Annular focusing ultrasonic phased array probe and control method thereof

Abstract

The application relates to a ring-shaped focusing ultrasonic phased array probe and a control method thereof, wherein the probe is in a spherical cap shape, a plurality of ring-shaped transducer array elements are arranged on the inner spherical surface, and the two sides are narrowed; at the same time, at least one ring-shaped transducer array element in a non-working state exists between two adjacent ring-shaped transducer array elements in a working state. Compared with the prior art, the application adopts a spherical cap array with the two sides of the spherical cap being narrowed, a plurality of independently controlled ring-shaped transducer array elements made of piezoelectric ceramic are arranged along the spherical surface, at least one ring-shaped transducer array element in a non-working state exists between two adjacent ring-shaped transducer array elements in a working state at the same time, the distance between adjacent array elements driven at the same time is increased without using a piezoelectric composite, and the crosstalk between the array elements is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ultrasonic transducer, in particular to a ring-shaped focusing ultrasonic phased array probe and a control method thereof. BACKGROUND

[0002] Piezoelectric ceramics is the most commonly used material for making ultrasonic transducers, which has good temperature stability, high damage threshold, and low cost, and is often used for processing small-sized curved HIFU transducers. However, piezoelectric ceramic material also has its unique shortcomings, that is, a relatively low Young's modulus, which means that if piezoelectric ceramic material is used, there will be a crosstalk problem when a phased array transducer is made by removing the electrode: that is, when adjacent elements will interfere with each other due to the conduction of mechanical vibration of piezoelectric ceramic material. This will cause the emitted ultrasonic waves to have amplitude and phase differences from the expected values, ultimately causing unexpected degradation of the phased focusing of the transducer, such as causing the -6dB focal region of the phased focusing of the transducer to be longer, or causing the focal point to have more than -8dB sidelobes in the space when the phased deflection occurs, thereby reducing the phased deflection range of the focal point.

[0003] Further, the independent elements of the spherical ring-shaped phased array transducer for transrectal prostate treatment are in the form of an elongated ring and are relatively small in size, so the influence of adjacent elements is greater than other types of structures. In order to reduce the mutual crosstalk between the elements, the spacing between the elements needs to be increased, but increasing the spacing between the elements will result in a decrease in the number of elements.

[0004] In summary, there is currently a lack of a ring-shaped focusing ultrasonic phased array probe to solve or partially solve the problem of mutual crosstalk between elements in a spherical ring-shaped phased array transducer. SUMMARY

[0005] The purpose of the present application is to overcome the defects of the prior art and provide a ring-shaped focusing ultrasonic phased array probe and a control method thereof to solve or partially solve the problem of mutual crosstalk between elements in a spherical ring-shaped phased array transducer.

[0006] The purpose of the present application can be achieved by the following technical solutions:

[0007] The purpose of the present application can be achieved by the following technical solutions:

[0008] In one aspect of the present application, a ring-shaped focusing ultrasonic phased array probe is provided,

[0009] The probe is provided with a first working area and a second working area, and the first working area and the second working area work alternately.

[0010] The first working area comprises a plurality of first transducer array elements;

[0011] The second working area comprises a plurality of second transducer array elements;

[0012] The cross-sectional area of each of the first transducer array elements is equal to the cross-sectional area of each of the second transducer array elements or the error is within ±5%.

[0013] As a preferred technical solution, the probe is arranged inside the probe and is in the shape of a spherical cap, and the first transducer array elements and the second transducer array elements are annular.

[0014] As a preferred technical solution, the first and second transducer array elements are narrowed on both sides.

[0015] As a preferred technical solution, a circular transducer array element is further arranged at the center of the spherical surface in the probe.

[0016] As a preferred technical solution, the first transducer array elements and the second transducer array elements are alternately arranged and alternately operated along the polar radius direction.

[0017] As a preferred technical solution, gaps are arranged between adjacent annular transducer array elements.

[0018] As a preferred technical solution, the total number of the first transducer array elements and the second transducer array elements is greater than or equal to 5.

[0019] Another aspect of the present application provides an ultrasonic transducer comprising the annular focusing ultrasonic phased array probe.

[0020] An aspect of the present application provides a control method for controlling the annular focusing ultrasonic phased array probe, and the control method comprises the following steps:

[0021] S1: presetting ablation target point parameters, n =1, 2, 3... N , N is the number of target points;

[0022] S2: setting the working parameters and single working time of the first working area and the second working area according to the preset target point parameters T ;

[0023] S3: driving the first transducer array elements of the first working area to work T , and then determining whether the target point is ablated, if yes, starting the ablation of the next target point; if no, performing S4;

[0024] S4: driving the second transducer array elements of the second working area to work TAfterwards, it is determined whether the target point is ablated, if yes, the next target point ablation is started, if no, S3 is executed;

[0025] S5: When all preset target points are ablated, the working of the annular focusing ultrasonic phased array probe is ended.

[0026] As a preferred technical solution, the working parameters include driving voltage and / or target point position and / or working time, working preset time threshold.

[0027] As a preferred technical solution, the condition for ending the working of the annular focusing ultrasonic phased array probe includes:

[0028] The temperature of the target point is higher than a preset value; and / or

[0029] The working time of the annular array is greater than a working preset time threshold, wherein the temperature is obtained based on B-ultrasound imaging or magnetic resonance imaging temperature measurement.

[0030] Compared with the prior art, the present application has at least the following beneficial effects:

[0031] In view of the problem that crosstalk exists between elements of a trans-catheter piezoelectric ceramic array, causing degradation, the present application adopts a ball cover with a narrow ball crown on both sides, and a plurality of independently controlled ring transducer elements of piezoelectric ceramic material are arranged along the spherical surface. By allowing at least one ring transducer element to be in a non-working state between two adjacent ring transducer elements in a working state at the same time, the distance between adjacent elements driven at the same time is increased, thereby reducing crosstalk between elements. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is a perspective view of the annular focusing ultrasonic phased array probe in the embodiment;

[0033] Figure 2 It is a top view of the annular focusing ultrasonic phased array probe in the embodiment;

[0034] Figure 3 It is a schematic diagram of the control method of the annular focusing ultrasonic phased array probe in the embodiment. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0036] Embodiment 1

[0037] In view of the problems in the prior art, the embodiment provides a ring-shaped focusing ultrasonic phased array probe, as shown in Figure 1 、 Figure 2 The probe is in the shape of a spherical cap, a plurality of ring-shaped transducer array elements are arranged on the inner spherical surface, and the two sides are cut narrow, gaps are arranged between adjacent ring-shaped transducer array elements, and at least one ring-shaped transducer array element is in a non-working state between two adjacent ring-shaped transducer array elements in a working state at the same time, so that the problem of mutual crosstalk between array elements is reduced.

[0038] In addition to the ring-shaped transducer array elements, a circular transducer array element is arranged at the center of the inner spherical surface, and the other ring-shaped transducer array elements are concentrically arranged with the circular transducer array element.

[0039] As shown in Figure 2 The transducer array element alternating driving mode of the present application is divided into array element groups, the array elements are grouped at intervals, and it is ensured that the array elements driven at the same time do not contain physically adjacent array elements, wherein the diagonal line represents group A, that is, the first group of array elements, and the white color represents group B, that is, the second group of array elements, and the two groups of array elements are driven separately in the present application. Specifically, the plurality of ring-shaped transducer array elements are divided into group A array and group B array in a staggered manner along the polar radius direction, and at the same time, only one group of array is in a working state.

[0040] As a preferred scheme, the area of each ring-shaped transducer array element is equal to the area of the circular transducer array element, that is, the sum of the left and right areas of the ring-shaped transducer array element after cutting is equal to the area of the circular transducer array element.

[0041] Under the premise that the power emitted by the array element unit area is fixed, the total power emitted by the ring-shaped transducer array element and the circular transducer array element is the same, and through such a design, the uniformity of transducer heating is ensured.

[0042] Embodiment 2

[0043] On the basis of embodiment 1, the present embodiment provides a control method for controlling the ring-shaped focusing ultrasonic phased array probe as described in embodiment 1, as shown in Figure 3 The method comprises the following steps:

[0044] S1: presetting an ablation target point parameters, n =1, 2, 3... N , N The target point parameters include three-dimensional coordinates, and in actual application, one or more target points with different positions can be included;

[0045] S2: setting the working parameters and single working time of group A array and group B array according to the preset target point parameters Twherein the working parameters include a driving voltage;

[0046] S3: driving the A group array to work T After that, it is determined whether the target point is ablated or not. If yes, the ablation of the next target point is started. If no, S4 is executed.

[0047] S4: driving the B group array to work T After that, it is determined whether the target point is ablated or not. If yes, the ablation of the next target point is started. If no, S3 is executed.

[0048] S5: when all the preset target points are ablated, the working of the annular focusing ultrasonic phased array probe is ended. Specifically, the conditions for ending the working of the annular focusing ultrasonic phased array probe include that the temperature of the target point is higher than a preset value and / or the working time of the annular array is greater than a preset value. The temperature of the target point is obtained based on the B-ultrasound image or the MR image.

[0049] The method is described below with reference to a specific embodiment,

[0050] Step 1: the annular elements are divided into two groups, A and B, and the working related parameters are set, such as the driving voltage 110V in the working process, the working time 500ms, and the initial phase of each element of the A group calculated according to the focusing position of the preset focal point.

[0051] Step 2: the A group elements are driven according to the preset parameters to perform thermal ablation treatment on the preset target area position.

[0052] Step 3: according to the relevant image feedback information, such as the B-ultrasound image or the MR temperature data of the target area, or according to the preset total ablation time, it is determined whether the ablation of the target point is completed. If yes, the ablation of the current target point is completed, and step 7 is executed. If no, step 4 is entered.

[0053] Step 4: the B group annular elements are selected, and the initial phase of each element of the B group calculated according to the focusing position of the preset focal point.

[0054] Step 5: the B group elements are driven according to the preset parameters to perform thermal ablation treatment on the preset target area position.

[0055] Step 6: according to the relevant image feedback information, such as the B-ultrasound image or the MR temperature data of the target area, or according to the preset total ablation time, it is determined whether the ablation of the target point is completed. If yes, the ablation of the current target point is completed, and step 7 is executed. If no, step 2 is entered.

[0056] ​​​Step 7, judging whether there is a next target point, if yes, resetting the target point parameter, executing step 1; if no, ending the work.

[0057] In summary, the method has the following beneficial effects:

[0058] (1) The different array elements are staggered and grouped for driving, which can better increase the distance between adjacent array elements driven at the same time and reduce the crosstalk between the array elements.

[0059] (2) By reducing the crosstalk, the sidelobe of the region near the focal point during the phased focal point deflection process can be effectively reduced, and the accuracy of ablation can be improved.

[0060] (3) By alternating heating of different groups, the f-number of the transducer is equivalent to being increased, which can increase the focusing focal domain size of the transducer to a certain extent and improve the efficiency.

[0061] (5) The method does not need to use the piezoelectric composite material with higher cost to reduce the crosstalk between the array elements of the ring array, and the cost is low and stable and reliable.

[0062] Example 3

[0063] The embodiment provides an ultrasonic transducer, which comprises the ring-shaped focusing ultrasonic phased array probe described in the embodiment 1.

[0064] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A ring-shaped focused ultrasonic phased array probe, characterized in that: the probe is provided with a first working area and a second working area, the first working area and the second working area work alternately; the first working area comprises a plurality of first transducer array elements; the second working area comprises a plurality of second transducer array elements; the cross-sectional area of each first transducer array element is equal to the cross-sectional area of each second transducer array element or the error is within ±5%; the probe is in the shape of a spherical cap, the first transducer array elements and the second transducer array elements are arranged in a ring shape on the inner surface of the probe, the first and second transducer array elements are narrowed on both sides, a circular transducer array element is further arranged at the center of the inner surface of the probe, the first transducer array elements and the second transducer array elements are arranged alternately along the polar radius direction and work alternately, a gap is provided between adjacent ring-shaped transducer array elements, and the area of each ring-shaped transducer array element is equal to the area of the circular transducer array element.

2. The annular focused ultrasound phased array probe of claim 1, wherein, The total number of the first transducer array elements and the second transducer array elements is greater than or equal to 5.

3. An ultrasonic transducer, characterized by, The ring-shaped focused ultrasonic phased array probe according to any one of claims 1-2.

Images