JPH021247A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

PURPOSE:To obtain a small-sized low cost ultrasonic diagnostic apparatus enhanced in the S/N ratio of ultrasonic data by making it possible to use an ultrasonic probe, wherein the number of ultrasonic vibrators are less than the number of the channels of a transmitting-receiving circuit, like an ultrasonic probe for mechanical scanning other than an ultrasonic probe for electronic scanning. CONSTITUTION:When an ultrasonic probe 17 for mechanical sector scanning is mounted on an apparatus main body, the probe 17 is confirmed by the driving condition setting means 15 in a CPU 13 and mechanical sector scanning is executed under the control of a transmitting-receiving control means 12. Four pulsers among many ones 3-1-3-m are connected in parallel with respect to the respective ultrasonic vibrators of the ultrasonic probe 17 in the transmission of an ultrasonic wave and four preamplifiers among many ones 6-1-6-m are connected in parallel in the reception of the ultrasonic wave. The respective vibrators are driven in parallel at the time of transmission by four transmission channels and the same ultrasonic echo is received at the time of reception by four receiving channels. Therefore, the load driving capacity of the transmission system and the S/N ratio of the receiving system are enhanced.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an ultrasound system that collects reflected components of ultrasound waves transmitted toward a subject and uses the reflected components from the subject for diagnosis. Related to diagnostic equipment.

(Prior Art) In an ultrasonic diagnostic apparatus, ultrasonic waves are transmitted toward a subject by applying a drive pulse (also called an excitation pulse), and reflected components (ultrasonic echoes) from the subject are transmitted.
It is equipped with an ultrasonic probe that receives the waves.

In an actual ultrasonic diagnostic apparatus, a plurality of different types of ultrasonic probes are prepared and used appropriately depending on the region to be diagnosed and the purpose.

In an ultrasound diagnostic apparatus equipped with an ultrasound probe that is composed of a plurality of ultrasound transducers arranged in an array and that enables ultrasound electronic scanning (linear scan, sector scan), the ultrasonic transducer of the probe is A transmitter/receiver circuit is provided which has a plurality of transmitting system channels for applying drive pulses and a plurality of receiving system channels for processing ultrasonic echo signals. This transmitting/receiving circuit is dedicated to an ultrasonic probe for electronic scanning, and the input/output impedance and the like are set to optimum values for the ultrasonic transducer in the probe.

(Problem to be Solved by the Invention) Incidentally, in such an ultrasonic diagnostic apparatus, ultrasonic information of a subject is collected using a probe other than the ultrasonic probe for electronic scanning, such as an ultrasonic probe for mechanical scanning. There are times when you want to. Ultrasonic probes for mechanical scanning are of the annular array type, which consists of a plurality of ring-shaped ultrasonic transducers arranged concentrically, and which enables electronic focusing, and the circular array type, which is made of a plurality of ring-shaped ultrasonic transducers arranged concentrically, and the circular array type, which enables electronic focusing.
There is a single type probe having two ultrasonic transducers, but in both types of probes, the area of the transducer is larger than the transducer of an ultrasonic probe for electronic scanning, and conversely the impedance is small.

As mentioned above, the transmitter/receiver circuit is optimally designed for the transducer in the ultrasonic probe for electronic scanning, so
Even if this transmitter/receiver circuit is used as is to drive the mechanical scanning ultrasound probe described above, the ultrasound information of the subject will be enhanced due to a decrease in the load (ultrasonic transducer) driving ability and a decrease in the S/N ratio in the receiving system. It is difficult to collect data with an S/N ratio, and it is necessary to add a separate transmitting and receiving circuit dedicated to the mechanical scanning ultrasonic probe. However, adding a transmitter/receiver circuit dedicated to a mechanical scanning ultrasonic probe increases the size and cost of the device.

Therefore, the present invention aims to eliminate the above-mentioned drawbacks, and uses an ultrasonic probe in which the number of ultrasonic transducers is smaller than the number of channels of the transmitting/receiving circuit, such as an ultrasonic probe for mechanical scanning, in addition to an ultrasonic probe for electronic scanning. The purpose of the present invention is to provide an ultrasonic diagnostic apparatus that is small in size and at low cost and that is capable of improving the S/N ratio of ultrasonic information.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, an ultrasonic diagnostic apparatus according to the present invention includes a plurality of transmission system channels for applying drive pulses to an ultrasonic transducer, An ultrasonic probe comprising a transmitting/receiving circuit having a plurality of receiving channels for processing sound wave echo signals and having a smaller number of ultrasonic transducers than the number of channels of the transmitting/receiving circuit. In the diagnostic apparatus, a first means for enabling parallel drive of the ultrasonic transducers of the ultrasonic probe by connecting output ends of a plurality of transmission system channels in parallel to the ultrasonic transducers of the ultrasonic probe; and a plurality of reception system channels. and at least one of a second means that enables reception processing of the same ultrasound echo signal on multiple channels by connecting the input end in parallel to the ultrasound transducer in the ultrasound probe. .

Here, it is preferable to provide a protection resistor against overcurrent corresponding to each transmission channel.

(Function) FIG. 7 shows a circuit in which a plurality of transmitting system channel output ends are connected in parallel to an ultrasonic transducer using the first means.

In the figure, ■P is the pulsar output voltage (considered as internal electromotive force) for each transmission channel, ZP is the output impedance of the pulsar, and ZL is the input impedance of the ultrasonic transducer.

Here, assuming the case of one pulser, the voltage V'L between both ends of the ultrasonic transducer in this case is expressed as, for example, Z
Under the condition of L=ZP, V'L=VP/2.

On the other hand, as shown in Figure 7, there are M pieces (M=2.3.4°...
・) When the pulsers of
Since M holds true, vtnlvp holds, and the voltage drop due to the output impedance ZP of the pulser can be ignored. Therefore, when a plurality of transmission channel output ends are connected in parallel to the ultrasonic transducer, the load driving ability of the transmission circuit is improved. Therefore, the transmission level of the ultrasound increases, and the increase in the reception level improves the S/N ratio of the ultrasound information.

FIG. 8 shows a circuit in which a plurality of receiving system channel input ends are connected in parallel to an ultrasonic transducer using the second means. In the figure, Zs is the output impedance of the ultrasonic transducer, Vs is the output signal voltage of the ultrasonic transducer (received echo without noise), vN is the noise voltage, and AMP is the preamplifier in each receiving channel. (Amplification degree Av='J-), and ADD
is an adder. There are M Vs and VN at the same time (M=2゜3
．． 4. ...) are simultaneously input to the preamplifier (AMP). In this case, since the signal components are correlated with each other, M
However, since the noise component of the preamplifier has no correlation, it is multiplied by ff. Preamplifier (A
When the input conversion noise Vni of MP) 9 is larger than the output noise VN of the ultrasonic transducer, the output voltage Vout is Vouj = M (Vs 10V [) +, r11 koT1
It is expressed as Go. Therefore, the S/N ratio in the receiving system is S/N - M - Vs/ L N + (MVnip,
When VN<Vold, the S/N ratio in the receiving system is improved.

Here, the transmitting/receiving circuit including a plurality of pulsers, a plurality of preamplifiers, and an adder is originally dedicated to the electronic scanning ultrasonic probe, and is not newly added.

Therefore, according to the present invention, an ultrasonic diagnostic apparatus that enables the use of an ultrasonic probe in which the number of ultrasonic transducers is smaller than the number of channels of a transmitting/receiving circuit, such as an ultrasonic probe for mechanical scanning, can be made small and at low cost. can be provided.

In addition, improving the drive capacity of the load (ultrasonic transducer) or receiving system S
By improving the /N ratio, the ultrasonic information of the entire device can be
/N ratio can be improved, so the above 1. Although it is ideal to have both of the second means, the object of the present invention can be achieved even if either one is provided.

(Example) The present invention will be specifically described below based on the example shown in the drawings.

FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. In the figure, reference numeral 1a denotes a connector, and the ultrasonic probe is detachably connected to the main body of the apparatus through this connector 1a. 2-1 to 2-m are transmission delay units that delay the drive timing of the transducer in the ultrasonic probe, and 3-1 to 3-m are pulsers that generate drive pulses used to excite the transducer. be. 4 is a group of high-voltage switches for switching and connecting the vibrators. 6-1 to 6-
m is a preamplifier that amplifies the ultrasonic echo signal (ultrasonic information) input from the transducer via the high voltage switch group 4, and 7-1 to 7-m are preamplifiers 6-1 to 6-m. This is a reception delay section that delays the output, and 8 is an adder that adds the outputs of the reception delay sections 7-1 to 7-m. Further, 9 is an echo signal processing unit that takes in the output of this adder 8 and processes the echo signal, 10 is a digital scan converter mainly configured with a frame memory, and 11 is a digital scan converter of this digital scan converter 10. This is a display unit that visualizes the output.

In addition, the above-mentioned pulsers 3-1 to 3-m, transmission delay section 2-1
2-m to 2-m, preamplifiers 6-1 to 6-m, reception delay sections 7-1 to 7-m, and adder 8, forming a transmitting/receiving circuit 14.

In addition, the probe for identifying the type of ultrasound probe [
D is recognized by the CPU 13.

The CPU 13 functionally includes a transmission/reception control means 12 and a driving condition setting means 15.

The transmission/reception control means 12 controls the operations of the high voltage switch group 4.degree. transmission delay sections 2-1 to 2-m, reception delay sections 7-1 to 7-m, and the like. The drive condition setting means 13 recognizes the type of ultrasound probe based on the probe ID information, and sets the drive conditions of the ultrasound probe based on the recognition result.

FIG. 2 shows a state in which the electronic scanning ultrasonic probe 16 is connected to the apparatus main body via connectors la and lb (la is the apparatus main body side connector, lb is the probe side connector). This ultrasonic probe 16 is made up of a plurality of transducers 19 arranged in an array, and enables linear scanning by turning on and off each switch in the high-voltage switch group 4.

In FIG. 3, an annular array type mechanical sector scanning ultrasonic probe 17 is connected to a connector la.

It shows a state where it is coupled to the main body of the device via lb'. This ultrasonic probe 17 is made up of a plurality of ring-shaped ultrasonic transducers 17 arranged concentrically. Ultrasonic transducer 20 in this ultrasonic probe 17
The number of channels is smaller than the number of channels of the transmitting/receiving circuit 14. At the probe side connector lb', every four channels are connected in parallel, and correspondingly, the high voltage switch group 4 is driven in units of four channels under the control of the transmission/reception control means 12. In other words, by turning on this high-voltage switch group 4, the transmitting system channel output terminals for four channels (meaning the pulsar output terminal) or the receiving system channel input terminals for four channels (meaning the preamplifier output terminal) become one. It will be connected in parallel to the ultrasonic transducer 20.

Therefore, the first aspect of the present invention. The second means is realized by a probe-side connector lb' in which a plurality of connector pins are short-circuited and a high-voltage switch group 4, as shown in FIG.

Next, the operation of the embodiment device configured as described above will be explained.

When the electronic scanning ultrasonic probe 16 is attached to the main body of the apparatus (see FIG. 2), the drive condition setting means 15 in the CPU 13 recognizes the probe 16,
A linear scan is executed under the control of the transmission/reception control means 12, and the ultrasonic information obtained thereby is processed by the echo signal processing section 9 and sent to the digital scan converter 10.
is displayed on the display unit 11 via. The operations of each part in this case are similar to those of the conventional device.

Next, when the ultrasonic probe 17 for mechanical sector scanning is attached to the main body of the device (see Fig. 3), the CPU 1
The probe 17 is recognized by the drive condition setting means 15 in step 3, and a mechanical sector scan is executed under the control of the transmission/reception control means 12. In this embodiment, four of the pulsers 3-1 to 3-m are connected in parallel to each ultrasonic transducer of the ultrasonic probe 17 when transmitting ultrasonic waves, and a preamplifier 6 is connected in parallel when receiving ultrasonic waves. -1
6-m are connected in parallel.

That is, by the action of the high-voltage switch group 4, the transmitting channel output terminals and the receiving channel input terminals are connected in parallel in units of four channels. According to this, each ultrasonic transducer is driven in parallel by four transmission channels during transmission, and the same ultrasound echo is received and processed by four reception channels during reception. . Therefore, for the reasons already mentioned, the load (ultrasonic transducer) driving ability of the transmitting system is improved, and the S/N ratio of the receiving system is improved.

In addition, in the mechanical sector scan by the probe 17, the delay times of the transmission delay sections 2-1 to 2-m and the reception delay sections 7-1 to 7-m are determined for each channel connected in parallel to the ultrasonic transducer. be the same.

In this way, in the device of this embodiment, the high voltage switch group 4
Due to the action of , multiple pulsar output terminals are connected in parallel and multiple preamplifier input terminals are connected in parallel.
Although the transmitter/receiver circuit 14 is dedicated to an ultrasound probe for electronic scanning, it is optimized for an annular array type and can collect good ultrasound information. Furthermore, since there is no need for a dedicated transmitter/receiver circuit for the annular array type mechanical sector scanning ultrasonic probe, it is possible to avoid an increase in the size and cost of the device.

Next, other embodiments will be described.

In the above embodiment, multiple transmission system channel output ends are connected in parallel to the same ultrasonic transducer, so if there is variation in delay time or malfunction between the transmission system channels, the output ends of each transmission system channel This is equivalent to a short circuit at the ends, and there is a risk of circuit destruction due to overcurrent flowing.

Therefore, in order to prevent this, as shown in FIG. 4, it is preferable to provide a protection resistor 21 for overcurrent in the transmission channel corresponding to each channel. This resistor 21 may be inserted and connected at any point as long as it is connected in series with the output end of the transmission system channel, but if you consider switching use of other ultrasonic probes, such as the ultrasonic probe 16 for electronic scanning, (See FIG. 2), it is preferable to arrange it on the ultrasonic probe side, specifically, inside the probe side connector lb' as shown in FIG. In this way, the protective resistor 21 will be connected in series with the transmission channel output end only when using the annular array type mechanical sector scanning ultrasonic probe 17, and when using other ultrasonic probes by switching. In this case, the involvement of the protective resistor 21 can be eliminated.

Here, the value of the protective resistor 20 is determined as follows.

FIG. 5 shows an equivalent circuit in the configuration shown in FIG. 4 when the transmitting system channel output end is connected in parallel to the ultrasonic transducer. vpt to VPM are pulse output voltages for each transmission channel, ZP is the output impedance of the pulser, and ZL is the input impedance of the ultrasonic transducer.

If the maximum current during transmission is ■, the value of the protective resistor 21AX is R, and the voltage (wave height) of the transmitted pulse is VH, then R can be found from the relationship Roov■/■MAX Ro = R+ZP. .

For example, as shown in FIG.
If only the HI delay time deviates, a current 1 due to the VPI flows to other transmission channels and the load ZL. The maximum value of (1) I I MAX' is 1. However, Ro = ZP + R. From this, it becomes as follows, and the value of R may be determined so as to satisfy this formula.

However, care must be taken because if R is made too large, the load driving ability will be significantly reduced.

By providing the protective resistor 21 in this way, even if there is a malfunction due to variations in the delay circuit or disturbance noise, no overcurrent will flow, and the circuit will be prevented from being destroyed. Also, due to the presence of the protective resistor 21, the load driving ability will be slightly lower than in the above embodiment;
However, in the case of reception, this protective resistor 21 can be almost ignored, and the improvement of the SZN ratio when multiple reception system channel input ends are connected in parallel to the ultrasonic transducer is similar to the case of the above embodiment. They are equivalent, and the S/N ratio of ultrasound information as a whole of the apparatus is improved compared to the conventional method.

Although the embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above embodiments, and that various modifications can be made.

For example, in the above embodiment, a case has been described in which an annular array type mechanical sector scanning ultrasonic probe is used. The present invention can be applied to all cases where an ultrasonic probe having the following is used. still,
If a transmission/reception delay time is unnecessary, such as in a single-type mechanical scanning ultrasonic probe, the delay time may be set to zero.

Furthermore, in the above embodiment, the ultrasound probe is recognized based on the probe ID information, and the operation of the high voltage switch group 4 is controlled according to the recognition result. A switch corresponding to the type may be provided, and the driving conditions may be set by operating the switch.

Furthermore, in the above embodiment, the first . Although a case has been described that includes both of the second means, either one of the means may be omitted.

Furthermore, the present invention can also be applied to a device that does not include the high-voltage switch group 4. That is, even in an ultrasonic diagnostic apparatus that has a transmitter/receiver circuit corresponding to the probe with the largest number of ultrasonic transducers among usable probes, and performs 0N10FF control of ultrasonic transmitter/receiver in this circuit, ultrasonic wave vibration It is possible to drive the ultrasound echo signals in parallel and to receive the same ultrasonic echo signal in a plurality of channels. Therefore, the same effects as in the above embodiment can be achieved. In this case, the first aspect of the present invention. The second means is formed by a connected probe-side connector and an ultrasonic transmitting/receiving 0N10FF control section of the transmitting/receiving circuit as shown in FIG.

[Effects of the Invention] As detailed above, according to the present invention, in addition to an ultrasonic probe for electronic scanning, an ultrasonic probe in which the number of ultrasonic transducers is smaller than the number of channels in a transmitting/receiving circuit can be used. It is possible to provide a small-sized and low-cost sonic diagnostic device that improves the S/N ratio of ultrasound information.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing one embodiment of the ultrasonic diagnostic device according to the present invention, Figs. 2 and 3 are detailed explanatory diagrams of the main parts of the device of this embodiment, and Fig. 4 is another embodiment. FIG. 5 is an equivalent circuit diagram for the configuration shown in FIG. 4, FIG. 6 is a timing chart of transmission pulses, and FIGS. 7 and 8 are diagrams explaining the principle of the present invention. (1b', 4)...first means, second means, 14.
... Transmission/reception circuit, 19.20... Ultrasonic transducer, 21... Protection resistor.

Claims (3)

[Claims] (1) A transmitting/receiving circuit having multiple transmitting system channels for applying drive pulses to the ultrasonic transducer and multiple receiving system channels for processing ultrasound echo signals, and a number of channels smaller than the number of channels of this transmitting/receiving circuit. In an ultrasonic diagnostic apparatus equipped with an ultrasonic probe having several ultrasonic transducers, a plurality of transmission system channel output ends are connected in parallel to the ultrasonic transducers of the ultrasonic probe, thereby reducing the vibration. The first means enables parallel driving of the same ultrasound echo signal in multiple channels by connecting a plurality of receiving system channel input terminals in parallel to the ultrasound transducer of the ultrasound probe. An ultrasonic diagnostic apparatus characterized by having at least one of a second means that enables reception processing. (2) The ultrasonic diagnostic apparatus according to claim 1, wherein a protection resistor against overcurrent of the transmission system channel is provided corresponding to each transmission system channel. (3) The ultrasonic diagnostic apparatus according to claim 2, wherein the protective resistor is provided on the ultrasonic probe side.