JPS5944051B2 - ultrasonic probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic probe used in an electronic scanning ultrasonic diagnostic apparatus, particularly in which noise caused by electrostatic induction generated between a signal electrode of an array-type ultrasonic probe and a human body is reduced.

Conventionally, as shown in FIGS. 1 and 2, as an array type ultrasonic probe, a small rectangular transducer 4 having a negative electrode 2 and a positive electrode 3 fixed to both sides of a piezoelectric element 1 is mounted in a straight line. In addition, the transducer array is arranged in an array shape at equal intervals, and the ultrasonic propagation material 5 and the acoustic lens 6 are attached to the surface of the transducer array that is touched by humans, and the sound absorbing material T is attached to the opposite surface. It has been known.

Since the transmission and reception of ultrasonic waves by this array type ultrasonic probe is carried out by each small transducer separately, the electrodes of the small transducers are individually connected to a drive circuit and a drive circuit using conductors 8 and 9. However, the conductor wires are normally connected to the electrodes of such a small vibrator by soldering, and the conductor wires 8 and 9 are connected to the electrodes of such a small vibrator as shown in Figure 1. In a structure in which the electrodes are taken out from both sides, the acoustic wave characteristics are impaired due to soldering to the surface that has piezoelectric properties, and manufacturing is not easy. A so-called single-sided electrode method is used in which the conductor wire can be drawn out. That is, the positive electrode 3 of the vibrator element 4 extends from the bottom surface of the piezoelectric element 1 around the side surface to a part of the top surface, and the negative electrode 2 extends from the end of the positive electrode 3 on the top surface of the piezoelectric element 1 with a small gap. Electrodes are attached extending to the bottom of the other side of the piezoelectric element 1, and covered conductor wires 8 and 9 are soldered to the respective electrodes at both ends of the upper surface and lead to the drive circuit and the reception circuit. . A filler 10 (see FIG. 1) is filled between each element of the transducer array consisting of four groups of transducer elements to form a transducer plate, and an ultrasonic propagation material 5 is provided on the upper surface, that is, the sound wave emitting surface. The impedance between the transducer and the human body is fixed by attaching a pine needle, and an acoustic lens 6 (the drawing shows the case of a concave lens) is provided on the upper surface of the transducer plate to focus the sound waves in the short axis direction of the transducer plate. ing. Further, a sound absorbing material T is attached to the back surface of the vibrator plate to absorb sound waves emitted from the back surface. The vibrator 4 having such a structure is installed in a probe case 12 having a shield member 11 on the inner wall thereof, and a gap around the probe case 12 is filled with a filler material 13 and fixed thereto. Such a probe irradiates the human body and emits ultrasonic waves,
In sector scanning, the direction of the emitted ultrasonic waves is changed by changing the phase of the excitation signal of each vibrator element to be excited, and the sound waves are focused in the long axis direction. It is obtained by combining the signals with the ultrasound direction and focusing delay.

In addition, in linear scanning, a combination of multiple vibrator elements to be excited is sequentially addressed to one vibrator element, and the ultrasonic wave is emitted by applying a phase change to the vibration signal of each vibrator element for focusing, and the received wave is transmitted to each vibrator element. However, as mentioned above, the ultrasonic propagation of the probe! Since the material 5 and the acoustic lens 6 are made of insulators such as synthetic resin materials, the part that goes around the top of the positive electrode or the conductor wire soldered to this causes electrostatic coupling with the human body and is unnecessary. The induced signal mixes into the received ultrasound signal,
This lowers the S/N ratio for signals that are absorbed and attenuated, such as signals reflected from deep parts of the human body, resulting in unclear ultrasonic images of deep parts and hindering diagnosis. The purpose of this invention is to provide an array type ultrasound probe for an electronic scanning ultrasound diagnostic device that eliminates such drawbacks. Below, this invention will be explained in detail based on FIG. 3, which shows an example of the invention. Describe.

In a vibrator element 4 in which electrodes 2 and 3 are attached to a piezoelectric element 1, the positive electrode 3 extends from the bottom surface of the piezoelectric element 1 around one side to a part of the top surface, and the negative electrode 2 extends from the bottom surface of the piezoelectric element 1 to a part of the top surface. A single-sided electrode system is used in which electrodes are attached from a part spaced apart from the end 3a to the other side surface, and a filler (
(corresponding to Fig. 1, not shown) to form a transducer plate, and a sound-absorbing material 7 for absorbing ultrasonic waves emitted from the back surface of the element is pasted on the back side.Both electrodes of each transducer element To attach the conductor to the sound absorbing material 7, solder the covered conductor at the end of the top surface.
The positive electrode 3 is connected to a signal terminal for transmitting and receiving waves, and the negative electrode 2 is connected to a ground terminal. On the other hand, an ultrasonic propagation material 5 is provided on the surface of the transducer plate, that is, the ultrasonic emission surface.
, and perform impedance matching between the transducer and the human body.Furthermore, an acoustic lens 6 (the drawing shows a concave lens) is attached to the top surface of the transducer plate, and the sound waves are focused in the short axis direction of the transducer plate. However, as mentioned above, the part of the positive electrode 3 on the ultrasonic radiation side generates electrostatic coupling with the human body and captures the induced signal, so to prevent this, the piezoelectric layer on the top surface of the electrode A conductor 15 insulated with an insulator 14 is provided on the surface of the conductor 9 placed on the inactive part and on the side, and this conductor 15 is connected to the conductor 16 and grounded to perform electrostatic shielding.〇Such an insulated conductor The body 15 is formed, for example, by applying a soft epoxy resin to the electrodes and conductive wires to form an insulating film, applying a conductive adhesive to the surface of the insulating film to form a conductive film, and then forming an insulating film on top of that. Since it is made of a resin similar to the ultrasonic propagation material 5, it is possible to block static electricity without impairing the sound wave characteristics.As described above, the present invention resides on the ultrasonic emission surface side of the vibrator. By electrostatically shielding the positive electrode, which is the signal electrode, with an insulated conductor made of the same resin as the ultrasonic propagation material, the induced signal is prevented from electrostatic coupling with the human body. The present invention provides an array-type ultrasonic probe that can clearly image an ultrasonic surface image of a deep part without being exposed to radiation, and greatly contributes to diagnosis.

[Brief explanation of the drawing]

Fig. 1 is a partial perspective view showing an example of a conventional probe, Fig. 2 is a sectional view showing another example of the conventional probe, and Fig. 3 is a sectional view showing an example of the present invention.・Piezoelectric element, 2, 3・
... Electrode, 4 ... Vibrator element, 5 ...
...Ultrasonic propagation material, 6...Acoustic lens, 7.
...Sound absorbing material, 8,9...Conductor wire, 11...
...Shield member, 12...Case, 10
, 13... filler, 14... insulator,
15... Conductor.

Claims (1)

[Claims] 1. A conductor made of conductive adhesive coated with resin is placed in a grounded state on the signal electrode of the piezoelectric inactive part of the vibrator array of the single-sided electrode type vibrating element and the top surface of its conductor wire, so that the signal electrode and the human body are connected. An ultrasonic probe characterized by preventing electrostatic induction that occurs between the probes.