A pen-type ultrasonic probe for micro-bone window channel imaging

Abstract

The application discloses a pen type ultrasonic probe for micro bone window channel imaging and belongs to the field of acoustic imaging. The pen type ultrasonic probe comprises a base, a patch array element arranged in the base, a flexible hinge, a support platform, a neodymium magnet and an electromagnetic drive unit. The two ends of the flexible hinge are fixed to the inner wall of the base and can rotate around the connecting line of the two ends. The support platform is arranged on the flexible hinge and is provided with the neodymium magnet on the two sides in the direction perpendicular to the connecting line of the two ends of the flexible hinge. The electromagnetic drive unit is located below the flexible hinge and comprises two inductance coils coaxially arranged with the neodymium magnet. When the electromagnetic drive unit receives the same frequency and opposite direction alternating current input, the electromagnetic drive unit generates an alternating magnetic field to drive the neodymium magnet to polarize and drive the support platform to rotate. The patch array element is arranged on the upper surface of the support platform and is used for emitting and receiving acoustic wave signals and transmitting the received acoustic wave signals to an external image processing unit for imaging. The application has the advantages of fast, accurate and wide imaging.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of neurosurgery, acoustic imaging and micro-electro-mechanical machine, and particularly relates to a pen-type ultrasonic probe for micro-bone window channel imaging. BACKGROUND

[0002] Spinal cord disease can refer to a class of clinical syndromes directly infiltrating the spinal cord or causing compression of the spinal cord and nerves due to primary or secondary lesions around the spinal cord, including primary or secondary tumors or metastatic tumors of the spinal cord or nerves, proliferative yellow ligament or protruding intervertebral disc causing spinal stenosis and compression of the spinal cord and nerves, and other diseases such as traumatic hemorrhage forming epidural hematoma directly compressing the spinal cord to cause decreased nerve function. In recent years, with the innovation of surgical techniques and the development of equipment, more and more doctors and patients tend to use minimally invasive surgical methods to remove tumor lesions or relieve compression on the spinal cord. Unlike other minimally invasive surgical methods, spinal cord minimally invasive technology not only requires a small skin incision and exposure of the approach, but also emphasizes the protection of nerves to preserve normal function as much as possible to accelerate postoperative recovery and improve the quality of prognosis. However, spinal cord surgery with minimally invasive technology is a great challenge to neurosurgical surgeons, such as the incision of the half-laminectomy approach surgery is 5-8 cm, the unilateral paraspinal muscle is stripped, and the long diameter of the bone window formed by grinding the lamina along the interlaminar space is less than 2 cm; such as percutaneous endoscopic or minimally invasive sleeve technology, a metal pipe with a diameter of about 1 cm is used to establish a working channel from the skin to the spinal cord, and the doctor observes the deep tissue from the pipe opening and performs the operation. Spinal cord minimally invasive surgery means extremely narrow operating space, which severely limits the intraoperative visual angle and field of view and cannot provide enough intraoperative information for the doctor, resulting in a much higher incidence of complications such as nerve damage in minimally invasive surgical methods than in traditional surgical methods.

[0003] Spinal cord surgery is a procedure that exposes the spinal cord layer by layer from skin incision, muscle stripping, bone removal. In minimally invasive surgery such as hemilaminectomy, the step of cutting the dura mater after bone windowing is particularly prone to injury to the underlying spinal cord and nerves. This is because the spinal cord and nerves are floating and changing in the dural sac, and preoperative CT or magnetic resonance imaging cannot accurately show the specific position of the nerve and tumor lesions in the dural sac. In addition, the doctor often needs to push the spinal cord and nerves to see the lesions on the ventral side of the dura mater. It is difficult to judge the position of the deeply buried lesions and the adjacent relationship only by vertical angle and narrow endoscopic view. This extremely high-risk 'blind operation' poses a great challenge to the doctor's clinical experience and operation ability, significantly increases the incidence of surgical complications, and causes great resistance to the development and promotion of minimally invasive technology. Therefore, this clinical 'pain point' problem has aroused strong demand for intraoperative imaging, which not only requires the imaging device to adapt to the extremely narrow operating space, but also requires a larger imaging range to observe the surrounding results, and a higher imaging resolution to distinguish the anatomical relationship. Generally speaking, the imaging in the hemilaminectomy incision needs to cover the entire dural sac, and the imaging in the percutaneous endoscopic approach needs to cover the head operating space, that is, the effective imaging range of 2×2 cm; in order to distinguish between tumor and normal nerve tissue, the imaging resolution needs to be <0.1 mm.

[0004] CT or magnetic resonance imaging cannot be used in surgery due to its large size and limited ability to image specific areas. Ultrasound has the characteristics of real-time, non-invasive and flexible imaging, and is the best intraoperative imaging modality. However, traditional ultrasound probes (flat or convex probes) are arranged in a multi-vibration element linear array, with a length of 6-15 cm. Even the endoscopic ultrasound probe and transesophageal echocardiography probe developed in recent years have a diameter of 2-6 cm, which cannot adapt to the narrow bone window channel or endoscopic tube with a diameter of less than 10 mm. The development of micro-electro-mechanical system (MEMS) technology and its application in the preparation of ultrasound transducers effectively reduces the size of the ultrasound probe. There are 15-30 mm long micro linear array probes for endoscopic ultrasound imaging for early cancer screening and subcutaneous thrombus evaluation. With a probe frequency of 20 MHz, it supports an imaging range of 3×3 cm and a transverse resolution of 0.2 mm. However, there is no mature technology and process to support stable imaging of a head-end ultrasound probe with a diameter of less than 10 mm. The MEMS scanning platform loads the imaging scheme of reflecting mirror polarized reflected light / sound waves, which is first applied to photoacoustic imaging. The scanning platform can be reduced to 10 mm. This scheme is also suitable for single sound wave reflection scanning imaging. However, this scheme requires the sound wave emission end, the scanning platform and the imaging target area to form a right triangle, which significantly increases the transverse size of the whole probe, which cannot adapt to the narrow imaging space in neurosurgery. At present, there is no scheme and product that can balance the probe size and imaging requirements for smaller imaging spaces. SUMMARY

[0005] To solve the problems in the prior art, the application provides a pen-type ultrasonic probe for micro-bone-window channel imaging.

[0006] The technical scheme of the application is as follows:

[0007] The application discloses a pen-type ultrasonic probe for micro-bone-window channel imaging, which comprises a base, a patch array element, a flexible hinge, a support platform, a neodymium magnet and an electromagnetic driving unit arranged in the base.

[0008] The two ends of the flexible hinge are fixed to the inner wall of the base, and the flexible hinge can rotate around the connecting line of the two ends thereof; the support platform is arranged on the flexible hinge, and the two sides of the support platform in the direction perpendicular to the connecting line of the two ends of the flexible hinge are both provided with a neodymium magnet; the electromagnetic driving unit is located below the flexible hinge and comprises two inductance coils, each inductance coil is coaxially arranged with a neodymium magnet, when the electromagnetic driving unit receives the same-frequency and opposite-phase alternating-current input, an alternating magnetic field is generated to drive the neodymium magnet to move, and the two neodymium magnets are polarized according to the time phase of the change of the magnetic field under the driving of the alternating magnetic field generated by the electromagnetic driving unit, so that the support platform rotates around the connecting line of the two ends of the flexible hinge; the patch array element is arranged on the upper surface of the support platform, the patch array element is used for transmitting and receiving acoustic wave signals and transmitting the received acoustic wave signals to an external image processing unit for imaging; when the support platform rotates around the connecting line of the two ends of the flexible hinge, the patch array element is driven to generate a one-degree-of-freedom polarization to form scanning imaging.

[0009] Further, the mass of the support platform and the length of the flexible hinge are arranged to make the resonant frequency of the deflection of the patch array element be 15 Hz and the deflection angle of the patch array element be maximum at this time.

[0010] Further, the mass of the support platform and the length of the flexible hinge are designed in the following manner:

[0011] 1) the mass of the support platform and the length of the flexible hinge in the initial condition are obtained;

[0012] 2) the resonant frequency of the deflection of the patch array element and the deflection angle of the patch array element at this time are measured;

[0013] 3) if the resonant frequency obtained in step 2) is greater than 15 Hz, the mass of the support platform is gradually increased and step 2) is repeated until the resonant frequency is equal to 15 Hz or the mass of the support platform reaches a preset upper limit; if the mass of the support platform has reached the upper limit and the resonant frequency is still greater than 15 Hz, the length of the flexible hinge is increased and step 2) is repeated until the resonant frequency is equal to 15 Hz;

[0014] If the resonance frequency obtained in step 2) is less than 15 Hz, then the mass of the support platform is gradually reduced and step 2) is repeated until the resonance frequency is equal to 15 Hz or the mass of the support platform reaches a preset lower limit; if the mass of the support platform has reached the lower limit and the resonance frequency is still less than 15 Hz, then the length of the flexible hinge is reduced and step 2) is repeated until the resonance frequency is equal to 15 Hz;

[0015] 4) In the case of ensuring that the resonance frequency is equal to 15 Hz, the length of the flexible hinge is increased and the mass of the support platform is reduced to maximize the deflection angle of the patch array element, and finally the mass of the support platform and the length of the flexible hinge at this time are obtained.

[0016] Further, the patch array element is a micro transduction unit composed of a single piezoelectric wafer; the transmission frequency of the patch array element is 10-30 MHz, and the imaging depth is greater than or equal to 30 mm, and the imaging focal point is located at 18-20 mm.

[0017] Further, the material for preparing the flexible hinge is a silica gel material, and the flexible hinge is twisted to accumulate potential energy during the twisting process, and when the support platform is not subjected to external force, the flexible hinge drives the support platform to restore to the initial state using the potential energy accumulated during the twisting process.

[0018] Further, the pen-type ultrasonic probe further comprises a sleeve cover, the bottom end of the base is provided with an opening, one end of the sleeve cover is fixedly connected with the opening of the base, and the sleeve cover and the base form a structure filled with water to form a sealed water immersion environment to provide a medium for the propagation of acoustic signals; wherein the electromagnetic driving unit is sealed by the coil sleeve outside the electromagnetic driving unit to avoid contact between the electromagnetic driving unit and water; the base is made of biocompatible plastic resin material;

[0019] The upper end of the sleeve cover is provided with a high molecular film, the high molecular film is made of polyurethane material with biocompatibility, the thickness of the high molecular film is half of the wavelength of ultrasonic wave transmission in the polyurethane material, and the acoustic impedance of the high molecular film material is 1.60 MRayl and the sound propagation speed is 1540 m / s.

[0020] Compared with the prior art, the beneficial effects of the present application are:

[0021] The pen test ultrasonic probe disclosed in the application is an ultrasonic scanning imaging device based on magnetic driving single-element polarization, which is different from the traditional linear array ultrasonic probe, and the pen test ultrasonic probe utilizes the regular change direction magnetic field generated by the alternating current energized inductive coil to drive the support platform to polarize around an axis, so that the sound beam fan-shaped scanning is formed to form an image. The pen test ultrasonic probe integrates the support platform and the patch array element together, and the volume is obviously reduced compared with the conventional probe. At the same time, the electromagnetic driving support platform deflection scanning response is fast, the angle is large and the precision is high, so that the imaging has the characteristics of fast, accurate and large range. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is an application schematic diagram of the pen test ultrasonic probe of example one in the imaging of the spinal micro-invasive semi-laminectomy approach surgery;

[0023] Figure 2 is an explosion schematic diagram of the structure of the pen test ultrasonic probe in the example;

[0024] Figure 3 is a deflection schematic diagram of the support platform of the pen test ultrasonic probe in the example;

[0025] Figure 4 is an imaging result diagram of the pen test ultrasonic probe of example one in the micro-invasive nerve surgery through the micro-bone window channel to the spinal cord and nerve;

[0026] Figure 5 is an imaging result diagram of the pen test ultrasonic probe of example two to the foramen bone channel and deep spinal cord nerve. DETAILED DESCRIPTION

[0027] The application will be further described and explained in conjunction with the specific embodiments. The examples are only demonstrations of the disclosure and do not define the limit range. The technical features of each embodiment in the application can be combined accordingly without conflict.

[0028] The application proposes a pen type ultrasonic probe for micro-bone window channel imaging, which can adapt to the narrow micro-bone window channel in the spinal cord minimally invasive surgery, provide the surgeon with a larger range and high resolution real-time imaging of the target area, help to quickly identify the relative relationship between important tissues such as lesions and nerves during the operation, and play a role in reducing the technical threshold of minimally invasive surgery and reducing the incidence of serious complications during the operation.

[0029] Referring to Figure 1 , the pen test ultrasonic probe 1 can pass through the micro-bone window channel 2 or the sleeve endoscope tool in the nerve minimally invasive surgery. Referring to Figure 4The pen type ultrasonic probe can provide the target area with a large range and high resolution image information in operation to guide the fine operation, thereby reducing the serious complications such as spinal cord nerve and blood vessel injury, improving the prognosis of patients and accelerating the postoperative rehabilitation.

[0030] Referring to Figure 2 and Figure 3 The pen type ultrasonic probe for micro-bone window channel imaging comprises a polymer film 3, a sleeve cover 5, a base 11, a bottom cap 12 and a patch array element 4, a neodymium magnet 6, a flexible hinge 8, an electromagnetic drive unit and a support platform 7 arranged in the base 11. The bottom cap 12 is connected with the base 11, and a cable is led out through a hole in the middle.

[0031] The flexible hinge 8 is fixed at both ends of the inner wall of the base 11, and can rotate around the connecting line at both ends of the flexible hinge 8. The support platform 7 is arranged on the flexible hinge 8, and the neodymium magnet 6 is arranged on both sides of the support platform 7 in the direction perpendicular to the connecting line at both ends of the flexible hinge 8. The electromagnetic drive unit comprises two inductance coils 9, and each inductance coil 9 is coaxially arranged with a neodymium magnet 6. When the electromagnetic drive unit receives the same frequency and opposite direction alternating current input, an alternating magnetic field is generated to drive the neodymium magnet 6 to move. The two neodymium magnets 6 are polarized according to the time phase of the magnetic field change under the driving of the alternating magnetic field generated by the electromagnetic drive unit, and drive the support platform 7 to rotate around the connecting line at both ends of the flexible hinge 8. The patch array element 4 is arranged on the upper surface of the support platform 7. The patch array element 4 is used for emitting and receiving acoustic signals, and transmitting the received acoustic signals to an external image processing unit for imaging. When the support platform 7 rotates around the connecting line at both ends of the flexible hinge 8, the patch array element 4 generates a one-degree-of-freedom polarization to form a scanning image.

[0032] In an embodiment of the present application, the outer diameter of the pen type ultrasonic probe is 12mm, the patch array element 4 is located at the front end of the pen type ultrasonic probe, the probe wire of the patch array element 4 and the enameled copper wire of the electromagnetic drive unit are led out from the rear end of the pen type ultrasonic probe, the probe wire is connected with the pulse transmitter and the image processing unit, and the enameled copper wire is connected with the programmable alternating current power supply. The formed pen type ultrasonic probe can image important tissues such as nerves in the deep spinal canal through the micro-bone window.

[0033] The bottom surface of the patch array element 4 for emitting and receiving acoustic signals is fixed flat on the support platform 7. The probe wire 13 and the grounding wire 14 are led out from the rear end of the pen type ultrasonic probe along the reserved channel on the base 11, the probe wire 13 is connected with the external pulse transmitter and the image processing unit, and is used for high-pressure acoustic wave emission and return signal processing; the grounding wire 14 is connected with the shielding layer for blocking electromagnetic interference. The probe wire 13 and the grounding wire 14 are both enameled copper materials, the wire quality is soft, the diameter is 0.05mm, and the interference stress of line pulling during the deflection of the pen type ultrasonic probe is reduced.

[0034] The patch array element 4 is a miniature transducing unit composed of a single piezoelectric wafer, which is a cylinder with a diameter of 5 mm. Different configurations can be set according to the conditions of different micro-invasive surgeries, the main difference being the probe outer diameter, the diameter of the patch array element 4 and the transmission frequency. For example, in the pen test ultrasonic probe for imaging the micro-bone window channel in the laminectomy, the transmission frequency of the patch array element 4 is greater than or equal to 20 MHz, the imaging depth is greater than or equal to 30 mm, and the imaging focal point is located at 18-20 mm.

[0035] In the preferred embodiment of the present application, the support platform 7 is composed of two circular plates arranged on the upper surface and the lower surface of the flexible hinge 8, respectively.

[0036] The material for preparing the flexible hinge 8 is high-elasticity silica gel material, which is corrosion-resistant and has good toughness, can withstand large amplitude torsion and continuously accumulate potential energy in the process, and assists in driving the support platform 7 to reverse deflection when the driving force changes direction.

[0037] The resonance frequency and the rotation angle (imaging range) of the support platform 7 are the results of multiple factors, in order to achieve at least 65° under the condition of the probe diameter of 12 mm and the specific resonance frequency (15 Hz), the motion of the flexible hinge 8 in the support platform 7 must be modeled to determine the influencing factors, and a simulation model is established to guide parameter setting. In this embodiment, when the electromagnetic driving force is applied to the support platform 7, the support platform 7 rotates around the center line with an angular displacement The driving can be modeled as a harmonic torque, and the motion of the flexible hinge is modeled and derived as a single degree of freedom system:

[0038]

[0039] wherein, is the torsional inertia moment of the support platform 7, which is determined by the mass of the support platform 7; is the angular acceleration; is the angular velocity; is the torsional damping coefficient, is the torsional stiffness coefficient of the flexible hinge 8, is the external driving torque, wherein represents the static torque of the flexible hinge, represents the thickness of the flexible hinge 8, represents the width of the flexible hinge 8, represents the phase difference. Thus, the natural frequency of the polarization motion of the support platform 7 driven by the magnet is calculated as .

[0040] The environmental damping existing when the support platform 7 is polarized is also taken into account, and the polarization motion of the support platform 7 under the damping condition is further modeled as is​ wherein is the damping ratio of the single degree of freedom system, .

[0041] The support platform 7 is loaded on the flexible hinge 8, and the torsional stiffness coefficient The torsional constraint of the flexible hinge 8 can be derived as .

[0042] wherein, is the shear modulus of the flexible hinge 8, which is determined by the material properties of the flexible hinge 8. is the length of the flexible hinge 8, is the thickness of the flexible hinge 8, is the width of the flexible hinge 8. Thus, the factors affecting the resonant frequency and the rotation angle of the support platform 7 are the shear modulus, thickness, width and length of the flexible hinge 8, and the mass of the support platform 7. To simplify the calculation and facilitate parameter adjustment, the shear modulus, thickness and width of the flexible hinge 8 are set to fixed values, and the length of the flexible hinge 8 and the mass of the support platform 7 are the key parameters. A plurality of parameterized simulations are performed on the motion of the flexible hinge 8, and the results show that the shorter the length of the flexible hinge 8, the smaller the rotation angle of the support platform 7, and the higher the resonant frequency of the deflection; the greater the total mass of the support platform 7, the greater the rotation angle of the support platform 7, and the lower the resonant frequency of the deflection.

[0043] Therefore, it is necessary to design the mass of the support platform 7 and the length of the flexible hinge 8 so that the resonant frequency of the deflection of the patch array element 4 is 15 Hz and the deflection angle of the patch array element 4 is maximum at this time. The mass of the support platform 7 and the length of the flexible hinge 8 are designed in the following manner:

[0044] 1) Set the initial value of the mass of the support platform 7 and the initial value of the length of the flexible hinge 8; in order to leave room for subsequent adjustment, a longer length of the flexible hinge 8 is selected at the initial stage, and a medium initial mass of the support platform 7 is selected;

[0045] 2) Measure the resonant frequency of the deflection of the patch array element 4 and the deflection angle of the patch array element 4 at this time;

[0046] 3) If the resonant frequency obtained in step 2) is greater than 15 Hz, gradually increase the mass of the support platform 7 and repeat step 2) until the resonant frequency is equal to 15 Hz or the mass of the support platform 7 reaches a preset upper limit; if the mass of the support platform 7 has reached the upper limit and the resonant frequency is still greater than 15 Hz, gradually increase the length of the flexible hinge 8 and repeat step 2) until the resonant frequency is equal to 15 Hz;

[0047] If the resonance frequency obtained in step 2) is less than 15 Hz, then the mass of the support platform 7 is gradually reduced and step 2) is repeated until the resonance frequency is equal to 15 Hz or the mass of the support platform 7 reaches a preset lower limit; if the mass of the support platform 7 has reached the lower limit and the resonance frequency is still less than 15 Hz, then the length of the flexible hinge 8 is gradually reduced and step 2) is repeated until the resonance frequency is equal to 15 Hz;

[0048] 4) In the case of ensuring that the resonance frequency is equal to 15 Hz, the length of the flexible hinge 8 is gradually increased, and at the same time, the mass of the support platform 7 is gradually reduced, so that the deflection angle of the patch array element 4 reaches the maximum, and finally the mass of the support platform 7 and the length of the flexible hinge 8 at this time are obtained. Wherein, each time the length of the flexible hinge 8 is increased, the length of the flexible hinge 8 is increased slightly, and at the same time, the mass of the support platform 7 is correspondingly reduced to maintain the resonance frequency equal to 15 Hz, and the deflection angle of the patch array element 4 is recorded each time until the deflection angle of the patch array element 4 no longer increases (or even starts to decrease), at this time, the corresponding length of the flexible hinge 8 and the mass of the support platform 7 are the optimal combination.

[0049] In a specific embodiment of the present application, as shown in Figure 2 The base 11 is open at one end close to the patch array element 4, the sleeve cover 5 is fixedly connected to the end of the base 11 close to the patch array element 4, and the structure formed by the sleeve cover 5 and the base 11 is filled with water to form a sealed water immersion environment, at this time, the patch array element 4, the support platform 7 and the flexible hinge 8 are all in the water immersion environment, which provides a medium for the propagation of sound wave signals. Wherein, the electromagnetic drive unit is sealed by the coil sleeve 10 outside the electromagnetic drive unit to avoid direct contact between the electromagnetic drive unit and water. The sleeve cover 5, the support platform 7, the coil sleeve 10, the base 11 and the sleeve cap 12 are made of biocompatible light-cured resin material.

[0050] The end of the sleeve cover 2 away from the patch array element 4 is covered with a high molecular film 3 made of polyurethane material with good biocompatibility. The thickness of the high molecular film 3 is half of the wavelength of the ultrasonic wave when transmitting in the polyurethane material, and the acoustic impedance of the high molecular film 3 is close to 1.60 MRayl, and the sound propagation speed is close to 1540 m / s.

[0051] In a preferred embodiment of the present application, a core is arranged in the inductor coil to increase the magnetic driving force; and the winding of the inductor coil is enameled copper wire.

[0052] Example one

[0053] The present application provides a pen-type ultrasonic probe, which is applied in surgery and refers to Figure 1Specifically, the pen-shaped ultrasound probe can adapt to the imaging conditions of the micro-bone-window channel in minimally invasive spinal surgery, and can perform wide-range and high-resolution ultrasound imaging of deep lesions and key tissues through the bone window, so as to help determine the relative relationship between the lesions and important tissues such as the spinal cord and nerves, and guide the design of the dural incision and the planned surgical approach. Thus, the intraoperative visual guidance operation can effectively reduce the incidence of serious complications such as spinal cord traction and nerve injury in minimally invasive surgery.

[0054] In this embodiment, the imaging step in the hemilaminectomy of spinal cord tumor is as follows:

[0055] Intraoperative bone window and probe positioning. The target segment is determined intraoperatively, and the paraspinal muscles on the diseased side are bluntly dissected through a midline incision. The hemilaminectomy is performed to establish a micro-bone-window channel, and the dural sac and the exit nerve sleeve under the channel are exposed. The probe is introduced, and the coupling agent is placed in front of the sterile envelope. The surgeon holds the rear end of the probe and pushes the probe in the vertical direction of the bone window until the front end gently touches the dural sac. Increase the water to increase the coupling and fix the probe.

[0056] Start the electromagnetic drive unit. By adjusting the voltage in the inductor coil, an alternating magnetic field is generated to act on the neodymium magnet 6 embedded in the support platform 7, driving the support platform 7 to deflect around the flexible hinge 8. Under the action of the changing magnetic field, the support platform 7 produces periodic vibration under the action of the flexible hinge 8, driving the patch array element 4 to move synchronously, forming a stable one-degree-of-freedom polarization scanning in the vertical hinge direction.

[0057] In this embodiment, the probe parameters are determined through kinematic modeling and simulation results. Finally, the mass of the support platform 7 is set to 3.7g, and the length, thickness and width of one side of the flexible hinge 8 are all 1mm. Through experimental verification, under the parameter condition, the resonance frequency of the support platform 7 is 15Hz, and the polarization angle is 66°.

[0058] Real-time imaging of echo processing. The image processing unit receives the echo signal and performs amplification and filtering to suppress noise interference and improve signal quality. Combined with the rotation angle and frequency parameters, a sector-shaped ultrasound B-Mode image is formed, which is transmitted to the intraoperative display screen in real time. The imaging frequency is determined by the resonance frequency of the support platform, which is 30Hz.

[0059] Auxiliary intraoperative operation decision. As shown in Figure 4 , the surgeon adjusts the image parameters such as layered gain and dynamic range according to the imaging results to clearly present the anatomical structure of the target region. Further, the surgeon can rotate the probe axially to obtain imaging results at different angles. The surgeon interprets the anatomical composition of the key surgical area at the probe head end, the relative relationship of important structures, etc. under the guidance of real-time imaging, and formulates the best dural incision and tumor resection approach.

[0060] In this embodiment, the pen-shaped ultrasound probe can image the target area through the micro-bone window in the minimally invasive spinal surgery Figure 4 , the fan-shaped B-ultrasound imaging range is large, containing the entire dural sac, bilateral nerve roots and marginal soft tissue. The surgeon can identify the dural sac 15, spinal cord 16, exiting nerve root 17 and subdural ventral fat pad 18 through the image. The anatomic morphology and signal intensity displayed through the image help the surgeon understand the spatial relationship between the lesion and other structures and the degree of nerve compression or decompression, thereby assisting in intraoperative decision making such as access planning, lesion resection and continued decompression.

[0061] Embodiment Two

[0062] This embodiment provides an application of the pen-shaped ultrasound probe as an endoscopic ultrasound probe, which can adapt to the small-diameter channel imaging conditions of the micro-bone window in percutaneous endoscopic spinal surgery. This embodiment has two imaging modes. One is to implement large-scale ultrasound imaging of the endoscope tip tissue through the straight and narrow channel to help determine the relative relationship between the lesion and important tissues such as vertebrae and nerves. The other is to rotate the pen-shaped ultrasound probe while capturing the generated image, volume-reconstructing a three-dimensional image of the endoscope tip region, guiding the direction under the endoscope, and identifying important tissues such as nerves. Thus, in-vivo visual guidance can effectively reduce the occurrence of disorientation and nerve damage during percutaneous endoscopic spinal surgery.

[0063] In this embodiment, the outer diameter of the pen-shaped ultrasound probe is set to 6 mm, and the pen-shaped probe can image the tissue in the intervertebral foramen or interlamina region of the endoscope tip through the straight tube-shaped channel of the endoscope.

[0064] In this embodiment, the diameter of the patch array element 4 used to transmit and receive acoustic wave signals is 3 mm, and the bottom surface of the patch array element 4 is flat and fixed on the support platform 7. The transmission frequency of the patch array element 4 is 10 MHz, the imaging center resolution is 120 μm, and the imaging depth is 30 mm.

[0065] In this embodiment, the probe parameters are determined through kinematic modeling and simulation results. Finally, the mass of the support platform 7 is set to 1.8 g, and the length, thickness and width of the flexible hinge 8 are all 1 mm. Through experimental verification, under this parameter condition, the resonance frequency of the support platform 7 (i.e. the resonance frequency of the deflection of the patch array element 4) is 10 Hz, and the deflection angle is 43°.

[0066] The pen-shaped ultrasound probe in this embodiment can be accommodated in a tubular endoscope and a sleeve tool to perform large-scale ultrasound imaging of important tissues such as the foramen bone channel and deep spinal cord nerves. For example Figure 5The left image of FIG. 1 shows that the reconstructed foramenal three-dimensional image can help the doctor to identify the upper transverse process 19, the lower transverse process 20 and the diseased side lamina 21, so as to adjust the endoscope angle to adapt to the foramenal passage 22, reduce the damage of bone structure and injury. The imaging of deep spinal cord and other nerve tissues is referred to Figure 5 The right image of FIG. 1 shows the dural sac 15, the exit nerve root 17 and the cauda equina nerve bundle 23 in the foramenal approach, which guides the doctor to fine-tune the approach, reduces the disturbance of the operation to the nerve and the dural sac, provides a reliable image basis for intraoperative nerve decompression, helps to improve the surgical prognosis and reduce the incidence of surgical complications.

[0067] The pen test ultrasonic probe can be used in the extremely narrow bone window channel of the minimally invasive spinal cord and other nerve approach operation, or can be accommodated in the tubular endoscope and sleeve tool, to perform high-resolution large-range ultrasonic imaging on the spinal cord nerve structure and blood vessels and other important tissues, help the surgeon to understand the relative position of the subdural lesion and the spinal cord and blood vessels, guide the development of the best dural incision and evaluate the intraoperative resection. The invention can minimize the damage to nerves and blood vessels caused by blind operation, effectively improve the surgical prognosis of patients. The visualization of the anatomical structure is intuitive, the learning cost is low, there is no radiation hazard, the consumable equipment investment is small, and it is suitable for popularization and use.

[0068] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the present application. For ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application.

Claims

1. A pen-type ultrasound probe for imaging through microbone windows, characterized in that, It includes a base and patch elements, flexible hinges, support platform, neodymium magnets and electromagnetic drive unit disposed within the base; The two ends of the flexible hinge are fixed to the inner wall of the base, and the flexible hinge can rotate around the line connecting its two ends. The support platform is set on the flexible hinge, and neodymium magnets are set on both sides perpendicular to the line connecting the two ends of the flexible hinge. The electromagnetic drive unit is located below the flexible hinge and includes two inductor coils. Each inductor coil is coaxially arranged with a neodymium magnet. When the electromagnetic drive unit receives an AC input with the same frequency but opposite direction, it generates an alternating magnetic field, which drives the neodymium magnet to move. Under the drive of the alternating magnetic field generated by the electromagnetic drive unit, the two neodymium magnets are polarized according to the phase of the magnetic field change, which drives the support platform to rotate around the line connecting the two ends of the flexible hinge. The patch array element is disposed on the upper surface of the support platform. The patch array element is used to transmit and receive acoustic wave signals and transmit the received acoustic wave signals to an external image processing unit for imaging. When the support platform rotates around the line connecting the two ends of the flexible hinge, it drives the patch single vibrator element to generate a degree of freedom of polarization to form a scanning image.

2. The pen-type ultrasound probe for microbone window channel imaging according to claim 1, characterized in that, The mass of the support platform and the length of the flexible hinge are designed to ensure that the resonant frequency of the patch array element deflection is 15Hz and that the deflection angle of the patch array element is maximized.

3. The pen-type ultrasound probe for microbone window channel imaging according to claim 2, characterized in that, The mass of the supporting platform and the length of the flexible hinge are designed as follows: 1) Set the initial values ​​for the mass of the support platform and the length of the flexible hinge; 2) Measure the resonant frequency of the patch array element deflection and the deflection angle of the patch array element at this time; 3) If the resonant frequency obtained in step 2) is greater than 15Hz, then gradually increase the mass of the support platform and repeat step 2) until the resonant frequency is equal to 15Hz or the mass of the support platform reaches the preset upper limit. If the mass of the supporting platform has reached its limit and the resonant frequency is still greater than 15Hz, then gradually increase the length of the flexible hinge and repeat step 2) until the resonant frequency is equal to 15Hz. If the resonant frequency obtained in step 2) is less than 15Hz, then gradually reduce the mass of the support platform and repeat step 2) until the resonant frequency is equal to 15Hz or the mass of the support platform reaches the preset lower limit; if the mass of the support platform has reached the lower limit but the resonant frequency is still less than 15Hz, then gradually reduce the length of the flexible hinge and repeat step 2) until the resonant frequency is equal to 15Hz. 4) While ensuring that the resonant frequency is equal to 15Hz, increase the length of the flexible hinge and simultaneously reduce the mass of the support platform to adjust the deflection angle of the patch element, and obtain the mass of the support platform and the length of the flexible hinge corresponding to the maximum deflection angle of the patch element.

4. The pen-type ultrasound probe for microbone window channel imaging according to claim 1, characterized in that, The patch array element is a transducer unit composed of a single piezoelectric crystal. The emission frequency of the patch array element is 10-30MHz, the imaging depth is greater than or equal to 30mm, and the imaging focal point is located at 18-20mm.

5. The pen-type ultrasound probe for microbone window channel imaging according to claim 1, characterized in that, The flexible hinge is made of silicone. The flexible hinge is twisted by the deflection of the support platform. During the twisting process, potential energy is accumulated. When the support platform is not subjected to external force, the flexible hinge uses the potential energy accumulated during the twisting process to drive the support platform back to its initial state.

6. The pen-type ultrasound probe for microbone window channel imaging according to claim 1, characterized in that, The inductor coil has an iron core to increase the magnetic driving force; the winding of the inductor coil is enameled copper wire.

7. The pen-type ultrasound probe for microbone window channel imaging according to claim 1, characterized in that, The neodymium magnet is cylindrical in shape, axially magnetized, and embedded in the support platform.

8. The pen-type ultrasound probe for microbone window channel imaging according to claim 1, characterized in that, The support platform consists of two circular pieces respectively disposed on the upper and lower surfaces of the flexible hinge, and the material constituting the circular pieces is a biocompatible photocurable resin.

9. The pen-type ultrasound probe for microbone window channel imaging according to claim 1, characterized in that, The pen-type ultrasonic probe also includes a cannula cap, an opening at the top of the base, and a fixed connection between the cannula cap and one end of the base opening. The structure formed by the cannula cap and the base is filled with water to create a sealed water immersion environment, providing a medium for the propagation of sound wave signals. The electromagnetic drive unit is sealed by a coil sleeve outside the electromagnetic drive unit to prevent the electromagnetic drive unit from contacting the water phase. The base is made of a biocompatible plastic resin material. The upper end of the sleeve cap is provided with a polymer film, which is made of biocompatible polyurethane material. The thickness of the polymer film is half the wavelength of the ultrasound when it is transmitted in the polyurethane material. The acoustic impedance of the polymer film material is 1.60 MRayl, and the sound propagation speed is 1540 m / s.

10. The pen-type ultrasound probe for microbone window channel imaging according to claim 1, characterized in that, The pen-type ultrasonic probe is 6-18 mm in diameter.

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