Magnetostrictive bone conduction transducer and method for receiving guided wave excitation in bone

Abstract

The application discloses a magnetostrictive bone conduction transducer and method for guided wave excitation and reception in a bone, comprising a super-magnetostrictive waveguide rod, an acoustic damping end, a magnetic material fixing end, a pen type top column end, a transducer frame, a static biasing device, a magnetic field enhancement backing and a magnetostrictive transducing module, the static biasing device comprising an upper magnetic yoke, a saddle-shaped lower magnetic yoke and a permanent magnet, the magnetostrictive transducing module comprising a magnetic concentrating layer, a dynamic solenoid coil layer, a strip layer and an acoustic coupling layer, and realizing energy conversion of guided wave electric signals and acoustic vibration signals. The application can effectively realize guided wave excitation and reception in a bone, greatly improves the form and method of guided wave excitation and reception compared with a guided wave excitation and reception transducer of a traditional piezoelectric transducer, adopts a pen type mode of the super-magnetostrictive waveguide rod to perform acoustic energy coupling with a measured bone muscle tissue, greatly improves the position accuracy of the guided wave excitation in the bone, and has important practical significance and clinical application value.

Description

Technical Field

[0001] This invention relates to the field of transducer technology for medical waveguide devices, and more specifically to a magnetostrictive bone conduction transducer and method for receiving guided wave excitation in bone. Background Technology

[0002] In the field of bone medicine, accurate assessment of bone health is crucial for the diagnosis and treatment of diseases such as osteoporosis and pathological fractures. Guided wave technology has significant practical implications for bone health detection, risk assessment, and prediction, including: 1. Providing bone structure information: Guided wave technology can provide information about bone structure by measuring the propagation characteristics of guided wave signals. By analyzing parameters such as the propagation speed and attenuation of guided wave signals, characteristics such as bone density, shape, and tissue structure can be understood. This is important for assessing bone health and detecting osteoporosis and other bone diseases. 2. Non-invasive assessment: Guided wave technology is a non-invasive assessment method that does not require surgery or the use of harmful substances such as radiation. Compared to traditional bone density scans or X-ray examinations, guided wave testing is more comfortable, safer, and reusable. This is of great importance for patient comfort and health safety. 3. Providing real-time monitoring and tracking: Guided wave technology can monitor and track bone health in real time. By continuously monitoring changes in guided wave signals, medical professionals can promptly understand changes in bone condition and provide appropriate interventions and treatments. 4. Monitoring Treatment Effectiveness: Guided wave technology can be used to monitor the effectiveness of bone treatment. After bone treatment, by comparing the guided wave signals before and after treatment, the effectiveness of the treatment and the recovery of the bone can be evaluated.

[0003] Traditional methods for exciting guided wave signals in bone mainly rely on the piezoelectric effect of piezoelectric transducers to induce mechanical deformation on or near the surface of long bones, thereby exciting guided wave signals. However, when applying excitation to the surface or vicinity of long bones using this traditional method, the piezoelectric material is often greatly affected by ambient temperature, leading to unstable guided wave signals and affecting detection results. Furthermore, piezoelectric transducers are relatively large. Guided wave transducers based on magnetostrictive materials offer advantages such as high sensitivity, long-distance detection, durability, and ease of implementation. They also possess advantages like a high Curie point, low power supply voltage, and flexibility, making them suitable for the close fit and acoustic-energy coupling of irregular structures in human skeletal and muscular tissues. Therefore, inventing a magnetostrictive bone conduction transducer and method for receiving guided wave excitation in bone is of significant importance. Summary of the Invention

[0004] The present invention proposes a magnetostrictive bone conduction transducer for receiving guided wave excitation in bone, which can solve the problems in the background art mentioned above.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A magnetostrictive bone conduction transducer for receiving guided wave excitation in bone includes a super magnetostrictive waveguide rod, an acoustic damping end, a magnetic material fixing end, a pen-shaped top column end, a transducer frame, a static bias device, a magnetic field enhancement backing, and a magnetostrictive transducer module. The static bias device includes an upper magnetic yoke, a saddle-shaped lower magnetic yoke, and a permanent magnet. The magnetostrictive transducer module includes a magnetic focusing layer, a dynamic solenoid coil layer, a strip layer, and an acoustic coupling layer.

[0007] The acoustic damping end is made of acoustic damping material to absorb the guided wave acoustic signal propagating to this end; the acoustic coupling layer is an ultrasonic coupling agent layer; the dynamic solenoid coil layer is a coil layer formed by winding enameled wire around the super magnetostrictive waveguide rod, and the coil has positive and negative poles to connect the positive and negative pole cables for exciting the guided wave signal; the static bias device consists of six groups, distributed around the circumference of the super magnetostrictive waveguide rod in a 360-degree circle, with each group occupying a 60-degree longitudinal region of the super magnetostrictive waveguide rod, and the included angle between each group of static bias devices is 60 degrees; each permanent magnet of each group of static bias devices is magnetically attracted to the super magnetostrictive waveguide rod through a saddle-shaped lower magnetic yoke; the magnetic field enhancement backing includes a static solenoid coil layer and a backing, wherein the backing has a cuboid structure, the backing is made of flexible non-ferromagnetic material, and the thickness is 0.1mm-0.3mm.

[0008] The transducer frame includes signal terminals, a contact adjustment device, signal cables, and fixing bolts. The contact adjustment device is a compression spring, and there are four fixing bolts. The signal terminals include dynamic magnetic field signal terminals and static magnetic field signal terminals. One end of the static bias device is attached to the junction of the magnetostrictive waveguide rod and the acoustic damping end via the saddle-shaped lower magnetic yoke. The strip layer is made of iron-cobalt-nickel alloy with a thickness of 1mm-3.5mm, and is a flexible sheet structure. The magnetostrictive waveguide rod is made of ferromagnetic material. The magnetic focusing layer is a soft magnetic ferrite material with high resistivity and high permeability, and its structure is a flexible thin film sheet structure formed by pressing soft magnetic ferrite material powder and rubber.

[0009] Furthermore, the dynamic solenoid coil layer and the dynamic magnetic field signal terminal are electrically connected through the signal cable; the signal cable is a conductive cable, which connects two sets of dynamic solenoid coil layers respectively. Each set of dynamic solenoid coil layers is a loop, corresponding to a waveguide excitation and reception signal loop, for a total of two loops; there are seven sets of contact adjustment devices, which are used to adjust the degree of contact between the pen-shaped top post and the tested skeletal muscle tissue during operation, increase the sound wave coupling transmission efficiency, and reduce the influence of noise. One end of each of the seven sets of contact adjustment devices is mechanically fixed to the transducer frame.

[0010] Furthermore, the pen-shaped top post is an acoustic metamaterial used to match the acoustic impedance of the magnetostrictive waveguide rod with that of the bone being tested. The magnetostrictive waveguide rod is cylindrical, with one end mechanically connected to the acoustic damping end, which in turn is mechanically connected to the magnetic material fixing end. The other end of the magnetostrictive waveguide rod is mechanically connected to the pen-shaped top post using a designed embedded sawtooth structure, thereby better matching the acoustic impedance of the magnetostrictive waveguide rod with that of the bone being tested, reducing acoustic impedance and sound energy reflection, and improving sound energy transmission. The dynamic solenoid coil layer is designed with a multi-layer overlapping structure, consisting of two sets of dynamic solenoid coil layers, each containing 1 to P solenoid layers. The winding direction of each set of dynamic solenoid coil layers is consistent. This design structure increases the current intensity by a factor of P without increasing the solenoid layer area. According to the magnetic effect of the current, the corresponding magnetic effect also increases by a factor of P.

[0011] Furthermore, the static solenoid coil layer and the static magnetic field signal terminal are electrically connected through the signal cable; there are six magnetic field enhancement backings in total, each corresponding to six 60-degree longitudinal regions on the super magnetostrictive waveguide rod, and they are all the same size.

[0012] On the other hand, the present invention also discloses a magnetostrictive bone conduction transducer and method for receiving guided wave excitation in bone, the operation method comprising the following steps:

[0013] Step 1: Add an acoustic coupling layer with a thickness of about 1.5-3mm to the super magnetostrictive waveguide rod; arrange a strip layer on the corresponding acoustic coupling layer. The strip layer and the super magnetostrictive waveguide rod are connected through the acoustic coupling layer.

[0014] Step 2: Using a permanent magnet, a bias magnetic field is preloaded onto the strip layer in the direction of the fixed permanent magnet's N and S poles. The permanent magnet slides from the acoustic damping end to the pen-shaped top column end in six 60-degree longitudinal regions of the super magnetostrictive waveguide rod where the six sets of static bias devices are located. Each 60-degree region is slid 4-8 times. Then, six magnetic field enhancement backings are arranged on the corresponding strip layer, with each magnetic field enhancement backing covering a 60-degree region.

[0015] Step 3: Arrange two sets of P-layer dynamic solenoid coil layers on the magnetic field enhancement backing, and further arrange the magnetic focusing layer on the P-layer dynamic solenoid coil layers;

[0016] Step 4: Arrange the static bias device on the super magnetostrictive waveguide rod, wherein the area where the six sets of static bias devices are located should cover the six 60-degree longitudinal areas of the preloaded bias magnetic field in step 2.

[0017] Step 5: Install the transducer frame onto the magnetostrictive waveguide rod from Step 4 using four fixing bolts. One end of each of the seven sets of close-fitting adjustment devices is fixed to the transducer frame, and the other end is magnetically attracted to the six static bias devices and the magnetic material fixing end, respectively. Electrically connect the dynamic magnetic field signal terminal and the dynamic solenoid coil layer through the signal cable, and electrically connect the static magnetic field signal terminal and the static solenoid coil layer through the signal cable, thereby completing the installation operation of the present invention.

[0018] Preferably, the super magnetostrictive waveguide rod is made of ferromagnetic material, specifically silicon steel.

[0019] Preferably, the magnetic concentrating layer is a soft magnetic ferrite material, specifically permalloy, silicon steel, or manganese-zinc ferrite, which are high-permeability materials. The magnetic concentrating layer can significantly improve the transducer efficiency.

[0020] Preferably, the permanent magnet can be a neodymium iron boron permanent magnet of grade N52.

[0021] Preferably, the materials of the upper magnetic yoke and the saddle-shaped lower magnetic yoke can be selected as DT4 industrial pure iron.

[0022] Preferably, the material used for the super magnetostrictive waveguide rod can be a rare-earth super magnetostrictive material or a terbium-dysprosium-iron alloy material.

[0023] Preferably, the acoustic damping material can be a polymer damping material.

[0024] As a preferred option, such as Figure 5 The number of layers P of the dynamic solenoid coil layer is taken as 2 layers.

[0025] Preferably, an embedded serrated pen-shaped top post is designed at the front end of the super magnetostrictive waveguide rod, and the pen-shaped top post is mechanically connected to the super magnetostrictive waveguide rod by embedding the pen-shaped top post into the other in an embedded serrated structure.

[0026] Preferably, the signal terminal is an aviation connector.

[0027] Preferably, the backing is made of a flexible non-ferromagnetic material, such as soft plastic, which can be easily attached to the cylindrical magnetostrictive waveguide rod.

[0028] As can be seen from the above technical solution, the contact adjustment device of the magnetostrictive bone conduction transducer for receiving guided wave excitation in bone of the present invention can, on the one hand, fix the transducer frame to the super-magnetostrictive waveguide rod and the static bias device; on the other hand, when the testing personnel operate, adjusting the pressing pressure can adjust the coupling and contact degree between the pen tip and the tested bone and muscle tissue, increasing the acoustic wave coupling transmission efficiency and reducing the influence of noise. The testing personnel hold the transducer frame and place the pen tip on the tested bone and muscle tissue. At this time, when the testing personnel press the transducer frame, the contact adjustment device will be compressed until it can no longer be compressed, which is the optimal pressing pressure. At this time, the contact force between the pen tip and the tested bone and muscle tissue is appropriate, and the acoustic wave coupling effect is optimal.

[0029] To compensate for the low waveguide transmission efficiency caused by the acoustic impedance difference between the magnetostrictive waveguide and the tested skeletal muscle tissue, resulting in sound wave reflection, scattering, and energy loss between the two, a pen-shaped tip with an embedded serrated structure is designed at the front end of the magnetostrictive waveguide. The pen-shaped tip is mechanically connected to the magnetostrictive waveguide via this embedded serrated structure (embedded into each other). The pen-shaped tip has a frequency range of 20 kHz - 500 kHz. The kHz acoustic metamaterial is a double-negative metamaterial with negative equivalent density and equivalent modulus. It can match the acoustic impedance difference between the supermagnetostrictive waveguide and the tested skeletal muscle tissue, achieving acoustic impedance matching, increasing the transmission and focusing of guided wave signals, and compensating for the loss and scattering of guided wave acoustic energy between different acoustic impedances. This greatly improves the problem of excessive acoustic energy loss at the interface between the transducer and the tested bone, resulting in less guided wave acoustic energy transmitted into the bone, as is common with traditional guided wave transducers. The guided wave excited by the transducer of this invention passes through the supermagnetostrictive waveguide, then through the pen-shaped top post end made of double-negative acoustic metamaterial, increasing the transmittance of the guided wave signal, and finally enters the tested bone. After propagating in the bone, the guided wave reflection echo signal can be efficiently received by the magnetostrictive transducer module through the pen-shaped top post end.

[0030] In summary, the magnetostrictive bone conduction transducer and method for receiving guided wave excitation in bone according to the present invention improves the transmission efficiency of guided wave signals through the close fit between the super-magnetostrictive waveguide rod and the musculoskeletal tissue, the pen-shaped top column end made of a designed double-negative acoustic metamaterial, and its embedded serrated structure. This increases the guided wave acoustic energy in the bone, thereby expanding the propagation range of the guided wave signal in the bone. In this way, the device can improve the efficiency and detection range of guided wave signal excitation reception in bone. Attached Figure Description

[0031] Figure 1 This is a system cross-sectional view of the present invention;

[0032] Figure 2 This is a partially enlarged view of the system of the present invention;

[0033] Figure 3 This is a schematic diagram of the static biasing device arrangement of the present invention;

[0034] Figure 4 This is a schematic diagram of the magnetostrictive transducer module and the magnetic field enhancement backing layer of the present invention;

[0035] Figure 5 This is a schematic diagram of two sets of dynamic solenoid coil layers (number of layers P=2) of the present invention;

[0036] Figure 6 This is a schematic diagram of the present invention unfolded along the circumferential direction of the supermagnetostrictive waveguide rod;

[0037] Figure 7 This is a cross-sectional view of the pen-type top column end and the embedded sawtooth structure of the super magnetostrictive waveguide rod designed in this invention;

[0038] Figure 8 This is a schematic diagram of the magnetic field enhancement backing of the present invention;

[0039] Figure 9 This is a schematic diagram of the detection of the tested skeletal muscle tissue in an embodiment of the present invention;

[0040] Figure 10 This is a guided wave waveform diagram of the detected skeletal muscle tissue in an embodiment of the present invention.

[0041] In the diagram: 1-Upper yoke; 2-Permanent magnet; 3-Saddle-shaped lower yoke; 4-Magnetorostrictive waveguide rod; 5-Acoustic damping end; 6-Magnetic focusing layer; 7-Dynamic solenoid coil layer; 8-Strip layer; 9-Acoustic coupling layer; 10-Transducer frame; 11-Dynamic magnetic field signal terminal; 12-Signal cable; 13-Pen-type top post end; 14-Close-fit adjustment device; 15-Magnetic material fixing end; 16-Fixing bolt; 17-Backing; 18-Static magnetic field signal terminal; 19-Magnetic field enhancement backing; 20-Static solenoid coil layer. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0043] like Figure 1 and Figure 2As shown in this embodiment, a magnetostrictive bone conduction transducer for receiving guided wave excitation in bone includes a detection device comprising a super magnetostrictive waveguide rod 4, an acoustic damping end 5, a magnetic material fixing end 15, a pen-shaped top column end 13, a transducer frame 10, a static bias device, a magnetic field enhancement backing 19, and a magnetostrictive transducer module. The static bias device comprises an upper magnetic yoke 1, a saddle-shaped lower magnetic yoke 3, and permanent magnets 2, with the south pole (S) and north pole (N) orientations of each permanent magnet 2.

[0044] The magnetostrictive transducer module includes a magnetic focusing layer 6, a dynamic solenoid coil layer 7, a strip layer 8, and an acoustic coupling layer 9; the acoustic damping end 5 is an acoustic damping material used to absorb the guided wave acoustic signal propagating to this end; the acoustic coupling layer 9 is an ultrasonic coupling agent layer; as... Figure 5 The dynamic solenoid coil layer 7 is a coil layer formed by winding enameled wire around the giant magnetostrictive waveguide rod 4. The coil has positive and negative poles, which are used to connect the positive and negative cables of the excitation guided wave signal. Figure 5 The solid black dot and cross represent the direction of current flow; for example... Figure 3 The static biasing devices consist of six groups, distributed 360 degrees around the circumference of the magnetostrictive waveguide rod 4. Each group occupies a 60-degree longitudinal region of the magnetostrictive waveguide rod, and the included angle between each group of static biasing devices is 60 degrees. Each permanent magnet of each group of static biasing devices is magnetically attracted to the magnetostrictive waveguide rod 4 via a saddle-shaped lower magnetic yoke 3. Figure 3 and 8 The magnetic field enhancement backing 19 includes a static solenoid coil layer 20 and a backing 17, wherein the backing 17 has a cuboid structure and is made of a flexible non-ferromagnetic material with a thickness of 0.2 mm.

[0045] like Figure 1The transducer frame 10 includes signal terminals, a contact adjustment device 14, a signal cable 12, and fixing bolts 16. The contact adjustment device 14 is a compression spring, and there are four fixing bolts 16. The signal terminals include a dynamic magnetic field signal terminal 11 and a static magnetic field signal terminal 18. One end of the static bias device is attached to the junction of the magnetostrictive waveguide rod 4 and the acoustic damping end 5 by the saddle-shaped lower magnetic yoke 3. The strip layer 8 is made of iron-cobalt-nickel alloy with a thickness of 1.5 mm and is a flexible sheet structure. The magnetostrictive waveguide rod 4 is made of ferromagnetic material. The magnetic focusing layer is a soft magnetic ferrite material with high resistivity and high permeability, and its structure is a flexible thin film sheet structure made of soft magnetic ferrite material powder and rubber. The dynamic solenoid coil layer 7 is electrically connected to the signal terminal block via the signal cable 12. The signal cable 12 is a conductive cable that connects two sets of dynamic solenoid coil layers 7. Each set of dynamic solenoid coil layers 7 is a loop, corresponding to a waveguide excitation and reception signal loop, for a total of two loops. There are seven sets of contact adjustment devices 14, which are used to adjust the degree of contact between the pen-type top post 13 and the tested skeletal muscle tissue during operation, thereby increasing the acoustic wave coupling transmission efficiency and reducing noise interference. One end of each of the seven sets of contact adjustment devices 14 is mechanically fixed to the transducer frame 10.

[0046] The pen-shaped top post 13 is an acoustic metamaterial used to match the acoustic impedance of the super magnetostrictive waveguide rod 4 and the bone being tested; the super magnetostrictive waveguide rod 4 is cylindrical, with one end mechanically connected to the acoustic damping end 5, and the acoustic damping end 5 mechanically connected to the magnetic material fixing end 15; Figure 7 The other end of the magnetostrictive waveguide rod 4 is mechanically connected to the pen-shaped top post end 13 using a designed embedded sawtooth structure, thereby better matching the acoustic impedance of the magnetostrictive waveguide rod 4 and the tested bone, reducing acoustic impedance and sound energy reflection, and improving sound energy transmission; the dynamic solenoid coil layer 7 is designed with a multi-layer overlapping structure, with two sets of dynamic solenoid coil layers 7, each set containing 1 to P solenoid layers, and the winding direction of each set of dynamic solenoid coil layers 7 is consistent. This design structure increases the current intensity by P times without increasing the solenoid layer area, and according to the magnetic effect of the current, the corresponding magnetic effect also increases by P times. The static solenoid coil layer 20 is electrically connected to the static magnetic field signal terminal 18 through the signal cable 12; there are six magnetic field enhancement backings 19, each corresponding to six 60-degree longitudinal regions on the magnetostrictive waveguide rod 4, and they are all the same size. Each magnetic field enhancement backing 19 is as follows: Figure 8 As shown, different Figure 5 , Figure 5 The dynamic solenoid coil layer 7 in the middle has a multi-layered overlapping structure, while Figure 8The static solenoid coil layer 20 in the middle has only one layer, and Figure 5 The dynamic solenoid coil layer 7 is located above the supermagnetostrictive waveguide rod 4, and Figure 8 The static solenoid coil layer 20 is on a thin sheet-shaped backing 17. As a beneficial effect, Figure 5 In this process, the coil direction of the static solenoid coil layer 20 on the backing 17 must be along the horizontal direction of the backing 17, thereby ensuring that the direction of the static magnetic field generated by the magnetic field enhancement backing 19 is consistent with that of the backing 17. Figure 3 The static magnetic fields generated by the six sets of static bias devices are consistent, which ultimately improves the strength and controllability of the guided wave signals generated in the bone.

[0047] During operation, firstly, an acoustic coupling layer 9, approximately 3 mm thick, is applied to the supermagnetostrictive waveguide rod 4; then, a strip layer 8 is placed on top of the corresponding acoustic coupling layer 9; secondly, as... Figure 6 A bias magnetic field is preloaded onto the strip layer 8 using a permanent magnet in the direction of the fixed permanent magnet's N and S poles. The permanent magnet slides from the acoustic damping end 5 to the pen-shaped top post end 13 in six 60-degree longitudinal regions of the supermagnetostrictive waveguide rod 4 where the six sets of static bias devices are located, sliding 4-8 times in each 60-degree region. Then, six magnetic field enhancement backings 19 are arranged on the corresponding strip layer 8, with each magnetic field enhancement backing 19 covering one 60-degree region. Next, two sets of P-layer dynamic solenoid coil layers 7 are arranged on the magnetic field enhancement backings 19, and the magnetic focusing layer is further arranged on the P-layer dynamic solenoid coil layers 7. Then, as... Figure 1 and 3 The static biasing devices are arranged on the supermagnetostrictive waveguide rod 4, wherein the area where the six sets of static biasing devices are located should cover as follows: Figure 6 The six 60-degree longitudinal regions of the preloaded bias magnetic field are shown. Next, the transducer frame 10 is fixed with four fixing bolts 16. One end of each of the seven sets of close-fitting adjustment devices 14 is fixed to the transducer frame 10, and the other end is magnetically attracted to the six static bias devices and the magnetic material fixing end 15. Then, the dynamic magnetic field signal terminal 11 and the dynamic solenoid coil layer 7 are electrically connected via the signal cable 12, and the positive and negative poles of the static magnetic field signal terminal 18 and the static solenoid coil layer 20 are electrically connected via the signal cable 12, thus completing the assembly of the bone conduction transducer of this invention.

[0048] Finally, as Figure 9As shown, this transducer requires an external guided wave excitation device, which is electrically connected to the external guided wave excitation device via signal terminals. The guided wave signal acquisition points are 659, the sampling frequency is 1MHz, and the guided wave excitation signal frequency is set to 72kHz. When the pen-type top post 13 is pressed onto the measured skeletal muscle tissue, the current pulse generated by the external guided wave excitation device, after passing through the magnetostrictive transducer module, generates a magnetic field that is parallel to and interacts with the magnetic field generated by the static bias device. Due to the magnetostrictive effect, a strained acoustic vibration pulse signal is excited in the super-magnetostrictive waveguide rod 4, such as... Figure 2 As shown, the signal propagates to the upper and lower ends of the supermagnetostrictive waveguide rod 4. The signal propagating at the upper end is absorbed by the acoustic damping end 5, while the signal propagating at the lower end is coupled into the bone via the pen-shaped top post end 13 to generate a guided wave signal. This longitudinal guided wave signal propagates in the bone at a certain sound speed. After encountering the guided wave reflection echo signal caused by the change in acoustic impedance, it passes through the pen-shaped top post end 13 and the supermagnetostrictive waveguide rod 4, and is received by the magnetostrictive transducer module due to the inverse magnetostrictive effect. The resulting signal is as follows: Figure 10 As shown, the amplitude of the guided wave signal is significant, thus realizing the transduction function of exciting and receiving guided wave signals in the bone.

[0049] In summary, the embodiments of the present invention can effectively realize the excitation and reception of guided waves in bones. Compared with the traditional piezoelectric transducer guided wave excitation and reception transducer, it greatly improves the form and method of excitation and reception of guided waves. By using a pen-like method with a super magnetostrictive waveguide rod to perform acoustic energy coupling with the tested skeletal and muscular tissue, the positional accuracy of the excitation guided wave in the bone is greatly improved, which has important practical significance and clinical application value.

[0050] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A magnetostrictive bone conduction transducer for guided wave excitation reception in a bone, characterized by, The application relates to a magnetostrictive waveguide rod, an acoustic damping end, a magnetic material fixed end, a pen-shaped top column end, a transducer frame, a static bias device, a magnetic field enhancement backing and a magnetostrictive transducer module. The magnetostrictive waveguide rod is cylindrical, one end of which is connected to the acoustic damping end by a mechanical method, and the acoustic damping end is connected to the magnetic material fixed end by a mechanical method. The other end of the magnetostrictive waveguide rod is connected to the pen-shaped top column end by a mechanical method in an embedded sawtooth structure. The pen-shaped top column end is an acoustic metamaterial and is used for matching the acoustic impedance of the magnetostrictive waveguide rod and the measured bone. The static bias device comprises an upper magnetic yoke, a saddle-shaped lower magnetic yoke and a permanent magnet. The magnetostrictive transducer module comprises a magnetic gathering layer, a dynamic solenoid coil layer, a strip layer and an acoustic coupling layer. The acoustic damping end is made of acoustic damping material and is used for absorbing guided wave acoustic signals propagating to the end. An acoustic coupling layer is added to the magnetostrictive waveguide rod, and the strip layer is arranged above the corresponding acoustic coupling layer, and the strip layer is connected to the magnetostrictive waveguide rod through the acoustic coupling layer. The dynamic solenoid coil layer is a coil layer formed by winding an enameled wire on the magnetostrictive waveguide rod, and the coil has positive and negative poles and is used for connecting positive and negative pole cables of an excitation guided wave signal. The static bias device is six groups and is distributed around the circumference of the magnetostrictive waveguide rod at 360 degrees, each group occupies a 60-degree longitudinal area of the magnetostrictive waveguide rod, and the included angle between each group of static bias devices is 60 degrees. Each permanent magnet of each group of static bias devices is magnetically adsorbed to the magnetostrictive waveguide rod through the saddle-shaped lower magnetic yoke. The static bias device is arranged on the magnetostrictive waveguide rod, and the six groups of static bias devices are arranged in six 60-degree longitudinal areas of the preloaded bias magnetic field. The transducer frame is mounted on the magnetostrictive waveguide rod, one end of the close-fitting adjusting device is fixed on the transducer frame, and the other end is magnetically adsorbed to the six groups of static bias devices and the magnetic material fixed end. The magnetic field enhancement backing comprises a static solenoid coil layer and a backing.

2. The magnetostrictive bone conduction transducer for guided wave excitation reception in bone according to claim 1, characterized by: One end of the static bias device is adsorbed and mounted at the junction of the magnetostrictive waveguide rod and the acoustic damping end through the saddle-shaped lower magnetic yoke.

3. The magnetostrictive bone conduction transducer for guided wave excitation reception in bone according to claim 1, characterized in that: The transducer frame comprises signal terminal posts, close-fitting adjusting devices, signal cables and fixing bolts, wherein the close-fitting adjusting devices are compression springs, the fixing bolts are four in number, and the signal terminal posts comprise dynamic magnetic field signal terminal posts and static magnetic field signal terminal posts.

4. The magnetostrictive bone conduction transducer for guided wave excitation reception in bone according to claim 1, characterized in that: The strip layer is made of iron-cobalt-nickel alloy material and has a thickness of 1mm-3.5mm, and the material is a flexible sheet structure.

5. The magnetostrictive bone conduction transducer for guided wave excitation reception in bone according to claim 1, characterized in that: The magnetostrictive waveguide rod is made of ferromagnetic material. The magnetic gathering layer is made of soft magnetic ferrite material with high resistivity and high magnetic permeability, and has a flexible film sheet structure formed by pressing soft magnetic ferrite material powder and rubber.

6. The magnetostrictive bone conduction transducer for guided wave excitation reception in bone according to claim 3, characterized in that: The dynamic solenoid coil layer is electrically connected to the dynamic magnetic field signal terminal posts through the signal cables. The static solenoid coil layer is electrically connected to the static magnetic field signal terminal posts through the signal cables. The signal cable is a conductive cable, respectively connecting two groups of dynamic solenoid coil layers, each group of dynamic solenoid coil layer is a loop, corresponding to a guided wave excitation and signal receiving loop, and there are two loops in total.

7. The magnetostrictive bone conduction transducer for guided wave excitation reception in bone according to claim 1, characterized by: The seven groups of close adjustment devices are used to adjust the coupling and close degree of the pen-shaped top column end and the measured skeletal muscle tissue during operation, increase the sound wave coupling transmission efficiency, and reduce the influence of clutter, one end of the seven groups of close adjustment devices is respectively mechanically fixed on the transducer frame.

8. The magnetostrictive bone conduction transducer for guided wave excitation reception in bone according to claim 1, characterized by: The dynamic solenoid coil layer is designed as a multi-layer overlapping structure, and there are two groups of dynamic solenoid coil layers, each group containing 1 to P layers of solenoid layers, and the winding direction of each group of dynamic solenoid coil layers is consistent, which increases the current intensity by P times without increasing the area of the solenoid layer, and according to the magnetic effect of current, the corresponding magnetic effect is also increased by P times.

9. The magnetostrictive bone conduction transducer for guided wave excitation reception in bone according to claim 1, characterized in that: The magnetic field enhancement backing is six in total, each magnetic field enhancement backing corresponds to six 60-degree longitudinal regions on the giant magnetostrictive waveguide rod, and the sizes are the same. The backing is a cuboid structure, and the backing is a flexible non-ferromagnetic material with a thickness of 0.1mm-0.3mm.

10. A method for fabricating a magnetostrictive bone conduction transducer for receiving guided wave excitation in bone, characterized in that: The method comprises the following steps, Step 1, adding an acoustic coupling layer to the giant magnetostrictive waveguide rod, the thickness is 1.5-3mm; arranging a strip layer on the corresponding acoustic coupling layer, and the strip layer is connected with the giant magnetostrictive waveguide rod through the acoustic coupling layer; Step 2, using a permanent magnet to pre-load a bias magnetic field on the strip layer according to the fixed N-S pole direction of the permanent magnet, the permanent magnet slides in the six 60-degree longitudinal regions of the giant magnetostrictive waveguide rod where the six groups of static bias devices are located from the acoustic damping end to the pen-shaped top column end, and slides 4-8 times in each 60-degree region, and then six magnetic field enhancement backings are arranged on the corresponding strip layer, each magnetic field enhancement backing covers one 60-degree region; Step 3, arranging two groups of P-layer dynamic solenoid coil layers on the magnetic field enhancement backing, and further arranging a magnetic concentration layer on the P-layer dynamic solenoid coil layer; Step 4, arranging the static bias device to the giant magnetostrictive waveguide rod, wherein the six groups of static bias devices are arranged in the six 60-degree longitudinal regions where the pre-loaded bias magnetic field is arranged in step 2; Step 5, mounting the transducer frame to the giant magnetostrictive waveguide rod in step 4 through four fixing bolts, one end of the seven groups of close adjustment devices is fixed on the transducer frame, and the other end is respectively adsorbed with the six groups of static bias devices and the magnetic material fixed end through magnetism; the dynamic magnetic field signal terminal and the dynamic solenoid coil layer are electrically connected through the signal cable, and the static magnetic field signal terminal and the static solenoid coil layer are electrically connected through the signal cable, thereby completing the mounting operation.

Images