KR20120047785A - Ultrasound probe including ceramic layer fromed with ceramic elements having different widths and ultrasound system using the same - Google Patents

Abstract

Disclosed is an ultrasonic probe capable of enlarging a focus characteristic and a low frequency bandwidth (BW) by forming a ceramic layer with different thicknesses of ceramic elements in a conversion element. The ultrasonic probe according to the present invention is an ultrasonic probe for transmitting and receiving an ultrasonic signal, and includes at least one conversion element each including a ceramic layer, and the ceramic layer includes a plurality of ceramic elements having different thicknesses.

Description

Ultrasonic probe including ceramic layer fromed with ceramic elements having different widths and ultrasound system using the same}

The present invention relates to an ultrasonic system, and more particularly, to an ultrasonic probe including a ceramic layer formed of ceramic elements having different thicknesses and an ultrasonic system using the same.

Ultrasound systems have non-invasive and non-destructive properties and are widely used in the medical field for obtaining information inside an object. Ultrasound systems are widely used in the medical field because they can provide a doctor with a high-resolution image of the inside of a subject in real time without the need for a surgical operation in which the subject is directly incised and observed.

The ultrasound system includes an ultrasound probe operative to transmit an ultrasound signal to the object and receive an ultrasound signal (ie, an ultrasound echo signal) reflected from the object. The ultrasonic probe includes at least one transducer element operative to convert an electrical signal into an ultrasonic signal.

The converter includes a ceramic layer, such as a piezoelectric element, to generate an ultrasonic signal in response to an electrical signal and to generate an electrical signal in response to an ultrasonic echo signal. The transmission ultrasonic beams output from each conversion element in response to the electrical signal exhibit high or low frequency characteristics depending on the characteristics of the ceramic layer. When the transmitting ultrasound beam has a high frequency characteristic, the focusing characteristic of the ultrasound beam is good in a region close to the probe, that is, a shallow region of the object, so that an image having high resolution may be obtained. On the other hand, the penetration of the ultrasound beam is relatively difficult in a region far from the probe, that is, a deep region of the object, and thus the transmission focusing characteristic is degraded, thereby degrading the resolution. On the contrary, when the transmitting ultrasound beam has a low frequency characteristic, the resolution near the probe, that is, the shallow region of the object, is lower than that of the transmitting ultrasound beam having the high frequency characteristic, whereas the transmission ultrasound beam has a low frequency characteristic. In this regard, penetration of the ultrasonic beam is relatively easy, so that an image having an improved resolution can be obtained. Accordingly, there is a need for an ultrasound probe capable of obtaining an image having an improved resolution in a deep region as well as a shallow region of an object.

The present invention includes at least one conversion element, and by forming a ceramic layer of a plurality of ceramic elements of different thickness in the conversion element ultrasonic probe capable of enlarging the focus characteristics and low frequency bandwidth (BW) of the transmitted and received ultrasonic signal and the same It provides an ultrasonic system used.

Ultrasonic probes for transmitting and receiving ultrasonic signals according to the present invention includes at least one conversion element each comprising a ceramic layer, the ceramic layer is composed of a plurality of different thickness ceramic elements.

The ultrasonic system according to the present invention includes an ultrasonic probe for transmitting and receiving an ultrasonic signal including at least one conversion element each including a ceramic layer, and the ceramic layer includes a plurality of ceramic elements having different thicknesses.

According to the present invention, longer focal zones and bandwidths can be expected by using ultrasonic probes including ceramic layers formed of ceramic elements having different thicknesses.

1 is a block diagram showing an ultrasound system according to an embodiment of the present invention.
2 is a cross-sectional view of an ultrasonic probe according to an embodiment of the present invention.
3 is a cross-sectional view of a conversion device according to an embodiment of the present invention.
4 is an exemplary view showing a profile of an ultrasonic beam transmitted from a conversion element according to an embodiment of the present invention.
5 is an exemplary view showing a profile of an ultrasonic beam transmitted from a conversion element according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention.

1 is a block diagram showing an ultrasound system 10 according to an embodiment of the present invention. The ultrasound system 10 may include a probe 100, a beam forming unit 200, a signal processor 300, a scan converter 400, an image processor 500, and a display unit 600. The ultrasound system 100 further includes a storage unit (not shown) such as a memory.

The probe 100 including at least one transducer element 110 transmits an ultrasound signal to an object in response to a transmission signal, which is an electrical signal output from a transmission signal generator (not shown), Receive the reflected echo signal. The probe 100 outputs a received signal which is an electrical signal in response to the received echo signal.

The beam forming unit 200 receives and focuses a reception signal output from the probe 110 to form a reception focus beam. The signal processor 300 forms an ultrasound image data by performing envelope detection on the reception focused beam output from the beam forming unit 200.

The scan converter 400 converts the ultrasound image data output from the signal processor 300 into a data format capable of displaying the image, and the image processor 500 processes the mode image data output from the scan converter 400. Transfer to display unit 600.

2 is a schematic cross-sectional view of an ultrasonic probe according to an embodiment of the present invention. Referring to FIG. 2, the ultrasound probe 100 includes at least one transducer element 110. In addition, the ultrasonic probe 100 further includes a lens, a membrane cover 120, and the like for ultrasound focusing.

According to an embodiment, each of the conversion elements 110 includes a ceramic layer 112 for converting electrical signals and ultrasonic signals. The ceramic layer 112 is made of a mixture of fine crystals arranged in an irregular direction, and exhibits a piezoelectric property that is polarized in response to an electrical signal or an ultrasonic signal, thereby transmitting and receiving ultrasonic waves. The ceramic layer 112 may be formed of a piezoelectric element such as lead zirconate titanate (PZT).

In addition, each conversion element 110 is output from the vibration of the ceramic layer 112 and the ceramic layer 112 immediately when the ceramic layer 112 is excited in response to a transmission pulse signal, which is an electrical signal, and transmits ultrasonic waves of an ultrasonic probe. And a backing layer 111 for absorbing the ultrasonic signal propagating in the opposite direction. The sound absorbing layer 111 is formed of a material having an acoustic impedance similar to that of the piezoelectric element forming the ceramic layer 112, and is formed to have the property of absorbing the ultrasonic waves transmitted to the sound absorbing layer 111.

In addition, each conversion element further includes a first matching layer 113 and a second matching layer 114 covering the ceramic layer 112 to reduce the difference in acoustic impedance between the ceramic layer 112 and the object. . In an embodiment, the thicknesses of the first matching layer 113 and the second matching layer 114 are substantially one quarter of the ultrasonic wavelength to minimize the acoustic impedance difference, and the first and second sound absorbing layers 113 and 114. ) Is preferably formed to have an intermediate value between the impedance of the ceramic layer 112 and the acoustic impedance of the object.

3 is a view schematically showing the configuration of the ceramic layer 112 in each conversion element 110 according to an embodiment of the present invention. Referring to FIG. 2, the ceramic layer 112 may be formed using a plurality of ceramic elements 112_1 to 112_n having different thicknesses. Here, the plurality of ceramic elements 112_1 to 112_n may be symmetrically formed in both length directions with respect to the ceramic element 112_c positioned at the center. The thickness of the ceramic element may be defined in the length direction of each conversion element in the ceramic layer 112.

In general, when the thickness of the ceramic device is thick, the characteristics of the low frequency are more pronounced than those of the high frequency. Therefore, when the ceramic layer is formed using a single ceramic element, the ceramic layer has transmission and reception characteristics of a single frequency range, whereas according to an embodiment of the present invention, a plurality of ceramic elements 112_1 to 112_n having different thicknesses are provided. In the case of forming a ceramic layer using), transmission and reception characteristics of a plurality of frequency ranges are obtained.

In an exemplary embodiment, the thickness of each ceramic element may be gradually thinned in both directions based on the ceramic element 112_c of the ceramic layer 112. 4 is a view schematically showing a profile of an ultrasonic transmission beam transmitted from an ultrasonic transducer when the thickness of the ceramic element is thinner toward both ends of the ceramic layer 112 according to an embodiment of the present invention.

As shown in FIG. 4, when the ceramic layer 112 is formed, the ultrasonic signal output from the ceramic element 112_c positioned in the relatively thick thickness has low frequency characteristics, and transmits focuses in a deep region. The ultrasonic signal output from the ceramic element formed relatively thin in both directions with reference to 112_c has a high frequency characteristic and becomes a transmission focus in a shallow region. Therefore, the high frequency characteristic insufficient in the ultrasonic beam output from the center ceramic element 112_c may be compensated by using the high frequency characteristic ultrasonic beams output from both ceramic elements. That is, due to the low frequency characteristics of the transmitting ultrasound beam, the resolution of the ultrasound image may be compensated for in a relatively shallow region of the object.

In addition, in another embodiment of the present invention, the thickness of each ceramic element may be gradually increased in both directions based on the ceramic element 112_c of the ceramic layer 112. FIG. 5 is a view schematically showing a profile of an ultrasonic beam transmitted from an ultrasonic transducer when the thickness of the ceramic element is increased toward both ends of the ceramic layer 112 according to an embodiment of the present invention.

As shown in FIG. 5, when the ceramic layer 112 is formed, the ultrasonic signal output from the ceramic element 112_c positioned in a relatively thin thickness has a high frequency characteristic to be focused on a shallow region, and the center ceramic element The ultrasonic signal output from the ceramic element formed relatively thick in both directions with reference to 112_c has a low frequency characteristic and becomes a transmission focus in a deep region. Therefore, the low frequency characteristic lacking in the ultrasonic beam output from the center ceramic element 112_c may be compensated by using the low frequency characteristic ultrasonic beams output from both ceramic elements. That is, the resolution of the ultrasound image may be compensated for in a relatively deep region of the object due to the high frequency characteristic of the transmitting ultrasound beam.

While the invention has been described and illustrated by way of preferred embodiments, those skilled in the art will recognize that various changes and modifications can be made therein without departing from the spirit and scope of the appended claims.

10: ultrasonic system 100: ultrasonic probe
200: beam forming unit 300: signal processing unit
400: scan conversion unit 500: image processing unit
600: display unit 111: sound absorbing layer
112: ceramic layer 113, 114: matching layer
120: lens, membrane

Claims (14)

An ultrasonic probe for transmitting and receiving ultrasonic signals,
At least one conversion element each comprising a ceramic layer,
The ceramic layer is an ultrasonic probe consisting of a plurality of ceramic elements of a different thickness. The ultrasonic probe of claim 1, wherein the ceramic layer comprises a first ceramic element and a plurality of second ceramic elements formed in both directions perpendicular to a transmission direction of an ultrasonic signal about the first ceramic element. The ultrasonic probe of claim 2, wherein the plurality of second ceramic elements are formed to be thicker in both directions with respect to the first ceramic element. The ultrasonic probe of claim 2, wherein the plurality of second ceramic elements are formed to be thinner in both directions with respect to the first ceramic element. The ultrasonic probe of claim 2, wherein the ceramic layer is formed of a piezoelectric element. The method of claim 2, wherein the conversion element,
A sound absorbing layer for absorbing the vibration of the ceramic layer and the ultrasonic signal output from the ceramic layer and propagating in a direction opposite to the transmission direction of the ultrasonic signal; And
Matching layer for reducing the acoustic impedance difference between the ceramic layer and the object
Including, an ultrasonic probe. 6. The method of claim 5, wherein the matching layer comprises a first matching layer and a second matching layer, the thickness of the first matching layer and the second matching layer is 1/4 of the ultrasonic wavelength, the first and second matching layer The acoustic impedance value of is an ultrasonic probe, which is the middle value between the acoustic impedance of the ceramic layer and the acoustic impedance of the object. As an ultrasound system,
Ultrasonic probe for transmitting and receiving an ultrasonic signal, including at least one conversion element each comprising a ceramic layer, wherein the ceramic layer is composed of a plurality of ceramic elements of different thickness, ultrasonic system. The ultrasonic system of claim 8, wherein the ceramic layer includes a first ceramic element and a plurality of second ceramic elements formed in both directions perpendicular to a transmission direction of an ultrasonic signal about the first ceramic element. The ultrasonic system of claim 9, wherein the plurality of second ceramic elements are formed thicker in both directions with respect to the first ceramic element. The ultrasound system of claim 9, wherein the plurality of second ceramic elements are formed to become thinner in both directions with respect to the first ceramic element. The ultrasonic system of claim 9, wherein the ceramic layer is formed of a piezoelectric element. The method of claim 8, wherein the conversion element,
A sound absorbing layer for absorbing the vibration of the ceramic layer and the ultrasonic signal output from the ceramic layer and propagating in a direction opposite to the transmission direction of the ultrasonic signal; And
Matching layer for reducing the acoustic impedance difference between the ceramic layer and the object
Including, ultrasonic system. 15. The method of claim 13, wherein the matching layer comprises a first matching layer and a second matching layer, wherein the thickness of the first matching layer and the second matching layer is 1/4 of an ultrasonic wavelength, and the first and second matching layers. Wherein the acoustic impedance value of is an intermediate value between the acoustic impedance of the ceramic layer and the acoustic impedance of the object.

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