Ultrasound diagnostic appartus with CMUT bias voltage discharge system

An ultrasound diagnostic system includes a connection section for detachably connecting an ultrasound device mounted with a capacitive micromachined ultrasonic transducer (C-MUT) and a transmission signal generation section that generates a transmission signal using a connector provided in the ultrasound device and a connector receiver provided in the ultrasound observation apparatus, a discharge section for discharging the charge applied to the C-MUT, a lock mechanism that keeps the connection section in a locked state and a released state and a switching section arranged on a signal line between the C-MUT and the ultrasound observation apparatus, wherein when a predetermined mounting state is set, the C-MUT is electrically connected to the transmission signal generation section via the signal line, and through switching by the switching section after an operation of unlocking the lock mechanism, a state is set in which the charge of the C-MUT of the ultrasound device is discharged.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an ultrasound diagnostic system using a capacitive micromachined ultrasonic transducer.

2. Description of the Related Art

An ultrasonic transducer using a capacitive micromachined ultrasonic transducer (hereinafter referred to as “C-MUT”), which is different from a piezoelectric transducer, has recently been developed, and an ultrasound diagnostic system is being proposed which is used for an inspection using ultrasound with an ultrasound probe or ultrasound endoscope mounted with the ultrasonic transducer connected therewith.

The C-MUT has a structure in which one cavity is provided in a silicon substrate and electrodes are provided on and below the cavity, and by applying an ultrasound drive signal (or transmission signal) together with a bias voltage to these electrodes, a film above the cavity is made to vibrate to transmit ultrasound, a returned echo signal is detected with the upper film and transmission/reception of ultrasound is thereby realized.

Since the C-MUT has a structure using a capacitive micromachined ultrasonic transducer, the C-MUT is liable to store charge and when the C-MUT continuously drives ultrasound for a long time, a certain amount of charge is accumulated.

In order to alleviate disadvantages of the deterioration in electric acoustic conversion efficiency in the upper film due to the accumulation of charge, International Publication No. 2007/029357 as a first related art discloses that sensitivity during transmission/reception is corrected by monitoring the amount of charge.

Furthermore, as a second related art, International Publication No. 2005/120359 discloses means for adjusting a DC bias voltage when the DC bias voltage is superimposed on a high frequency pulse as a transmission signal and applied to the C-MUT.

SUMMARY OF THE INVENTION

An ultrasound diagnostic system according to one aspect of the present invention includes an ultrasound device mounted with a capacitive micromachined ultrasonic transducer, a connection section for detachably connecting the ultrasound device and an ultrasound observation apparatus provided with a transmission signal generation section that generates a transmission signal to drive the capacitive micromachined ultrasonic transducer using a connector provided in the ultrasound device and a connector receiver provided in the ultrasound observation apparatus, a discharge section for discharging the charge applied to the capacitive micromachined ultrasonic transducer, a lock mechanism that keeps, when the connector is set in a predetermined mounting state with respect to the connector receiver, a locked state in which the connector is prevented from disconnecting from the connector receiver, and that sets a released state in which the locked state is released through an unlock operation and a switching section arranged on a signal line between the capacitive micromachined ultrasonic transducer and the ultrasound observation apparatus, wherein when the predetermined mounting state is set, the capacitive micromachined ultrasonic transducer is electrically connected to the transmission signal generation section via the signal line, and through switching of the switching section after the unlock operation with respect to the lock mechanism, a state is set in which the charge of the capacitive micromachined ultrasonic transducer in the ultrasound device that can be disconnected from the ultrasound observation apparatus is discharged by the discharge section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

First Embodiment

FIG. 1illustrates an overall configuration of an ultrasound diagnostic system1according to a first embodiment of the present invention. The ultrasound diagnostic system1includes an ultrasound probe unit2as an ultrasound device for inspecting a subject using ultrasound and an ultrasound endoscope3as an ultrasound device inserted into the body cavity of the subject and provided with a function of performing an inspection using ultrasound and an endoscope function.

Furthermore, the ultrasound diagnostic system1is provided with connector receivers5A and5B constituting connection sections to which connectors4A and4B of the ultrasound probe unit2and the ultrasound endoscope3are detachably connected and is also constructed of an ultrasound observation apparatus body (hereinafter simply abbreviated as “observation apparatus body”)6A provided with a transmission/reception signal processing system that transmits/receives ultrasound and a monitor6B as a display apparatus. The observation apparatus body6A and the monitor6B constitute an observation apparatus6.

The ultrasound probe unit2includes an ultrasound probe13incorporating, for example, a mechanical scan capacitive micromachined ultrasonic transducer (hereinafter abbreviated as “C-MUT”)10as an ultrasonic transducer for transmitting/receiving ultrasound, an ultrasound probe drive unit (hereinafter abbreviated as “drive unit”)11to which the ultrasound probe13is detachably connected and a cable section12that extends from the drive unit11. The connector4A detachably connected to the above described connector receiver5A is provided at an end of the cable section12. The connector receiver5A constitutes a connection section to which an ultrasound device driven according to a mechanical scan scheme such as the ultrasound probe unit2is detachably connected.

On the other hand, the above described connector receiver5B constitutes a connection section of an ultrasound device driven according to an electronic scan such as the ultrasound endoscope3.

The ultrasound endoscope3is provided with an insertion portion14inserted into the body cavity of the subject, an operation section15provided at a rear end (proximal end) of the insertion portion14and a universal cable section16that extends from the operation section15.

An endoscope connector17connected to an endoscope light source device (not shown) and a processor is provided at an end of the universal cable section16. A cable section18extends from the endoscope connector17and the connector4B detachably connected to the above described connector receiver5B is provided at an end of the cable section18.

For example, an electronic scan C-MUT9as an ultrasonic transducer for transmitting/receiving ultrasound is provided at a distal end portion19provided at a distal end of the insertion portion14of the above described ultrasound endoscope3.

A C-MUT10mounted at a distal end portion of the ultrasound probe13in the ultrasound probe unit2performs, for example, radial mechanical scan and the C-MUT9mounted on the ultrasound endoscope3performs, for example, sector electronic scan.

FIG. 2Aillustrates an internal configuration of the electric system of the ultrasound probe unit2and the observation apparatus6in an operating state andFIG. 2Billustrates an internal configuration of the electric system of the ultrasound endoscope3and the observation apparatus6in an operating state.

As shown inFIG. 2B, in (the distal end portion19of) the insertion portion14of the ultrasound endoscope3, for example, a plurality of C-MUT elements9a, . . . ,9nare arranged along a curved surface to form the sector electronic scan C-MUT9.

In each C-MUT element9i(i=a, . . . , n), an upper electrode21iand a lower electrode22iare formed facing each other across a cavity. The upper electrode21iin each C-MUT element9iis connected to a ground (G inFIG. 2B), that is, grounded via a signal line23i.

On the other hand, a DC bias voltage and a transmission signal (also referred to as “drive signal”) are applied to the lower electrode22ifrom the observation apparatus6via a signal line24iin the operating state shown inFIG. 2B.

In the present embodiment, the signal line24i, one end of which is connected to the lower electrode22iis connected to a common contact c of a switch25iprovided, for example, in the connector4B and the common contact c of each switch25iis selectively connected with one of two contacts a and b.

Each switch25iis connected to a lever27B that operates to connect or disconnect the ultrasound endoscope3to/from the observation apparatus6via a connection section26.

Furthermore, the contact a of each switch25iis connected to a connection contact29iof the connector4B via a signal line28iand the contact b of each switch25iis connected to one end of a signal line30iand the signal line30iis connected to the ground, that is, grounded via a resistor R making up a discharge section31.

On the other hand, the connector receiver5B of the observation apparatus6is provided with a connection contact32iconnected to the above described connection contact29iand each connection contact32iis connected to a contact i of the multiplexer34via a signal line33i.

The contact i of the multiplexer34is selectively connected to the common contact c sequentially from contact a to n under the switching control of a control section39. The common contact c is connected to one end of a signal line38.

Furthermore, the observation apparatus6includes a transmission signal generation section36that generates a transmission signal (drive signal) for sequentially driving each C-MUT element9imaking up the above described C-MUT9and transmitting ultrasound in a sector form. Furthermore, the observation apparatus6includes a DC bias voltage generation section37that generates a DC bias voltage to be superimposed on the transmission signal and outputs the transmission signal and the DC bias voltage to the ultrasound endoscope3side via the signal line38, multiplexer34or the like.

When an operator operates a DC bias voltage adjustment knob or the like, the DC bias voltage generation section37generates a DC bias voltage of an adjusted value. The DC bias voltage generation section37may also be enabled to adjust a DC bias voltage generated under the control of the control section39.

Furthermore, the observation apparatus6includes an amplifier40that amplifies an ultrasound echo signal (simply referred to as “echo signal”) as a received signal received by each C-MUT element9iof the C-MUT9and converted from ultrasound to an electric signal and a reception processing section41that performs signal processing on the echo signal as the received signal and generates a video signal.

The video signal outputted from the reception processing section41is outputted to the monitor6B as display means and the monitor6B displays an ultrasound tomographic image corresponding to the video signal.

Furthermore, a capacitor42is provided at some midpoint on the signal line38which prevents the DC bias voltage of the DC bias voltage generation section37from being applied to the transmission signal generation section36and the amplifier40. The control section39controls operations of the transmission signal generation section36, the DC bias voltage generation section37, the reception processing section41and the like.

In the observation apparatus6according to the electronic scan shown inFIG. 2B, the transmission signal generation section36may also be constructed of, for example, a plurality of transmission signal generation sections36a, . . .36qas shown inFIG. 2C, and similarly the amplifier40inFIG. 2Bmay also be constructed of a plurality of amplifiers40a, . . .40qas shown inFIG. 2C.

A configuration may also be adopted in which transmission signal generation timings of the plurality of transmission signal generation sections36a, . . .36qmay be shifted so that the plurality of C-MUT elements9iare simultaneously driven via the capacitors42a, . . .42qand the multiplexer34A.

Furthermore, in this case, echo signals received by the plurality of C-MUT elements9iare amplified by the amplifiers40a, . . .40qand outputted to the reception processing section41. This makes it possible to scan or cause to converge ultrasound in a direction different from the array shape of the plurality of C-MUT elements9a,9b, . . .9n.

In this case, the DC bias voltage generation section37inFIG. 2Bmay be constructed of a plurality of DC bias voltage generation sections37a, . . .37qas shown inFIG. 2Cand the multiplexer34A may also be constructed so as to switch between signal lines38iin units of a plurality of signal lines. The configuration inFIG. 2Cmay also be applied to other embodiments inFIG. 9or the like as will be described later.

On the other hand, in the case of the ultrasound probe unit2shown inFIG. 2A, one C-MUT10is arranged inside the ultrasound probe13and the C-MUT10is driven to rotate by a motor (not shown) or the like and ultrasound is then radially subjected to radial mechanical scanning.

The C-MUT10has a configuration corresponding to one C-MUT element9iin the C-MUT9inFIG. 2B. That is, in the C-MUT10, an upper electrode21and a lower electrode22are formed so as to face each other across the cavity. The upper electrode21in the C-MUT10is connected to the ground (G inFIG. 2A), that is, grounded via the signal line23.

On the other hand, in the operating state shown inFIG. 2A, a DC bias voltage and a transmission signal are applied to the lower electrode22from the observation apparatus6side via a signal line24.

In the present embodiment, the signal line24, one end of which is connected to the lower electrode22, is connected, for example, to a common contact c of a switch25provided in a connector4A and the common contact c of the switch25is selectively connected to one of the two contacts a and b.

The switch25is connected to a lever27A that connects or disconnects the ultrasound probe unit2to/from the observation apparatus6via a connection section26.

Furthermore, the contact a of the switch25is connected to a connection contact29of the connector4A via a signal line28, the contact b of the switch25is connected to one end of a signal line30, and the signal line30is connected to the ground, that is, grounded via a resistor R making up a discharge section31.

On the other hand, a connector receiver5A of the observation apparatus6is provided with a connection contact32connected to the above described connection contact29and the connection contact32is connected to a DC bias voltage generation section37via a signal line33.

Furthermore, the observation apparatus6includes a transmission signal generation section36that generates a transmission signal (drive signal) for driving the above described C-MUT10to transmit ultrasound and the DC bias voltage generation section37that generates a DC bias voltage to be superimposed on the transmission signal, and outputs the transmission signal and the DC bias voltage to the ultrasound probe unit2side via the signal line33.

Furthermore, the observation apparatus6includes an amplifier40that amplifies an echo signal as a received signal received by the C-MUT10and converted from ultrasound to an electric signal and a reception processing section41that performs signal processing on the echo signal and generates a video signal.

A video signal outputted from the reception processing section41is outputted to a monitor6B as display means and the monitor6B displays an ultrasound tomographic image corresponding to the video signal.

Furthermore, a capacitor42is provided at some midpoint on the signal line33which prevents the DC bias voltage of the DC bias voltage generation section37from applying to the transmission signal generation section36and the amplifier40. A control section39controls operations of the transmission signal generation section36and the reception processing section41and the like according to the ultrasound endoscope3or ultrasound probe unit2connected to the observation apparatus6.

The present embodiment may also adopt a configuration in which the transmission signal generation section36, the DC bias voltage generation section37, the reception processing section41and the like of the observation apparatus6are used in common between the C-MUTs9and10or two sets of the transmission signal generation section36and the like may be provided in correspondence with the ultrasound endoscope3and the ultrasound probe unit2.

FIG. 3AandFIG. 3Billustrate how the operator connects or disconnects the connector4A of the ultrasound probe unit2to/from the observation apparatus6. As shown inFIG. 3A, when mounting (connecting) the connector4A of the ultrasound probe unit2on (to) the observation apparatus6, the operator inserts the connector4A on (the connector receiver5A of) the observation apparatus6side as shown by a blank arrow.

After the insertion, the operator turns the lever27A as shown by an arrow. The turning of the lever27A changes the state of the connection contact29of the connector4A which is not connected to the connection contact32of the connector receiver5A to a predetermined mounting state in which the connection contact29is connected to the connection contact32.

Furthermore, when unmounting the connector4A of the ultrasound probe unit2mounted on the connector receiver5A of the observation apparatus6, the operator performs an operation opposite to that inFIG. 3Aas shown inFIG. 3B. That is, as shown inFIG. 3B, the operator turns the lever27A in a direction opposite to that inFIG. 3A. This turning operation unlocks the mounting state and also causes the connection contact29of the aforementioned connector4A to change the state in which the connection contact29is connected to the connection contact32of the connector receiver5A to a state in which the connection contact29is not connected and is ready to be disconnected (also referred to as “released state”).

After that, the operator pulls out the connector4A from (the connector receiver5A of) the observation apparatus6side as shown by a blank arrow, and can thereby disconnect the connector4A from the connector receiver5A of the observation apparatus6. Thus, the connector4A and the connector receiver5A making up the connection section of the present embodiment are provided with a lock mechanism that keeps a locked state of preventing or regulating disconnection of the connector4A from the connector receiver5A (due to careless disconnection operation) in a predetermined mounting state and releases the locked state in a released state set by the turning operation of the lever27A. The following connector4B and connector receiver5B are likewise provided with the lock mechanism.

Furthermore,FIG. 4AandFIG. 4Bare diagrams illustrating a case where the connector4B of the ultrasound endoscope3is connected or disconnected to/from the connector receiver5B of the observation apparatus6, that is, a case where the connector4B is attached/detached. As is clear from a comparison withFIG. 3AandFIG. 3B, the attachment/detachment operation is the same as the attachment/detachment operation of the connector4A of the ultrasound probe unit2to/from the connector receiver5A of the observation apparatus6and the operation thereof is also the same.

FIG. 5illustrates a structure example in which the operation of the aforementioned lever27A causes a contact pin51as the connection contact29of the connector4A to be attached/detached to/from a contact pin52as the connection contact32in the connector receiver5A of the observation apparatus6.

FIG. 5(A)shows an unconnected state in which the contact pin51of the connector4A is separate from the contact pin52of the connector receiver5A,FIG. 5(B)shows a state in which although the connector4A is inserted into and connected to the connector receiver5A, the contact pin51is not connected to the contact pin52andFIG. 5(C)shows a predetermined mounting state in which the lever27A in the state ofFIG. 5(B)is turned and the contact pin51is connected to the contact pin52and locked.

As shown inFIG. 5(A)or the like, the connector4A has a housing53that accommodates the proximal end side of the contact pin51and a contact pin holding frame (hereinafter, simply abbreviated as “holding frame”)54provided at a distal end of the housing53, in which a substantially central portion in a longitudinal direction of the contact pin51is inserted and from which the distal end side of the contact pin51protrudes.

The holding frame54is moved by a rotating ellipsoidal cam55in the direction (vertical direction inFIG. 5) orthogonal to the longitudinal direction of the contact pin51(horizontal direction inFIG. 5) in conjunction with the turning operation of the lever27A.

On the other hand, the connector receiver5A has a housing57that includes a concave section56having an opening into which the contact pin51is inserted and accommodates the contact pin52which is electrically connected to the distal end of the contact pin51through contact therewith along the bottom of the concave section56. When the contact pin51is inserted into the connector receiver5A as shown inFIG. 5(B), the contact pin51is inserted along the top surface of the concave section56, and in this state, the contact pin51is set so as not to contact (separate from) the contact pin52disposed along the bottom surface of the concave section56.

Furthermore, in the state ofFIG. 5(B), when the lever27A is turned to cause the cam55to rotate 90° as shown inFIG. 5(C), an outer circumferential portion in the major axis direction of the cam55causes the holding frame54to move downward.

The movement of the holding frame54causes the central portion of the contact pin51to be pressed downward by a convex section provided on an inner surface of the holding frame54. Since the proximal end side of the contact pin51is regulated, the contact pin51closer to the distal end side than the proximal end is deformed while moving downward, and in that case, the distal end of the contact pin51moves downward and comes into contact with the contact pin52.

Furthermore, as described above, the state inFIG. 5(C)is a predetermined mounting state in which the contact pins51and52remain in contact with each other, and the state in which contact pin51is in contact with the contact pin52is kept and a locked state is in place in which even if the operator attempts to pull out the connector4A from the connector receiver5A, the connector4A cannot be disconnected.

On the other hand, in the case of the connector4B of the ultrasound endoscope3and the connector receiver5B, there are as many configurations shown inFIG. 5as the number of connection contacts29iand32i(that is, connection contacts29ato29n) and one of such configurations is as shown inFIG. 6.

The configuration shown inFIG. 6is similar to the case where the connection contacts29and32shown inFIG. 5(A)are replaced by one set of connection contacts29iand32i. With such replacement, the contact pins51and52inFIG. 5have a structure in which these are replaced by one set of contact pins51iand52ias shown inFIG. 6.

In the case of the connector4B and the connector receiver5B, there are a plurality of sets of the contact pins51iand52ihaving the structure (shown by the surface of the sheet ofFIG. 6) in the direction perpendicular to the surface of the sheet ofFIG. 6and a plurality of sets of the connection contacts29iand32iare changed as shown inFIG. 6together with the cam55that rotates in conjunction with the turning operation of the lever27B.

The connector structure itself described with reference toFIG. 5andFIG. 6in which the contact pins51(51i) and52(52i) are detachably connected is a publicly known technique.

With such a structure, the present embodiment changes the destination of the common contact c of the switches25and25ifrom the contact a to the contact b or from the contact b to the contact a using the cam55or the like making up the connection section26in conjunction with the turning operation of the levers27A and27B described inFIG. 2AandFIG. 2B.

For this reason, in the present embodiment, the connection contact29(contact pin51inFIG. 5) inFIG. 2Aforms the common contact c of the switch25(seeFIG. 6), and as shown inFIG. 5, a contact member58bhaving the function of the contact b of the switch25is provided, for example, at a position near the opening in the upper part of the inner surface of the housing53.

The contact member58bis electrically connected to the discharge section31via the signal line30as shown inFIG. 5andFIG. 2A. Furthermore, the contact pin52(connection contact32inFIG. 2A) shown inFIG. 5is provided with the function of the contact a as the connector receiver5A.

Therefore, the electrical connection structure in the present embodiment corresponding toFIG. 5(A)toFIG. 5(C)is as shown inFIG. 7(A)toFIG. 7(C).FIG. 7(A)corresponds toFIG. 5(A)and shows the contact pin51having the function of the connection contact29and the common contact c and the contact pin51is not connected to the connection contact32and the contact pin52that makes up the contact a.

In this state, the signal line24connected to the lower electrode22is electrically connected to the discharge section31via the contact member58bthat contacts the contact pin51(having the function of the contact b).

In the state ofFIG. 7(B)corresponding toFIG. 5(B), the contact pin51is set at a position above the contact pin52. Furthermore, the contact pin51in this state is in the same electric connection state as inFIG. 7(A).

When the lever27A is turned in the state ofFIG. 5(B), a state inFIG. 5(C)is set, and in the state inFIG. 7(C)corresponding toFIG. 5(C), the contact pin51moves downward, detached from the contact member58b, the distal end of the contact pin51comes into contact with the contact pin52and is thereby electrically connected.

In the case of the ultrasound endoscope3, a contact member58bis provided as shown inFIG. 6(as in the case ofFIG. 5) and the contact member58bis electrically connected to the discharge section31via the signal line30ias shown inFIG. 6andFIG. 2B.

In correspondence withFIG. 7corresponding toFIG. 5in the case of the ultrasound probe unit2, the diagram corresponding toFIG. 6in the case of the ultrasound endoscope3is as shown inFIG. 8. By renaming components inFIG. 8corresponding to those inFIG. 5andFIG. 6(e.g., reading reference numeral29as29i,30as30i,32as32i,33as33i,51as51iand52as52i), both operations become similar, and so descriptions thereof will be omitted.

As described above, although a difference between mechanical scan and electronic scan exists between the configuration of the ultrasound probe unit2and the observation apparatus6corresponding to the ultrasound probe unit2that transmits/receives ultrasound and the configuration of the ultrasound endoscope3and the observation apparatus6corresponding to the ultrasound endoscope3that transmits/receives ultrasound, these configurations are the same in the sense that they have principal features in the present embodiment.

For this reason, descriptions of the case corresponding to the ultrasound endoscope3will be omitted.

Thus, in the present embodiment, when the ultrasound probe unit2or ultrasound endoscope3as the ultrasound device mounted with the C-MUT10or9and the observation apparatus6to which the ultrasound device is detachably attached and which includes a transmission/reception processing system that performs transmission/reception signal processing on the C-MUT10or9are connected, the common contact c of the switches25and25iis set to be connected to the contact a so that the C-MUT10or9is connected to the transmission/reception processing system and the DC bias voltage generation section37.

Furthermore, when the ultrasound device is disconnected from the observation apparatus6, the ultrasound device cannot be disconnected from the observation apparatus6unless the lever27A or27B is operated so as to set the common contact c of the switches25and25ito be connected to the contact b of the discharge section31side. That is, when the ultrasound device is mounted on the observation apparatus6and ready for use, such a structure is provided that the ultrasound device cannot be carelessly disconnected from the observation apparatus6.

The ultrasound diagnostic system1of the present embodiment in such a configuration includes the ultrasound probe unit2or the ultrasound device made up of the ultrasound endoscope3mounted with the capacitive micromachined ultrasonic transducer (C-MUT10or9), the connector4A (or4B) and connector receiver5A (or5B) as the connection section for detachably connecting the ultrasound device and the observation apparatus6provided with the transmission signal generation section36that generates a transmission signal to drive the C-MUT, the discharge section31to discharge the charge applied to the C-MUT and the switches25and25ias the switching section arranged on the signal line between the C-MUT and the observation apparatus6.

When the ultrasound device is set to a predetermined mounting state with respect to the observation apparatus6according to the attachment/detachment state of the connection section between the ultrasound device and the observation apparatus6, the C-MUT is electrically connected to the transmission signal generation section36via the signal line and when the ultrasound device is disconnected from the observation apparatus6, switching of the switches25and25iis performed so that the charge of the C-MUT is discharged by the discharge section31.

Operation of the present embodiment having such a configuration will be described.

When the ultrasound probe unit2is used connected to the observation apparatus6to perform an ultrasound inspection, as shown inFIG. 3A, the connector4A is inserted so as to engage with the connector receiver5A, and then the lever27A is turned to set a predetermined mounting state.

The common contact c of the switch25is electrically connected to the contact a (from the contact b via the contact member58a) so that the signal line24connected to the lower electrode22of the C-MUT10is connected to the contact pin52(connection contact32) of the observation apparatus6as shown inFIG. 7(C).

Therefore, the C-MUT10of the ultrasound probe unit2can be driven by the observation apparatus6. The operator sets the DC bias voltage generation section37so as to output a DC bias voltage suitable for driving the C-MUT10.

Through the signal line33or the like, a transmission signal from the transmission signal generation section36is superimposed on the DC bias voltage and outputted to the ultrasound probe unit2side. As shown inFIG. 2A, since the common contact c is electrically connected to the contact a, the DC bias voltage on which the transmission signal is superimposed is applied to the lower electrode22of the C-MUT10and the mechanically scanned C-MUT10transmits ultrasound to the subject side.

Ultrasound reflected by a portion of the subject where an acoustic impedance is changing is received by the C-MUT10and becomes an echo signal.

The echo signal superimposed on the DC bias voltage passes through the switch25, whose DC bias voltage is cut by the capacitor42and the signal is then amplified by the amplifier40.

The echo signal amplified by the amplifier40is subjected to signal processing by the reception processing section41, converted to a video signal, outputted to the monitor6B and an ultrasound tomographic image is displayed on the display screen of the monitor6B.

After the ultrasound inspection using ultrasound, the operator turns OFF the power to the observation apparatus6to stop the function of transmitting/receiving ultrasound (and the function of generating a DC bias voltage).

When the ultrasound probe unit2is disconnected from the observation apparatus6, the lever27A is turned as shown inFIG. 3Band it is thereby possible to disconnect the connector4A of the ultrasound probe unit2from the connector receiver5A of the observation apparatus6.

In conjunction with the turning of the lever27A at this time, the common contact c of the switch25is connected to the contact b, that is, the resistor R making up the discharge section31. As a result, the charge of the C-MUT10is discharged to ground via the resistor R of the discharge section31shown inFIG. 2A. This makes it possible to eliminate the charge present in the C-MUT10.

Therefore, according to the present embodiment, when the ultrasound probe unit2as the ultrasound device mounted with the C-MUT10as the capacitive micromachined ultrasonic transducer is disconnected from the observation apparatus6, it is possible to discharge and eliminate the charge so that the charge of the C-MUT10is not accumulated.

Furthermore, according to the present embodiment, (since the charge present in the C-MUT10can be eliminated as described above), it is possible to reliably eliminate the possibility that the charge present in the C-MUT10may cause discharge when the connector4A is disconnected from the connector receiver5A causing deterioration of the contact (contact pin) or a high voltage at the time of discharge may damage the transmission/reception processing system that performs transmission/reception in the observation apparatus6.

Furthermore, according to the present embodiment, it is also possible to reduce or prevent the advance of deterioration of the C-MUT10itself due to the charge accumulated in the capacitive micromachined ultrasonic transducer (C-MUT)10for a long time. Moreover, by preventing charge from being accumulated in the C-MUT10, it is possible to ensure stable sensitivity for a long period of time. In addition, it is possible to realize an ultrasound diagnostic system1with a high degree of reproducibility.

Furthermore, according to the present embodiment, when the connector4A and the connector receiver5A are connected and the lever27A is set to a lock position, the connector4A cannot be disconnected from the connector receiver5A, and it is thereby possible to reliably prevent the ultrasound probe unit2from being carelessly disconnected from the observation apparatus6during an ultrasound inspection. The present embodiment can provide the ultrasound diagnostic system1with a high degree of operability and reliability.

Furthermore, operation when the ultrasound endoscope3is detachably connected to the observation apparatus6also has similar operation and effects. In this case, by reading the C-MUT10as C-MUT9or C-MUT element9i, switch25as25i, lever27A as lever27B, connector4A as connector4B, connector receiver5A as connector receiver5B, similar operation and effects can be obtained.

For example, as shown inFIG. 4A, when the connector4B of the ultrasound endoscope3is attached to the connector receiver5B of the observation apparatus6, the operator inserts the connector4A on (the connector receiver5B of) the observation apparatus6side as shown by a blank arrow.

After the insertion, the operator turns the lever27B as shown by the arrow. When the lever27B is turned, as shown inFIG. 8(A)andFIG. 8(B), the signal line24i(connected to the lower electrode22iof each C-MUT element9imaking up the C-MUT9) connected to the contact b is changed to a state in which it is connected to the contact pin52i(connection contact32i) of the observation apparatus6.

It is then possible to set a state in which the observation apparatus6can transmit/receive ultrasound to/from the C-MUT9of the ultrasound endoscope3.

Furthermore, when the connector4B of the ultrasound endoscope3connected to the connector receiver5B of the observation apparatus6is disconnected, as shown inFIG. 4B, operation opposite to that inFIG. 4Ais performed. That is, as shown inFIG. 4B, the operator turns the lever27B in the direction opposite to that inFIG. 4A.

With this turning operation, the mounting state is unlocked and the signal line24iconnected to the lower electrode22iof each C-MUT element9imaking up the C-MUT9is changed to a state in which it is connected to the contact b. In this state, it is possible to discharge the charge accumulated in the electrode of each C-MUT element to ground through the discharge section31.

Furthermore, the operator performs operation of separating the connector4B from (the connector receiver5B of) the observation apparatus6side, and can thereby disconnect the connector4B from the connector receiver5B of the observation apparatus6. The present embodiment provides effects similar to those in the case of the aforementioned ultrasound probe unit2.

InFIG. 2AandFIG. 2B, the resistor R is used as the discharge section31, but other devices such as a diode may also be used.

A configuration has been described above where the contacts a and b of the switches25and25iare changed in conjunction with the turning operation of the lever27A or27B, but the present invention is not limited to the structure in which the ultrasound device and the observation apparatus6are detachably connected through the turning operation of the lever27A or27B. For example, the lever27A or27B may be moved sliding to change the contact of the switches25and25i.

In the above configuration, the observation apparatus6is provided with the connection section to detachably connect both mechanical scan and electronic scan ultrasound devices, but the present invention is not limited to such a configuration and it is obvious that the present invention is also applicable to an observation apparatus in which any one of those scan ultrasound devices is detachably connected to the ultrasound device.

Second Embodiment

The configuration shown inFIG. 2AandFIG. 2Bhas been described as a configuration in which a DC bias voltage and a transmission signal are applied to the lower electrodes22and22iof the C-MUT10or9. By contrast, a configuration may also be adopted in which, for example, a transmission/reception signal is applied to the upper electrode21iside of each C-MUT element9imaking up the C-MUT9and a DC bias voltage is applied to the lower electrode22iside.

FIG. 9shows a configuration of an ultrasound endoscope3and an observation apparatus6in an ultrasound diagnostic system according to a second embodiment of the present invention corresponding to this case. In the configuration shown inFIG. 9, switches25iand25i′ that form a pair (instead of the switch25iinFIG. 2B) are provided via a connection section26connected to a lever27B in the configuration ofFIG. 2B.

A common contact c of the switch25iis connected to a lower electrode22ivia a signal line24iand a common contact c′ of the switch25i′ is connected to the upper electrode21ivia a signal line23i.

Furthermore, a contact b of the switch25iis connected to a ground via a resistor R of a discharge section31via a signal line30iand a contact b′ of the switch25i′ is connected to the ground via a signal line30i′. Furthermore, a contact a of the switch25iand a contact a′ of the switch25i′ are connected to connection contacts29iand29i′ of a connector4A via signal lines28iand28i′ respectively.

Furthermore, a connection contact32iof a connector receiver5B connected to a connection contact29iof the connector4A is connected to a DC bias voltage generation section37via a signal line33i, a multiplexer34and a signal line38.

Furthermore, a connection contact32i′ of the connector receiver5B connected to the connection contact29i′ of a connector4B is connected to a transmission signal generation section36and an input end of an amplifier40via the signal line33i′, a multiplexer34′ and a signal line38′. Switching of the multiplexers34and34′ is controlled by a control section39.

The present embodiment adopts a configuration with no capacitor42inFIG. 2B.

The lever27B, the connection section26and the switches25iand25i′ of the present embodiment shown inFIG. 9can be formed in a configuration similar to that shown, for example, inFIG. 6andFIG. 8.

That is, a configuration similar to that of the connection contacts29iand32idescribed inFIG. 6andFIG. 8may also be applied to the connection contacts29i′ and32i′ added from the connection contacts29iand32iof the first embodiment.

As described in the first embodiment, when the mounting state is set in which the lever27B is locked as shown inFIG. 6(C), the common contacts c and c′ of the switches25iand25i′ are connected to the contacts a and a′ respectively. That is, also in the present embodiment, in a predetermined mounting state in which the ultrasound endoscope3is connected to the observation apparatus6, the common contacts c and c′ of the switches25iand25i′ are connected to the contacts a and a′ as shown inFIG. 9.

In this state, the upper electrode21iof each C-MUT element9imaking up the C-MUT9is connected to the transmission/reception signal system of the observation apparatus6via the switch25i′. Furthermore, the lower electrode22iof each C-MUT element9iis connected to the DC bias voltage generation section37of the observation apparatus6via the switch25i.

Applying a transmission signal and a DC bias voltage from the observation apparatus6to the C-MUT element9iallows ultrasound to be outputted from each C-MUT element9i. Furthermore, an ultrasound tomographic image is displayed on the monitor6B by performing signal processing on the echo signal received through each C-MUT element9i.

When the ultrasound inspection ends, the ultrasound endoscope3can be disconnected from the observation apparatus6by turning the lever27B and setting the connector4B at a position where it can be disconnected from the connector receiver5B (released position where the connection can be released) as in the case described in the first embodiment.

When the lever27B is turned and the released position where the connection can be released is set, that is, when a state corresponding to that inFIG. 6(B)is set, the common contacts c and c′ of the switches25iand25i′ are connected to the contacts b and b′ respectively and the charge of each C-MUT element9iis discharged to ground.

Furthermore, even when the connector4B is disconnected from the connector receiver5B in the state inFIG. 6(B)and set in the unconnected state inFIG. 6(A), the connection state of the switches25iand25i′ inFIG. 6(B)is maintained.

Therefore, although the present embodiment adopts a configuration in which the switch25iof the first embodiment is modified into a pair of the switches25iand25i′, the present embodiment has substantially the same operations as those of the first embodiment. Moreover, the present embodiment has effects similar to those of the first embodiment.

InFIG. 9, a case with the electronic scan ultrasound endoscope3has been described, but it is obvious that the present invention is also applicable to a case with a mechanical scan ultrasound probe unit2. That is, one of the plurality of C-MUT elements9imaking up the C-MUT9inFIG. 9is replaced with the C-MUT10, and similar operation and effects can be obtained in this case, too.

InFIG. 9, since charge may be accumulated also on the upper electrode21iside, a configuration may also be adopted in which the contact b′ of the switch25i′ inFIG. 9is connected to the ground via a discharge device that discharges the charge. In this configuration, the signal line23iconnected to the upper electrode21iis changed to the signal line28i′ side of the contact a′ and the discharge device side of the contact b′ through the switching by the switch25i′ in conjunction with the operation of the lever27B.

Thus, when the signal line23iis switched so as to be electrically continuous with the discharge device side through the operation of the lever27B, it is possible to discharge the charge of the upper electrode21ialso on the upper electrode21iside as in the case of the lower electrode22iside.

Third Embodiment

Next, a third embodiment of the present invention will be described. When the connection between the ultrasound probe unit2or ultrasound endoscope3and the observation apparatus6is released (disconnected) through the structure using the aforementioned levers27A and27B, it is preferable to set a state in which the discharge section31is electrically connected to the C-MUT10or9before the connection contact29of the connector4A of the ultrasound probe unit2or the connection contact29i(29i) of the ultrasound endoscope3is separated from the connection contact32or32i(32i) of the connector receiver5A or5B of the observation apparatus6through the disconnection.

The aforementioned first and second embodiments are configured to realize this and another configuration example for realizing this is shown using a table inFIG. 10.FIG. 10shows a lever59provided with a button61to change the switch25(25iin the case of the ultrasound endoscope3) of the ultrasound probe unit2and a state in which the button is pressed determines whether the turning of the lever59is regulated or not.

As shown on the left side of the table inFIG. 10, a white circle represents a state of the button61in which the button61is not pressed and a black circle represents a state of the button61in which the button61is pressed.

When the button61is not pressed as shown on the right side ofFIG. 10, the switch25is connected to a DC bias/transmission/reception section62on the observation apparatus6side.

Here, the DC bias/transmission/reception section62represents the DC bias voltage generation section37connected to the signal line33, the transmission signal generation section36connected via the capacitor42, the amplifier40and the reception processing section41inFIG. 2A.

On the other hand, in the case of the ultrasound endoscope3, the DC bias/transmission/reception section62represents the multiplexer34connected to the signal line33i, the DC bias voltage generation section37, the transmission signal generation section36connected via the capacitor42, the amplifier40and the reception processing section41inFIG. 2B.

On the other hand, when the button61is pressed, the switch25is connected to the discharge section31side. A structure is adopted for the lever59in such a configuration in which the lever59cannot be turned unless the button61is pressed (state shown by the black circle inFIG. 10) and the ultrasound probe unit2cannot be disconnected from the observation apparatus6unless the lever59is turned.

When such a configuration is adopted, for the connection between the ultrasound probe unit2and the observation apparatus6, turning the lever before the disconnection causes the C-MUT10to be electrically connected to the discharge section31.

FIG. 11shows this state. The left figure ofFIG. 11shows a state in which the ultrasound probe unit2and the observation apparatus6are unconnected. Since the button61of the lever59is pressed, the switch25is connected to the discharge section31and the horizontal position of the lever59indicates that the ultrasound probe unit2is not connected to the observation apparatus6.

The figure in the middle ofFIG. 11shows a state in which the ultrasound probe unit2and the observation apparatus6are connected. In this case, the lever59is turned to an upright position indicating that the ultrasound probe unit2is connected to the observation apparatus6. However, the switching state of the switch25remains as shown in the lower part ofFIG. 10.

The right figure ofFIG. 11indicates that the button61of the lever59is operated to be set (changed) to a state in which the button61is not pressed, showing that the ultrasound probe unit2is connected to the observation apparatus6in a predetermined mounting state and that the switch25inFIG. 10is changed to the DC bias/transmission/reception section62side.

The operation for disconnecting the ultrasound probe unit2from the observation apparatus6is opposite to these operations and by operating the button61to cause the switch25ito be connected to the discharge section31(middle of FIG.11) and then turning the lever59, the ultrasound probe unit2can be disconnected from the observation apparatus6.

According to the present embodiment, when the ultrasound probe unit2is released (disconnected) from the observation apparatus6, it is possible to get the discharge section31connected to the C-MUT10before the release. The present embodiment also has effects similar to those of the first embodiment and the second embodiment.

As described in the case with the ultrasound probe unit2, the present embodiment is likewise applicable to a case with the electronic scan ultrasound endoscope3and can obtain similar effects.

Fourth Embodiment

In the aforementioned embodiments, the switches25and25i(25i′) and the discharge section31are present on the ultrasound probe unit2or ultrasound endoscope3side, but these may be set up on the observation apparatus6.FIG. 12illustrates an ultrasound endoscope3and an observation apparatus6according to a fourth embodiment as such a configuration example.

The present embodiment adopts a lever59provided with a button61on the ultrasound endoscope3side instead of the lever27B in the configuration ofFIG. 2B. Moreover, the switch25iand the discharge section31provided on the ultrasound endoscope3side inFIG. 2Bare set up on the observation apparatus6.

As shown inFIG. 12, a signal line24iconnected to a lower electrode22iis connected to a connection contact29i, a connection contact32iis connected to a common contact c of the switch25iprovided inside the observation apparatus6via a signal line70i. Furthermore, a contact a of the switch25iis connected to a contact i of a multiplexer34via a signal line33i.

Furthermore, a contact b of the switch25iis connected to the discharge section31via a signal line30i.

Furthermore, in the present embodiment, a transmission section71transmits control information for controlling the switch25ior a control state to the switch25ifrom the lever59.

As a configuration example in this case, ON/OFF by the pressing operation of the button61provided in the lever59is transmitted to the switch25iinside the observation apparatus6via a signal line72a, connection contacts4dand5dand a signal line72bthat form a transmission section71.

As shown inFIG. 12, a configuration may also be adopted in which the transmission section71is connected to a control section39that manages the entire operation of the observation apparatus6via a signal line72cconnected to the signal line72b. That is, the ON/OFF operation of the button61in the lever59may be transmitted to the control section39.

In this way, the control section39decides whether the button61of the lever59is pressed or not and sends the decision result to a reception processing section41. The reception processing section41has an information display processing section41athat generates an information display video signal to display information corresponding to the switching state of the switch25iaccording to the decision result.

The reception processing section41superimposes the information display video signal on a video signal of an ultrasound tomographic image, outputs the signal to a monitor6B and the monitor6B displays the information.

As in the aforementioned case, the control section39controls operations of a transmission signal generation section36, a DC bias voltage generation section37and the reception processing section41. The control section39may also perform a switching operation of the switch25iaccording to the decision result of the button61. Alternatively, switching between the contacts of the switch25imay be directly performed using a signal through the operation of the button61. Furthermore, the switch25imay be configured as an electric switch, relay switch or the like.

FIG. 13illustrates a display example of information on the monitor6B. While the ultrasound endoscope3is connected to the observation apparatus6, for example, an information display area19bof a peripheral section of a display area19aof an ultrasound tomographic image on a screen of the monitor6B as shown inFIG. 13(A)displays information such as a message “discharging.”

This information need not always be displayed but may be displayed according to the display control operation from an operation section (not shown) that operates the observation apparatus6.

On the other hand, when the ultrasound endoscope3is disconnected from the observation apparatus6, if the operator attempts to disconnect the ultrasound endoscope3before discharge, a message “not discharged” may be displayed on the monitor6B in a large size as shown inFIG. 13(B). After allowing the operator to discharge, a message may be given to the operator to guide the operator to perform a disconnection operation.

Other effects of the present embodiment are substantially the same as those of the aforementioned embodiments.

Although the present embodiment has been described by taking a case of the electronic scan ultrasound endoscope3, the present embodiment is also applicable to a case of the mechanical scan ultrasound probe unit2. The present embodiment can obtain operation and effects similar to those of the electronic scan ultrasound endoscope3.

In the aforementioned embodiments, the ultrasound probe unit2may be adapted to an electronic scan configuration. Alternatively, a mechanical scan ultrasound endoscope may be adapted instead of the electronic scan ultrasound endoscope3. Moreover, the ultrasound probe unit2shown inFIG. 1has a configuration in which the ultrasound probe13to be used inserted in the body is detachably attached to the drive unit11, but a structure may also be adopted in which the ultrasound probe unit2is integrated with the drive unit11. Furthermore, the ultrasound probe unit2may also be an ultrasound probe to be used outside the body.

Fifth Embodiment

FIG. 14illustrates a configuration example of, for example, a mechanical scan ultrasound probe unit2E and an observation apparatus6E according to a fifth embodiment of the present invention. The present embodiment adopts, for example, a connector4E and a connector receiver5E as a connection section different from that in the first embodiment.

As shown inFIG. 14, the ultrasound probe unit2E is mounted with one C-MUT10having the same configuration as that shown inFIG. 2A. Furthermore, as shown inFIG. 2A, a connection contact32in the observation apparatus6E is connected to a DC bias voltage generation section37via a signal line33.

In the present embodiment, as shown inFIG. 15A, the connector4E and the connector receiver5E have a cylindrical connector housing (simply referred to as “housing”)84E and a connector receiver housing (simply referred to as “housing”)85E provided with a columnar concave section with which the cylindrical housing84E is engaged.

A connection contact29is provided on a front end face of the housing84E inFIG. 14and the connection contact32which is in contact with and electrically connected to the connection contact29is provided on an innermost part of the concave section in the housing85E.

Furthermore, a rotatable lever79protrudes from a cylindrical side of the housing84E. On the other hand, the housing85E of the connector receiver5E is provided with a guide groove82awhich serves as a guide when the housing84E of the connector4E is connected/disconnected (attached/detached).

Furthermore, the housing85E is provided with a circumferential groove82bformed in a direction orthogonal to the guide groove82afor a contact switching operation by the lever79, setting the connector4E and the connector receiver5E in a locked state in conjunction with the switching operation and changing the locked state to a released state.

As is clear fromFIG. 15A, when the lever79enters the circumferential groove82bside from a position shown by a dotted line (released position), a locked state is in place in which it is possible to prevent (regulate) disconnection of the connector4E from the connector receiver5E through pulling out thereof.

The proximal end side of the lever79is connected to a rotor-side disk83aarranged inside the housing of the connector4E and rotated as shown inFIG. 15Bto form a connection section26and a common contact c which forms a switch25connected to a signal line24is provided on one surface (back surface inFIG. 15B) of the rotor-side disk83a.

Opposite to the rotor-side disk83a, a stator-side disk83bthat contacts the rotor-side disk83ais arranged, and a contact a and a contact b that selectively contact and are electrically connected to the common contact c through the turning operation of the lever79are formed in the stator-side disk83b.

Both disks83aand83bare formed of an insulating member. Furthermore, signal lines connected to the contacts a and b, and the common contact c are omitted inFIG. 15B.

In the position (lock position) of the lever79shown by a solid line inFIG. 15A, the common contact c is electrically connected to the contact a as shown inFIG. 14. This lock position becomes a predetermined mounting state when the connector4E and the connector receiver5E are used connected together.

On the other hand, in the position (released position) of the lever79shown by the dotted line inFIG. 15A, the common contact c is set to a state in which the common contact c is electrically connected to the contact b as shown by a dotted line inFIG. 14. Furthermore, there is such a structure that the connector4E cannot be disconnected from the connector receiver5E unless the lever79is set to the released position as described above.

Furthermore, as will be described in later operation, the present embodiment can realize a structure provided with the function described in the third embodiment.

Next, operation of the present embodiment will be described.

When the ultrasound probe unit2E is used, connected to the observation apparatus6E to perform an ultrasound inspection, the connector4E is engaged with the connector receiver5E and the lever79is then set to a lock position. As shown inFIG. 14, the common contact c of the switch25is electrically connected to the contact a.

Therefore, the C-MUT10of the ultrasound probe unit2E is ready to be driven by the observation apparatus6E. A transmission signal from a transmission signal generation section36is then superimposed on a DC bias voltage via the signal line33and outputted to the ultrasound probe unit2E side.

As shown inFIG. 14, since the common contact c is electrically connected to the contact a, a transmission signal is superimposed on the DC bias voltage and applied to the lower electrode22of the C-MUT10and the C-MUT10transmits ultrasound to the subject side in the body cavity.

Ultrasound reflected by a part of the subject where an acoustic impedance is changing is received by the C-MUT10and becomes an echo signal.

The echo signal superimposed on the DC bias voltage passes through the switch25, the DC bias voltage thereof is cut by the capacitor42and the signal is amplified by the amplifier40. The echo signal amplified by the amplifier40is subjected to signal processing by the reception processing section41, converted to a video signal, and then outputted to the monitor6B and an ultrasound tomographic image is displayed on the display screen of the monitor6B.

After performing the ultrasound inspection using ultrasound, the operator turns OFF the power to the observation apparatus6E to stop the function of transmitting/receiving ultrasound (and the function of generating a DC bias voltage).

When the ultrasound probe unit2E is disconnected from the observation apparatus6E, the lever79is turned to a released position shown by the dotted line inFIG. 15A, and it is thereby possible to disconnect the connector4E of the ultrasound probe unit2E from the connector receiver5E of the observation apparatus6E.

In conjunction with the turning of the lever79in this case, the common contact c of the switch25is connected to the contact b, that is, a resistor R making up a discharge section31via the connection section26. As a result, the charge of the C-MUT10is discharged to ground inFIG. 14via the resistor R of the discharge section31. It is thereby possible to eliminate the charge present in the C-MUT10.

Therefore, according to the present embodiment (since the charge present in the C-MUT10can be eliminated), it is possible to reliably prevent deterioration of the contact due to discharge when the connector4E is disconnected from the connector receiver5E caused by the charge present in the C-MUT10or eliminate the possibility that a high voltage during discharge may damage the transmission/reception processing system that performs transmission/reception in the observation apparatus6E.

Furthermore, according to the present embodiment, it is possible to reduce or prevent the advance of deterioration of the C-MUT10device itself due to the charge accumulated for a long time in the capacitive micromachined ultrasonic transducer (C-MUT)10. The present embodiment prevents the charge from being accumulated in the C-MUT10device, and can thereby secure stable sensitivity for a long period of time. The present embodiment can also realize an ultrasound diagnostic system with a high level of reproducibility.

Furthermore, according to the present embodiment, the connector4E cannot be disconnected from the connector receiver5E when the connector4E is connected to the connector receiver5E and the lever79is set to a lock position, it is thereby possible to reliably prevent the ultrasound probe unit2E from being carelessly disconnected from the observation apparatus6E during an ultrasound inspection. The present embodiment can provide an ultrasound diagnostic system with a high level of operability and reliability.

Furthermore, the present embodiment may be adapted to have a configuration having effects similar to those of the aforementioned third embodiment. For example, instead of the circular contact b shown by the solid line inFIG. 15B, an arc-shaped contact that extends in the direction of the contact a as shown by a two-dot dashed line may be adopted.

When the lever79is turned from the lock position corresponding to a predetermined mounting state to a released position, adopting such an arc-shaped contact causes the common contact c to have an electric connection (continuity) with the arc-shaped contact slightly before the lever79is set to the released position. The electric connection thereof is maintained until the lever79is set to the released position.

Therefore, when the operator sets the ultrasound probe unit2E to a released position (of the connection section) where the ultrasound probe unit2E can be disconnected from the observation apparatus6E, the C-MUT10is electrically connected to the discharge section31in the connection state of the switch25at the released position.

In this state, the charge between the lower electrode22and the upper electrode21of the C-MUT10is discharged by the discharge section31and the contact a of the switch25(connected to the connection contact29of the connector4E) is in a released state, and it is thereby possible to disconnect the ultrasound probe unit2E from the observation apparatus6E without any problem, that is, without causing any adverse influence on the transmission/reception processing system or the like of the observation apparatus6E.

An embodiment formed by partially combining the configurations of the aforementioned embodiments or the like also belongs to the present invention.