JP2010042042A - Ultrasonic diagnostic system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To correspond to an increase in the number of piezoelectric elements in an ultrasonic diagnostic system constituted so that an ultrasonic probe equipped with an ultrasonic vibrator is connected to the body apparatus through a cable. <P>SOLUTION: In the ultrasonic probe 2, an ultrasonic receiving signal is subjected to A/D conversion by an analog/digital converter 28 and, after the obtained digital signal of a plurality of channels and a plurality of bits is subjected to P/S conversion by a parallel/serial converter 29, the obtained signal is converted to a light signal by an electrooptical transducer 30 to be transmitted by an optical fiber 52. In the body apparatus 3, the light signal is converted to an electric signal by an electrooptical transducer 31 and, after the electric signal is parallelly converted by an S/P converter 32, usual processing on and after a beam former circuit 33 is performed. Accordingly, serial communication is used to reduce the number of wires, to prevent the complication of connection, to make the cable 5 thin to ensure flexibility and to enhance manipulative operability. Further, since the optical fiber 52 is used only for the receiving signal, the lowering of the strength of the cable 5 can be suppressed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an apparatus in which a main body apparatus and an ultrasonic probe are connected via a cable, and an ultrasonic transducer is arranged with a large number of piezoelectric elements.

  An ultrasonic diagnostic apparatus is a medical imaging device that non-invasively obtains a tomographic image of soft tissue in a living body from a body surface by an ultrasonic pulse reflection method. Compared to other medical imaging equipment, this ultrasonic diagnostic device is small and inexpensive, and it is safe without exposure to X-rays, etc., so the circulatory system (heart coronary artery), digestive system (gastrointestinal), Widely used in internal medicine (liver, pancreas, spleen), urology (kidney, bladder), and obstetrics and gynecology. In particular, in recent years, in breast diagnosis, ultrasonic diagnosis has made it possible to highly diagnose tumors and tumors, and has made a great contribution to the discovery of breast cancer, and its importance has been increasingly recognized.

  An ultrasonic probe used in such a medical ultrasonic diagnostic apparatus generally uses the piezoelectric effect of a piezoelectric ceramic in order to transmit and receive high-sensitivity and high-resolution ultrasonic waves. In this case, as a vibration mode of the transmitting piezoelectric vibrator (piezoelectric element), a single probe which is a single piezoelectric vibrator or an array probe in which a plurality of piezoelectric vibrators are arranged one-dimensionally or two-dimensionally are often used. . Since a two-dimensional array can obtain a fine image, it is widely used for medical ultrasonic diagnosis. However, in the ultrasonic probe in which the piezoelectric vibrators are arranged one-dimensionally, the number of elements is, for example, about 128, and the arithmetic processing for driving the ultrasonic probe is about 128 piezoelectric vibrators. In the two-dimensional array ultrasonic probe in which the piezoelectric vibrators are arranged in two dimensions, for example, the number of elements when the vibrators are arranged in 64 × 64 is 4096. In 128 * 128, it reaches 16384 pieces. Therefore, the calculation processing for driving the two-dimensional array ultrasonic probe drives 4096 to 16384 transducers, and the processing of received signals obtained from the transducers is also added, so that the processing load is extremely high. It has come to increase.

  In addition, in order to oscillate each piezoelectric vibrator by applying a voltage (individual delay time pulse) for obtaining a desired beam profile, the number of signal lines increases accordingly, and the ultrasonic probe is connected to the main unit. There is a problem that the wiring of the signal wiring becomes very complicated. In addition, the coaxial cable formed by bundling the signal wiring becomes thicker, the cable is difficult to handle, the operability of the ultrasonic probe is inferior, and the coaxial cable has a large capacity, so loss and impedance matching Is a problem.

  On the other hand, digital signal processing technology has progressed, and small arithmetic processing chips have been developed to perform digital arithmetic processing within the ultrasound probe rather than performing digital processing within the main body of the ultrasonic diagnostic apparatus. However, it is possible to avoid mixing noise in the coaxial cable communication described above by transmitting a signal from which noise has been removed. Therefore, an ultrasonic reception signal generated in a living body is converted from an analog signal into a digital signal in an ultrasonic probe and transmitted to the main body apparatus, and the received signal is converted into digital data in an ultrasonic diagnostic apparatus for processing. The analog / digital converter for this purpose generally has a parallel output because of its high signal extraction speed. Therefore, the number of signal lines between the ultrasonic probe and the main unit is proportional to the product of the number of reception channels of the ultrasonic probe and the number of output signals (bits) of the analog / digital converter. As the number of reception channels (number of elements) and the number of bits of the analog / digital converter increase, the number of digital signal lines increases.

As described above, in the ultrasonic diagnostic apparatus, the number of output bits of the analog / digital converter and the number of reception channels of the apparatus tend to increase in order to improve image quality and three-dimensional imaging. In other words, in the circuits after the analog / digital converter, the number of signal lines for transmitting received data tends to increase. This causes problems such as a complicated board design, an increase in the number of pins of the inter-board connection connector, an increase in the number of wires in the coaxial cable, and an increase in manufacturing cost. Therefore, Patent Document 1 has proposed a technique for converting a parallel signal into a serial signal and transmitting it.
JP 2003-10187 A

  However, the power of the transmission signal is large for weak received signals, particularly harmonic signal components that are effective for image quality improvement and three-dimensional imaging as described above, and even digital signals have an effect (crosstalk). Etc.). Therefore, a separate power (power supply) line is used, and an optical fiber is used for both transmission and reception. The transmission signal that is actually given to the piezoelectric vibrator is also transmitted as an optical signal from the main unit and converted into an electrical signal within the ultrasonic probe. It is conceivable to avoid the influence of the crosstalk and the like.

  However, optical fibers are fragile and can break. In particular, if the refractive index is increased to prevent light leakage (enhance efficiency), it becomes harder and the tendency becomes stronger.

  An object of the present invention is to provide an ultrasonic diagnostic apparatus in which a transmission signal does not affect a reception signal and a cable can have a required strength as the number of piezoelectric elements increases. It is.

  The ultrasonic diagnostic apparatus of the present invention is an ultrasonic diagnostic apparatus in which an ultrasonic probe including an ultrasonic transducer in which a plurality of piezoelectric elements are arranged is connected to a main body device via a cable. From a coaxial cable comprising at least a plurality of electrical signal lines for transmitting a transmission ultrasonic signal to be transmitted from the ultrasonic transducer and an optical fiber for transmitting a reception ultrasonic signal received by the ultrasonic transducer. The ultrasonic probe includes an analog / digital converter for analog / digital conversion of signals received by the piezoelectric elements of the ultrasonic transducer, and parallel / serial of the obtained multi-bit digital signals. A parallel / serial converter for conversion, and an electro-optic conversion element that converts the obtained serial electrical signal into an optical signal and enters the optical fiber, and the main body The transmitter includes a transmission circuit that generates a transmission ultrasonic signal to each of the piezoelectric elements, a photoelectric conversion element that converts the optical signal emitted from the optical fiber into an electrical signal, and a serial signal obtained. A serial / parallel converter that performs parallel / parallel conversion, and a signal processing unit that reconstructs a tomographic image from the obtained multi-channel, multi-bit digital signals.

  According to the above configuration, in an ultrasound diagnostic apparatus in which an ultrasound probe including an ultrasound transducer in which a plurality of piezoelectric elements are arranged is connected to a main body device via a cable, As the number of piezoelectric elements increases, the number of lines connecting the main unit and the ultrasonic probe is reduced. On the ultrasonic probe side, signals are received by a large number of piezoelectric elements of the ultrasonic transducer. The signal is analog / digital converted by an analog / digital converter, and the obtained multi-bit digital signal is parallel / serial converted by a parallel / serial converter and transmitted to the main unit. Correspondingly, in the main unit, the received serial signal is serial / parallel converted by the serial / parallel converter, and the tomographic image is regenerated by the signal processing unit from the obtained multi-channel multi-bit digital signal. Constitute. In this way, the received signal with a large amount of information is transmitted as a serial signal from the ultrasound probe to the main unit, thereby reducing the number of wires mentioned above, preventing complicated connections, and making the cable thinner and flexible. And operability of the procedure can be improved.

  However, the transmission signal and the appropriate control signal are transmitted from the main unit to the ultrasonic probe with an electric signal line as before, whereas an optical fiber is used to transmit the reception signal. Therefore, the ultrasonic probe is provided with an electro-optic conversion element, and the main body device is provided with a photoelectric conversion element.

  Therefore, the transmission signal with a large power does not affect the reception signal (crosstalk etc.) as in the case where all electric signal lines are used, and the cable is not used as in the case where an optical fiber is used for both transmission and reception. There is no case where the optical fiber is broken due to a decrease in strength. Thus, transmission by cable is performed in a signal format suitable for an ultrasonic diagnostic apparatus in which a transmission signal is an electrical signal and a reception signal is an optical signal, so that an increase in the number of piezoelectric elements can be accommodated.

  In the ultrasonic diagnostic apparatus of the present invention, each piezoelectric element in the ultrasonic transducer is formed by laminating an organic piezoelectric layer for reception on an inorganic piezoelectric layer for transmission.

  According to the above-described configuration, an inorganic ceramic element (inorganic piezoelectric layer) such as PZT suitable for transmission of high-power ultrasonic waves, and a piezoelectric polymer film such as vinylidene fluoride suitable for reception of the above-described harmonics By laminating the (organic piezoelectric layer), it is possible to realize a piezoelectric element capable of supplementing higher harmonic signal components effective for image quality improvement and three-dimensional imaging with higher sensitivity. In addition to the GND signal line, this organic-inorganic laminated piezoelectric element requires a signal line for the transmitting piezoelectric element (inorganic piezoelectric layer) and a signal line for the receiving piezoelectric element (organic piezoelectric layer). Since the number of signal lines increases, the present invention that realizes a reduction in the number of lines is particularly suitable.

  Furthermore, in the ultrasonic diagnostic apparatus of the present invention, the optical fiber is an organic optical fiber.

  According to the above configuration, various kinds of materials such as an inorganic type such as quartz glass and an organic polymer type can be used for the optical fiber. It is suitable for the operability of the procedure at the time of ultrasonic diagnosis.

  In the ultrasonic diagnostic apparatus of the present invention, the electro-optic conversion element is an optical device using an optical transmission photonic crystal.

  According to the above configuration, the optical device using the optical transmission photonic crystal can be about several times the wavelength of the light to be guided, compared with the size of the diameter of the optical fiber. Therefore, the diameter of the optical fiber can be reduced.

  As described above, the ultrasonic diagnostic apparatus of the present invention is an ultrasonic diagnostic apparatus in which an ultrasonic probe including an ultrasonic transducer in which a plurality of piezoelectric elements are arranged is connected to a main body device via a cable. In order to reduce the number of lines connecting the main body device and the ultrasonic probe as the number of piezoelectric elements increases with the increase in resolution, many ultrasonic transducers are used on the ultrasonic probe side. The signal received by the piezoelectric element is analog / digital converted by an analog / digital converter, and the resulting multi-bit digital signal is parallel / serial converted by a parallel / serial converter and sent to the main unit. Correspondingly, in the main unit, the received serial signal is serial / parallel converted by a serial / parallel converter, and a signal processing unit is obtained from the obtained multi-channel multi-bit digital signal. While reconstructing tomographic images, transmission signals and appropriate control signals are transmitted from the main unit to the ultrasound probe using electrical signal lines as before. The acoustic probe is provided with an electro-optic conversion element, the main body device is provided with a photoelectric conversion element, and an optical fiber is used.

  Therefore, since a received signal with a large amount of information is transmitted as a serial signal from the ultrasonic probe to the main unit, the number of wires is reduced, the connection is prevented from becoming complicated, and the cable is thinned and flexible. And operability of the procedure can be improved. In addition, the transmission signal with a large power does not affect the reception signal (crosstalk etc.) as in the case where all electric signal lines are used, and the cable is not used as in the case where an optical fiber is used for both transmission and reception. There is no case where the optical fiber is broken due to a decrease in strength. Thus, transmission by cable is performed in a signal format suitable for an ultrasonic diagnostic apparatus in which a transmission signal is an electrical signal and a reception signal is an optical signal, so that an increase in the number of piezoelectric elements can be accommodated.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted.

  FIG. 1 is a diagram showing an external configuration of an ultrasonic diagnostic apparatus 1 according to an embodiment of the present invention. The ultrasonic diagnostic apparatus 1 transmits an ultrasonic wave to a subject such as an unillustrated living body and receives an ultrasonic wave from the subject, and the ultrasonic probe 2. Wired type ultrasonic waves that are connected via a flexible coaxial cable 5 to a main body device 3 that creates a transmission signal at the same time and processes the received signal to reconstruct an ultrasonic tomographic image in the subject. It is a diagnostic device.

  FIG. 2 is a perspective view showing the structure of the ultrasonic transducer 20 in the ultrasonic probe (ultrasonic probe) 2. The ultrasonic transducer 20 is configured by arranging a large number of piezoelectric elements 22 on a substrate 21 (in the example of FIG. 2, for simplification of the drawing, 6 × 4 = 24 two-dimensional arrays). Yes. FIG. 3 is a cross-sectional view of each piezoelectric element 22, and FIG. 3 shows an example of an organic and inorganic composite piezoelectric vibrator. In the piezoelectric element 22, the acoustic lens 221, the first matching layer 222, the organic piezoelectric layer 223, the first backing layer 224, the second matching layer 225, the inorganic piezoelectric layer 226, and the second are arranged from above the element (subject side). A backing layer 227, a heat conductive layer 228, and the substrate 21 are included. A cooling layer 229 is formed on the substrate 21.

  This composite piezoelectric element uses an inorganic ceramic element (inorganic piezoelectric layer 226) such as PZT for radiation transmission of ultrasonic waves, and receives vinylidene fluoride from the primary wave from the living body to the second and higher harmonics. By stacking a piezoelectric polymer film (organic piezoelectric layer 223) like this via the matching layer 225 and the backing layer 224, the signal components of higher harmonics effective for image quality improvement and three-dimensional imaging are supplemented with higher sensitivity. This is a piezoelectric element that can be used. Therefore, in addition to the signal line 23 for GND, the signal line 24 of the transmitting piezoelectric element (inorganic piezoelectric layer 226) and the signal line 25 of the receiving piezoelectric element (organic piezoelectric layer 223) are required, so the number of signal lines However, a highly sensitive tomographic image can be obtained. As described above, in the 128 × 128 two-dimensional array of the three signal lines 23 to 25 for each piezoelectric element 22, it is necessary to wire 49152 or more signal lines to the coaxial cable 5. In the following description, a technique for subtracting the signal lines 23 to 25, which is a point of the present invention, will be described in detail.

  FIG. 4 is a block diagram showing an electrical configuration of the ultrasonic diagnostic apparatus 1. It should be noted that in the present embodiment, first, a received signal having a large amount of information is transmitted as a serial signal from the ultrasonic probe 2 to the main unit 3, thereby reducing the number of lines and making the connection complicated. In other words, the cable 5 is made thin and the flexibility is secured to improve the maneuverability. Next, transmission signals and control signals (control signal lines are omitted in FIG. 4) are transmitted from the main unit 3 to the ultrasonic probe 2 through the electric signal lines 51 as they are. On the other hand, by using the optical fiber 52 for transmission of the reception signal, the influence (crosstalk etc.) of the transmission signal with a large power on the reception signal is eliminated, and the strength of the coaxial cable 5 is appropriately maintained. .

  Specifically, in the ultrasonic probe 2, the transmission signal from the main body device 3 is transmitted from the electric signal line 51 of the coaxial cable 5 through the signal line 24 to the transmission piezoelectric element of each piezoelectric element 22. (Inorganic piezoelectric layer 226). The received signal at each receiving piezoelectric element (organic piezoelectric layer 223) is input to the receiving circuit 26 from the signal line 25, amplified by the amplifier circuit 27, and then amplified by the analog / digital converter 28. Every 22 is converted into a digital signal having a predetermined number of bits. The multi-bit digital signal is converted into a serial signal by the parallel / serial converter 29, further converted into an optical signal by the electro-optic conversion element 30, and incident on the optical fiber 52 of the coaxial cable 5. The amplification circuit 27 also includes a variable gain adjustment circuit that amplifies the received signal in accordance with the input range (dynamic range) of the analog / digital converter 28.

  On the other hand, in the main unit 3, the optical signal from the optical fiber 52 is first converted into an electrical signal by the photoelectric conversion element 31, converted into a parallel signal by the serial / parallel converter 32, and then the beamformer circuit 33. Is input. The beamformer circuit 33 converts the address signal generated by the address generation circuit 35 at the timing created by the synchronization circuit 34, so that the received signal at each piezoelectric element 22 is adjusted with a delay time. Phase addition is performed to form a beam having a desired shape at a desired depth. The beam-formed signal is filtered by the filtering circuit 36 into the first-order wave having the same frequency as the transmission ultrasonic wave, and the higher-order harmonics such as the second-order wave are filtered by frequency, and further detected by the detection circuit 37. It is transmitted to a digital signal processing circuit (DSP) 38 to reconstruct the tomographic image. The tomographic image is imaged by a display device 39 such as a liquid crystal display element or an EL display element. The beam former circuit 33, the synchronization circuit 34, the address generation circuit 35, the filtering circuit 36, the detection circuit 37 and the DSP 38 constitute a signal processing unit for reconstructing a tomographic image.

  The DSP 38 performs various arithmetic processes such as logarithmic conversion processing, filter processing, and γ correction as preprocessing for imaging the received beam. The digital scan converter (not shown in the figure, but between the DSP 38 and the display device 39) forms image data by the data output from the DSP 35 every time the ultrasonic beam is scanned. A digital display capable of displaying data as it is is used.

  On the other hand, from the signal reception by the DSP 38 to the image formation based on the reception result, the creation of the transmission signal is controlled by the central processing circuit 41 in the transmission circuit 40 which is an overall control unit. The central processing circuit 41 controls the transmission control circuit 42 to form a beam with a desired shape at the desired depth, and from the drive signal generation circuit 43 via the electric signal line 51 to each piezoelectric element. A high-power transmission signal (pulse) is output to 22.

  In the ultrasonic diagnostic apparatus 1 configured as described above, for the diagnosis, the ultrasonic probe 2 is brought into contact with the body surface of the examination site of the subject, and a scanning numerical value such as a transmission focal depth is obtained from the operation panel 44. When an ultrasonic scan start command is input after input, the central processing circuit 41 controls each circuit and starts ultrasonic scanning. First, the central processing circuit 41 outputs a drive pulse output command and a command for setting a delay time according to the transmission focal depth (beam shape) to the transmission control circuit 42. In response to these commands, the transmission control circuit 42 causes the drive signal generation circuit 43 to generate a drive signal (pulse) to each piezoelectric element 22, and the drive signal is transmitted to each piezoelectric element 22 via the electric signal line 51. Given to. When a drive signal (pulse) is input, the piezoelectric element selected by the selection command in the ultrasonic probe 2 vibrates at a predetermined fundamental frequency, and sequentially transmits ultrasonic waves into the subject.

  A part of the ultrasonic wave transmitted into the subject in this way is reflected by different surfaces of the tissue or organ in the living body where the acoustic impedance is different, and a fundamental reflected wave and higher harmonics are generated to generate an ultrasonic probe. Reach Tactile 2 In order to receive this reaching wave, the central processing circuit 41 controls the receiving system through the DSP 38. The piezoelectric element used for reception at this time is selected by the DSP 38 controlled by the central processing circuit 41 in accordance with the scanning numerical condition input from the operation panel 44, and the beam former circuit 33 further selects the beam element circuit 33. Beam forming is performed by controlling the delay time of the received signal from the selected piezoelectric element and performing addition. By these controls, ultrasonic waves generated as the ultrasonic waves propagate from a shallow part to a deep part in the subject are received.

  At that time, the signal received by the ultrasound probe 2 is converted into a digital signal by the analog / digital converter 28 and then converted by the parallel / serial converter 29 from the number of output bits of the analog / digital converter 28. In other words, the data is transmitted to the serial / parallel converter 32 in the main body device 3 through a small number of optical fibers 52. For example, if the output of the analog / digital converter 28 is 8 bits, the parallel / serial converter 29 combines 8 bits into one optical fiber, or the 8 bits per element of the piezoelectric element 22. Yes, when a plurality of elements are combined, bits that are several times the number of elements are combined and transmitted through a single optical fiber.

  As a result, the number of lines connecting the main body device 3 and the ultrasonic probe 2 can be reduced even when the number of the piezoelectric elements 22 increases with the increase in resolution, thereby preventing complicated connection. In addition, the coaxial cable 5 can be thinned to ensure flexibility and improve the maneuverability. In addition, with respect to the electric signal line 51 of the transmission signal of high power, the optical fiber 52 is used for the transmission by using the electro-optic conversion element 30 and the photoelectric conversion element 31 for the reception signal. Even if the transmission signal and the reception signal go close to each other within 5, the occurrence of signal current crosstalk can be prevented and the need for reception impedance control is eliminated. In addition, when the optical fiber 52 is used for both transmission and reception, the strength of the coaxial cable may be reduced and the optical fiber may be broken. Therefore, transmission through the coaxial cable 5 is performed in a signal format suitable for the ultrasonic diagnostic apparatus 1 in which the transmission signal is an electrical signal and the reception signal is an optical signal, so that the increase in the number of piezoelectric elements 22 can be accommodated. it can.

  For the optical fiber 52, various types of materials such as an inorganic type such as quartz glass and an organic polymer type can be used. Is preferable. In the above description, the electric signal line 51 and the optical fiber 52 are bundled in the coaxial cable 5, but the thin optical fiber 52 may be attached to the thick electric signal line 51. However, it is preferable to unite into one cable from the said procedure operativity. At that time, whether or not to apply twist may be appropriately selected according to the thickness of the cable and the number of wires.

  On the other hand, the electro-optic conversion element 30 is preferably an optical device using an optical transmission photonic crystal. A photonic crystal is an optical device obtained by arranging periodic refractive index changes in a material transparent to light, such as silicon dioxide. For example, holes are periodically stacked in a material. Can be created. The photonic crystal has a wavelength region where light cannot enter by the refractive index control layer, and has a property of strongly reflecting light in this region. The size of the optical device using this photonic crystal can be made several times the wavelength of the light to be guided. For example, the size of an optical device using quartz glass can be about 40 to 80 μm because the wavelength of light used for optical communication is about 1.6 μm and the refractive index of quartz glass is about 2. . Thus, the optical device using the photonic crystal is sufficiently smaller than the diameter of the optical fiber, and the diameter of the optical fiber 52 can be reduced to about 100 μm.

  By the way, to configure the system, it is necessary to optically couple the electro-optic conversion element 30 and the optical fiber 52. Therefore, there are various methods for optically coupling the electro-optic conversion element 30 and the optical fiber 52. For example, a method for optically coupling the electro-optic conversion element 30 and the optical fiber 52 using an optical lens. In addition, there is a method of optically coupling the electro-optic conversion element 30 and the optical fiber 52 by providing the function of an optical lens to the end portion by machining the end portion of the optical fiber 52 to be tapered. The element 30 and the optical fiber 52 are coupled while optically aligning. In order to couple the electro-optic conversion element 30 and the optical fiber 52 by such a method, the core portion and the clad portion of the optical fiber 52 are directly structurally processed in order to give freedom in alignment of the coupling. Thus, an optical fiber configuration method using a photonic crystal may be employed.

  FIG. 5 is a cross-sectional view showing a specific structure example of the coaxial cable 5. As described above, when the optical fiber 52 and the electric signal line 51 made of metal such as copper are arranged in the same cable 5 to reduce the crosstalk of the electric signal, the coaxial cable 5a in FIG. The example which has arrange | positioned the optical fiber 52 outside the signal wire | line 51 is shown. The coaxial cable 5b in FIG. 5B shows an example in which the optical fiber 52 is also arranged on the inner core side. The coaxial cable 5c in FIG. 5C shows an example in which the optical fiber 52 and the electric signal line 51 are arranged so as to be sparse and the influence of interference on the transmission signal itself is reduced. The electric signal lines 51 are preferably arranged so that they are not adjacent to each other as much as possible, and an arrangement as shown in FIG. There are other arrangements that avoid mutual interference, but can be selected as appropriate.

  In the example of FIG. 5, the number of electrical signal lines 51 and optical fibers 52 are drawn substantially equal, that is, the electrical signal lines 51 and the optical fibers 52 for each piezoelectric element 22 except for the common GND line. 1 is provided, but a buffer memory is provided in front of the parallel / serial converter 29, and the number of optical fibers 52 is reduced by multiplexing the time axis for a plurality of channels as described above. It can be greatly reduced.

  Although the invention made by the inventor of the present application has been specifically described above based on the embodiment of the invention, the invention is not limited to the embodiment of the invention and does not depart from the gist of the invention. Of course, various changes can be made.

1 is a diagram showing an external configuration of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. It is a perspective view which shows the structure of the ultrasonic transducer | vibrator in an ultrasonic probe (ultrasonic probe). It is sectional drawing of the piezoelectric element in the said ultrasonic transducer | vibrator. 2 is a block diagram showing an electrical configuration of the ultrasonic diagnostic apparatus. FIG. It is sectional drawing which shows the specific structural example of a coaxial cable.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ultrasonic diagnostic apparatus 2 Ultrasonic probe 3 Main body apparatus 5 Coaxial cable 20 Ultrasonic transducer 21 Substrate 22 Piezoelectric element 221 Acoustic lens 222 First matching layer 223 Organic piezoelectric layer 224 First backing layer 225 Second matching layer 226 Inorganic piezoelectric layer 227 Second backing layer 228 Thermal conduction layer 229 Cooling layer 23 GND signal line 24 Signal line for transmission 25 Signal line for reception 26 Reception circuit 27 Amplifier circuit 28 Analog / digital converter 29 Parallel / serial conversion Device 30 electro-optic conversion device 31 photoelectric conversion device 32 serial / parallel converter 33 beam former circuit 34 synchronization circuit 35 address generation circuit 36 filtering circuit 37 detection circuit 38 digital signal processing circuit (DSP)
39 Display device 40 Transmission circuit 41 Central processing circuit 42 Transmission control circuit 43 Drive signal generation circuit 51 Electrical signal line 52 Optical fiber

Claims (4)

In an ultrasonic diagnostic apparatus in which an ultrasonic probe including an ultrasonic transducer in which a plurality of piezoelectric elements are arranged is connected to a main body device via a cable.
The cable includes at least a plurality of electric signal lines that transmit a transmission ultrasonic signal to be transmitted from the ultrasonic transducer, and an optical fiber that transmits a reception ultrasonic signal received by the ultrasonic transducer. Consisting of a coaxial cable
The ultrasonic probe includes an analog / digital converter for analog / digital conversion of signals received by the piezoelectric elements of the ultrasonic transducer, and parallel / serial conversion of the obtained multi-bit digital signals. A parallel / serial converter; and an electro-optic conversion element that converts the obtained serial electrical signal into an optical signal and enters the optical fiber;
The main body device includes a transmission circuit that generates a transmission ultrasonic signal to each piezoelectric element, a photoelectric conversion element that converts the optical signal emitted from the optical fiber into an electrical signal, and an obtained serial signal. An ultrasonic diagnostic apparatus comprising: a serial / parallel converter for serial / parallel conversion; and a signal processing unit for reconstructing a tomographic image from the obtained multi-channel multi-bit digital signals.   2. The ultrasonic diagnostic apparatus according to claim 1, wherein each piezoelectric element in the ultrasonic transducer is formed by laminating an organic piezoelectric layer for reception on an inorganic piezoelectric layer for transmission.   The ultrasonic diagnostic apparatus according to claim 1, wherein the optical fiber is an organic optical fiber.   The ultrasonic diagnostic apparatus according to claim 1, wherein the electro-optic conversion element is an optical device using an optical transmission photonic crystal.

Images