CN119741905A

CN119741905A - Acoustic lens, ultrasonic probe and ultrasonic imaging equipment

Info

Publication number: CN119741905A
Application number: CN202411930243.5A
Authority: CN
Inventors: 魏浩杰; 司康; 刘聪; 程正
Original assignee: Wuhan United Imaging Healthcare Co Ltd
Current assignee: Wuhan United Imaging Healthcare Co Ltd
Priority date: 2024-12-25
Filing date: 2024-12-25
Publication date: 2025-04-01

Abstract

The present application relates to an acoustic lens, an ultrasonic probe and an ultrasonic imaging device, wherein the acoustic lens has a front surface, and the acoustic lens includes a middle area and side areas located on both sides of the middle area in the direction of the curved surface change of the front surface; the focal length of the middle area is greater than the focal length of the side areas. The acoustic lens adjusts the focal length by partitioning to achieve multi-dimensional and multi-point focusing, and enables the ultrasonic waves passing through the middle area to focus on the deeper part of the target to be measured, and the ultrasonic waves passing through the side areas to focus on the shallower part of the target to be measured, and the beam is narrowed significantly, so that clear images from shallow to deep can be obtained when detecting objects with complex structures to be measured, thereby improving the quality of ultrasonic images.

Description

Acoustic lens, ultrasonic probe, and ultrasonic imaging apparatus

Technical Field

The application relates to the technical field of acoustic materials, in particular to an acoustic lens, an ultrasonic probe and ultrasonic imaging equipment.

Background

Ultrasonic imaging devices typically utilize the electroacoustic conversion properties of piezoelectric materials in ultrasonic transducers to physically deform the piezoelectric materials by applying voltage pulses thereto to produce corresponding ultrasonic signals and to receive echo signals from different tissue portions of the human body to ultimately produce an image of the desired tissue. Among them, the ultrasonic transducer and the acoustic lens are core components of the ultrasonic imaging apparatus, and are widely used in the medical diagnosis and treatment process of various ultrasonic imaging apparatuses.

The acoustic lens is positioned at the outermost layer of the transducer and needs to meet the requirements of protection, focusing, sound transmission and the like. With the accumulation and development of ultrasound technology, users have increasingly demanded the definition of image quality. In order to improve ultrasonic imaging quality, some researchers make the center and the outer side of the acoustic lens have different shapes by optimizing the shape of the acoustic lens, but the acoustic lens is easy to deform in the process of contacting with a human body, so that ultrasonic beams cannot be focused at target depth, and in addition, some researchers dynamically adjust the curvature of the acoustic lens by adopting memory alloy, the curvature of the acoustic lens can be adjusted by controlling current, but the preparation process of the acoustic lens is complex, and the requirement on the material quality of the acoustic lens is higher. Therefore, it is difficult for the current acoustic lens to meet clinical accuracy and simplification requirements, and it is difficult to obtain a clear image when a complex organ or tissue is examined, thereby making it difficult to accurately identify a target position.

Disclosure of Invention

Based on this, it is necessary to provide an acoustic lens, an ultrasonic probe, and an ultrasonic imaging apparatus capable of improving imaging quality.

In one aspect of the application, an acoustic lens is provided, the acoustic lens has a front surface, the acoustic lens comprises a middle area and side areas positioned at two sides of the middle area in the curved surface change direction of the front surface, and the focal length of the middle area is larger than that of the side areas.

According to the multi-dimensional multi-point focusing method, the focal length of the sound lens is adjusted in a partitioning mode, the focal length of the middle area of the sound lens is larger than that of the side area, multi-dimensional multi-point focusing is achieved by adjusting the focal length to change the focusing position of the sound lens, the limitation of the sound lens with the fixed focal length is avoided, the definition of an ultrasonic image is improved, and a user can accurately identify the position of a target from the ultrasonic image. The ultrasonic lens enables ultrasonic waves passing through the middle area to be focused at a deeper position of a measured object, ultrasonic waves passing through the side areas to be focused at a shallower position of the measured object, and clear images from shallow to deep can be obtained when the measured object with a complex structure is detected, so that the quality of ultrasonic images is further improved.

The acoustic lens can enable the wave beam to be obviously narrowed and more uniform, and the wave beam width at different depths of the object to be detected is close, so that the ultrasonic image quality is further improved.

After the ultrasonic wave is focused by the acoustic lens, narrower wave beams can be formed in the object to be measured, the energy of the narrower wave beams is more concentrated, the spatial resolution can be improved, the signal intensity and the contrast can be increased, and the sidelobe interference can be reduced, so that the boundary of adjacent structures in the object to be measured and the fine structures in the object to be measured can be more accurately distinguished, the boundary and the fine structures can be more clearly displayed on an image, and the imaging blurring caused by the fact that the coverage area of the wave beams is too large to be clearly distinguished is avoided.

In some embodiments, in the curved surface changing direction of the front surface, the length of the middle area is 10% -40% of the total length of the acoustic lens, and the length of the side area on one side is 5% -45% of the total length of the acoustic lens.

In some of these embodiments, the acoustic lens satisfies at least one of the following conditions:

(1) The number of the side regions at the two sides of the middle region is the same;

(2) The lengths of the side regions at the two sides of the middle region are the same in the curved surface change direction of the front surface.

In some of these embodiments, the adjacent regions have a difference in acoustic velocity greater than or equal to 50m/s and the adjacent regions have a difference in acoustic impedance less than or equal to 0.1Mrayl.

In some embodiments, the acoustic lens is a convex lens, and the sound velocity of the middle region and each of the side regions is less than or equal to 1500 m/s, or

The acoustic lens is a concave lens, and the sound velocity of the middle area and each side area is greater than 1500 m/s.

In some of these embodiments, the lateral zone on one side comprises n sequentially connected sub-zones in the curved surface change direction of the front surface, the focal length of the n sequentially connected sub-zones decreasing in a direction from the intermediate zone away from the intermediate zone, wherein n is a natural number greater than or equal to 1.

In some embodiments, the acoustic lens is a convex lens, the front surface is a convex surface, the front surface has equal curvature in the middle region and each of the side regions, and the sound velocity in the middle region is greater than the sound velocity in the side regions.

In some embodiments, the acoustic lens is a convex lens, and the lateral region on one side includes n sub-regions connected in sequence in a curved surface change direction of the front surface, and sound speeds of the n sub-regions connected in sequence decrease in a direction from the middle region to a direction away from the middle region, where n is a natural number greater than or equal to 1.

In some embodiments, the material of the middle region and each of the side regions is at least one of silicone rubber and modified silicone rubber.

In some embodiments, the preparation raw materials of the modified silicone rubber comprise 60% -80% of silicone rubber, 10% -40% of high sound velocity component and 0% -10% of compatilizer according to mass content, and the sound velocity of the high sound velocity component is greater than or equal to 1100 m/s.

In some embodiments, the preparation raw materials of the modified silicone rubber comprise 60% -75% of silicone rubber, 22% -40% of high sound velocity component and 1% -5% of compatilizer by mass.

In some embodiments, the modified silicone rubber has an acoustic velocity of 1100m/s to 1400m/s.

In some of these embodiments, the high acoustic velocity component comprises at least one of silicone, polyurethane, epoxy, fluorosilicone, polysulfide, and nitrile rubber.

In some embodiments, the compatibilizing agent comprises at least one of a silane coupling agent and a modified silicone oil.

In some of these embodiments, the silicone rubber comprises at least one of RTV 630 silicone rubber, DC 184 silicone rubber, 6610/60 silicone rubber, and LSR 7080 silicone rubber.

In some embodiments, the acoustic lens is a concave lens, the front surface is a concave surface, the front surface has equal curvature in the middle region and each of the side regions, and the speed of sound in the middle region is less than the speed of sound in the side regions.

In some embodiments, the acoustic lens is a concave lens, the lateral region on one side includes n sequentially connected sub-regions in a curved surface change direction of the front surface, and sound speeds of the n sequentially connected sub-regions increase in a direction from the intermediate region to a direction away from the intermediate region, where n is a natural number greater than or equal to 1.

In some of these embodiments, the material of the central region and each of the side regions is a thermoplastic polymer.

In some of these embodiments, the thermoplastic polymer comprises at least one of thermoplastic polyurethane, polyether polyamide block copolymer, silicone-based thermoplastic elastomer, styrene-isobutylene-styrene block copolymer, poly 4-methylpentene, polypropylene, and polyamide resin.

In a second aspect of the application there is provided an ultrasound probe comprising an acoustic lens as described in the first aspect.

In a third aspect of the present application, there is provided an ultrasound imaging apparatus comprising an acoustic lens as described in the first aspect or an ultrasound probe as described in the second aspect.

Drawings

Fig. 1 is a schematic diagram of the installation state of an acoustic lens and an ultrasonic transducer.

Fig. 2 is a schematic view of an acoustic lens structure with a single side dividing n sub-regions (n is a natural number greater than or equal to 1).

Fig. 3 is a schematic view of the acoustic lens structure of embodiment 1.

Fig. 4 is a schematic view of the acoustic lens structure of embodiment 2.

Fig. 5 is a schematic view of the acoustic lens structure of embodiment 3.

Fig. 6 is a schematic view of the acoustic lens structure of embodiment 4.

Fig. 7 is a schematic view of the acoustic lens structure of embodiment 5.

Fig. 8 is a schematic view of the acoustic lens structure of embodiment 6.

Fig. 9 is a schematic view of the acoustic lens structure of comparative example 1.

Fig. 10 is a schematic view showing the structure of the acoustic lens of comparative example 1 after the radius of curvature is increased.

Fig. 11 is a schematic view of the acoustic lens structure of comparative example 2.

Fig. 12 is a schematic view showing the structure of the acoustic lens of comparative example 1 after the radius of curvature is reduced.

FIG. 13 is a graph showing the contrast of the beam width of the acoustic lens of the present application and a conventional single-material acoustic lens at different depths of a target to be measured.

Reference numerals illustrate:

1. backing layer, 2, piezoelectric material, 3, matching layer, 4, acoustic lens, 41, front surface.

Detailed Description

In order that the invention may be readily understood, a more complete description of the invention will be rendered by reference to the appended drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

An ultrasonic transducer is a device capable of converting electric energy and ultrasonic energy into each other, and its operation is based on a piezoelectric effect and an inverse piezoelectric effect. When an electric field is applied to some crystal materials (such as piezoelectric ceramics), the materials deform, which is called an inverse piezoelectric effect, and when alternating voltage is applied to two ends of the piezoelectric materials, the materials periodically stretch and contract to emit ultrasonic waves, on the contrary, when the ultrasonic waves act on the piezoelectric materials, the piezoelectric materials generate an electric field due to mechanical stress, which is the piezoelectric effect, and by detecting the electric field, the ultrasonic transducer can convert received ultrasonic signals into electric signals, so that the ultrasonic signals are received. The ultrasonic imaging equipment generates images of the required tissues by receiving echo signals from different tissue parts of the object to be detected.

Referring to fig. 1, the main components of the ultrasonic transducer include a backing layer 1, a piezoelectric material 2 and a matching layer 3 connected in sequence, wherein the piezoelectric material 2 is a core portion of the ultrasonic transducer, the matching layer 3 is located in front of the piezoelectric material 2, the backing layer 1 is located on the back of the piezoelectric material 2, i.e. along the ultrasonic emission direction, the backing layer 1 is located upstream of the piezoelectric material 2, and the matching layer 3 is located downstream of the piezoelectric material 2. An acoustic lens 4 is connected to the matching layer 3 downstream of the matching layer 3.

The acoustic lens can change the propagation direction of ultrasonic waves, so that ultrasonic beams are focused in a specific area to improve the ultrasonic energy intensity of the area, thereby obtaining clearer image details, the acoustic lens can also play a role of matching acoustic impedance, the reflection of ultrasonic waves at the interface of the transducer and an object to be detected can be reduced, and in addition, the acoustic lens can shape the divergent ultrasonic beams emitted by the ultrasonic transducer into a shape more suitable for detection requirements.

With the development of ultrasound technology, the demands of users for definition of image quality are increasing, and ultrasound imaging apparatuses are required to have high spatial resolution so that users can accurately identify the position of a target from an ultrasound image. However, the current ultrasonic imaging technology has a certain limitation, and the image quality of ultrasonic imaging is difficult to meet the definition requirement, especially when the structure of the object to be detected is complex.

In view of this, according to a first aspect of the present application, an embodiment provides an acoustic lens having a front surface, the acoustic lens including a middle region and side regions located on both sides of the middle region in a curved surface changing direction of the front surface, a focal length of the middle region being greater than a focal length of the side regions.

The acoustic lens may be used to focus the acoustic wave and then emit it through the front surface of the acoustic lens. In an ultrasound imaging device, for example, an acoustic lens is located in front of an ultrasound transducer. After being focused by the acoustic lens, the ultrasonic wave generated by the transducer is emitted to the position of the detected object, such as human tissue, through the front surface, so that a narrower wave beam is formed inside the detected object, such as human tissue, and further ultrasonic imaging is realized.

The "front surface" of the acoustic lens refers to the surface of the acoustic lens that is intended to face toward or be in contact with the object to be identified. Since the acoustic lens is entirely a lens, the front surface has a curved structure of the lens. The curved surface structure has a curved surface changing direction, such as the Y direction shown in fig. 1. Specifically, as shown in fig. 1, the acoustic lens is entirely a convex lens, the front surface thereof is a convex surface, and it has a curved surface change in the Y direction, and since the acoustic lens is entirely square, it has no curved surface change in the X direction. Specifically, as shown in fig. 1, the front surface is thickest in the middle region in the Y direction, extends from the middle region to the side regions on both sides, and has a tendency to gradually descend toward the acoustic lens body. It will be appreciated that for an acoustic lens that is a concave lens, as shown in fig. 7, the front surface is thinnest in the middle region in the Y direction, extending from the middle region to the side regions on both sides, with the front surface tending to rise progressively away from the acoustic lens body.

According to the multi-dimensional multi-point focusing device, the focal length of the middle area of the acoustic lens is adjusted in a partitioning mode and is larger than that of the side areas, multi-dimensional multi-point focusing is achieved by adjusting the focal length to change the focusing position of the acoustic lens, the limitation of the acoustic lens with the fixed focal length in the clinical actual scanning process is avoided, clear images from shallow to deep can be obtained in complex organ or tissue examination, ultrasonic imaging quality is greatly improved, ultrasonic image definition is improved, and a user can accurately detect the position of an object from an ultrasonic image. The ultrasonic lens enables ultrasonic waves passing through the middle area to be focused at a deeper position of a measured object, ultrasonic waves passing through the side areas to be focused at a shallower position of the measured object, so that the wave beam is obviously narrowed, the wave beam is more uniform, the wave beam widths at different depths are close, and the ultrasonic image quality is further improved.

It is understood that a single-sided side region may be one or more.

As an example, the length of the intermediate zone may be 10%、11%、12%、13%、14%、15%、16%、17%、18%、19%、20%、21%、22%、23%、24%、25%、26%、27%、28%、29%、30%、31%、32%、33%、34%、35%、36%、37%、38%、39%% and 40% of the total length of the acoustic lens, or may be in a range formed by any two of the above-mentioned point values as end values.

The length of the middle area accounts for 20% -40% of the total length of the acoustic lens.

As an example, the length of the side area on one side may be 5%、6%、7%、8%、9%、10%、11%、12%、13%、14%、15%、16%、17%、18%、19%、20%、21%、22%、23%、24%、25%、26%、27%、28%、29%、30%、31%、32%、33%、34%、35%、36%、37%、38%、39%、40%、41%、42%、43%、44% and 45% of the total length of the acoustic lens, or may be in a range formed by any two points as the end values.

The length of the side area of the single side accounts for 10% -35% of the total length of the acoustic lens.

In some of these embodiments, the number of side regions on either side of the central region of the acoustic lens is the same.

In some of these embodiments, the length of the side regions on either side of the central region is the same in the direction of curvature change of the front surface.

In some embodiments, the number of side regions on both sides of the intermediate region of the acoustic lens is the same, and the lengths of the side regions on both sides of the intermediate region are the same in the direction of curvature change of the front surface. The number and the length of the side regions on the two sides are the same, the acoustic lens has symmetrical geometric shapes, and the acoustic waves can undergo similar refraction processes, so that acoustic wave energy can be converged towards a focus more uniformly, and further, the energy focusing is more uniform and efficient.

Further, the side regions on both sides have the same sound velocity. When the number, the length and the sound velocity of the side regions on two sides are the same, the acoustic lens has symmetrical geometric shapes and physical characteristics, and the sound waves can undergo the same refraction process, so that the sound wave energy can be more uniformly converged towards the focus, the energy focusing is more uniform and efficient, and the acoustic lens with the symmetrical structure is favorable for reducing the sound wave distortion.

The adjacent region is understood to mean two regions of the acoustic lens which are adjacent and differ in acoustic velocity, either a side region of the intermediate region adjacent to the intermediate region or two adjacent sub-regions of the side region.

The difference of sound velocity of the adjacent areas is larger than or equal to 50m/s, so that multi-point focusing is facilitated, imaging quality is improved, the difference of sound impedance of the adjacent areas is smaller than or equal to 0.1Mrayl, the difference of sound impedance between the different areas is small, impedance consistency is met, interface refraction is reduced, when the difference of sound velocity of the adjacent areas is larger than or equal to 50m/s, the difference of sound impedance of the adjacent areas is smaller than or equal to 0.1Mrayl, beam narrowing is obvious, the beam is more uniform, imaging resolution is improved, detection depth and penetrating power are increased, beam shielding and interference are reduced, and detection sensitivity is improved.

As an example, the sound velocity difference of the adjacent regions may be 50m/s、60m/s、70m/s、80m/s、90m/s、100m/s、106 m/s、110m/s、120m/s、130m/s、140m/s、150m/s、160m/s、170m/s、180m/s、190m/s、196 m/s、200m/s、210m/s、220m/s、230m/s、240m/s、250m/s、260m/s、270m/s、280m/s、290m/s、300m/s、310m/s、320m/s、330m/s、340m/s、350m/s、360m/s、370m/s、380m/s、390m/s、400m/s、410m/s、420m/s、430m/s、440m/s、450m/s、460m/s、470m/s、480m/s、490m/s and 500m/s, or may be in a range constituted by any two of the above-described point values as end values. The sound velocity difference of the adjacent areas is preferably 100 m/s-350 m/s.

As an example, the difference in acoustic impedance between adjacent regions may be 0、0.01Mrayl、0.02Mrayl、0.03Mrayl、0.04Mrayl、0.05Mrayl、0.06Mrayl、0.07Mrayl、0.08Mrayl、0.09Mrayl、0.095 Mrayl and 0.1 to Mrayl, or may be within a range formed by any two of the above-described point values as end values. The difference in acoustic impedance between adjacent regions is preferably 0 to 0.05mrayl.

In some embodiments, the difference in acoustic velocity between adjacent regions is 100 m/s to 350 m/s and the difference in acoustic impedance between adjacent regions is 0to 0.05Mrayl. The wave beam narrowing effect of the sound velocity difference and the sound impedance difference of adjacent areas is better in the range, and the resolution of an image obtained by ultrasonic imaging is higher and clearer.

The front surface of the convex lens protrudes outwards to form a convex surface, when ultrasonic waves propagate from one side, the convex surface of the convex lens can enable the ultrasonic waves to be refracted towards the central axis direction, the structure can converge divergent ultrasonic beams to a focus, and therefore focusing imaging is achieved, the convex lens can effectively focus the ultrasonic waves sent by the transducer to a specific depth area of an object to be detected, and imaging resolution is improved.

The front surface of the concave lens is concave inwards to form a concave surface, and the concave lens acts opposite to the convex lens, so that ultrasonic wave beams can be dispersed, and the concave lens can be used for expanding the coverage range of ultrasonic waves or performing proper dispersion adjustment on the focused beams.

The sound wave tends to deviate from the normal line of the interface when being transferred from the material with the faster sound velocity to the material with the slower sound velocity, is designed to be convex in the radiation direction of the ultrasonic wave when the sound velocity of the acoustic lens material is lower than the sound velocity of the object to be measured, and is designed to be concave when the sound velocity is higher than the sound velocity of the object to be measured.

In some embodiments, the acoustic lens is a convex lens, the front surface is a convex surface, the front surface has equal curvature in the middle region and each of the side regions, and the sound velocity in the middle region is greater than the sound velocity in the side regions. The curvatures of the middle area and the side areas are equal, so that deformation phenomenon caused by contact of the acoustic lens and an object to be measured can be avoided, the acoustic lens is facilitated to realize multi-dimensional multi-point focusing, and the sound velocity of the middle area is higher than that of the side areas, so that ultrasonic waves passing through the middle area are facilitated to be focused at a deeper position of the object to be measured, and ultrasonic waves passing through the side areas are facilitated to be focused at a shallower position of the object to be measured.

In some embodiments, the acoustic lens is a convex lens, and the lateral region on one side includes n sub-regions connected in sequence in a curved surface change direction of the front surface, and sound speeds of the n sub-regions connected in sequence decrease in a direction from the middle region to a direction away from the middle region, where n is a natural number greater than or equal to 1. The sound velocity of n sub-areas connected in turn decreases in the direction from the middle area to the far away from the middle area, that is, the middle area focal length is the largest, and the side area focal length is gradually reduced, so that the ultrasonic beam passing through the middle area Ln+1 of the acoustic lens is converged at the deeper part of the object to be measured, and the ultrasonic beam passing through the side area is converged at the shallower part of the object to be measured, so that the ultrasonic beam with a narrow width in the Y direction is realized.

As will be understood, referring to fig. 2, the lateral zone on one side includes n sub-zones connected in turn in the curved surface changing direction of the front surface, a convex lens with 2n+1 zone structure is formed (n is a natural number greater than or equal to 1), the materials with different sound speeds are selected by the zones so that the sound speed of the middle zone ln+1 is fastest, the sound speed of the lateral zone is gradually reduced (V _Ln＞V_Ln-1＞…＞V_L2＞V_L1,V_Ln+2＞V_Ln+3＞…＞V_L2n＞V_L2n+1), that is, the focal length of the middle zone is largest, and the focal length of the lateral zone is gradually reduced, thereby realizing that the ultrasonic beam with narrow width in the Y direction is converged at the deeper part of the object to be measured by the ultrasonic beam passing through the acoustic lens middle zone ln+1, and the ultrasonic beam with narrow width is converged at the shallower part of the object to be measured by the ultrasonic beam passing through the lateral zone. The materials used can be selected from components with similar impedance, and the sound velocity of the materials selected in the middle area is ensured to be the fastest, and the sound velocity of the materials selected in the side areas is gradually reduced. The materials selected for the symmetrical subareas in the two side areas can be the same or different.

Further, the acoustic lens is a convex lens, and sound speeds of the n sub-regions connected in sequence decrease in a direction from the middle region to a direction away from the middle region, wherein n is a natural number of 1.ltoreq.n.ltoreq.5.

Further, the acoustic lens is a convex lens, and sound speeds of the n sub-regions connected in sequence decrease in a direction from the middle region to a direction away from the middle region, wherein 1.ltoreq.n.ltoreq.3 is a natural number.

In some embodiments, the material of the middle region and each of the side regions is at least one of silicone rubber and modified silicone rubber. The silicone rubber can hardly generate fatigue in the process of contacting with human body, and can recover to the original shape before deformation after use, thereby playing a good role in protection. Because the sound velocity of the silicon rubber is mostly about 1000m/s, obvious sound velocity difference cannot be formed, and the modified silicon rubber can ensure that the sound attenuation of the modified silicon rubber is not obviously increased while ensuring that the silicon rubber has obvious sound velocity difference.

In some embodiments, the modified silicone rubber is prepared from a raw material containing, by mass, 50% or more of silicone rubber, 40% or less of high sound velocity component, and 10% or less of compatibilizer.

As an example, the mass content of the silicone rubber may be 50%、51%、52%、53%、54%、55%、56%、57%、58%、59%、60%、61%、62%、63%、64%、65%、66%、67%、68%、69%、70%、71%、72%、73%、74%、75%、76%、77%、78%、79%、80%、81%、82%、83%、84%、85%、86%、87%、88%、89% and 90%, or may be in a range formed by any two of the above-mentioned point values as end values. The mass content of the silicone rubber is preferably 60% -80%, more preferably 60% -75%.

As an example, the mass content of the high sound velocity component may be 5%、10%、11%、12%、13%、14%、15%、16%、17%、18%、19%、20%、21%、22%、23%、24%、25%、26%、27%、28%、29%、30%、31%、32%、33%、34%、35%、36%、37%、38%、39% and 40%, or may be in a range constituted by any two of the above-mentioned point values as end values. The mass content of the high sound velocity component is preferably 10% -40%, more preferably 22% -40%.

As an example, the mass content of the compatibilizing agent may be 0, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% and 10%, or may be in a range in which any two of the above-mentioned points are defined as end values. The mass content of the compatibilizer is preferably 0.5% -5%, more preferably 1% -5%.

In some embodiments, the preparation raw materials of the modified silicone rubber comprise 60% -80% of silicone rubber, 10% -40% of high sound velocity component and 0% -10% of compatilizer according to mass content, and the sound velocity of the high sound velocity component is greater than or equal to 1100 m/s. The modified silicon rubber ensures that the sound attenuation of the modified silicon rubber is not obviously increased while the sound velocity difference is proved, the sound attenuation of 5MHz is successfully controlled within 30 dB/cm, and the beam is more obviously narrowed by the sound lens containing the modified silicon rubber, so that the imaging is clearer.

In some embodiments, the preparation raw materials of the modified silicone rubber comprise 60% -75% of silicone rubber, 22% -40% of high sound velocity component and 1% -5% of compatilizer by mass. The modified silicon rubber ensures that the sound attenuation of the modified silicon rubber is not obviously increased while the sound velocity difference is proved, the sound attenuation of 5MHz is successfully controlled within 20 dB/cm, and the sound lens containing the modified silicon rubber has better beam narrowing effect and higher quality of the obtained ultrasonic image.

In some of these embodiments, the high sound velocity component is a high sound velocity resin having a sound velocity of greater than or equal to 1100 m/s or a high sound velocity rubber having a sound velocity of greater than or equal to 1100 m/s.

Further, the high sound velocity component includes at least one of silicone resin, polyurethane resin, epoxy resin, fluorosilicone rubber, polysulfide rubber, and nitrile rubber.

Still further, the high acoustic velocity component includes a curing agent.

In some embodiments, the acoustic lens is a concave lens, the front surface is a concave surface, the front surface has equal curvature in the middle region and each of the side regions, and the speed of sound in the middle region is less than the speed of sound in the side regions. The concave lenses with the front surfaces having equal curvatures in the middle area and the side areas can avoid deformation phenomenon caused by contact between the acoustic lens and an object to be measured, so that the acoustic lens is beneficial to realizing multi-dimensional multi-point focusing, and the sound velocity in the middle area is smaller than that in the side areas, so that the ultrasonic waves passing through the middle area are focused at a deeper position of the object to be measured, and the ultrasonic waves passing through the side areas are focused at a shallower position of the object to be measured.

In some embodiments, the acoustic lens is a concave lens, and the material of the middle region and each of the side regions is a thermoplastic polymer. The characteristic that the thermoplastic polymer can be molded is utilized, a secondary injection molding mode can be combined with liquid silicone rubber to prepare the zoned acoustic lens of the liquid silicone rubber-thermoplastic polymer, and the characteristic of the thermoplastic polymer can also be utilized to prepare the zoned acoustic lens by adopting a secondary injection molding mode.

In some of these embodiments, the thermoplastic polymer comprises a thermoplastic elastomer or a thermoplastic resin. Thermoplastic elastomers and thermoplastic resins have a large difference in elastic modulus, while also having a large difference in acoustic velocity. The thermoplastic elastomer is a copolymer formed by alternately polymerizing or dynamically and mechanically mixing chain segments with different chemical structures, has the characteristics of controllable molecular weight, narrow molecular weight distribution and designable molecular structure and composition, and can be manufactured or selected according to the needs. The thermoplastic resin has better processability, can be designed and injection molded into complex shapes according to the needs, and has higher production efficiency.

In some of these embodiments, the thermoplastic elastomer comprises at least one of a thermoplastic polyurethane, a polyether polyamide block copolymer, a silicone-based thermoplastic elastomer, and a styrene-isobutylene-styrene block copolymer.

In some of these embodiments, the thermoplastic resin comprises at least one of poly 4-methylpentene, polypropylene, and polyamide resin.

In some of these embodiments, the ultrasound probe includes an ultrasound transducer and an acoustic lens, the acoustic lens being located in front of the ultrasound transducer.

Referring to fig. 1, the main components of the ultrasonic transducer include a backing layer 1, a piezoelectric material 2 and a matching layer 3 connected in sequence, wherein the piezoelectric material 2 is a core portion of the ultrasonic transducer, the matching layer 3 is located in front of the piezoelectric material 2, the backing layer 1 is located on the back of the piezoelectric material 2, i.e. along the ultrasonic emission direction, the backing layer 1 is located upstream of the piezoelectric material 2, and the matching layer 3 is located downstream of the piezoelectric material 2. An acoustic lens 4 is connected to the matching layer 3 downstream of the matching layer 3. The ultrasonic probe comprises an ultrasonic transducer, an ultrasonic lens, an ultrasonic transducer, an ultrasonic probe and a control circuit, wherein the ultrasonic lens can change the propagation direction of ultrasonic waves to play a role of focusing the ultrasonic waves, ultrasonic waves generated by the ultrasonic transducer are subjected to optimization treatment through the ultrasonic lens, focused and reduced in reflection and then emitted to an object to be tested, and when receiving ultrasonic echoes, the echoes firstly pass through the ultrasonic lens and are then received by the ultrasonic transducer and converted into electric signals for subsequent treatment, and the ultrasonic probe capable of effectively transmitting and receiving the ultrasonic waves is formed by the ultrasonic lens and the ultrasonic transducer. The ultrasonic probe realizes multidimensional and multipoint focusing by optimizing the acoustic lens structure, so that the ultrasonic wave beam is obviously narrowed in the object to be detected, the beam is uniform, the detection sensitivity and the imaging quality are improved, and the target position can be rapidly and accurately identified.

In a third aspect of the present application, there is provided an ultrasonic imaging apparatus comprising at least one of the acoustic lens as set forth in the first aspect and the ultrasonic probe as set forth in the second aspect.

In some of these embodiments, the ultrasound imaging apparatus includes a control unit, an ultrasound probe, a signal processing unit, an image generation system, and an image display system.

The control unit controls the transmitting circuit to generate a high-frequency electric pulse signal according to the setting, the high-frequency electric pulse signal is transmitted to the piezoelectric material of the ultrasonic transducer, the piezoelectric material converts the electric pulse into mechanical vibration based on the piezoelectric effect to generate ultrasonic waves, the ultrasonic waves are transmitted to an object to be tested after being optimized by the acoustic lens, the echo waves are processed by the signal processing unit to optimize the beam characteristics after passing through the acoustic lens, and then the image generating system generates a two-dimensional or three-dimensional ultrasonic image through a specific algorithm according to the delay time, the intensity and other information of the echo signals and transmits the image to the image display system for display. The ultrasonic imaging device realizes multidimensional multi-point focusing by optimizing the acoustic lens structure, so that ultrasonic wave beams are obviously narrowed in an object to be detected, the beams are uniform, clear images from shallow to deep can be obtained, the ultrasonic imaging quality is improved, and a user can accurately identify the position of a target from the ultrasonic images.

The following are specific examples.

The following materials can be selected in the examples:

Silicone rubber (one)

The liquid silicone rubber can be divided into room temperature vulcanized silicone Rubber (RTV) and Liquid Silicone Rubber (LSR) according to different molding modes, the RTV silicone rubber is suitable for molding by a pouring method, the RTV silicone rubber can be poured into a mold cavity for molding after being uniformly mixed, the LSR silicone rubber has higher molding temperature and higher viscosity in general, can be molded by an LSR injection molding machine, and is suitable for double-color or multi-color injection molding or secondary injection molding.

Silicone rubber a the main component of silicone rubber a is michigan (mobile) RTV630 (RTV 630 for short).

The performance test process of the silicone rubber A comprises the steps of weighing 20g of RTV630 silica gel and 2g of curing agent, mechanically stirring until the materials are uniformly mixed, obtaining a mixture after vacuum centrifugal defoaming, pouring the mixture into a die, and vulcanizing the mixture at room temperature for 24 hours to obtain the cured product silicone rubber A, and carrying out acoustic performance test on the cured product silicone rubber A, wherein the density of the silicone rubber A is 1.28g/cm ³, the acoustic velocity is 1050 m/s, the acoustic impedance is 1.34MRayl, and the acoustic attenuation of 5MHz is less than 25dB/cm.

Silicone rubber B the main component of silicone rubber B is a Dow corning SYLGARD 184 (DC 184 for short).

The performance test process of the silicone rubber B comprises the steps of weighing 184 g of the silicone rubber component and 2g of the curing agent, mechanically stirring until the silicone rubber component and the curing agent are uniformly mixed, obtaining a mixture after vacuum centrifugal defoaming, pouring the mixture into a mold, vulcanizing the mixture at room temperature for 48 hours to obtain a cured product, and carrying out acoustic performance test on the cured product to obtain the silicone rubber B with the density of 1.03 g/cm ³, the acoustic velocity of 1020 m/s, the acoustic impedance of 1.05 MRayl and the acoustic attenuation of 5 MHz of less than 20 dB/cm.

Silicone rubber C the main component of silicone rubber C is Watt (WACKER) SIPURAN 6610:6610/60 (abbreviated as 6610/60).

The performance test process of the silicone rubber C comprises the steps of preparing a sample by using a liquid silica gel injection molding machine, wherein the size of a used mould is 100 mm*100 mm*5 mm, the process condition is 165 ℃ for primary vulcanization for 5 minutes, and the sample is obtained after secondary vulcanization for 4 hours at 200 ℃, and carrying out acoustic performance test on the sample to obtain the silicone rubber C with the density of 1.23 g/cm ³, the sound velocity of 1030 m/s, the acoustic impedance of 1.27 MRayl and the acoustic attenuation of 5 MHz of less than 25 dB/cm.

Silicone rubber D the main component of silicone rubber D is michigan LSR 7080 (LSR 7080 for short).

The performance test process of the silicone rubber D comprises the steps of preparing a sample by using a liquid silica gel injection molding machine, wherein the size of a used mould is 100 mm*100 mm*5 mm, the process condition is 130 ℃ for primary vulcanization for 15 minutes, and the sample is obtained after secondary vulcanization for 2 hours at 200 ℃, and carrying out acoustic performance test on the sample to obtain the silicone rubber D with the density of 1.06 g/cm ³, the sound velocity of 1020 m/s, the acoustic impedance of 1.08 MRayl and the acoustic attenuation of 5 MHz of less than 20dB/cm.

(II) modified Silicone rubber

The preparation raw materials of the modified silicone rubber E comprise RTV 630, polyurethane resin, isocyanate Propyl Triethoxysilane (IPTS), hydroxyl-terminated silicone oil and a curing agent, wherein the polyurethane resin is bi-component, and the recommended dosage of the polyurethane resin and the curing agent is 10:1.

The preparation process and performance test of the modified silicone rubber E comprises the steps of weighing RTV630 silica gel component 20 g, adding polyurethane resin 7g, isocyanate Propyltriethoxysilane (IPTS) 0.2g, hydroxyl-terminated silicone oil 0.5 g, adding polyurethane resin curing agent 0.7 g and RTV630 curing agent 2g after mechanical stirring until the materials are uniformly mixed, obtaining a mixture after vacuum centrifugal defoaming, pouring the mixture into a mold, vulcanizing at room temperature for 24 hours to obtain a modified silicone rubber E sample, and carrying out sound performance test on the modified silicone rubber E, wherein the density of the modified silicone rubber E is 1.16 g/cm ³, the sound velocity is 1170 m/s, the acoustic impedance is 1.36 MRayl, and the sound attenuation of 5 MHz is less than 20 dB/cm.

The preparation raw materials of the modified silicone rubber F comprise DC 184, epoxy resin, a silane coupling agent KH560 and a curing agent, wherein the epoxy resin is a double component, and the mass ratio of the epoxy resin to the curing agent is 5:1.

The preparation process and performance test of the modified silicone rubber F comprises the steps of weighing a DC 184 silica gel component 20g, adding an epoxy resin 4g, adding a silane coupling agent KH 560.8 g, mechanically stirring uniformly, adding an epoxy resin curing agent 0.8g, adding a DC 184 curing agent 2g, mechanically stirring until the mixture is uniformly mixed, vacuum centrifuging and defoaming to obtain a mixture, pouring the mixture into a mold, and vulcanizing at room temperature for 48 hours to obtain a modified silicone rubber F sample, and carrying out acoustic performance test on the modified silicone rubber F, wherein the density of the modified silicone rubber F is 1.16 g/cm ³, the acoustic velocity is 1280 m/s, the acoustic impedance is 1.34 MRayl, and the acoustic attenuation of 5 MHz is less than 20 dB/cm.

The preparation raw materials of the modified silicone rubber G comprise DC 184, polysulfide rubber, a silane coupling agent KH-580 and a curing agent, wherein the polysulfide rubber is a double-component, and the mass ratio of the polysulfide rubber to the curing agent is 4:1.

The preparation process and performance test of the modified silicone rubber G are that the DC 184 silica gel component 20G is weighed, the liquid polysulfide rubber 8G, the silane coupling agent KH-580.5G is added, the polysulfide rubber curing agent 2G and the DC 184 curing agent 2G are added after mechanical stirring is carried out uniformly, the mixture is obtained after mechanical stirring and vacuum centrifugal defoaming, the mixture is poured into a mould for room temperature vulcanization for 48 hours, the modified silicone rubber G sample is obtained, the acoustic performance test is carried out on the modified silicone rubber G, the density of the modified silicone rubber G is 1.06G/cm ³, the acoustic velocity is 1330 m/s, the acoustic impedance is 1.41 MRayl, and the acoustic attenuation of 5 MHz is less than 30 dB/cm.

The preparation raw materials of the modified silicone rubber H comprise 6610/60 and silicone resin, wherein the used silicone resin is of a single-component thermosetting type, and the curing temperature is not lower than 60 ℃ and not higher than 150 ℃.

The preparation process and performance test of the modified silicone rubber H are as follows, silicone resin is respectively mixed into A, B parts of 6610/60, the mass fraction of the A part of 6610/60 in the mixed A part is 80%, the mass fraction of the silicone resin is 20%, the mass fraction of the B part of 6610/60 in the mixed B part is 80%, and the mass fraction of the silicone resin is 20%. The mixture was mixed with a kneader for 60 minutes to obtain a homogeneous mass, and a sample was prepared with a liquid silica gel injection molding machine using a mold size of 100mm x 100mm x 5 x mm, and a modified silicone rubber H sample was obtained after a two-stage vulcanization at 160℃for 10 minutes and 200℃for 4 hours, and was subjected to acoustic performance testing, the density of the modified silicone rubber H was 1.19 g/cm ³, the acoustic velocity was 1120 m/s, the acoustic impedance was 1.33 MRayl, and the acoustic attenuation at 5 MHz was less than 25 dB/cm.

The preparation raw materials of the modified silicon rubber I comprise LSR 7080, nitrile rubber and a curing agent, wherein the used liquid nitrile rubber is a double-component, and the mass ratio of the liquid nitrile rubber to the curing agent is 2:1.

The preparation process and performance test of the modified silicone rubber I are as follows, mixing a liquid nitrile rubber curing agent into a component A of LSR 7080, wherein the mass fraction of the component A of the LSR 7080 in the mixed component A is 70%, the mass fraction of the liquid nitrile rubber is 10%, the mass fraction of the liquid nitrile rubber curing agent is 20%, meanwhile, mixing the liquid nitrile rubber into a component B, the mass fraction of the component B of the LSR 7080 in the mixed component B is 70%, and the mass fraction of the liquid nitrile rubber is 30%. Mixing for 60 minutes by a kneader to obtain a uniform substance, preparing a sample by a liquid silica gel injection molding machine, wherein the size of a used mould is 100 mm x 100 mm x 5 x mm, performing primary vulcanization for 10 minutes at 130 ℃ and performing secondary vulcanization for 2 hours at 200 ℃ to obtain a modified silicone rubber I sample, and performing acoustic performance test on the modified silicone rubber I sample to obtain a component I with the density of 1.10 g/cm ³, the acoustic velocity of 1226 m/s, the acoustic impedance of 1.35 MRayl and the acoustic attenuation of 5 MHz of less than 25 dB/cm.

The preparation raw materials of the modified silicone rubber J comprise LSR 7080, fluorosilicone rubber, vinyl fluorosilicone oil and methyl fluorosilicone oil, wherein the liquid fluorosilicone rubber is a double-component, and the mass ratio of the fluorosilicone rubber to the curing agent is 1:1.

The preparation process and performance test of the modified silicone rubber J comprises the steps of mixing fluorosilicone rubber and vinyl fluorosilicone oil into an A component of LSR7080, wherein the mass fraction of the A component of LSR7080 in the mixed A component is 65%, the mass fraction of the fluorosilicone rubber is 30%, the mass fraction of the vinyl fluorosilicone oil is 5%, the mass fraction of the B component of LSR7080 is mixed with fluorosilicone rubber curing agent and methyl fluorosilicone oil, the mass fraction of the B component of LSR7080 in the mixed B component is 65%, the mass fraction of the fluorosilicone rubber curing agent is 30%, the mass fraction of the methyl fluorosilicone oil is 5%, mixing for 60 minutes by a kneader respectively to obtain a uniform substance, preparing a sample by a liquid silica gel injection molding machine, obtaining a modified silicone rubber J sample after initial vulcanization for 10 minutes at 130 ℃ and two-stage vulcanization for 2 hours at 200 ℃, and carrying out sound performance test on the modified silicone rubber J sample, wherein the sound velocity is m/s, the sound resistance of 1.13/g cm/³, and the sound impedance of 1120A is 1.26 MHz and the sound attenuation of 5 cm/498 cm is reduced by 4.

(III) thermoplastic elastomer

Thermoplastic elastomer K adopts Thermoplastic Polyurethane (TPU), specifically adopts Desmopan DP 9370AU of Korskoff (COVESTRO), and adopts a sample wafer made of raw materials to carry out acoustic performance test, wherein the density of the thermoplastic elastomer K is 1.06 g/cm ³, the sound velocity is 1640 m/s, the acoustic impedance is 1.77 MRayl, and the acoustic attenuation of 5MHz is less than 20 dB/cm.

Thermoplastic elastomer L adopts polyether polyamide block copolymer (PEBAX), specifically adopts Acomax (ARKEMA) PEBAX 4533, and adopts a sample wafer prepared from raw materials for acoustic performance test, wherein the density of the thermoplastic elastomer L is 1.01 g/cm ³, the acoustic velocity is 1750 m/s, the acoustic impedance is 1.76 MRayl, and the acoustic attenuation of 5 MHz is less than 30 dB/cm.

Thermoplastic elastomer M is an organosilicon thermoplastic elastomer (TPSiV), specifically DuPont (DUPONT) TPSiV 5300-80A, and the acoustic performance test is carried out by preparing sample pieces from raw materials to obtain the component M with the density of 0.95 g/cm ³, the sound velocity of 1430M/s, the acoustic impedance of 1.36 MRayl and the acoustic attenuation of 5 MHz of less than 35 dB/cm.

Thermoplastic elastomer N the thermoplastic elastomer N adopts styrene-isobutylene-styrene block copolymer (SIBS), specifically adopts clocked (KANEKA) SIBSTAR 062T, uses raw material to make sample wafer to make sound property test, the density of thermoplastic elastomer N is 0.94 g/cm ³, sound velocity is 1980 m/s, acoustic impedance is 1.86 MRayl, and sound attenuation of 5 MHz is less than 25 dB/cm.

(IV) thermoplastic resin

Thermoplastic resin O the thermoplastic resin O adopts poly 4-methylpentene (TPX), specifically adopts Sanjingchu chemical (Mitsul Chemicals) TPX RT-31, and uses the raw material to make sample wafer to make sound performance test so as to obtain the density of thermoplastic resin O is 0.84 g/cm ³, sound velocity is 2090 m/s, acoustic impedance is 1.77 MRayl, and sound attenuation of 5MHz is less than 15 dB/cm.

The thermoplastic resin P adopts polypropylene (PP), specifically, the music day chemistry (LOTTE CHEMICAL) Titanpro 6431 is selected, a sample is prepared by raw materials, and the acoustic performance test is carried out, so that the density of the thermoplastic resin P is 0.90 g/cm ³, the acoustic velocity is 2600 m/s, the acoustic impedance is 2.34 MRayl, and the acoustic attenuation of 5 MHz is less than 20 dB/cm.

Thermoplastic resin Q adopts polyamide resin (PA), specifically adopts Acomax (ARKEMA) RILSAN CLEAR G to 820, and uses raw materials to prepare sample wafer for acoustic performance test, so that the density of the thermoplastic resin Q is 1.05 g/cm ³, the acoustic velocity is 2260 m/s, the acoustic impedance is 2.37 MRayl, and the acoustic attenuation of 5 MHz is less than 20 dB/cm.

The main components and acoustic performance parameters of the foregoing materials are listed in table 1 below:

TABLE 1

The materials of different subareas of the acoustic lens can be selected in the table 1 according to the principle of acoustic impedance matching and acoustic velocity difference, and the forming processing sequence of each subarea can be adjusted according to actual conditions due to different material forming modes. The specific implementation mode is as follows:

Example 1

Referring to fig. 3, an acoustic lens has a front surface, and the acoustic lens includes a middle region L2 and first and second side regions L1 and L3 located at both sides of the middle region from the middle of the front surface to both sides along a curved surface. Along the Y-axis, the L2 length is 40% and the L1 and L3 lengths are 30% each.

The acoustic lens of example 1 is a convex lens with a three-zone structure prepared by multi-color injection molding, the material of the middle zone L2 is modified silicone rubber I, the material of the first side zone L1 is silicone rubber C, and the material of the second side zone L3 is modified silicone rubber J. The middle zone L2 has the fastest speed of sound, and the first and second side zones L1 and L3 have lower speeds of sound. The focal length F2 of the intermediate zone L2 is greater than the focal length F1 of the first side zone L1, and the focal length F2 of the intermediate zone L2 is also greater than the focal length F3 of the second side zone L3.

The above-mentioned acoustic lens has 3 focuses of different focal lengths, the ultrasonic beam passing through the middle area L2 converges on the deeper part of the object to be measured, the ultrasonic beam transmitted through the first side area L1 and the second side area L3 converges on the shallower part of the object to be measured, realize the ultrasonic beam with narrow width in the Y direction.

Example 2

Referring to fig. 4, embodiment 2 is substantially the same as embodiment 1 except that both the first side area L1 and the second side area L3 use silicone rubber C. Along the Y-axis direction, the lengths of L1/L2/L3 are equal and are 33.3 percent.

The acoustic lens has 2 focuses with different focal lengths, the sound velocity of the middle area L2 is fastest, the focal length is largest, the sound velocity of the first side area L1 and the second side area L3 is lower, the focal length is smaller, the ultrasonic wave beams transmitted through the side areas L1 and L3 are converged at the deeper part of the target to be tested, and the ultrasonic wave beams with narrow width in the Y direction are converged at the shallower part of the target to be tested.

Example 3

Referring to fig. 5, an acoustic lens has a front surface, and the acoustic lens includes a middle area L3 and first, second, third and fourth side areas L1, L2, L4 and L5 located at both sides of the middle area from the middle of the front surface to the lifting direction. Along the Y-axis direction, the length of L3 accounts for 30%, and the length of L1/L2/L4/L5 accounts for 17.5%.

The acoustic lens of example 3 is a convex lens of a five-zone structure, the material of the middle zone L3 is a thermoplastic elastomer M, the material of the first side zone L1 and the fourth side zone L5 is a silicone rubber C, and the material of the second side zone L2 and the third side zone L4 is a modified silicone rubber H. Firstly, a secondary injection molding mode is adopted, a second side area L2 and a third side area L4 are injection molded at two sides of a middle area L3, and then a double-color injection molding mode is used for injection molding a first side area L1 and a fourth side area L5. The sound velocity of the middle zone L3 is the fastest, and the sound velocity of the two side zones is gradually reduced (V _L2＞V_L1,V_L4＞V_L5), namely the focal length of the middle zone is the largest, and the focal length of the two side zones is gradually reduced.

The above-mentioned acoustic lens has 3 focuses of different focal lengths, the ultrasonic beam passing through the middle area L3 of the acoustic lens converges at the deeper part of the object to be measured, the ultrasonic beam transmitted through the first side area L1, the second side area L2, the third side area L4 and the fourth side area L5 converges at the shallower part of the object to be measured, realizing an ultrasonic beam having a narrow width in the Y direction.

Example 4

Referring to fig. 6, an acoustic lens has a front surface, and the acoustic lens includes a middle region L4 and first, second, third, fourth, fifth and sixth side regions L1, L2, L3, L5, L6 and L7 located at both sides of the middle region from the middle of the front surface along a curved surface change direction to both sides. In the Y-axis direction, the length of the intermediate zone L4 is 25%, the L1 and L7 are 15%, the L2 and L6 are 12.5%, and the L3 and L5 are 10%.

The acoustic lens of example 4 is a convex lens with a seven-segment structure, the material of the middle region L4 is modified silicone rubber G, the material of the first side region L1 and the sixth side region L7 is silicone rubber a, the material of the second side region L2 and the fifth side region L6 is modified silicone rubber E, and the material of the third side region L3 and the fourth side region L5 is modified silicone rubber F. And preparing the acoustic lens by adopting a mode of pouring in batches. The sound velocity of the middle zone L4 is the fastest, and the sound velocity of the two side zones is gradually reduced (V _L3＞V_L2＞V_L1,V_L5＞V_L6＞V_L7), namely the focal length of the middle zone is the largest, and the focal length of the two sides is gradually reduced.

The above-mentioned acoustic lens has 4 focuses of different focal lengths, the ultrasonic beam passing through the middle area L4 of the acoustic lens is converged at a deeper portion of the object to be measured, and the ultrasonic beam transmitted through the first side area L1, the second side area L2, the third side area L3, the fourth side area L5, the fifth side area L6 and the sixth side area L7 is converged at a shallower portion of the object to be measured, so that the ultrasonic beam having a narrow width in the Y direction is realized.

Example 5

Referring to fig. 7, an acoustic lens has a front surface, and the acoustic lens includes a middle area L2 and first and second side areas L1 and L3 located at both sides of the middle area from the middle of the front surface to the lifting direction. In the Y-axis direction, the L2 length is 30% and the L1 and L3 are 35% each.

The acoustic lens of example 5 is a concave lens of a three-zone structure, the material of the intermediate zone L2 is thermoplastic resin P, and the material of the first side zone L1 and the second side zone L3 is thermoplastic resin Q. The middle zone L2 has the slowest speed of sound and the first and second side zones L1 and L3 have faster speeds of sound. The focal length F1 of the middle region L2 is greater than the focal lengths F2 of the first and second side regions L1 and L3.

The above-mentioned acoustic lens has 2 focuses of different focal lengths, the ultrasonic beam passing through the middle area L2 converges on the deeper part of the object to be measured, the ultrasonic beam transmitted through the first side area L1 and the second side area L3 converges on the shallower part of the object to be measured, realize the ultrasonic beam with narrow width in the Y direction.

Example 6

Referring to fig. 8, an acoustic lens has a front surface, and the acoustic lens includes a middle area L3 and first, second, third and fourth side areas L1, L2, L4 and L5 located at both sides of the middle area from the middle of the front surface to the lifting direction. Along the Y-axis direction, the lengths of L1/L2/L3/L4/L5 are equal, and the ratio of the lengths is 20%.

The acoustic lens of example 6 is a convex lens of a five-zone structure, the material of the middle zone L3 is a thermoplastic elastomer K, the material of the first side zone L1 and the fourth side zone L5 is a thermoplastic resin O, and the material of the second side zone L2 and the third side zone L4 is a thermoplastic elastomer L. And a secondary injection molding mode is adopted. The sound velocity of the middle zone L3 is the slowest, and the sound velocity of the two side zones is gradually increased (V _L2<V_L1,V_L4<V_L5), namely the focal length of the middle zone is the largest, and the focal length of the two side zones is gradually reduced.

Example 7

Example 7 is substantially the same as example 1 except that the material of the intermediate zone L2 is modified silicone rubber F.

Comparative example 1

Referring to fig. 9, comparative example 1 is substantially the same as example 1 except that the acoustic lens is entirely made of a modified silicone rubber I.

Comparative example 2

Referring to fig. 11, comparative example 2 is substantially the same as example 5 except that the thermoplastic resin P is used as the whole acoustic lens.

The acoustic lenses prepared in examples 1 to 7 and comparative examples 1 to 2 were subjected to beam width test, and the test results are shown in table 2 below.

The specific testing method comprises the steps of setting up a testing environment according to sound field scanning equipment, respectively installing and debugging ultrasonic transducers using different acoustic lenses, setting a plane wave transmitting and receiving mode, and carrying out ZY Sacn scanning to obtain the beam widths of the acoustic lenses of different embodiments.

The beam width of the single convex lens in comparative example 1 was defined as d ₁, and the beam width of the single concave lens in comparative example 2 was defined as d ₂. The different examples were compared by acoustic lens type, specifically, the test results d _Measuring and d ₁ of examples 1 to 4 and example 7, and the test results d _Measuring and d ₂ of examples 5 to 6. The narrowing effect was evaluated as follows, narrowing effect α= (d ₁-d_Measuring）/d₁ or (d ₂-d_Measuring）/d₂).

Definition evaluation, namely narrowing effect A is alpha >10%;

The narrowing effect B is that alpha is 5 percent and less than or equal to 10 percent;

the narrowing effect C is 2 percent, alpha is less than or equal to 5 percent;

the narrowing effect D is 0 percent < alpha is less than or equal to 2 percent.

A schematic diagram of beam width contrast of the acoustic lens of the present application and a conventional single-material acoustic lens at different depths of a target to be measured is shown in fig. 13. It can also be seen from fig. 3 that the acoustic lens of the present application makes the beam narrowing apparent and the beam more uniform, and the beam widths at different depths of the object to be measured are close.

TABLE 2

From the data in table 2, it can be seen that the acoustic lens of the present application can achieve multi-point focusing, the beam narrowing is obvious, and the beam is more uniform, thereby obtaining higher quality ultrasound images.

As can be seen from the embodiment 1 and the comparative example 1, referring to fig. 9, the comparative example 1 is a convex lens made of a single material, the convex lens of the comparative example 1 has a fixed sound velocity and a fixed focal length, if the focal length is to be changed, the convex lens can only be changed by changing the radius of curvature, referring to fig. 10 (if the focal length F1 is to be increased, the radius of curvature R1 is to be increased, wherein F1< F2 and R1< R2) can not be increased), and when the beam passes through the acoustic lens of the embodiment 1, the beam in the embodiment 1 is more uniform in the object to be measured and the beam width at a different depth is close than that of the acoustic lens of the comparative example 1, so that a higher quality ultrasonic image can be obtained, as can also be seen from fig. 13.

As can be seen from example 5 and comparative example 2, please refer to fig. 11, comparative example 2 is a concave lens made of a single material, the concave lens of comparative example 2 has a fixed sound velocity and a fixed focal length, if the focal length is to be changed, the concave lens can only be changed by changing the radius of curvature, please refer to fig. 12 (if the focal length F1 is to be increased, the radius of curvature R1 is only to be decreased, wherein F1< F2, R1< R2), the function of focal length change cannot be realized, and the beam has no narrowing effect. As can be seen from the combination of examples 1-7 with Table 1, the acoustic lens is prepared from the following raw materials and the mass content of the modified silicone rubber (such as modified silicone rubber E, modified silicone rubber F, modified silicone rubber H and modified silicone rubber J) by 60-80% of silicone rubber, 10-40% of high sound velocity component and 0-10% of compatilizer, and has the advantages of more obvious beam narrowing and smaller sound attenuation. The acoustic lens is prepared from 60-75% of silicon rubber, 22-40% of high-sound-speed component and 1-5% of compatilizer, wherein the mass content of the modified silicon rubber (such as modified silicon rubber E and modified silicon rubber F) is higher than that of the prepared raw materials, the beam narrowing degree is higher than 10%, and the acoustic attenuation is further reduced.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. The acoustic lens is characterized by comprising a front surface, wherein the acoustic lens comprises a middle area and side areas positioned at two sides of the middle area in the curved surface changing direction of the front surface, and the focal length of the middle area is larger than that of the side areas.

2. The acoustic lens of claim 1 wherein the length of the central zone is 10% to 40% of the total length of the acoustic lens and the length of the side zones on one side is 5% to 45% of the total length of the acoustic lens in the direction of curvature change of the front surface.

3. The acoustic lens of claim 1, wherein at least one of the following conditions is satisfied:

4. The acoustic lens of claim 1 wherein the difference in sound velocity of adjacent regions is greater than or equal to 50m/s and the difference in acoustic impedance of adjacent regions is less than or equal to 0.1Mrayl.

5. The acoustic lens of claim 1 wherein the acoustic lens is a convex lens and the speed of sound in the middle region and each of the side regions is less than or equal to 1500 m/s, or

6. The acoustic lens of claim 1 wherein the side region on one side comprises n sequentially connected sub-regions in a curved surface change direction of the front surface, a focal length of the n sequentially connected sub-regions decreasing in a direction from the intermediate region away from the intermediate region, wherein n is a natural number greater than or equal to 1.

7. The acoustic lens of any of claims 1 to 6 wherein the acoustic lens is a convex lens and the front surface is a convex surface, the front surface having equal curvature in the medial region and each of the lateral regions, the speed of sound in the medial region being greater than the speed of sound in the lateral regions.

8. The acoustic lens of claim 7 wherein the acoustic lens is a convex lens and the lateral zone on one side comprises n sequentially connected sub-zones in the direction of curvature change of the front surface, the sound velocity of the n sequentially connected sub-zones decreasing in a direction from the intermediate zone away from the intermediate zone, wherein n is a natural number greater than or equal to 1.

9. The acoustic lens of claim 7 wherein the material of the medial region and each of the lateral regions is at least one of silicone rubber and modified silicone rubber.

10. The acoustic lens of claim 9, wherein the preparation raw materials of the modified silicone rubber comprise 60% -80% of silicone rubber, 10% -40% of high sound velocity component and 0% -10% of compatilizer by mass content, and the sound velocity of the high sound velocity component is greater than or equal to 1100 m/s.

11. The acoustic lens of claim 10, wherein the modified silicone rubber is prepared from 60% -75% silicone rubber, 22% -40% high sound velocity component, and 1% -5% compatilizer by mass.

12. The acoustic lens of claim 10 wherein the modified silicone rubber has an acoustic velocity of 1100m/s to 1400m/s.

13. The acoustic lens of any of claims 10 to 12 wherein the high acoustic velocity component comprises at least one of silicone, polyurethane, epoxy, fluorosilicone, polysulfide and nitrile rubber.

14. The acoustic lens of any of claims 10 to 12, wherein the compatibilizing agent comprises at least one of a silane coupling agent and a modified silicone oil.

15. The acoustic lens of any of claims 9 to 12, wherein the silicone rubber comprises at least one of RTV 630 silicone rubber, DC 184 silicone rubber, 6610/60 silicone rubber, and LSR 7080 silicone rubber.

16. The acoustic lens of any of claims 1 to 6 wherein the acoustic lens is a concave lens and the front surface is a concave surface, the front surface having equal curvature in the medial region and each of the lateral regions, the speed of sound in the medial region being less than the speed of sound in the lateral regions.

17. The acoustic lens of claim 16 wherein the acoustic lens is a concave lens and the lateral zone on one side comprises n sequentially connected sub-zones in the direction of curvature change of the front surface, the sound velocity of the n sequentially connected sub-zones increasing in a direction from the intermediate zone away from the intermediate zone, wherein n is a natural number greater than or equal to 1.

18. The acoustic lens of claim 16 wherein the material of the middle region and each of the side regions is a thermoplastic polymer.

19. The acoustic lens of claim 18, wherein the thermoplastic polymer comprises at least one of a thermoplastic polyurethane, a polyether polyamide block copolymer, a silicone-based thermoplastic elastomer, a styrene-isobutylene-styrene block copolymer, poly 4-methylpentene, polypropylene, and a polyamide resin.

20. An ultrasonic probe comprising an acoustic lens according to any one of claims 1 to 19.

21. An ultrasound imaging apparatus comprising an acoustic lens according to any one of claims 1 to 19 or an ultrasound probe according to claim 20.