JP4776344B2 - Ultrasonic probe, ultrasonic imaging device - Google Patents

Description

The present invention relates to an ultrasonic imaging apparatus which takes an image of the ultrasonic image as a diagnostic image of the subject. In particular, to ultrasonic imaging device or the like including an ultrasound probe having a capacitive micromachined ultrasonic transducer.

Conventionally, as an ultrasonic transducer for transmitting and receiving ultrasonic waves in an ultrasonic diagnostic apparatus, piezoelectric ceramics represented by PZT (lead zirconate titanate) and piezoelectric elements such as PVDF (polyvinylidene fluoride) are used. . Generally, these transducers are used in the form of an array that is finely separated into hundreds of elements in an ultrasonic probe. Each separation element is connected to an electric wiring and has several hundred signal channels. A structure is realized.
In addition, an electrical signal → optical signal → electric signal conversion is performed between the analog signal processing unit and the digital signal processing unit of the ultrasonic imaging apparatus, and leakage electromagnetic waves are captured in the MRI measurement system during imaging by MRI (Magnetic Resonance Imaging). There has been proposed an ultrasonic imaging apparatus that prevents entry (see, for example, [Patent Document 1]).

In addition, as an ultrasonic probe using a device other than a piezoelectric transducer, there is a capacitive micro-machined ultrasonic transducer (cMUT) manufactured using a semiconductor film forming technique (for example, [Non- (See Patent Document 1].)
Since the cMUT uses a semiconductor film forming process such as photolithography microfabrication, the cMUT is manufactured with a size of several μm to several tens of μm on a small thin chip having a thickness of several tens to several hundreds of μm. Furthermore, it is possible to mount devices including various electric circuits such as transistors on the same chip. The cMUT has a wide-band acoustic characteristic that is difficult to realize with a piezoelectric vibrator, and is not only small, but can also be used as a transducer for a broadband ultrasonic probe (for example, [Non-Patent Document 2]). reference.).

JP 2004-242886 A Butas T. Khuri-Yakub et al, “SurfaceMicro-machined Capacitive Ultrasound Transducers” IEEE Transactions onUltrasonics, Ferroelectrics, and Frequency control, Vol. 45, No. 3, May 1998. Omer Oralkan et al, “CapacitiveMicromachined Ultrasonic Transducers: Next-Generation Arrays for AcousticImaging?” IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequencycontrol, Vol. 49, No. 11, Nov. 2002.

  However, in an ultrasonic imaging apparatus using a conventional piezoelectric vibrator, signal transmission / reception is performed between each channel of the piezoelectric vibrator and the apparatus body by analog electric communication. Therefore, when an ultrasonic probe using a piezoelectric transducer array is routed, it is necessary to simultaneously route cables including several hundreds of coaxial metal wires. A multi-core coaxial metal cable has a problem in that it has a low weight and a large flexibility when routed, and the operability and work efficiency are reduced and the labor load is increased.

  In a conventional ultrasonic imaging apparatus, signals are transmitted and received between each channel of the piezoelectric vibrator and the apparatus main body by analog electric communication. For this reason, an electrical wiring cable that connects between the ultrasonic probe and the apparatus main body requires electrical wiring of nearly 200 channels. Also, since the received echo signal is generally very low, the metal lines are not simple strands, but are coaxial lines each with its own signal line and conductive shield. Therefore, the ultrasonic probe and the apparatus are connected by a multi-core coaxial metal cable which is composed of coaxial metal wires having 200 cores or more and is large in structure and weight.

  In addition, with regard to leakage current in applied pulse transmission or bias voltage and semiconductor circuit power supply by a conventional electric wire, if the insulation performance is pursued, the cable becomes thicker and harder and operability is lowered. In addition, regarding electromagnetic compatibility and reduction of unnecessary radiation, a pulse is transmitted by an electric wire and a weak reception signal is received through the same path. In addition, it is often unavoidable that external noise is mixed into the screen, and it is also necessary to sacrifice sensitivity in order to comply with the standard. Furthermore, in order to keep unwanted radiation within the standard, measures such as lowering the voltage are necessary, which may lead to performance degradation.

  As described above, in the ultrasonic probe using the piezoelectric transducer array, the high flexibility of the connection cable between the ultrasonic probe and the apparatus main body and the reduction in size and weight of the ultrasonic probe itself are not achieved. There is a trade-off relationship.

  The present invention has been made in view of the above problems, and can improve the flexibility of the connection cable between the ultrasonic probe and the apparatus main body, and can improve the operability and work efficiency. An object of the present invention is to provide an ultrasonic imaging apparatus.

In order to achieve the above-described object, the first invention is an ultrasonic probe for an ultrasonic imaging apparatus that transmits and receives ultrasonic waves to and from a subject using a cMUT , the ultrasonic probe . A detachable part that can be attached to and detached from the main body part of the child, and the detachable part includes a photoelectric signal conversion element that converts an optical signal into an electrical signal, or an electrical / optical signal conversion element that converts the electrical signal into an optical signal , The cMUT, and a bias voltage supply unit are provided, and the ultrasonic wave is related to the ultrasonic wave using a first optical fiber cable that connects the detachable unit and the main body of the ultrasonic imaging apparatus. There line transmission and reception of signals, the detachable unit, as the bias voltage supply unit, comprising a photoelectric energy converting element which converts light energy into electrical energy, wherein said detachable portion of the main body portion of the ultrasonic imaging apparatus Connect between The optical energy input through a second optical fiber cable different from the first optical fiber cable is converted into electrical energy by the photoelectric energy conversion element, and a bias voltage is supplied to the cMUT. This is an ultrasonic probe.
A second invention is an ultrasonic probe for an ultrasonic imaging apparatus that transmits and receives ultrasonic waves to and from a subject using a cMUT, and is attached to and detached from a main body of the ultrasonic probe. An attachable / detachable part, wherein the attachable / detachable part includes at least one of an optical / electrical signal conversion element that converts an optical signal into an electric signal, an electric / optical signal conversion element that converts the electric signal into an optical signal, and the cMUT, A bias voltage supply unit, and transmits and receives signals related to the ultrasonic wave using a first optical fiber cable that connects between the detachable unit and the main body of the ultrasonic imaging apparatus, and the detachable unit The ultrasonic probe has a rechargeable battery and a bias control circuit as the bias voltage supply unit, and supplies a bias voltage from the rechargeable battery to the cMUT via the bias control circuit. Is

As the ultrasonic transducer, it is desirable to use a capacitive micromachine ultrasonic transducer (cMUT). The photoelectric signal conversion element is a photodiode or the like. The electro-optical signal conversion element is a surface emitting laser or the like. The ultrasonic probe is provided with a device mixed chip including an optical communication module and an ultrasonic transducer.
An optical fiber is used in place of the metal wire for the connection cable that connects the main body of the ultrasonic imaging apparatus and the ultrasonic probe. Signals and energy are transmitted and received between the main body of the ultrasonic imaging apparatus and the ultrasonic probe via a cable having an optical fiber.
Thereby, without increasing the weight and volume of the ultrasonic probe itself, the flexibility of the connection cable between the ultrasonic probe and the apparatus main body can be improved, and the operability and work efficiency can be improved. it can.

According to the first invention or the second invention , the portion in contact with the subject can be made disposable or replaceable. Since it is not necessary to use the same ultrasonic radiation surface for many subjects at the time of ultrasonic diagnosis, it is possible to improve hygiene.
Further, the main body of the ultrasonic imaging apparatus and the ultrasonic probe are connected by a connection cable including only an optical fiber. Compared with a connection cable having a coaxial metal wire, a connection cable having a light weight and high flexibility can be used, and the ultrasonic diagnostic workability can be greatly improved. Since no metal wire is used, the problem of electromagnetic radiation noise can be solved.

It is preferable that an optical modulator for changing the phase of the light is provided, and the modulated light from the optical modulator is transmitted by the first optical fiber cable . Thereby, high-speed modulation is possible by the optical external modulation method, and the communication speed and the transmission amount can be improved.
The detachable portion includes a chip on which the cMUT is provided and a substrate on which the chip is mounted, and an ultrasonic absorption layer is provided between the chip and the substrate or on the back surface of the substrate. It is desirable. This makes it possible to prevent ultrasonic radiation from the chip to the substrate side.

According to a third aspect of the present invention, there is provided an ultrasonic probe that transmits and receives ultrasonic waves to and from a subject using a cMUT , a transmission unit that supplies a drive signal to the ultrasonic probe, and the ultrasonic probe Ultrasound including receiving means for processing a reception signal output from the child, image processing means for reconstructing an ultrasonic image based on the signal output from the receiving means, and display means for displaying the ultrasonic image In the imaging apparatus, the ultrasonic probe includes an attachment / detachment portion that is attachable / detachable to / from a main body portion of the ultrasonic probe, and the attachment / detachment portion includes light that converts an optical signal into an electrical signal. At least one of an electrical signal conversion element or an electrical / optical signal conversion element that converts the electrical signal into an optical signal , the cMUT, and a bias voltage supply unit are provided, and the attachment / detachment unit and the main body of the ultrasonic imaging apparatus First optical fiber cable connecting between There line transmission and reception of signals relating to the ultrasonic using Le, the detachable unit, as the bias voltage supply unit, comprising a photoelectric energy converting element which converts light energy into electrical energy, wherein said detachable portion exceeds A light energy input through a second optical fiber cable different from the first optical fiber cable is converted into electric energy by the photoelectric energy conversion element. An ultrasound imaging apparatus, wherein a bias voltage is supplied to the cMUT .
According to a fourth aspect of the present invention, there is provided an ultrasonic probe that transmits and receives ultrasonic waves to and from a subject using a cMUT, a transmission unit that supplies a driving signal to the ultrasonic probe, and the ultrasonic probe Ultrasound including receiving means for processing a reception signal output from the child, image processing means for reconstructing an ultrasonic image based on the signal output from the receiving means, and display means for displaying the ultrasonic image In the imaging apparatus, the ultrasonic probe includes an attachment / detachment portion that is attachable / detachable to / from a main body portion of the ultrasonic probe, and the attachment / detachment portion includes light that converts an optical signal into an electrical signal. At least one of an electrical signal conversion element or an electrical / optical signal conversion element that converts the electrical signal into an optical signal, the cMUT, and a bias voltage supply unit are provided, and the attachment / detachment unit and the main body of the ultrasonic imaging apparatus First optical fiber cable connecting between The transmission / reception unit includes a rechargeable battery and a bias control circuit as the bias voltage supply unit, and the rechargeable battery is connected to the cMUT via the bias control circuit. An ultrasonic imaging apparatus that supplies a bias voltage.

  2nd invention is invention regarding an ultrasonic imaging apparatus provided with the ultrasonic probe of 1st invention.

  ADVANTAGE OF THE INVENTION According to this invention, the flexibility of the connection cable between an ultrasonic probe and an apparatus main body can be improved, and operativity and work efficiency can be improved.

  Hereinafter, preferred embodiments of an ultrasonic imaging apparatus according to the present invention will be described in detail with reference to the accompanying drawings. In the following description and the accompanying drawings, the same reference numerals are given to components having substantially the same functional configuration, and redundant description will be omitted.

(1. First embodiment)
First, the ultrasonic imaging apparatus 100 according to the first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a schematic configuration diagram of an ultrasonic imaging apparatus 100.
The ultrasonic imaging apparatus 100 is configured by connecting an apparatus main body 1 and an ultrasonic probe 3 with a connection cable 5.
The ultrasonic imaging apparatus 100 transmits / receives ultrasonic waves to / from the subject 27 by the ultrasonic probe 3, performs image processing in the apparatus main body 1, and outputs a captured image of the subject to the display unit 29.

The apparatus main body 1 includes a control unit 11, a transmission phasing circuit 12, an E / O element 13, a receiving phasing circuit 23, and an O / E element 22. The apparatus main body 1 is connected to a display unit 29 such as a display via an image processing unit 28 including an image processor.
The connection cable 5 is an optical fiber-metal composite cable, and includes a metal wire 25, an optical fiber 14, and an optical fiber 21.

The ultrasonic probe 3 includes an O / E element 15, a D / A converter 16, a transmission / reception selector switch 17, an amplifier 18, an A / D converter 19, an E / O element 20, and a cMUT 26 (capacitive micromachine ultrasonic transducer). Is provided.
The O / E element 15 and the O / E element 22 are elements that convert optical signals into electrical signals, and are, for example, photodiodes.
The E / O element 13 and the E / O element 20 are elements that convert electrical signals into optical signals, and are, for example, surface emitting lasers.
A D / A converter 16, a transmission / reception selector switch 17, an amplifier 18, an A / D converter 19, and a cMUT 26 are provided on the same mixed chip 7.

The transmission / reception electrical pulse signal is converted into an optical signal after being converted into a digital signal by the apparatus main body 1 or the ultrasonic probe 3, and the apparatus main body 1 and the ultrasonic probe are transmitted using the optical fiber 14 and the optical fiber 21 of the connection cable 5 as media. It is transmitted between the touch 3.
A bias voltage or the like for driving devices such as the cMUT 26, the O / E element 15, and the E / O element 20 is applied through the metal wire 25 of the connection cable 5.

  The control unit 11 of the apparatus main body 1 sends a digital electric signal to the wave transmission phasing circuit 12. The transmission wave phasing circuit 12 performs beam forming processing on the digital electric signal and sends the transmission digital electric signal to the E / O element 13. The E / O element 13 converts the transmitted digital electrical signal into a transmitted digital optical signal and transmits it to the optical fiber 14. The transmitted digital optical signal is transmitted to the ultrasonic probe 3 through the optical fiber 14.

The O / E element 16 of the ultrasonic probe 3 converts the transmitted digital optical signal into a transmitted digital electric signal. The D / A converter 16 converts the transmitted digital electrical signal into analog form. The transmitted analog electrical signal is applied to the cMUT 26 at a timing designated by the transmission / reception changeover switch 17 and is irradiated to the subject 27 as an ultrasonic pulse.
The ultrasonic echo signal reflected from the subject 27 is detected by the cMUT 26 and converted into a received analog electrical signal. The amplifier 18 amplifies the received analog electrical signal. The A / D converter 19 digitizes the received analog electrical signal and applies it to the E / O element 20.
The E / O element 20 of the ultrasonic probe 3 converts the received digital electrical signal into a received digital optical signal. The received digital optical signal is transmitted to the apparatus main body 1 through the optical fiber 21.
The processes from the D / A converter 16 to the A / D converter 19 can all be performed on the mixed chip 7.

  The O / E element 22 of the apparatus main body 1 converts the received digital optical signal into a received digital electric signal. The received wave phasing circuit 23 performs beam forming processing on the received digital electric signal. The image processing unit 28 performs addition processing, detection processing, and the like on the digital electrical signal sent from the wave receiving phasing circuit 23 to display an ultrasound diagnostic image on the display unit 29.

FIG. 2 is a structural diagram of the cMUT 26.
FIG. 3 is a diagram showing the arrangement of the cMUT 26.

The cMUT 26 includes a substrate 45 such as silicon (Si), a flexible thin film 43 formed on the surface of the substrate 45, an insulating material 42 such as silicon nitride (Si ₃ N ₄ ) that supports the periphery of the thin film 43, and a substrate 45. ~ A vacuum gap layer 44 formed between the thin films 43, a lower electrode 46, and an upper electrode 41.

The cMUT 26 is a transducer whose ultrasonic transmission / reception sensitivity changes according to the magnitude of a bias voltage applied in a superimposed manner on a drive signal for driving the cMUT 26. When transmitting / receiving ultrasonic waves by the cMUT 26, the transmission / reception sensitivity of the cMUT 26 is adjusted to a predetermined value by applying a predetermined bias to the cMUT 26 to change the electromechanical coupling coefficient of the vibrator.
When an appropriate voltage signal is applied between the upper electrode 41 and the lower electrode 46, the cMUT 26 functions as a capacitive ultrasonic transducer cell. A received electrical signal is obtained by capturing an ultrasonic echo signal as a change in kinetic energy of the thin film 43 and detecting a change in current value associated therewith.
As shown in FIG. 3, a plurality of (for example, several tens) cMUTs 26 are used.

FIG. 4 is a schematic configuration diagram of the ultrasonic probe 3.
FIG. 5 is a schematic perspective view of the ultrasonic probe 3.

The mixed chip 7 is mounted on the printed board 33. In order to prevent ultrasonic radiation from the mixed chip 7 to the printed circuit board 33 side, it is desirable to adhere an ultrasonic absorption layer (backing layer) between the mixed chip 7 and the printed circuit board 33 or to the back surface of the printed circuit board 33.
The wire 34 is an electrical wiring provided between the mixed chip 7 and the printed board 33.
A printed circuit board 33 provided on the back side of the ultrasonic radiation surface has a PIN (p-intrinsic-n) photodiode 31 as the O / E element 15 and a surface emitting laser 32 (a type of semiconductor laser as the E / O element 20). A VCSEL (Vertical Surface Emitting Laser) and electrical wiring connector 35 are attached.

The PIN photodiode 31, the surface emitting laser 32, and the electrical wiring connector 35 are connected to the optical fiber 14, the optical fiber 21, and the metal wire 25 of the connection cable 5, respectively. The connection cable 5 is connected to the apparatus main body 1.
The connection terminal with the apparatus main body 1 is an optical fiber and metal wire connection connector. For optical fiber connection, for example, an MT connector that is an optical fiber multi-core collective connector can be used. Moreover, regarding metal wire connection, it is possible to easily connect between devices by using, for example, a connector fitting pin.

As described above, in the ultrasonic imaging apparatus 100 according to the first embodiment, an optical fiber is used in place of the metal wire for the connection cable connecting the apparatus main body 1 and the ultrasonic probe 3, and the ultrasonic probe is used. A device mixed chip including an optical communication module and a cMUT is provided on the contact 3.
Therefore, it is possible to realize miniaturization of the ultrasonic probe, low crosstalk of the cable, improvement of cable flexibility, large-capacity communication, and optical interconnection in the housing.
That is, without increasing the weight or volume of the ultrasonic probe itself, the flexibility of the connection cable between the ultrasonic probe and the apparatus main body can be improved, and the operability and work efficiency can be improved. .

When a beam is formed with 64 channels at the time of cMUT driving, the sampling rate is 40 MHz, and the conversion rate by the A / D converter is 12 bits / ch / clock, the transmission rate of the communication medium needs to be 30 Gbps at the minimum.
ITU-T (International Telecommunication Union Telecommunication Standardization Sector) G. currently used in short-distance optical communication. A graded index (GI) graded multi-mode optical fiber represented by 650 has already been put into practical use at a wavelength of 850 nm and satisfying a transmission rate of 10 Gbps / km.
In addition, for optical communication for ultra short distances, a plastic optical fiber (POF: Plastic optical fiber) having a large core diameter and high flexibility assuming a laying distance of several tens of meters has also achieved a transmission speed of 10 Gbps. .

Accordingly, when digital communication is performed between an ultrasonic probe and an ultrasonic imaging device using an optical fiber, an ultrasonic signal can be transmitted theoretically if there is a minimum of four-core optical fibers. A method of connecting a four-core fiber tape with an MT connector has already been put into practical use in conventional optical communication, and a connection with very low loss is possible.
Further, wavelength multiplexed communication can be performed by performing single mode optical communication using a single mode optical fiber or the like. In this case, it is necessary to use light of all different wavelengths for signals, and to provide fiber Bragg gratings, couplers, etc. in the ultrasonic probe and the ultrasonic imaging apparatus, but ultimately one optical fiber. Signal transmission can be performed at

The E / O element and the O / E element are both semiconductor components and ultra-small devices.
A semiconductor laser is generally used as the E / O element. In particular, surface emitting lasers that are being used in recent years for optical interconnection and the like can extract light in the direction of the semiconductor film stacking as compared with conventional semiconductor lasers such as LD (Laser Diode), and thus can be easily arrayed. In addition, it has features such as low power consumption, high conversion efficiency, low threshold operation, and high-speed direct modulation, and is most practical as an electro-optical conversion element when performing electro-optical mixed mounting. As a light emitting material used for the surface emitting laser, a compound using an element such as Ga (gallium), In (indium), Al (aluminum), P (phosphorus), As (arsenic), or N (nitrogen) is used. A surface emitting laser is manufactured by forming these compounds into a multilayer film on a GaAs (gallium arsenide) substrate. This multilayer structure is selected and optimized according to the wavelength used.

  A photodiode can be used as the O / E element. A photodiode is a device manufactured using a semiconductor film-forming technique, and it is necessary to use a high-sensitivity specification for the wavelength used. A bias current for driving the photodiode is supplied by a metal line. For example, when a surface emitting laser is used as a light source and light having a communication wavelength of 850 nm is used, it is optimal to use a photodiode using Si (silicon). On the other hand, when light having a wavelength longer than 1 μm is used for communication, a material having a smaller forbidden bandwidth than Si (silicon) is used, and Ge (germanium), Ga (gallium), In (indium), It is made of a compound made of a material such as As (arsenic). The optical communication wavelength in the present invention is preferably selected in accordance with the relationship between the detection sensitivity wavelength dependency of the light source and the photodetector and the transmission rate of the optical fiber.

As a system in the ultrasonic imaging apparatus, the received signal is processed at high speed by an in-apparatus computer and imaged. As the amount of calculation processing increases, the load on the computer in the apparatus increases and the processing capability decreases. Therefore, it is desirable to use a computer with high processing capability capable of high-speed calculation processing as much as possible as the computer in the ultrasonic imaging apparatus.
Computers based on current electrical mounting using copper wiring have problems such as signal degradation, increased power consumption, electromagnetic interference, and the like as clock speed increases. For example, even if a CMOS (Complementary Metal-Oxide Semiconductor) base transistor is increased in speed, the clock frequency of the microprocessor is improved by increasing the integration density, and a data transmission rate of 20 Gbps can be realized, the communication speed is actually about 15 Gbps. Becomes the limit. In order to solve this problem, an optical interconnection technology for performing signal transmission / reception within a computer using an optical signal is being developed. Optical interconnection technology has many advantages over metal line interconnection, including low transmission loss, low crosstalk, and wide bandwidth even at high frequencies.

  This optical interconnection technology is expected to be applied in the future to computers in ultrasonic diagnostic apparatuses that require high-speed arithmetic processing. The present invention constructs an ultrasonic imaging apparatus system in that an optical signal transmitted to an ultrasonic probe can be directly transmitted to an in-apparatus computer in response to such in-apparatus computer optical interconnection. Has the advantage that can be facilitated.

Although FIG. 4 shows the shape of a linear type probe, a probe having the same structure can be configured with respect to a convex type or sector type structure.
In this case, a multi-chip configuration in which bare chips of different processes are mounted on a substrate, or a method of forming the same semiconductor is possible. Also, a method in which a plurality of processes are performed on the same semiconductor material is possible. The same applies to the embodiments described later.

(2. Second Embodiment)
Next, an ultrasonic imaging apparatus 200 according to the second embodiment of the present invention will be described with reference to FIGS. 6 and 7.

FIG. 6 is a schematic configuration diagram of the ultrasonic imaging apparatus 200.
FIG. 7 is a schematic configuration diagram of the ultrasonic probe 203.

The ultrasonic imaging apparatus 200 is configured by connecting an apparatus main body 201 and an ultrasonic probe 203 with a connection cable 205.
The apparatus main body 201 and the connection cable 205 are the same as the apparatus main body 1 and the connection cable 5 of the first embodiment.

  The apparatus main body 201 and the ultrasound probe 203 have an E / O element 13 and an O / E element 22, an O / E element 15 and an E / O element 20, respectively. The connection cable 205 is a composite cable of the metal wire 25, the optical fiber 14, and the optical fiber 21.

  The ultrasonic probe 203 includes an ultrasonic probe main body portion 8 and an attachment / detachment portion 9 that can be attached to and detached from the ultrasonic probe main body portion 8. The detachable part 9 includes a mixed chip 7. Power supply and signal transmission / reception between the apparatus main body 201 and the attachment / detachment unit 9 are performed in a non-contact manner at the connection point 53, the connection point 54, and the connection point 55.

  The ultrasonic probe body 8 includes a non-contact power transmission coil 51 for supplying power, and the detachable unit 9 includes a non-contact power reception coil 52 for receiving power. By the non-contact power supply method, power can be supplied to the embedded chip 7 to drive each device of the embedded chip 7.

A digital optical signal for signal transmission / reception is transmitted between the optical fiber 14 and the O / E element 15 and between the optical fiber 21 and the E / O element 20 by spatial connection.
In addition, a connection loss can be reduced by arrange | positioning an optical lens in a space connection site | part. When optical signals are connected by spatial connection, transmission loss due to optical axis misalignment is likely to occur. Therefore, it is desirable to fit the ultrasonic probe main body 8 and the detachable portion 9 by precise alignment.

As described above, in the second embodiment, an optical fiber is used for the connection cable instead of the metal wire, and the device including the optical communication module and the cMUT is provided on the ultrasonic probe. This has the same effect as the embodiment.
In the ultrasonic imaging apparatus 200 according to the second embodiment, the ultrasonic probe 203 includes an ultrasonic probe main body 8 and a detachable portion 9 that can be attached to and detached from the main body 8.
Therefore, the portion that contacts the subject can be made disposable or replaceable. Since it is not necessary to use the same ultrasonic radiation surface for many subjects at the time of ultrasonic diagnosis, it is possible to improve hygiene.

(3. Third embodiment)
Next, an ultrasonic imaging apparatus 300 according to the third embodiment of the present invention will be described with reference to FIG.

FIG. 8 is a schematic configuration diagram of the ultrasonic imaging apparatus 300.
The ultrasonic imaging apparatus 300 is configured by connecting an apparatus main body 301 and an ultrasonic probe 303 by a connection cable 305.
The ultrasonic imaging apparatus 300 according to the third embodiment performs power feeding by a rechargeable battery instead of the non-contact power feeding in the ultrasonic imaging apparatus 200 according to the second embodiment.
Therefore, the apparatus main body 301 is not provided with the bias control circuit 24. Further, although the optical fiber 14 and the optical fiber 21 are provided in the connection cable 305, the metal wire 25 is not provided. Further, the ultrasonic probe 303 is not provided with the non-contact power transmission coil 51 and the non-contact power reception coil 52.

  On the other hand, the attachment / detachment unit 9 is provided with a rechargeable battery 56 and a bias control circuit 57. The detachable portion 9 is removed from the ultrasonic probe main body portion 8, and the rechargeable battery 56 is charged from the external power source via the connection point 58. After charging, the detachable portion 9 is attached to the ultrasonic probe main body 8, and power is supplied from the rechargeable battery 56 to the mixed chip 7, the O / E element 15, etc. via the bias control circuit 57.

As described above, in the third embodiment, an optical fiber is used instead of a metal wire for the connection cable, and the device-embedded chip including the optical communication module and the cMUT is provided for the ultrasonic probe. This has the same effect as the embodiment.
Further, in the ultrasonic imaging apparatus 300 according to the third embodiment, the rechargeable battery 56 is provided in the attaching / detaching unit 9, and the rechargeable battery 56 supplies power to each device of the ultrasonic probe 303. Therefore, as in the second embodiment, the portion in contact with the subject can be made disposable or replaceable, and the hygiene can be improved. Further, in the third embodiment, it is not necessary to provide a bias control circuit on the apparatus main body 301 side, and no power supply metal line is required.

(4. Fourth embodiment)
Next, an ultrasonic imaging apparatus 300 according to the fourth embodiment of the present invention will be described with reference to FIG.

FIG. 9 is a schematic configuration diagram of the ultrasonic imaging apparatus 400.
The ultrasonic imaging apparatus 400 is configured by connecting an apparatus main body 401 and an ultrasonic probe 403 by a connection cable 405.

The apparatus main body 401 is provided with a light source 61. The light source 61 is a light source such as an ultraviolet light laser, a visible light laser, a white light source, or a deuterium lamp.
The connection cable 405 is provided with an optical fiber 62 instead of the metal wire 25 of the connection cable 5 of the first embodiment.
The ultrasonic probe 403 is provided with an O / E element 63 that converts light energy into electric energy. The O / E element 63 is not a photodiode but a photoelectric conversion element using amorphous silicon, silicon single crystal, polycrystal, compound semiconductor, dye-sensitized solar cell, or the like.

Between the apparatus main body 401 and the ultrasonic probe 403, not only the ultrasonic transmission / reception signal but also the bias current is converted into light and transmitted through the optical fiber 62.
The O / E element 63 of the ultrasonic probe 403 converts light energy into electric energy and supplies a bias voltage to each device of the ultrasonic probe 403.
It should be noted that the devices of the light source 61 and the O / E element 63 are preferably selected so as to have the highest conversion efficiency.

As described above, in the fourth embodiment, an optical fiber is used for the connection cable instead of the metal wire, and the ultrasonic probe is provided with the device mixed chip including the optical communication module and the cMUT. This has the same effect as the embodiment.
In the fourth embodiment, the apparatus main body 401 and the ultrasonic probe 403 are connected by a connection cable 405 including only an optical fiber. For example, when the number of cores of the connection cable 405 is 8 cores for ultrasonic signal transmission / reception and 2 cores for bias supply, the total number is about 10 cores.
Therefore, compared to a connection cable having a coaxial metal wire, a connection cable having a light weight and high flexibility can be used, and the ultrasonic diagnostic workability can be greatly improved. Further, since a metal wire is not used as a connection cable between the apparatus main body 401 and the ultrasonic probe 403, the problem of electromagnetic radiation noise can be solved.

Similarly to the second embodiment, an attaching / detaching portion 409 is provided, and the attaching / detaching portion 409 is provided with the O / E element 63, the O / E element 15, the E / O element 20, and the mixed chip 7. The part in contact with the specimen can be made disposable or replaceable. Since it is not necessary to use the same ultrasonic radiation surface for many subjects at the time of ultrasonic diagnosis, it is possible to improve hygiene.
Furthermore, since the fourth embodiment is electrically insulated, it can be designed without limiting the part to be replaced. In this case, the optical communication connection portion corresponding to power supply and signal application requires accuracy, but can be implemented by application of a commonly used optical communication connector. In addition, unlike conventional products that require mechanical micromachining such as PZT (lead zirconate titanate) vibrators, the manufacturing cost can be reduced because the main part is a semiconductor process.

(5. Fifth embodiment)
Next, an ultrasonic imaging apparatus 500 according to the fifth embodiment of the present invention will be described with reference to FIGS.

FIG. 10 is a schematic configuration diagram of the ultrasonic imaging apparatus 500.
The ultrasonic imaging apparatus 500 is configured by connecting an apparatus main body 501 and an ultrasonic probe 503 by a connection cable 505.

The apparatus main body 501 is provided with an E / O element 72, an O / E element 74, and a detection circuit 75.
The ultrasonic probe 503 is provided with an optical modulator 71. The optical modulator 71 is mounted on the ultrasonic probe 503 as a device different from the embedded chip 7.
The connection cable 505 is an optical fiber-metal composite cable, and an optical fiber 73 is provided. The optical fiber 73 mediates transmission of an optical signal between the optical modulator 71 on the ultrasonic probe 503 side and the E / O element 72 and the O / E element 74 on the apparatus main body 501 side.

  The ultrasonic echo signal reflected from the subject 27 is detected by the cMUT 26 and converted into a received analog electrical signal. The amplifier 18 amplifies the received analog electrical signal. The A / D converter 19 digitizes the received analog electrical signal and applies it to the optical modulator 71.

  Monochromatic light from a semiconductor laser such as a surface emitting laser on the apparatus main body 501 side enters an optical modulator 71 on the ultrasonic probe 503 side through an optical fiber 73. The incident monochromatic light is modulated by the optical modulator 71 and again enters the apparatus main body 501 through the optical fiber 73. The detection circuit 75 detects the modulated light and acquires an ultrasonic signal.

As described above, in the fifth embodiment, an optical fiber is used instead of a metal wire for the connection cable, and a device mixed chip including an optical communication module and a cMUT is provided on the ultrasonic probe. This has the same effect as the embodiment.
Also, in the ultrasonic imaging apparatus 500 of the fifth embodiment, the optical modulator 71 is provided on the ultrasonic probe 503 side, and the detection circuit 75 is provided on the apparatus main body 501 side.
Therefore, high-speed optical modulation is possible by the optical external modulation method, and the communication speed and transmission amount can be improved.

  The optical modulator 71 is a device using a MEMS mirror (Micro Electro Mechanical System), a multilayer mirror, a refractive index anisotropic change type modulator, and a refractive index change type modulator.

  A MEMS mirror is a micro device manufactured by microfabrication. The MEMS mirror can change the angle of the mirror by an external electric signal. Since the monochromatic light emitted from the optical fiber by the MEMS mirror is polarized, the MEMS mirror can be operated as a light intensity modulation element.

The multilayer mirror is manufactured, for example, by bonding a PZT (lead zirconate titanate) element to a multilayer film composed of materials having different refractive indexes such as SiO ₂ (silicon oxide) / TiO ₂ (titanium oxide). The multilayer mirror can be used as a device utilizing an acoustooptic effect. A digital electric signal transmitted from the embedded chip is applied to the PZT element to change the film thickness of the multilayer film. The Bragg grating wavelength is determined by the film thickness and refractive index of the multilayer film, and the applied digital electric signal changes the reflected light wavelength. By detecting the light intensity at a certain wavelength using this effect, the multilayer mirror can be operated as a light intensity modulation element.

As for the refractive index anisotropy change type modulator, a crystal exhibiting an electrooptic effect such as LiTaO ₃ (lithium tantalate) can be used. Light waves passing through these crystals are divided into ordinary light and extraordinary light depending on the direction of the plane of polarization, and travel at different speeds. At this time, when a voltage is applied to the crystal, the speed of these light rays changes, a phase difference is generated, and the light intensity can be modulated.

In addition, as a refractive index change type modulator that changes the refractive index of the medium itself by electricity, an optical waveguide element constituted by an MZ (Mach-Zehnder) type interferometer using LiNbO ₃ (lithium niobate) or the like is used. can do.

FIG. 11 is a schematic configuration diagram of a refractive index change type modulator 80 as the optical modulator 71.
FIG. 12 is a schematic configuration diagram of a refractive index change type modulator 83 as the optical modulator 71.

Branched and aggregated waveguides are provided on the optical waveguide element 81, and the optical fiber 73 is coupled to the entrance and exit. An electrode 82 is provided so that an electric field is applied to one of the branched waveguides. Electrical wiring from the embedded chip 7 is connected to the electrode 82.
When an electrical signal is applied to the waveguide, a refractive index change due to the electro-optic effect is induced, and the interference pattern of the emitted light changes. By detecting this interference light, the light intensity modulation can be detected.

In FIG. 11, the optical signal is extracted by coupling the optical fiber 73 in the direction parallel to the waveguide circuit. However, by providing a mirror 84 in the waveguide as shown in FIG. It can also be taken out.
The optical modulator 71 has been described as being mounted on the ultrasonic probe 403 as a device separate from the embedded chip 7. However, the optical modulator 71 using a MEMS mirror is provided on the embedded chip 7. It may be.

(6. Others)
The preferred embodiments of the ultrasonic imaging apparatus according to the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea disclosed in the present application, and these are naturally within the technical scope of the present invention. Understood.

  Although the first embodiment to the fifth embodiment have been described, an ultrasonic imaging apparatus can be configured by appropriately combining them.

Schematic configuration diagram of the ultrasonic imaging apparatus 100 Structure diagram of cMUT26 The figure which shows arrangement | positioning of cMUT26 Schematic configuration diagram of the ultrasound probe 3 Schematic perspective view of the ultrasound probe 3 Schematic configuration diagram of the ultrasonic imaging apparatus 200 Schematic configuration diagram of the ultrasound probe 203 Schematic configuration diagram of the ultrasonic imaging apparatus 300 Schematic configuration diagram of the ultrasonic imaging apparatus 400 Schematic configuration diagram of the ultrasonic imaging apparatus 500 Schematic configuration diagram of a refractive index change type modulator 80 as an optical modulator 71 Schematic configuration diagram of a refractive index change type modulator 83 as an optical modulator 71

Explanation of symbols

100, 200, 300, 400, 500... Ultrasonic imaging device 1, 201, 301, 401, 501... Device main body 3, 203, 303, 403, 503 ..... Ultrasonic probe 5, 205 , 305, 405, 505 ......... Connection cable 7 ......... Mixed chip 8 ......... Ultrasonic probe main body 9 ......... Removable part 11 ......... Control part 12 ......... Transmission phasing circuit 13 , 20, 32, 72... E / O element (surface emitting laser, etc.)
14, 21, 62, 73 ..... Optical fiber 15, 22, 31, 74 ..... O / E element (photodiode etc.)
16 ......... D / A converter 17 ......... Transmission / reception selector switch 18 ......... Amplifier 19 ......... A / D converter 23 ......... Receiving phasing circuit 24, 57 ......... Bias control circuit 25 ......... Metal wire 26 ………… cMUT
27 .... Subject 28 ..... Image processing unit (image processor)
29 ……… Display (display)
51 ......... Non-contact power transmission coil 52 ......... Non-contact power reception coil 53, 54, 55, 58 ......... Connection point 56 ......... Rechargeable battery 61 ......... Light source 63 ......... O / E element (amorphous silicon) etc)
71 .... Optical modulator 75 ..... Detection circuit 80, 83 ........ Refractive index modulator 81 .... Optical waveguide element 82 ..... Electrode

Claims (8)

An ultrasound probe for an ultrasound imaging apparatus that transmits and receives ultrasound with a subject using a cMUT ,
A detachable part detachably attached to the main body of the ultrasonic probe,
The attachment / detachment unit includes at least one of an photoelectric signal conversion element that converts an optical signal into an electrical signal or an electrical / optical signal conversion element that converts the electrical signal into an optical signal , the cMUT, and a bias voltage supply unit. Provided,
There line transmission and reception of signals relating to the ultrasonic waves using a first optical fiber cable that connects the main body portion of said detachable unit and the ultrasonic imaging apparatus,
The attachment / detachment unit includes a photoelectric energy conversion element that converts light energy into electrical energy as the bias voltage supply unit ,
The photoelectric energy conversion element connects light energy input through the second optical fiber cable different from the first optical fiber cable by connecting the detachable part and the main body of the ultrasonic imaging apparatus. An ultrasonic probe that converts the electric energy into a bias voltage to the cMUT .   An ultrasound probe for an ultrasound imaging apparatus that transmits and receives ultrasound with a subject using a cMUT,
  A detachable part detachably attached to the main body of the ultrasonic probe,
  The attachment / detachment unit includes at least one of an photoelectric signal conversion element that converts an optical signal into an electrical signal or an electrical / optical signal conversion element that converts the electrical signal into an optical signal, the cMUT, and a bias voltage supply unit. Provided,
  Sending and receiving signals related to the ultrasonic wave using a first optical fiber cable connecting the detachable part and the main body part of the ultrasonic imaging apparatus,
  The detachable unit includes a rechargeable battery and a bias control circuit as the bias voltage supply unit,
  An ultrasonic probe, wherein a bias voltage is supplied from the rechargeable battery to the cMUT via the bias control circuit. Comprises an optical modulator for varying the phase of light, ultrasonic feeler according to light modulated by the optical modulator to claim 1 or claim 2, wherein the transmitting by the first optical fiber cable Child.   The detachable portion is provided with a chip provided with the cMUT and a substrate on which the chip is mounted,
  The ultrasonic probe according to any one of claims 1 to 3, wherein an ultrasonic absorption layer is provided between the chip and the substrate or on the back surface of the substrate. An ultrasonic probe that transmits and receives ultrasonic waves to and from a subject using a cMUT , a transmission unit that supplies a drive signal to the ultrasonic probe, and a reception that is output from the ultrasonic probe An ultrasonic imaging apparatus comprising: a receiving unit that processes a signal; an image processing unit that reconstructs an ultrasonic image based on a signal output from the receiving unit; and a display unit that displays the ultrasonic image.
The ultrasonic probe comprises a detachable part that can be attached to and detached from the main body of the ultrasonic probe,
The attachment / detachment unit includes at least one of an photoelectric signal conversion element that converts an optical signal into an electrical signal or an electrical / optical signal conversion element that converts the electrical signal into an optical signal , the cMUT, and a bias voltage supply unit. Provided,
There line transmission and reception of signals relating to the ultrasonic waves using a first optical fiber cable that connects the main body portion of said detachable unit and the ultrasonic imaging apparatus,
The attachment / detachment unit includes a photoelectric energy conversion element that converts light energy into electrical energy as the bias voltage supply unit ,
The photoelectric energy conversion element connects light energy input through the second optical fiber cable different from the first optical fiber cable by connecting the detachable part and the main body of the ultrasonic imaging apparatus. An ultrasonic imaging apparatus, wherein a bias voltage is supplied to the cMUT after being converted into electric energy.   An ultrasonic probe that transmits and receives ultrasonic waves to and from a subject using a cMUT, a transmission unit that supplies a drive signal to the ultrasonic probe, and a reception that is output from the ultrasonic probe An ultrasonic imaging apparatus comprising: a receiving unit that processes a signal; an image processing unit that reconstructs an ultrasonic image based on a signal output from the receiving unit; and a display unit that displays the ultrasonic image.
  The ultrasonic probe comprises a detachable part that can be attached to and detached from the main body of the ultrasonic probe,
  The attachment / detachment unit includes at least one of an photoelectric signal conversion element that converts an optical signal into an electrical signal or an electrical / optical signal conversion element that converts the electrical signal into an optical signal, the cMUT, and a bias voltage supply unit. Provided,
  Sending and receiving signals related to the ultrasonic wave using a first optical fiber cable connecting the detachable part and the main body part of the ultrasonic imaging apparatus,
  The detachable unit includes a rechargeable battery and a bias control circuit as the bias voltage supply unit,
  An ultrasonic imaging apparatus, wherein a bias voltage is supplied from the rechargeable battery to the cMUT via the bias control circuit. The ultrasonic imaging apparatus according to claim 5 , further comprising: an optical modulator that changes a phase of light, wherein the modulated light by the optical modulator is transmitted by the first optical fiber cable. . The detachable portion is provided with a chip provided with the cMUT and a substrate on which the chip is mounted,
The ultrasonic imaging apparatus according to claim 5, wherein an ultrasonic absorption layer is provided between the chip and the substrate or on the back surface of the substrate .

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