Patent Application
20130190627
This application claims the benefit of Korean Patent Application No. 10-2012-0006227, filed on Jan. 19, 2012 in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference.
1. Field
Exemplary embodiments of the present disclosure relate to a probe for an ultrasonic diagnostic apparatus which may increase sensitivity of the probe, and a method of manufacturing the same.
2. Description of the Related Art
An ultrasonic diagnostic apparatus is a noninvasive apparatus that transmits an ultrasound signal to a body surface of a subject towards a target organ in the body and obtains cross-sectional images of soft tissue and blood flow using information from a reflected ultrasound signal. Compared to other medical imaging systems such as, for example, X-ray imaging systems, computed tomography (CT) scanners, magnetic resonance imaging (MRI) systems and diagnostic systems for nuclear medicine, the ultrasonic diagnostic apparatus may have a compact size and low price, display images in real time, and provide a high level of safety by eliminating exposure to radiation such as X-rays. For at least these reasons, ultrasonic diagnostic apparatuses have been widely used for diagnosis in many medical disciplines such as, for example, cardiac medicine, abdominal imaging, urology, obstetrics and gynecology.
An ultrasonic diagnostic apparatus includes a probe which transmits an ultrasound signal to a subject and receives an ultrasound echo signal reflected from the subject to obtain an ultrasound image of the subject.
A probe for an ultrasonic diagnostic apparatus may include a transducer, a case with an open upper end, and a cover coupled to the open upper end of the case to directly contact a surface of the subject.
The transducer may include a piezoelectric layer composed of piezoelectric materials which converts an electric signal into an acoustic signal, and vice versa, through vibration of the piezoelectric materials, an acoustic matching layer for reducing a difference in acoustic impedance between the piezoelectric layer and the subject to improve the transferability of ultrasonic waves generated in the piezoelectric layer to the subject, a lens layer for focusing the ultrasonic waves traveling away from a front of the piezoelectric layer on a given point, and a backing member for blocking the ultrasonic waves from traveling in an opposite direction through a rear of the piezoelectric layer to prevent image distortion.
In order to increase attenuation of the acoustic impedance of the backing member, powder, a network sheet, and a porous sheet in combination with an epoxy resin has been used. However, in such a configuration, the powder may not be regularly distributed, and it may be difficult to produce powder with a uniform size. Further, pores that are unexpectedly produced inside the epoxy resin are a characteristic that is uncontrollable and not predetermined during mass production, and thus may cause efficiency to vary from one product to another.
Therefore, it is an object of the present disclosure to provide a probe for an ultrasonic diagnostic apparatus which may increase attenuation of the acoustic impedance of a backing member of the probe to enhance performance efficiency of the probe, and a method of manufacturing the same.
Additional aspects of the disclosure will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned from practice of the disclosure.
In accordance with one aspect of the present disclosure, a probe for an ultrasonic diagnostic apparatus includes a case, a piezoelectric member provided inside the case, at least one acoustic matching layer disposed at a front of the piezoelectric member, an acoustic lens disposed at a front of the at least one acoustic matching layer, and a backing member disposed at a rear of the piezoelectric member and provided with a plurality of pores to reduce sound waves transmitted to the rear of the piezoelectric member and to adjust acoustic impedance.
The pores may be formed through the backing member.
The pores may be arranged in a predetermined pattern.
The backing member may further include at least one empty particle formed of glass with a hollow inside.
The backing member may include at least one empty particle formed of glass with a hollow inside to form the pores.
The backing member may include glass particles in a proportion over a certain proportion to control attenuation, hardness and density of the backing member.
Upper and lower sides of the piezoelectric member may be provided with an electrode to provide an electric signal to the piezoelectric member, and a printed circuit board (PCB) may be provided between the electrodes and the backing member to connect electrically the electrode and a main body of the ultrasonic diagnostic apparatus.
The backing member may include a backing layer positioned at a lower side of the PCB and a backing block positioned at a lower side of the backing layer.
In accordance with another aspect of the present disclosure, a method of manufacturing a backing member used for a probe for an ultrasonic diagnostic apparatus includes pouring a fluid forming the backing member into a mold including a mold base provided with sticks having a shape corresponding to pores to be provided in the backing member and a mold guide to form an outer shape of the backing member, hardening the fluid poured into the mold, and removing the mold.
The sticks provided in the mold base may be regularly arranged.
The fluid forming the backing member may include at least one hollow particle to form pores in the backing member.
The fluid forming the backing member may further include at least one glass particle.
The hardening may be performed at a temperature between about 30° C. and about 100° C.
In accordance with another aspect of the present disclosure, a probe for an ultrasonic diagnostic apparatus includes a piezoelectric member, at least one acoustic matching layer disposed at a front of the piezoelectric member, and a backing member disposed at a rear of the piezoelectric member, the backing member may include a plurality of first pores arranged and configured according to a predetermined design.
At least one of the plurality of first pores may extend through the backing member from a first outer surface of the backing member to a second outer surface of the backing member.
At least one of the plurality of first pores may have a columnar shape.
The backing member may further include a plurality of second pores arranged in different portions of the backing member than the plurality of first pores.
At least one of the plurality of second pores may include at least one empty particle formed of glass with a hollow inside.
The backing member may further include at least one glass particle.
The backing member may include an epoxy resin and the backing member may further include a plurality of second pores arranged in the epoxy resin.
These and/or other aspects of the disclosure will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
Reference will now be made in detail to exemplary embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
As shown in
The acoustic lens (6), acoustic matching layers 2 and 3, piezoelectric member 4 and backing member 10 may be arranged in this order from a front face of the transducer.
The piezoelectric member 4 may be positioned inside the case (100), and connected to a front surface of the backing member 10. The piezoelectric member 4 is provided with electrodes (7) on opposite lateral sides thereof for converting an electric signal into an ultrasonic wave, i.e., an acoustic signal which is sent into the living body, and for converting an ultrasonic wave reflected from the living body into an electric signal which is sent to the apparatus.
The piezoelectric member 4, which generates an ultrasonic wave using the phenomenon of resonance, may be composed of, for example, lead zirconate titanate (PZT) ceramics, PZNT single crystals made of a solid solution of lead zinc niobate and lead titanate, PZMT single crystals made of a solid solution of lead magnesium niobate and lead titanate, or the like, or a combination thereof.
The electrodes (7) disposed on opposite lateral sides of the piezoelectric member 4 may be composed of a metal with high conductivity such as, for example, gold, silver and/or copper, or may be composed of a graphite, or the like.
The acoustic matching layers 2 and 3 are installed on a front of the piezoelectric member 4. The acoustic matching layers 2 and 3 serve to match the acoustic impedance of the piezoelectric member 4 with that of a subject to effectively transfer an ultrasonic signal generated by the piezoelectric member 4 to the subject. To this end, the acoustic impedance of the acoustic matching layers 2 and 3 may be adapted to have a middle value between the acoustic impedances of the piezoelectric member 4 and the subject.
The acoustic matching layers 2 and 3 may be f composed of glass or a resin material, or a combination thereof. Alternately, a plurality of acoustic matching layers composed of different materials may be provided to allow the acoustic impedance to gradually vary from the piezoelectric member 4 to the subject.
A printed circuit board (PCB) 5 may be arranged between the backing member 10 and the piezoelectric member 4. The PCB 5 is provided to convert an electric signal generated at the electrodes (7) into an ultrasonic signal and vice versa. The PCB 5 may be disposed perpendicular to the direction in which the backing member 10 and the piezoelectric member 4 are stacked. In addition to a printed circuit board, the PCB 5 may include other constituents such as, for example, a flexible printed circuit board (FPCB) adapted to supply signals or electricity.
An acoustic lens (6) is disposed on a front of the acoustic matching layers 2 and 3. The acoustic lens (6) focuses an ultrasonic signal traveling forward from the piezoelectric member 4 on a given point.
The backing member 10 is disposed at a rear of the piezoelectric member 4. The backing member 10 reduces a pulse width of an ultrasonic wave by suppressing free vibration of the piezoelectric member 4, and prevents image distortion by blocking unnecessary propagation of the ultrasonic wave in a rearward direction of the piezoelectric member 4.
The backing member 10 includes pores 11 to reduce the density of the backing member 10. The pores 11 not only reduce the density of the backing member 10, but also reduce sound waves transferred to the backing member 10. The pores 11 may be formed through the backing member 10. Also, the pores 11 may be arranged in a predetermined pattern.
According to one exemplary embodiment of the present disclosure, the pores 11 are arranged in lengthwise and widthwise directions with a uniform interval therebetween. However, embodiments of the present disclosure are not limited thereto. The pores 11 may be arranged with a narrower and/or wider interval therebetween than the interval shown in
The shape and interval of the pores 11 may vary depending on the shape of a mold base 30, which will be described later.
Since the backing member 10 includes the pores 11, the density of the backing member 10 is lowered, which is related to acoustic impedance. The acoustic impedance is an indicator of the acoustic characteristics of a medium through which sound travels. When the acoustic impedance is Z, the density of the medium is p, and sound speed is C, the acoustic impedance is expressed by the following equation.
Acoustic impedance (Z)=Density of medium(ρ)+Sound speed(C).
For the backing member 10 to effectively prevent an ultrasonic wave from being unnecessarily propagated in the rearward direction of the piezoelectric member 4, the acoustic impedance of the backing member 10 should be adjusted for a particular application. Accordingly, the backing member 10 should be manufactured such that the acoustic impedance of the backing member 10 is high or low according to the acoustic design. When the backing member 10 includes the pores 11 as in the present disclosure, the density of the backing member 10 may be adjusted by adjusting the number of pores 11 in the backing member 10. Thereby, as the acoustic impedance of the backing member is allowed to be adjusted as intended by the designer, a flexible design may be enabled in terms of acoustic impedance. Further, the pores 11 of the backing member 10 may serve to absorb vibration generated by the piezoelectric member 4.
The backing member 10 may be composed of a material including an epoxy resin.
As shown in
The probe 1 may be of a linear type which has a linear surface, or of the convex type which has a convex surface formed in a curved shape.
As shown in
The upper and lower sides of the mold guide 20 have openings, and the mold base 30 is coupled with the mold guide 20 to form a bottom. A fluid to form the backing member 10 is poured into the opening on the upper side of the mold guide 20.
The sticks 31 of the mold base 30 may be provided in various shapes and with various arrangements, and the pores 11 of the backing member 10 may be formed in various shapes and with various arrangements that are predetermined. Because the pores 11 are defined by the sticks 31 of the mold base 30, the pores 11 of the backing member 10 may be regularly arranged. Accordingly, when the pores 11 of the backing member 10 are made using the mold (e.g., mold guide 20 and mold base 30), the pores 11 may be provided with a regular arrangement, pattern and shape that are predetermined in contrast with conventional cases in which powder was used. Since the arrangement, pattern and shape of the backing member 10 may be altered by changing the shape, arrangement and pattern of the sticks 31 of the mold base 30, it may be possible to provide a proper impedance value to the backing member 10 according to purpose.
The pores 12 may include particles formed of glass with a hollow inside. Since the insides of the particles 12 are empty, the particles 12 may increase attenuation of a sound wave propagated through the backing member 10.
Further, if the empty particles 12 and glass particles 13 are mixed in a certain ratio, it may be possible to control the degree of attenuation, hardness, and density of the backing member 10 simultaneously. That is, it may be possible to adjust the acoustic impedance.
When the pores 12 are formed using the empty particles, the backing member 10 may have a low density and provide more effective attenuation of ultrasonic waves.
As shown in
In addition to the operations above, one or more additional operations may be added by one of ordinary skill in the art.
The operation of preparing a fluid (S100) includes preparing an epoxy resin which is a material used for the backing member 10. Also, when including the additional pores 12 shown in
The operation of pouring the prepared fluid into a mold (S200) includes pouring the fluid into the mold configured with the mold guide 20 and the mold base 30. The mold guide 20 and the mold base 30 are allowed to be coupled with each other, and the mold base 30 is provided with the sticks 31 having a shape corresponding to that of the pores 11 to be provided in the backing member 10. The sticks 31 provided at the mold base 30 may be regularly arranged and the pores 11 formed in the backing member 10 are provided with a shape corresponding to the sticks 31 of the mold base 30.
In the operation of hardening the mold (S300), the fluid in the mold is hardened in the shape of the backing member 10 with the pores 11. The fluid is hardened at a temperature between about 30° C. and about 100° C.
Thereafter, the operation of removing the mold (S400) is performed, and the backing member 10 is manufactured. The backing member 10 with the pores 11 regularly arranged may be obtained by removing the mold guide 20 and the mold base 30.
As is apparent from the above description, because of pores provided in a backing member, efficiency of a probe for an ultrasonic diagnostic apparatus may be increased by increasing attenuation of the acoustic impedance of a backing member, and a backing member with low density and low weight may be manufactured.
Although a few embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2012-0006227 | Jan 2012 | KR | national |
