JPS6218019B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention electronically controls transmission and reception of ultrasonic waves,
The present invention relates to an ultrasonic device that performs high-speed linear scanning.

In an ultrasonic diagnostic apparatus that obtains tomographic images using ultrasonic waves, a transducer in which a plurality of ultrasonic transducers are arranged in an array at a pitch of d is used as an ultrasonic transducer. A predetermined number of each ultrasonic transducer in this transducer is selected in turn and is responsible for transmitting and receiving ultrasonic waves. For such selection of each ultrasonic transducer, an ultrasonic transducer control device is used.

FIG. 1 is a configuration diagram of a conventionally known ultrasonic transducer control device. This device consists of transducer 1
A plurality of ultrasonic transducers 1 to n in 00 are combined into a set of m pieces (8 pieces in this case), and the transmitting/receiving circuit 2
00, n lead wires led from each of the ultrasonic transducers 1 to n, and m signal wires led from m terminals of the transmitting/receiving circuit 200. A switch is provided at each intersection, and these switches are sequentially closed in a predetermined combination. That is, first, close the 0 mark shown in the diagram and select ultrasonic transducers 1 to m, then close the ◎ mark and select ultrasonic transducers 2 to m+1, and then select them by shifting them one by one in the same way. It is something that will continue.
Each switch is driven by a switch drive circuit 300.

In such devices, the number of switches is
Total number of ultrasonic transducers in transducer 100 n
and the number m of ultrasonic transducers selected at the same time approximately corresponds to the product n,m, so the total number of switches used becomes extremely large. In addition, since a number of switches approximately equal to the total number n of each ultrasonic transducer are connected in parallel to each terminal of the transmitter/receiver circuit 200, a relatively large delay may occur in the transmission characteristics of the transmitter/receiver signal due to the influence of their capacitance. There is a constant, and therefore conventional devices lack high speed.

The present invention aims to provide an ultrasonic transducer control device that reduces the total number of switches used and eliminates the drawbacks of conventional devices.

In the present invention, the ultrasonic transducers in the transducer 100 are grouped according to the ultrasonic transducers to be selected simultaneously without duplication in the order of arrangement, and these are grouped into several matrix circuits having switches only at predetermined intersections. It is designed to be connected to the transmitting and receiving circuit through the transmitter and receiver.

FIG. 2 is a block diagram showing an embodiment of the present invention. In the figure, 100 is a transducer, and 1 to n are ultrasonic transducers constituting this transducer. Lead wires l 1 to _{l o} are led out from these transducers ₁ to n, respectively, and m pieces (eight in this case) equal to the number of transducers to be simultaneously selected are connected from the end of the transducer 100. They are grouped in order of arrangement. Within each group, the lead wire l ₁ ~ from the ultrasonic transducer
l ₈ , l ₉ ~ l ₁₇ ...... is the switch S ₁₁ ~ S ₁₈ , S ₂₁ ~
S ₂₈ ...... m signal lines a ₁ to a ₈ (in this case 8 lines) are connected one-to-one, that is, one lead wire is connected to one signal line via a switch that corresponds to only one signal line. connected. The m signal lines a ₁ to _{a 8} are connected to the m (eight in this case) communication lines b ₁ at the same time.
~ _b8 , and constitutes the first matrix circuit MX1. This first matrix circuit MX
1, switches are provided at predetermined intersections marked with O marks to connect lines that intersect with each other. That is, contact line b ₁ is switch T ₁₁
~ T ₁₄ to signal lines A ₁ to _{A 4} , connection line B ₂ to switch T ₂₁ to signal lines A ₂ to A ₅ through T ₂₄ , and in the same way, connection line B ₈ to switch T It is configured to be connected to signal lines _a8 , _a1 to _a3 , respectively, via lines ₈₁ to _T84 . The m connection lines b ₁ to _{b 8} are connected to m (here, 8) signal processing circuits 2 which are similar to this.
It intersects the terminal wires O ₁ to _{O 8} coming out from 00, and the second
This constitutes the matrix circuit MX2. In the second matrix circuit MX2, switches are provided at predetermined intersections marked with ◯ marks to connect lines that intersect with each other. That is, the terminal wire O ₁ is connected to the connection wires b ₁ and b ₅ via the switches U ₁₁ and U ₁₂ , and the terminal wire O ₂ is connected to the switches U ₂₁ and U ₂₂ .
Connect wires B ₂ , B ₆ through terminal wire O ₃ , switch
The terminal wire O ₈ is connected to the communication lines b ₃ and b ₇ via the switches U ₃₁ and U ₃₂ , and in the same way, to the communication lines b ₈ and b ₄ via the switches U ₈₁ and U ₈₂ , respectively. It is composed of

Figure 3 shows the first matrix circuit MX1 and the second
FIG. 2 is a connection diagram in which the matrix circuit MX2 of FIG.

The first matrix circuit MX1 includes eight sets of four-contact switches T ₁ -T ₈ , and the movable terminals of each switch T ₁ -T ₈ are respectively connected to respective communication lines b ₁ -b ₈ . In addition, the second matrix circuit MX2
includes eight sets of two-contact switches U ₁ to _{U 8} , and the movable terminals of these switches are connected to terminal lines O ₁ to O ₈ from the signal processing circuit 200 . In addition, in these switches, for example, switch T ₁
The corresponding contact 1 or the switch in Fig. 2
Assume that T ₁₁ corresponds to T ₁ and contact 2 such that T ₁₂ corresponds to T 11 .

The operation of the device configured as described above is as follows. Here, an example will be explained in which eight ultrasonic transducers are selected and driven at the same time, and the ultrasonic beam is scanned while shifting them one by one.

The switch control circuit 300 initially controls the switch.
S ₁₁ ~ S ₁₈ , Switch T ₁₁ ~ _{T 81} and Switch U ₁₁
~Close U ₈₁ (connection state shown in Figure 3). When closed like this, the first eight ultrasonic transducers 1~
8 are connected to the terminal wires O ₁ to O ₈ of the signal processing circuit 200, and for example, during transmission, these ultrasonic transducers 1 to 8 emit ultrasonic beams with a directivity center near the center of the whole. be done. Also, during reception, these receive reflected waves. In this state, the first transmission and reception of the ultrasonic beam is performed.

Next, switch S ₁₂ ~ S ₁₈ , S ₂₁ , switch T ₁₂
~T ₇₂ , T ₈₂ , close switches U ₁₁ ~ _{U 81} (second
In the figure, the movable pieces of switches T ₁ to _{T 8} are connected to the contact 2 side). When closed in this way, the ultrasonic transducers 2 to 9 are connected to the terminal wires _O1 to _O8 , and these ultrasonic transducers are now responsible for transmitting and receiving ultrasonic beams. In order, ultrasonic transducers 3 to 10,
4 to 11... are selected in sequence, and the ultrasonic beam can be scanned.

In the first matrix circuit MX1 and the second matrix circuit MX2, switches U ₁ to U ₈ are connected to contact 1 in FIG.
switches T ₁ to _{T 8} connect to contacts 1, 2, 3, and 4 in sequence while switches U ₁ to _{U 8}
is connected to contact 2, switches T ₁ to _{T 8}
This is achieved by sequentially connecting contacts 1, 2, 3, and 4, and then repeating this process.

In the device configured in this way, the total number of switches So is n switches _S11 to _SK8 (n is the total number of ultrasonic transducers), and the first matrix circuit
There are 32 switches T ₁₁ to _{T 84} used in MX1, and 32 switches used in second matrix circuit MX2.
There are 16 U ₁₁ to _{U 82} and can be expressed by formula (1).

So=n+32+16=n+48 (1) In this example, the number of ultrasonic transducers to be selected at the same time is 8, and two sets of matrix circuits are provided, but the number of ultrasonic transducers to be selected at the same time is other than this. If this number increases, more matrix circuits may be provided accordingly.

A general example of cascading two or more matrix circuits will now be described.

As is clear from the above description and the connection diagram in FIG. 3, the functions of multiple sets (l sets) of matrix circuits connected in cascade to each other are as follows: m signal lines a ₁ to a _n and m terminal lines O The purpose is to connect ₁ to O _n in a 1:1 ratio and to switch them in order. Now, as shown in Fig. 3, each matrix circuit is composed of switches with one multi-contact circuit (in the figure, the first matrix circuit MX1 is composed of switches _T1 to _T8 with one circuit of four contacts, and the second The matrix circuit MX2 is composed of switches _U1 to _U8 of two contacts and one circuit), and the number of contacts of each switch constituting the first, second...l matrix circuit _{is n1.} ,n ₂ ,…
………If n _l (number of contacts of switches T ₁ to T ₈ n ₁
is 4, and the number of contacts n ₂ of switches U ₁ to _{U 8} is 2),
Each matrix circuit MX1, MX2……MXl
If we pay attention to the signal paths of switches T ₁ and U ₁ , they are connected in cascade, so equation (2) holds true.

Since m signal paths for each switch T ₁ and U ₁ are provided in parallel, the total number of contacts (which ultimately corresponds to the number of switches provided at the intersections of the matrix) S ₀ can be calculated using equation (3). It is expressed as

In each matrix circuit, how many of the intersections to connect, that is, how many switches (number of contacts) should be determined so that equation (2) is satisfied and equation (3) is minimized. will be selected.

FIG. 5 shows the number m of vibrators to be selected simultaneously and the total number So of switches (minimum case). The larger m is, the more the number of switches can be reduced.

Further, since the number of switches connected in parallel per terminal system of the signal processing circuit 200 is reduced accordingly, the influence of capacitance caused by each switch can be reduced.

Note that although the explanation above has been made on the assumption that the number m of vibrators to be selected at the same time does not always change, this number m may be changed, for example, to 7 or 8. In this case, the scanning pitch of the ultrasonic beam can be made finer.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a conventionally known ultrasonic transducer control device, FIG. 2 is a configuration block diagram showing an embodiment of the present invention, and FIG. 3 is a connection diagram in which the matrix circuit of the circuit in FIG. 2 is rewritten. , FIG. 4 is an explanatory diagram showing the operation of each switch in the apparatus shown in FIG. 2, and FIG. 5 is an explanatory diagram showing the relationship between the number of ultrasonic transducers selected simultaneously and the total number of switches. 100...Transducer, 1-n...Ultrasonic transducer, MX1-MX2...Matrix circuit, 200...Transmission/reception circuit (signal processing circuit), 3
00...Switch drive circuit, S ₁₁ ~S _kn , T ₁₁ ~
T ₈₄ , U ₁₁ ~ _{U 82} ... switch.

Claims (1)

[Claims] 1. Using a transducer in which a plurality of ultrasonic transducers (n pieces) are arranged, some (m pieces) of the plurality of ultrasonic transducers are simultaneously selected as one set. In a device that electronically scans an ultrasonic beam by sequentially shifting this set, n lead wires l ₁ to l _o led from the plurality of ultrasonic transducers; m signal lines a ₁ to _{a n} equal to the number of ultrasonic transducers to be selected at the same time, and n switches for sequentially connecting the n lead wires to the m signal lines every m. S ₁₁ ~ _{S kn}
and a first matrix circuit MX1 composed of the m signal lines a ₁ to a _n and m connection lines b ₁ to b _n that intersect with these signal lines, and the first matrix circuit n _i (n ₁ < m ² ) switches T ₁₁ to _{T 84} that are connected only at predetermined intersection points at the intersections of the m signal lines and the m connection lines.
, a second matrix circuit MX2 composed of the m connecting lines b ₁ to b _n and m terminal lines O ₁ to _{O n} intersecting these connecting lines; and the second matrix circuit n ₂ (n ₂ < n ₁ ) switches U ₁₁ to U ₈₂ that are connected only at predetermined intersections at the intersections of the m connection lines and the m terminal wires.
and a signal processing circuit 200 coupled to the plurality of ultrasonic transducers via the m terminal wires, the second and first matrix circuits, and turning on and off each of the switches in a predetermined combination. An ultrasonic device comprising: a switch drive circuit 300 for scanning an ultrasonic beam from the ultrasonic transducer.