JPS62179440A - Ultrasonic probe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention connects to a medical ultrasound diagnostic device, converts electric pulses from the device into ultrasound, emits it to a living body, and transmits ultrasound from inside the living body. 1 for converting sound wave echoes into electrical signals
~ Concerning an ultrasonic probe that is a lance deuser.

[Technical background of the invention and its problems] Generally, in order to converge the ultrasound beam in this type of ultrasound probe, a convex lens or a concave lens whose cross-sectional profile curve is hyperbolic is used. The conditions for
The acoustic impedance 2<=ρC) expressed by is the acoustic impedance of the biological epidermis 1.55 to 1.6X10 BK!
Be as close as possible to J/rd-set.

■ The speed of sound is not the same as the sound speed of a living body, which is 1530 m/sec, but is as different as possible (if the sound speed is slower than that of a living body, it will be a convex lens, and if it is faster, it will be a concave lens).

■ Attenuation of ultrasonic waves should be as small as possible.

■ Low permeability of gases and liquids such as water vapor.

etc. can be mentioned.

Therefore, conventional ultrasonic probes use silicone rubber as a lens (acoustic impedance Z = 1 to 1° 5 x 10θ at 3/rd-sec, sound velocity C'' = 1000 m/sec
, ultrasonic attenuation is 5) IH2, 4 dB/s, water vapor transmission rate is approximately 10 to 100 times that of plastic, etc.),
Since the speed of sound is slower than that of living organisms, a convex lens was used. Diagnosis was then performed by bringing this ultrasound probe into direct contact with a living body.

However, in ultrasonic diagnosis, as shown in FIG. When the surface of the rubber membrane 4 is used against a living body after being closed with a conventional ultrasonic probe, when used for a long period of time, water vapor may pass through the lens 5 due to the high water vapor permeability of silicone rubber. This has the disadvantage that it acts on the acoustic material and causes performance deterioration such as softening of the resin used in the acoustic matching layer. Another problem with silicone rubber is that it has a large attenuation of ultrasonic waves.

[Object of the Invention] The present invention has been made in view of the above circumstances, and uses an acoustic lens that has the lowest possible gas permeability and water permeability, and also has the lowest possible attenuation of ultrasonic waves. The purpose of the present invention is to provide an ultrasonic probe that is optimal for ultrasonic diagnosis using acoustic media such as.

[Summary of the Invention] A summary of the present invention for achieving the above object is that in an ultrasonic probe equipped with an acoustic lens that collects an ultrasonic beam, the acoustic lens is formed of plastic.

[Embodiments of the invention] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an example of the ultrasonic probe of the present invention, in which 10 is a case, and 11 is an acoustic lens attached closely to the case 10.

As shown in FIGS. 2 and 3, the acoustic lens 11 is formed as a concave lens with a hyperbolic concave portion 12 formed on its upper surface, and is made of plastic such as low-density polyethylene, ethylene vinyl acetate, polymethylpentene, or the like. All of these plastics have an acoustic impedance of about 1.7 to 1.
75X10BKg/ TIt-sec, sound speed is approximately 20
00 m/sec (for this reason, it is formed as a concave lens), and the attenuation of the ultrasonic wave is 2.5 to 4 d at 58H2.
B/s is smaller than silicone rubber. Also, the gas permeability is about 1/100 of that of silicon. acoustic lens 11
On the inside thereof, acoustic matching layers 13 and 14, a piezoelectric vibrator 15, and a back damping material 16 are sequentially arranged with an adhesive layer 17 in between. The piezoelectric vibrator 15 is for mutually converting electric signals and ultrasonic waves, and has electrodes 15a, 15a provided on both sides.
is connected to a medical ultrasonic diagnostic apparatus (not shown) via a cable 18 (see FIG. 1). The back damping material 16 plays the role of sending out short pulses from this piezoelectric sensor 15, and the acoustic matching layer 13.
This is to efficiently radiate ultrasonic waves from the body to the living body.

Now, the above-mentioned ultrasonic probe is used by being connected to a medical ultrasonic diagnostic device using the cable 18 as mentioned earlier, and converts electric pulses from the device into ultrasonic waves using the piezoelectric vibrator 15. The acoustic lens 11 efficiently converges the ultrasonic beam and radiates it to the living body, and the piezoelectric vibrator 1 converts the ultrasonic echo from inside the living body into an electrical signal, which can be transmitted to a medical diagnostic device.

Since the acoustic lens 11 is made of plastic such as the low-density polyethylene, the attenuation of ultrasonic waves is small and the gas permeability is very low, especially when used in liquid as shown in FIG. However, there is no performance deterioration due to liquid intrusion, etc., and the initial characteristics can be maintained.

Although one embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to the above-mentioned embodiment, and can be modified and implemented as appropriate within the scope of the gist of the present invention.

[Effects of the Invention] As detailed above, according to the present invention, since the acoustic lens is made of plastic, gas permeability and water permeability can be reduced, and ultrasonic attenuation can be reduced.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of the ultrasonic probe of the present invention;
Figure 2 is a partial perspective view of the same as above, Figure 3 is a cross-sectional view of Figure 2,
FIG. 4 is a diagram illustrating the state of use, and FIG. 5 is a diagram illustrating the state of use of a conventional ultrasonic probe. 11... Acoustic lens. Agent Patent Attorney Nori Chika Ken Shu
Norio Ogo 1st Officer\

Claims (2)

[Claims] (1) An ultrasonic probe equipped with an acoustic lens for collecting an ultrasonic beam, characterized in that the acoustic lens is made of plastic. (2) The ultrasound probe according to claim 1, wherein the acoustic lens is made of low density polyethylene, ethylene vinyl acetate, or polymethylpentene.