JPS6346145A - Ultrasonic endoscope apparatus - Google Patents

Abstract

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

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is an ultrasonic device for medically observing the inside of a body cavity using a plurality of ultrasonic transducers (hereinafter simply referred to as "1 transducer"). The present invention relates to a sonic endoscope device, and in particular to a receiving circuit of this device.

[Conventional technology]

For example, as disclosed in Japanese Patent Application Laid-open No. 11026/1983, an endoscope apparatus has been proposed in which two transducers having different frequencies are installed in one ultrasonic probe tζ. There is. One of these transducers has a higher resonant frequency than the other (C), and is therefore designed to be focused at a short distance.Such a transducer has a gold drive. Images obtained from transducers with respective characteristics are combined to obtain image information from short distances to long distances.

[Problem that the invention seeks to solve]

In the conventional endoscope apparatus described above, two transducers are simultaneously driven to collect and synthesize ultrasonic echo information. Therefore, since two sets of transmitting and receiving circuits are required, there is a disadvantage in that it is structurally difficult to incorporate into an endoscope system compared to an extracorporeal ultrasonic diagnostic device. That is, there is a drawback that miniaturization cannot be achieved.

Furthermore, since two transducers are driven simultaneously, there is a problem in that ultrasonic echoes (reflected waves) from one transducer mix into the other transducer as noise. That is, when receiving echo signals from both transducers, the characteristics of these signals are different, so that they appear as noise on the image.

Therefore, an object of the present invention is to provide an ultrasonic endoscope apparatus that eliminates the various drawbacks of the conventional apparatus described above and prevents noise from entering the apparatus.

[Means and effects for solving the problems] The present invention has the following features:
Installing multiple transducers with different ultrasonic characteristics,
A common receiving circuit is connected to these transducers via a common switch means, and a transmitting circuit is also connected to each transducer. The present invention is characterized in that only a predetermined one of the transducers is activated, and the remaining transducers are placed in a non-operational state.

According to the present invention, it is possible to prevent the mixing of signals from other transducers.

〔Example〕

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a circuit diagram of an embodiment of the ultrasonic endoscope apparatus of the present invention.

Two transducers 1 and 2 having different ultrasonic characteristics, such as resonance frequencies, are rotatably provided, and these transducers 1 and 2 are connected to a common reception amplifier 4 via a switch means 3. The transducers 1 and 2 are also connected to transmitter circuits 5 and 6 that generate drive (drive, excitation) signals whose frequencies are tuned to their own resonant frequencies, respectively. These transmission circuits 5 and 6 are connected to a transmission selection circuit 7, which is connected to a transducer selection switch 8, and also to an observation device (hereinafter referred to as a monitor) 9.

This transducer selection switch 8 is also connected to the switch means 3, so that a predetermined transducer 1 can be selected.
or 2 is designed to operate the corresponding transmission circuit 5 or 6 via the transmission selection circuit 7.

Also, a transmission signal from the monitor 9 is sent to the transmission selection circuit 7. A connection line from transducer selection switch 8 to monitor 9 is for displaying the resonant frequency of the currently selected and driven transducer.

Switch Means Next, with reference to FIG. 2, a specific circuit of the switch means 3, which is a feature of the present invention, will be explained.

The basic configuration of FIG. 2 consists of two sets of transducers Tr,
(corresponding to 1 in Fig. 1) and Tr, (corresponding to 2 in Fig. 1), respectively, a diode switch circuit (D, , D, :D, , D4)'J? and a switching transistor control circuit (Tl +
Tl + Tl ) are connected.

Next, the operation when the transducer Tr is selected will be explained.

First, when the switch SWX is open, the diode (DN
The current flowing through the junction) causes a photoelectric current to flow in the capacitor C8 connected to these common paces, so that the supply voltage at point D, +vco, of this capacitor C,:d,
At this time, these transistors T, , T
, becomes reverse biased and becomes OFF'. One transistor T, is grounded (GND) through the path of resistor R4, diode D1, inductance L1, resistor R1, and resistor R,,R, so the potential at point F (i.e., collector potential) is grounded. level.

From point B, the drive signal for the transducer Tr is connected so that it is input to the transmission selection circuit 7, but as described above, at present, the drive signal for the other transducer Tr is input.
Since rl is selected, no drive signal is supplied.

On the other hand, since the transistor T is in the OFF' state, its collector is connected to the ground level by the resistor R. As a result, the transistor T1 has resistors R,,R
, and is turned ON because a forward bias is applied thereto. If we set the resistor R1 as Rs '' R* << Rs and consider that the ON resistance of the transistor T1 is small, the potential at point E will be R,, Dl, L, , R1 and R1°D2 .
It is determined by the current flowing through R.

Diode D1. D and D form a diode switch, and since the forward direction pipes are applied to these as described above, the signal from the transducer Tr1 driven through the A point is output to the output point C. will be done. This output is amplified to a predetermined level by the reception amplifier 4 shown in FIG. 1, and displayed as an ultrasound image on the monitor 9.

In this case, considering the DC potential, point F is at ground level,
Since point E is at a certain positive potential, a reverse bias is applied to the other diode switches D, . . . D4, and the diode switches D, .

As a result, the received signal from the transducer Try is
It is not supplied to output point C.

Next, when switch SW8 is closed, transistors T, .
The pace of T is grounded through a resistor R1°.

As a result, a forward voltage is applied to the transistor, which turns it on, and furthermore, the diode switch D
3+D4 are both in a forward bias state. As a result, the received signal of the transducer Trl becomes K so that it is supplied to the output point CK. In this case, the transistor T, is O
Since they are in the N state, the potentials of the resistors R6 and Ro are approximately equal to the power supply voltage, that is, the potential at point D, but there is a voltage drop corresponding to the ON resistance of the transistor T. This causes the current flowing through the pace of transistor T8 to
The resistor R1 can prevent this transistor T1 from being turned on. As a result, the transistor T1 is turned off and the potential at the point E is at the ground level, so the diode switches D, D, are reverse biased, and the signal from the transducer Trl is not supplied to the output point C.

Figure 3 shows that the inductor LL, resistor R1, and capacitor C1 on the cathode side of the switching diode D are combined with the equivalent circuit of the transducer Tr1 (circuit configuration shown in Figure 3) to function as matching during transmission. It represents the state of

The same applies to the other transducer Tr2, so the explanation will be omitted.

By the above circuit operation, the ultrasonic reception signal obtained at the output point C becomes the state shown in FIG. 4A, and it becomes clear that noise can be prevented from being mixed in compared to the conventional reception signal shown in FIG. 4B.

Modification also includes a diode switch D1. If each of the diodes D, , Dl, and D4 is configured with a diode with a high reverse withstand voltage, reception will be performed only on one side without switching the transmitting circuits 5 and 6, so if noise intrusion is reduced to a certain extent, , the transmission selection circuit 7 can be omitted.

Further, these transducers may have the same resonant frequency and different focal lengths, or may have the same focal length and different resonant frequencies. Further, it is also possible to employ lenses having different resonance frequencies and focal lengths. It is possible to increase the number not only by two but also by more.

The switch SW1 for switching the transducer can be provided on the endoscope or on the monitor.

〔Effect of the invention〕

As described in detail above, according to the present invention, there is an effect that it is possible to prevent reception signals from other than the desired transducer from being mixed in. Further, the structure of the receiving circuit becomes simple, and there is an advantage that a high quality image without noise contamination can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a linear diagram showing a circuit of an embodiment of the endoscope apparatus of the present invention, FIG. 2 is a circuit diagram showing a circuit of the switch means in FIG. 1, and FIG. 3 is a diode switch. FIG. 4 is a circuit diagram showing the main and prong states of the transducer, and FIG. 4 is a received signal waveform diagram according to the conventional method and the present invention. 1 + 2 + T rl * T r2... Transducer, 3... Switch means, 4... Reception amplifier, 5.6... Transmission port weight 7... Transmission selection circuit, 8.
...Transducer selection switch, 9...Monitor,
D, ~D4...Diode switch, T1~T,...
・Switching transistor. Applicant's agent Patent attorney Atsushi Tsuboi L-11111 Figure 3 Figure 4B--m--- Procedural amendment 62.5.14 Showa date

Claims (4)

[Claims] (1) A plurality of transducers (ultrasonic transducers) with different ultrasonic characteristics provided at the tip of the endoscope, a plurality of transmitting circuits that drive each of these transducers, and a predetermined In an ultrasonic endoscope apparatus comprising a switch means for selectively switching and outputting received echo signals from only the transducer, and a selection control means for selectively controlling the switch means, an ultrasonic endoscope apparatus comprising: An ultrasonic endoscope apparatus, characterized in that, by switching and operating the switch means, only the received echo signal from a predetermined transducer can be received as an output signal. (2) The ultrasonic endoscope apparatus according to claim 1, wherein the switch means is constituted by a diode switch. (3) The ultrasonic endoscope apparatus according to claim 1, wherein the switch means is provided within an endoscope. (4) Claim 1, characterized in that the switch means is provided in an observation device used in combination with an endoscope.
The ultrasonic endoscope device described in Section 1.