end of the cam 26 pushes one end of the slide plate 20 to flip downward, the other end of the slide plate 20 flips upward accordingly, and stretches the periodic load spring 21 to extend and accumulate elastic potential energy; so that when the cam 26 no longer applies thrust to the slide plate 20, the force of the periodic load spring 21 to restore the deformation is used to pull the slide plate 20 to return to its initial horizontal state; that is, as the motor 12 continues to rotate, under the mutual cooperation of the periodic load spring 21 and the cam 26, the slide plate 20 performs a reciprocating up and down swinging action.

[0027] In the simulation experiment, the bone sample 23 is set under the skateboard 20 and abuts against the center of the bottom surface of the skateboard 20; then, on the one hand, by adjusting the length of the load bolt 14 extending into the closed chamber 2, the deformation of the pressure spring 15 is adjusted, so that the pressure generated by the deformation of the pressure spring 15 is applied to the bone sample 23 below, thereby simulating the state of pressure on the bones of people with different weights; on the other hand, by controlling the rotation speed of the motor 12, the swing frequency of the skateboard 20 is adjusted to simulate the step frequency of people in different motion states. For example, when the skateboard 20 does not swing, it simulates the state of human standing; when the swing frequency of the skateboard 20 is slow, it simulates the state of human walking; and when the swing frequency of the skateboard 20 is fast, it simulates the state of human running.

[0028] See also Figure 2 Two screw holes are symmetrically provided on another set of opposite side panels of the closed chamber 2, and adjusting bolts are respectively threadedly installed in the two screw holes; the two adjusting bolts are horizontally inserted into the side panels of the closed chamber 2, so as to adjust the length of the ends of the adjusting bolts extending into the closed chamber 2 by cooperating with the threads of the screw holes on the side panels; the first bone block sample clamping plate 17 and the second bone block sample clamping plate 16 are also symmetrically arranged in the closed chamber 2, and the two are respectively fixed on the ends of the two adjusting bolts, so as to be used to clamp on both sides of the bone block sample 23 and block the flow channels on both sides of the bone block sample 23.

[0029] The first bone block sample clamping plate 17 and the second bone block sample clamping plate 16 both include a clamping plate body; specifically, the clamping plate body includes a vertical plate and a pressure block, the upper side of one side of the vertical plate is vertically fixed on the end face of the adjusting bolt, and the pressure block is fixed on the lower side of the other side of the vertical plate; in order to prevent the bone block sample 23 from being damaged, a buffer layer is also provided on the contact surface between the pressure block and the bone block sample 23, and the buffer layer is specifically a rubber layer or a silicone layer.

[0030] The simulated liquid perfusion mechanism includes a perfusion rack 8 fixed on a horizontal platform, on which a culture medium bottle 9 and a peristaltic pump 11 are fixed; wherein the culture medium bottle 9 is used to configure and contain a body fluid simulated liquid containing a tracer, and a liquid inlet end and a liquid outlet end are arranged on the bottle body; the liquid inlet end of the injection tube 28 in the peristaltic pump 11 is connected with the liquid outlet end of the culture medium bottle 9 and forms a connection, and the liquid outlet end is inserted into the closed chamber 2 through the injection hole 24, so that the body fluid simulated liquid in the culture medium bottle 9 is pumped into the closed chamber 2 under the driving action of the peristaltic pump 11; the liquid outlet hole 22 of the closed chamber 2 is connected with one end of the liquid return tube 3, and the liquid return tube 3 The other end is connected to the liquid inlet end of the culture medium bottle 9 and forms a connection, so that the body fluid simulation liquid circulates in the culture medium bottle 9 and the closed chamber 2; a throttle valve 10 is provided on the return pipe 3 to control the reflux flow of the body fluid simulation liquid in the closed chamber 2, and adjusts the hydraulic pressure of the body fluid simulation liquid in the closed chamber 2 by cooperating with the body fluid simulation liquid pumping flow of the peristaltic pump 11; in the simulated liquid perfusion mechanism, the peristaltic pump 11 is used to pump the body fluid simulation liquid, so that the body fluid simulation liquid circulates between the closed chamber 2 and the culture medium bottle 9 in a pulsed dynamic flow mode, which is closer to the flow of human body fluids. The inner cavity volume of the culture medium bottle 9 is larger than the inner cavity volume of the closed chamber 2, so as to ensure that the body fluid simulation liquid contained in the culture medium bottle 9 is sufficient to fill the closed chamber 2, and the hydraulic pressure in the closed chamber 2 can be adjusted.

[0031] As a preferred technical solution of this embodiment, a pressure gauge 1 is installed on a side panel of the closed chamber 2 to monitor the hydraulic pressure in the closed chamber 2 in real time.

[0032] In the simulation experiment, there are two ways to set the bone block sample 23; one is to set it alone. In this setting state, the bone block sample 23 can fully contact with the body fluid simulation liquid in the circumferential direction, thereby realizing the simulation of the free diffusion process of bone mass transfer; the other is to be clamped by the first bone block sample clamping plate 17 and the second bone block sample clamping plate 16. In this setting state, the left and right surfaces of the bone block sample 23 are in contact with the body fluid simulation liquid, thereby realizing the simulation of the convection transmission process of bone mass transfer.

[0033] See also Figure 1 and Figure 4 The low-intensity pulsed ultrasound generating mechanism includes a piezoelectric ceramic placement block 4, an oscilloscope 6 and a signal generator 7; wherein,

[0034] The piezoelectric ceramic storage block 4 is a cubic block fixed on a horizontal platform, and an overflow groove 29 is provided on the top surface thereof, which matches the sealed chamber 2, so that the bottom end of the sealed chamber 2 can be tightly inserted and fixed in the overflow groove 29, so that the sealed chamber 2 and the piezoelectric ceramic storage block 4 are assembled and fixed as a whole, and the piezoelectric ceramic storage block 4 is used to close the bottom opening of the sealed chamber 2 to prevent the overflow of the body fluid simulation liquid; in this embodiment, since the sealed chamber 2 is a cubic structure, the overflow groove 29 is an annular rectangular groove; in order to ensure the sealing of the joint between the two, a sealing layer is provided on the groove walls on both sides of the annular rectangular groove; in order to avoid signal interference to the piezoelectric ceramic 27, the sealed chamber 2 and the piezoelectric ceramic storage block 4 are both made of titanium alloy.

[0035] A cylindrical groove is centrally provided on the top surface of the piezoelectric ceramic placement block 4, and the inner diameter of the groove is slightly larger than the outer diameter of the bottom end of the bone block sample 23; wherein a piezoelectric ceramic 27 is arranged and fixed at the bottom of the groove, and a bone block bracket 30 is arranged on the groove wall located above the piezoelectric ceramic 27 to avoid direct contact between the lower end of the bone block sample 23 and the piezoelectric ceramic 27; specifically, the bone block bracket 30 is composed of four clamping columns evenly distributed along the circumferential direction, the four clamping columns are vertically fixed on the groove wall, and surround a clamping hole with an inner diameter adapted to the outer diameter of the bottom end of the bone block sample 23, so that the bone block sample 23 can be fixed above the piezoelectric ceramic 27 at intervals by inserting the bottom end of the bone block sample 23 between the four clamping columns, and be arranged in a center with the piezoelectric ceramic 27.

[0036] The bottom of the piezoelectric ceramic 27 is connected to the signal generator 7 and the oscilloscope 6 respectively through the wire 5, so that in the simulation experiment, the signal generation parameters of the signal generator 7 can be adjusted to drive the piezoelectric ceramic 27 to vibrate and generate low-intensity pulse ultrasound of different frequencies and intensities; the oscilloscope 6 is used to display the waveform of the ultrasound vibrated by the piezoelectric ceramic; therefore, the bone block sample 23 can complete the bone mass transfer simulation test under different low-intensity pulse ultrasound conditions.

[0037] In order to ensure the complete sealing of the sealed chamber 2, before pumping liquid into the sealed chamber 2, a sealing layer is formed by injecting sealant between the injection hole 24 and the injection pipe 28 of the sealed chamber 2, between the liquid outlet hole 22 and the return pipe 3, between the shaft hole and the output shaft of the motor 12, between the adjusted load bolt 14 and the screw hole, and between the adjusted adjusting bolt and the screw hole to prevent the liquid in the sealed chamber 2 from overflowing during the experiment and to control the pressure in the sealed chamber 2 to remain stable during the entire experiment.

[0038] See also Figure 1 The working principle of the experimental device for promoting bone mass transfer by low-intensity pulsed ultrasound is as follows:

[0039] (I) Setting of simulation experiment conditions, including:

[0040] (1) Setting of human body weight or weight-bearing state, i.e., by adjusting the load bolt 14, the pressure spring 15 applies different pressures to the bone sample 23 through different compression amounts, i.e., simulating the pressure on the bone under different body weights or weight-bearing states;

[0041] (2) Setting the human motion state, that is, by adjusting the rotation speed of the motor 12, the skateboard 20 does not swing or swings at different frequencies; if the skateboard 20 does not swing, it simulates the human standing state; if the skateboard 20 swings at a slower frequency, it simulates the human walking state; if the skateboard 20 swings at a faster frequency, it simulates the human running state;

[0042] (3) bone mass transfer diffusion state setting, that is, not using two bone sample clamping plates to clamp the bone sample 23, then simulating the free diffusion process of bone mass transfer; and using two bone sample clamping plates to clamp the bone sample 23, then simulating the convection transmission process of bone mass transfer;

[0043] (4) Hydraulic setting in the closed chamber, i.e., by adjusting the flow rate of the throttle valve 10 and the pumping rate of the peristaltic pump 11, the inlet flow rate and the outlet flow rate of the body fluid simulation liquid in the closed chamber 2 are controlled, so as to realize the strong regulation of the body fluid simulation hydraulic pressure in the closed chamber 2 by utilizing the difference between the inlet flow rate and the outlet flow rate; when the inlet flow rate and the outlet flow rate of the body fluid simulation liquid in the closed chamber 2 are equal, the body fluid simulation liquid in the closed chamber 2 is in a normal pressure state; when the inlet flow rate of the body fluid simulation liquid in the closed chamber 2 is greater than the outlet flow rate, the body fluid simulation liquid in the closed chamber 2 is in an overpressure state;

[0044] (5) Setting the frequency and intensity of low-intensity pulsed ultrasound, that is, by adjusting the signal generation parameters of the signal generator 7 to drive the piezoelectric ceramic 27 to vibrate, so as to generate low-intensity pulsed ultrasound of a specified frequency and intensity;

[0045] (ii) According to the experimental conditions set in the above step (i), a simulation experiment is performed on the bone block sample 23, and the specific steps are as follows:

[0046] Step 1: Follow Figure 1 As shown, assemble the experimental apparatus and set up the experimental conditions;

[0047] Step 2, preparing a body fluid simulation liquid containing a tracer in a culture medium bottle 9;

[0048] Step 3, starting the peristaltic pump 11, so that the body fluid simulation liquid containing the tracer circulates in the culture medium bottle 9 and the closed chamber 2 in a pulse pumping manner, and continues for a specified simulation time;

[0049] After the above steps 1 to 3, the bone block sample 23 completes the bone mass transfer transmission simulation experiment under the specified load state, movement state, bone mass transfer diffusion state, and low-intensity pulsed ultrasound state; further, after the experiment is completed, by performing subsequent analysis on the experimental bone block sample 23, the transmission effect of bone mass transfer under different experimental setting conditions can be obtained.

[0050] In order to further verify the effectiveness of the experimental device for promoting bone mass transfer using low-intensity pulsed ultrasound, a verification experiment was conducted using the experimental device to determine the effectiveness of the experimental simulation of the experimental device.

[0051] Example 1: Exploring the effect of micro-overload on the growth of human bones

[0052] The verification experiment conditions are set as follows: by adjusting the extension amount of the load bolt 14, the pressure spring 15 is adjusted to simulate the bone sample 23 as a human load-bearing state; by adjusting the rotation speed of the motor 12, the slide plate 20 is used to simulate the bone sample 23 in a walking posture, the bone sample 23 is set in a free diffusion state of bone mass transfer, and the hydraulic pressure in the closed chamber 2 is set to normal pressure, and the low-intensity pulse ultrasound is not turned on; correspondingly, the control experiment conditions are set as follows: through the same operation sequence as above, the bone sample 23 is simulated in a non-load-bearing, walking posture, and a free diffusion state of bone mass transfer, and the hydraulic pressure in the closed chamber 2 is set to normal pressure, and the low-intensity pulse ultrasound is not turned on; after experimental testing, the mass transfer efficiency of the bone fossa and bone canalicular system of the bone sample under load is higher than the mass transfer efficiency of the bone sample in the free diffusion state. The experimental results prove that micro-overload can promote the growth of human bones, which is consistent with the conclusion known in the art, proving that the device can effectively simulate the difference in human bone mass transfer under different loading conditions.

[0053] Example 2: Investigating the effect of different sound intensities on LCS mass transfer

[0054] Set the low-intensity pulsed ultrasound parameters: frequency 1.5 MHz, repetition rate 1 kHz, pulse duration 200 μs, spatial intensity 20 mW / cm 2 Ultrasound was irradiated for 20 min, and the bone samples were sliced. The mass transfer of the tracer in the lacunar canalicular system (LCS) was observed using a confocal microscope. The spatial intensity was set to 30 mW / cm 2 The ultrasound was irradiated for 20 min, and the mass transfer of the tracer in the LCS was observed on the bone slices. The spatial intensity was then set to 45 mW / cm 2 After 20 minutes of ultrasound irradiation, the mass transfer of the tracer in the LCS was observed on the bone slices. By observing the mass transfer in the LCS at different intensities and comparing the fluorescence intensity, the results showed that 45 mW / cm 2It has the greatest effect on promoting LCS mass transfer. It can be seen that the experimental device can effectively obtain reliable experimental data on the effect of low-intensity pulsed ultrasound on promoting bone mass transfer under the cooperation of low-intensity pulsed ultrasound conditions.

Claims

1. An experimental device for promoting bone mass transfer using low-intensity pulsed ultrasound, characterized in that: It comprises a bone environment simulation mechanism, a low-intensity pulsed ultrasound generation mechanism and a simulation liquid perfusion mechanism which are arranged on a base (13); The bone environment simulation mechanism comprises a sealed chamber (2) with an opening at the bottom; a load bolt (14) is vertically penetrated in the center of the top surface of the sealed chamber (2); the bottom end of the load bolt (14) located in the sealed chamber (2) is connected to a pressure spring (15); the bottom end of the pressure spring (15) is fixed to the center of the top surface of a horizontally arranged slide plate (20) through a pressure sensor (19); a group of opposite side plates of the sealed chamber (2) are symmetrically provided with injection holes (24) and outlet holes (22); A motor (12) is fixed on the outer wall above the side plate with the injection hole (24), and the motor (12) is arranged in a manner that its output shaft (25) is horizontally inserted into the closed chamber (2), and a cam (26) is fixed to the shaft end of the output shaft (25); the large-size end of the cam (26) is initially arranged downward and abuts against the top surface of one end of the slide plate (20); a periodic load spring (21) is arranged below the other end of the slide plate (20), and is arranged vertically, and its two ends are respectively fixed to the slide plate (20) and the closed chamber (2); The low-intensity pulsed ultrasound generating mechanism comprises a piezoelectric ceramic storage block (4), an oscilloscope (6) and a signal generator (7); the piezoelectric ceramic storage block is fixed on a base, and an anti-overflow groove (29) capable of being tightly fitted with the bottom end of a sealed chamber (2) is provided on the top surface of the piezoelectric ceramic storage block (4) to close the bottom opening of the sealed chamber (2); a groove is provided on the top surface of the piezoelectric ceramic storage block (4), a piezoelectric ceramic (27) is provided at the bottom of the groove, and a bone block bracket (30) is provided on the groove wall above the piezoelectric ceramic (27), so that the bone block sample (23) is arranged above the piezoelectric ceramic (27) and can be against the center of the bottom surface of the slide plate (20); the piezoelectric ceramic (27) is connected to the signal generator (7) and the oscilloscope (6) respectively through a wire (5); The simulated liquid perfusion mechanism is connected to the liquid injection hole (24) and the liquid outlet hole (22) respectively through pipelines to pump the body fluid simulated liquid into the closed chamber (2).

2. The experimental device for promoting bone mass transfer by low-intensity pulsed ultrasound according to claim 1, characterized in that: Two screw holes are symmetrically provided on another set of opposite side plates of the sealed chamber (2) to respectively threadably assemble adjusting bolts. The two adjusting bolts are horizontally inserted into the side plates of the sealed chamber (2) and the length of the ends of the adjusting bolts extending into the sealed chamber (2) is adjusted by threading with the screw holes on the side plates. A first bone block sample clamping plate (17) and a second bone block sample clamping plate (16) are also symmetrically provided in the sealed chamber (2). The top sides of the two bone block sample clamping plates are respectively vertically fixed on the end surfaces of the two adjusting bolts located in the sealed chamber (2), and the bottom sides of the two bone block sample clamping plates are located on both sides of the bone block sample (23), so that the two bone block sample clamping plates can be adjusted to clamp on both sides of the bone block sample (23) through the two adjusting bolts.

3. The experimental device for promoting bone mass transfer by low-intensity pulsed ultrasound according to claim 2, characterized in that: The first bone block sample clamping plate (17) and the second bone block sample clamping plate (16) comprise a vertical plate and a pressure block, wherein the upper side of one side of the vertical plate is fixed to the end surface of the adjusting bolt located in the sealing chamber (2), and the pressure block is fixed to the lower side of the other side of the vertical plate; a buffer layer is also provided on the contact surface between the pressure block and the bone block sample (23).

4. The experimental device for promoting bone mass transfer by low-intensity pulsed ultrasound according to claim 1, characterized in that: A pressure gauge (1) is installed on a side plate of the sealed chamber (2) to monitor the hydraulic pressure in the sealed chamber (2) in real time.

5. The experimental device for promoting bone mass transfer by low-intensity pulsed ultrasound according to claim 1, characterized in that: The simulated liquid perfusion mechanism comprises a perfusion rack (8) fixed on a horizontal platform, on which a culture medium bottle (9) and a peristaltic pump (11) are fixed; wherein the culture medium bottle (9) is an open bottle body for containing body fluid simulated liquid, and is provided with a liquid inlet end and a liquid outlet end; the liquid inlet end of the injection tube (28) in the peristaltic pump (11) is connected to the liquid outlet end of the culture medium bottle (9), and the liquid outlet end injection hole (24) of the injection tube (28) extends into the closed chamber (2); the liquid outlet hole (22) of the closed chamber (2) is connected to one end of the reflux pipe (3), and the other end of the reflux pipe (3) is connected to the liquid inlet end of the culture medium bottle (9), so that the body fluid simulated liquid can flow back from the closed chamber (2) through the reflux pipe (3) to the culture medium bottle (9); a throttle valve (10) is also provided on the reflux pipe (3).

6. The experimental device for promoting bone mass transfer by low-intensity pulsed ultrasound according to claim 1, characterized in that: The bone block support (30) is composed of four identical clamping columns evenly arranged on the groove wall along the circumferential direction. The four clamping columns are vertically fixed on the groove wall to enclose a clamping hole with an inner diameter adapted to the outer diameter of the bottom end of the bone block sample (23), so that the bottom end of the bone block sample (23) is inserted and clamped between the four clamping columns.

7. The experimental device for promoting bone mass transfer by low-intensity pulsed ultrasound according to claim 1, characterized in that: A sealing layer is provided between the injection hole (24) and the injection pipe (28) of the sealing chamber (2), between the liquid outlet hole (22) and the return pipe (3), between the shaft hole on the side plate and the output shaft of the motor (12), between the adjusted load bolt (14) and the screw hole matched therewith, and between the adjusted adjustment bolt and the screw hole matched therewith.

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