Ultrasonic observation system and an ultrasonic endoscope system

What is claimed is:

1. A probe for observing an ultrasonic image, comprising:

an insertion section for being inserted into an object to be observed,

an ultrasonic transmitting and receiving means provided in a distal end portion of said insertion section for transmitting an ultrasonic wave to the object and for receiving the ultrasonic wave reflected on the object, in which the received ultrasonic wave is converted into an electric signal, and

an ultrasonic driving motor for rotating said ultrasonic transmitting and receiving means to effect a mechanical scanning operation using the ultrasonic wave with respect to the object to be observed, said ultrasonic motor comprising a rotor connected to said ultrasonic transmitting and receiving means and a stator secured to one of said insertion section and a member fixed relative to said insertion section, said rotor being in contact with said stator.

2. A probe according to claim 1, wherein said ultrasonic driving motor is arranged in the distal end portion of said insertion section.

3. A probe according to claim 2, wherein said stator is fixed to a hard tip part of the distal end portion.

4. A probe according to claim 3, wherein an ultrasonic vibrating element provided in said ultrasonic transmitting and receiving means is rotatably secured to the hard tip part, and the rotor of the ultrasonic driving motor is connected to the ultrasonic vibrating element.

5. A probe according to claim 4, wherein an ultrasonic linear motor is provided in the distal end portion, and the ultrasonic vibrating element and the ultrasonic driving motor are moved integrally along a rotation shaft of the ultrasonic vibrating element by means of the ultrasonic linear motor.

6. A probe according to claim 4, wherein a rotation shaft connected to a holder in which the ultrasonic vibrating element is fixed is rotatably secured to the hard tip part via a bearing, and one of the rotation shaft and the bearing is used for the rotor while the other of them is used for the stator.

7. A probe according to claim 3, wherein said ultrasonic transmitting and receiving means comprises an ultrasonic vibrating element fixed to the hard tip part and an ultrasonic reflection mirror secured rotatably to the hard tip part, and the rotor of the ultrasonic driving motor is connected to the ultrasonic reflection mirror of said ultrasonic transmitting and receiving means.

8. A probe according to claim 7, wherein the rotor is constructed as a part of the reflection mirror.

9. A probe according to claim 3, wherein the rotor is coaxially arranged with respect to the stator.

10. A probe according to claim 1, wherein an operation section is arranged in a proximal end of said insertion section, and said ultrasonic driving motor is arranged in the operation section.

11. A probe according to claim 10, further comprising a rotation shaft extended in said insertion section, one end of said rotation shaft being connected to said ultrasonic transmitting and receiving means, and wherein said rotor is connected to a proximal end of the rotation shaft and said member to which said stator is fixed is a housing of said operation section.

12. A probe according to claim 11, wherein an ultrasonic vibrating element provided in said ultrasonic transmitting and receiving means is rotatably secured to a hard tip part of the distal end portion, and the rotor of the ultrasonic driving motor is connected to the ultrasonic vibrating element of said ultrasonic transmitting and receiving means through the rotation shaft.

13. A probe according to claim 11, wherein the rotation shaft is integrally formed with the rotor.

14. A probe according to claim 11, wherein said ultrasonic transmitting and receiving means comprises an ultrasonic vibrating element of said ultrasonic transmitting and receiving means, fixed to a hard tip part of the distal end portion and an ultrasonic reflection mirror secured rotatably to the hard tip part, and the rotor of the ultrasonic driving motor is connected to the ultrasonic reflection mirror of said ultrasonic transmitting and receiving means through the rotation shaft.

15. A probe according to claim 11, wherein the rotor and the stator are arranged coaxially with respect to the rotation shaft.

16. A probe according to claim 11, wherein center axes of the rotor and the stator are shifted with respect to an axis of the rotation shaft, and a rotation power transmitting means is arranged between the rotor and the rotation shaft.

17. A probe according to claim 1, wherein a drive section is arranged between said insertion section and an operation section provided in a proximal end of said insertion section, and said ultrasonic driving motor is arranged in the drive section.

18. A probe according to claim 17, further comprising a rotation shaft extended in said insertion section, one end of said rotation shaft being connected to said ultrasonic transmitting and receiving means, and wherein said rotor is connected to a proximal end of the rotation shaft and said member to which said stator is fixed is a housing of said drive section.

19. A probe according to claim 18, wherein an ultrasonic vibrating element provided in said ultrasonic transmitting and receiving means is rotatably secured to a hard tip part of the distal end portion, and the rotor of the ultrasonic driving motor is connected to the ultrasonic vibrating element of said ultrasonic transmitting and receiving means through the rotation shaft.

20. A probe according to claim 18, wherein the rotation shaft is integrally formed with the rotor.

21. A probe according to claim 18, wherein said ultrasonic transmitting and receiving means comprises an ultrasonic vibrating element of said ultrasonic transmitting and receiving means, fixed to a hard tip part of the distal end portion and an ultrasonic reflection mirror secured rotatably to the hard tip part, and the rotor of the ultrasonic driving motor is connected to the ultrasonic reflection mirror of said ultrasonic transmitting and receiving means through the rotation shaft.

22. A probe according to claim 18, wherein the rotor and the stator are arranged coaxially with respect to the rotation shaft.

23. A probe according to claim 18, wherein center axes of the rotor and the stator are shifted with respect to an axis of the rotation shaft, and a rotation power transmitting means is arranged between the rotor and the rotation shaft.

24. A probe according to claim 4 or 7, further comprising an observation means for obtaining an optical image of the object to be observed.

25. A probe according to claim 24, wherein a through hole is arranged in the ultrasonic vibrating element, and said observation means is extended in the through hole.

26. A probe according to claim 24, wherein a second ultrasonic motor is arranged in the distal end portion spaced apart from the ultrasonic driving motor and said observation means is rotated by the second ultrasonic motor.

27. A probe according to claim 24, wherein said observation means comprises a light guide extended in said insertion section, an objective lens provided in the distal end portion, and an image guide extended in said insertion section.

28. A probe according to claim 1, wherein said ultrasonic transmitting and receiving means has a plurality of ultrasonic vibrating elements having different focal distances with each other.

Description Submit all comments and votes

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a probe for an ultrasonic endoscope which observes an object inside a body cavity by using an ultrasonic wave, and relates to an ultrasonic endoscope system, an ultrasonic observation system and an ultrasonic video endoscope system, all of which utilize the probe mentioned above.

2. Related Art Statement

An ultrasonic endoscope system utilizing a probe has been known for example from Japanese Patent Laid-Open Publication No. 57-190,552, wherein an object inside the body cavity is diagnosed with an ultrasonic wave by rotating mechanically an ultrasonic vibrating element arranged in a distal end of an insertion section of the probe by means of a driving member arranged apart from the insertion section.

FIG. 1 is a schematic view showing an embodiment of the probe disclosed in the Japanese Patent Laid-Open Publication No. 57-190,552. In this embodiment, A is the insertion section and B is the driving member.

In a distal end of the insertion section A, an ultrasonic vibrating element 1 is rotatably secured by means of a bearing 2, and a tip portion of a flexible shaft 3 is connected to the ultrasonic vibrating element 1. The flexible shaft 3 is held in a flexible outer tube 5 through a liquid paraffin 4 and a proximal end of the flexible shaft 3 is introduced to the driving member B.

The driving member B comprises an electric motor 6 as a driving means, a gear box 7 for decelerating a rotation speed of the electric motor 6, an output shaft 8 including a shaft member 8a and a bearing 8b, for transmitting the decelerated rotation to the flexible shaft 3, and a potentiometer 9 arranged to the electric motor 6.

The prior art ultrasonic endoscope system mentioned above has drawbacks mentioned below. In the case that a patient swallows the insertion section A of the probe, it is a matter of course that the patient can easily swallow the insertion section A if it is thin. However, if the flexible shaft 3 is made thinner so as to make the insertion section A thin, kinks are liable to occur on the flexible shaft 3, and thus the rotation of the electric motor 6 is not transmitted accurately. That is to say, if the above kinks are generated, the rotation of the ultrasonic vibrating element 1 is decreased correspondingly, and thus if an amount of kinks reaches to a predetermined level, the rotation of the ultrasonic vibrating element 1 is increased over a normal rotation level. As a result, a time-angle characteristic of the rotation of the ultrasonic vibrating element 1 is vibrated as shown in FIG. 2 by a solid line. Moreover, characteristics during respective scanning periods T1, T2 . . . are varied one another. Therefore, as shown in FIG. 3 by a solid line M and a dotted line N, the clinical image obtained by the known ultrasonic endoscope system becomes large or small with respect to the normal one, and thus an accurate diagnosis is not realized.

Further, as clearly understood from FIG. 2, since the time-angle characteristic is varied pulsatory as shown by a solid line with respect to the normal linear variation as shown by a dotted line and this pulsatory variation occurs irregularly, a starting point of the next scanning operation is varied. As a result, the obtained image position is varied correspondingly, For example, this variation becomes at a rate of .DELTA..theta.=20.degree., and thus accurate diagnosis cannot be achieved.

To eliminate the distortion and the positional variation in the clinical image, if the flexible shaft 3 is made thick and stiff, the following disadvantages occur. If the flexible shaft 3 is made thick and stiff, the kinks remain on the shaft 3 because it is normally long. Therefore, the rotation of the motor 6 becomes somewhat stable, but the scanning characteristic of the ultrasonic vibrating element 1 is not linear but still pulsatory. Moreover, in this case, since the insertion section A becomes large and stiff (not flexible), the patient does not swallow the insertion section A easily and an operationability of the insertion section A in the body cavity becomes bad.

Contrary to this, since use is made of a D.C. motor as the electric motor 6, so-called brush noise is generated on a signal line of the ultrasonic vibrating element 1. As a result, a flicker effect is generated on an image displayed on a CRT by a scanning operation of the ultrasonic vibrating element 1. This flicker effect can be eliminated by a noise reduction circuit such as a filter. However, in this case, since it is necessary to arrange a specific noise reduction circuit, the ultrasonic endoscope system becomes large and complicated, and further a reliability becomes low.

Further, in the known ultrasonic endoscope system, since use is made of the electric motor which is large in size and complicated in mechanism, there is a drawback that the operationability thereof becomes bad.

SUMMARY OF THE INVENTION

The object of the present invention is to eliminate the drawbacks mentioned above and to provide a probe for an ultrasonic endoscope which car obtain a good ultrasonic image with no distortion and no flicker in an easy and reliable manner.

The another object of the invention is to provide an ultrasonic endoscope system which can display a good ultrasonic image and a good optical image without generating a distortion and a flicker.

The still another object of the invention is to provide an ultrasonic observation system which can display a good ultrasonic image in an easy manner without generating a distortion and a flicker.

The still another object of the invention is to provide an ultrasonic video endoscope system utilizing a solid state image pick-up device which can display a good ultrasonic image and a good optical image without generating a distortion and a flicker.

According to the invention, a probe for observing an ultrasonic image comprises an insertion section for being inserted into an object to be observed, an ultrasonic transmitting and receiving means provided in a distal end portion of said insertion section for transmitting an ultrasonic wave to the object and for receiving the ultrasonic wave reflected on the object, in which the received ultrasonic wave is converted into an electric signal, and an ultrasonic driving means for driving said ultrasonic transmitting and receiving means to effect a mechanical scanning operation using the ultrasonic wave with respect to the object to be observed.

According to the invention, a probe for observing an ultrasonic image comprises

an insertion section for being inserted into an object to be observed,

an ultrasonic transmitting and receiving means provided in a distal end portion of said insertion section for transmitting an ultrasonic wave to the object and for receiving the ultrasonic wave reflected on the object, in which the received ultrasonic wave is converted into an electric signal, and

an ultrasonic driving means for driving said ultrasonic transmitting and receiving means to effect a mechanical scanning operation using the ultrasonic wave with respect to the object to be observed.

According to the invention, an ultrasonic endoscope system comprises

a probe having an insertion section for being inserted into an object to be observed; an ultrasonic transmitting and receiving means provided in a distal end portion of said insertion section for transmitting an ultrasonic wave to the object and for receiving the ultrasonic wave reflected on the object, in which the received ultrasonic wave is converted into an electric signal; an ultrasonic driving means for driving said ultrasonic transmitting and receiving means to effect a mechanical scanning operation using the ultrasonic wave with respect to the object to be observed; and an observation means for obtaining an optical image of the object through said insertion section, and

a display device having means for displaying an ultrasonic image obtained from said ultrasonic transmitting and receiving means and means for displaying the optical image obtained from said observation means.

According to the invention, an ultrasonic image observation system comprises

a probe having an ultrasonic transmitting and receiving means for transmitting an ultrasonic wave to an object to be observed and for receiving the ultrasonic wave reflected on the object, in which the received ultrasonic wave is converted into an electric signal; and an ultrasonic driving means for driving said ultrasonic transmitting and receiving means to effect a mechanical scanning operating using the ultrasonic wave with respect to the object to be observed, and

a display device for displaying an ultrasonic image obtained from said ultrasonic transmitting and receiving means.

According to the invention, an ultrasonic video endoscope system comprises

a video probe having an insertion section for being inserted into an object to be observed; an ultrasonic transmitting and receiving means provided in a distal end portion of said insertion section for transmitting an ultrasonic wave to the object and for receiving the ultrasonic wave reflected on the object, in which the received ultrasonic wave is converted into an electric signal; an ultrasonic driving means for driving said ultrasonic transmitting and receiving means to effect a mechanical scanning operation using the ultrasonic wave with respect to the object to be observed; and an observation means including a light guide extended in said insertion section, an objective lens provided in the distal end portion of said insertion section and a solid state image sensor, and

a display device having means for displaying an ultrasonic image obtained from said ultrasonic transmitting and receiving means and means for displaying the optical image obtained from said observation means.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing an embodiment of a known probe of an ultrasonic endoscope;

FIG. 2 is a graph for explaining a scanning characteristic of the known probe shown in FIG. 1;

FIG. 3 is a schematic view showing a clinical image obtained from the known probe;

FIG. 4 is a schematic view illustrating a first embodiment of a probe of an ultrasonic endoscope according to the invention;

FIG. 5 is a graph for explaining a scanning characteristic of the probe shown in FIG. 4;

FIG. 6A is a perspective view showing a construction of an ultrasonic motor according to the invention;

FIG. 6B is a schematic view illustrating an electrode construction of the ultrasonic motor shown in FIG. 6A;

FIG. 7 is a block diagram depicting a circuit of the ultrasonic motor shown in FIG. 4;

FIG. 8 is a schematic view showing a second embodiment of a probe of an ultrasonic endoscope according to the invention;

FIG. 9 is a cross sectional view illustrating a driving portion of the second embodiment shown in FIG. 8;

FIGS. 10 and 11 are schematic views illustrating another embodiment of the driving portion respectively;

FIGS. 12 and 13 are cross sectional views depicting a third and fourth embodiments of the probe according to the invention respectively;

FIG. 14 is a cross sectional view showing an embodiment cut along A--A line of the embodiment shown in FIG. 13;

FIG. 15 is a cross sectional view illustrating a fifth embodiment of the probe according to the invention;

FIG. 16A is a schematic view depicting a sixth embodiment of the probe according to the invention;

FIG. 16B is a schematic view showing an inner construction of an operation section of the probe shown in FIG. 16A;

FIG. 17 is a schematic view illustrating a seventh embodiment of an inner construction of the operation section according to the invention;

FIGS. 18 to 21 are cross sectional views depicting an eighth embodiment to an eleventh embodiment of the probe according to the invention respectively;

FIGS. 22 and 23 are schematic views showing a twelfth embodiment and a thirteenth embodiment of the probe according to the invention respectively;

FIG. 24 is a schematic view illustrating a fourteenth embodiment of the probe according to the invention;

FIGS. 25 and 26 are cross sectional views depicting embodiments cut along A--A' line and B--B' line of the embodiment shown in FIG. 24 respectively;

FIGS. 27 and 28 are cross sectional views showing a fifteenth embodiment of the probe according to the invention in a shrink state and an elongated state respectively;

FIG. 29 is a schematic view illustrating an embodiment of an ultrasonic endoscope system and an ultrasonic video endoscope system according to the invention;

FIG. 30 is a schematic view depicting an embodiment of an insertion section of the ultrasonic video endoscope system according to the invention;

FIG. 31 is a block diagram showing an embodiment of the ultrasonic video endoscope system according to the invention;

FIG. 32 is a schematic view illustrating an embodiment of an operation section of the ultrasonic video endoscope system according to the invention;

FIG. 33 is a cross sectional view depicting an embodiment cut along A--A line of the embodiment shown in FIG. 32;

FIG. 34 is a schematic view showing an embodiment of the driving member of the embodiment shown in FIG. 33; and

FIG. 35 is a schematic view illustrating another embodiment of the insertion section of the ultrasonic video endoscope system according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 4 is a schematic view showing a first embodiment of a probe of an ultrasonic endoscope according to the invention, wherein an ultrasonic motor is arranged in a distal end of an insertion section. In FIG. 4, a numeral 10 is an ultrasonic vibrating element secured in a distal end of an insertion section A. The ultrasonic vibrating element 10 comprises a vibration plate 11 and a damper member 12, and an acoustic medium 13 is filled around the ultrasonic vibrating element 10. A rotation shaft 14 arranged at one end of the ultrasonic vibrating element 10 is rotatably secured by a bearing member 20.

The bearing member 20 is constructed by a pair of bearings 21 and 22. A rotation detection member 23 is secured to the rotation shaft 14 at a position between the bearings 21 and 22, and a rotation start pulse detection sensor 24 is secured to the rotation shaft 14 at a position opposite to the rotation detection member 23. Moreover, an ultrasonic motor 30 is arranged between the bearing member 20 and the ultrasonic vibrating element 10.

The ultrasonic motor 30 comprises a rotor 31 secured to one end of the ultrasonic vibrating element 10 and rotatably arranged around the rotation shaft 14 and a stator 32 secured to one end of the bearing member 20 and rotatably arranged around the rotation shaft 14, and the rotor 31 is brought into contact with the stator 32 under pressure. Rotary transformer elements 33 and 34 for supplying transmitting and receiving signals in a non-contact manner are arranged at a center of the rotor 31 and the stator 32 respectively in an opposite and non-contact manner. In the ultrasonic motor 30, a pair of electrodes of the stator 32 and an earth electrode are connected respectively to one ends of feeders 41, 42 and 43 extended inside the insertion section A. A coil of the first rotary transformer element 34 is connected to one end of a signal transmission line 44 extended also inside the insertion section A. The other ends of the feeders 41, 42 and 43 and the signal transmission line 44 are introduced to an operation section B.

The operation section B comprises a driving member of the ultrasonic vibrating element 10 and a signal control member. The driving member comprises an oscillator 50 for driving the ultrasonic motor 30, an amplifier 51 for amplifying an output of the oscillator 50 and for supplying the amplified signal through the feeder 41, a variable phaser 53 for shifting the output of the oscillator 50 by .pi./2, an amplifier 52 for amplifying an output of the variable phaser 53 and for supplying the amplified signal through the feeder 42, and a phase comparator 54 for comparing a rotation phase of the ultrasonic motor 30 obtained through the feeder 43 with an output phase of the oscillator 50 and for supplying the phase difference to the variable phaser 53 as a feedback signal. Moreover, the signal control member comprises a transmitter 60, a signal transmitting and receiving member 61 for supplying an output signal of the transmitter 60 through the signal transmission line 44 and for receiving a signal reflected on the object, a pre-amplifier 62 for amplifying the reflect signal obtained from the signal transmitting and receiving member 61, and a signal output line 63 for supplying an output signal of the pre-amplifier 62.

In this embodiment, a liquid paraffin is filled around the bearings 21 and 22 of the bearing member 20, the rotation detection member 23, the detection sensor 24 and the ultrasonic motor 30. Since the liquid paraffin has a lubricity and an insulation function, it is no problem to immerse the motor etc. therein. In this case, it is necessary to effect a mold on lead wires etc.

According to the first embodiment mentioned above, since the ultrasonic vibrating element 10 arranged rotatably in the distal end of the insertion section A is directly driven by the ultrasonic motor 30 arranged near the ultrasonic vibrating element 10, it is not necessary to use the flexible shaft 3 for driving the ultrasonic vibrating element 1 as usual. Therefore, since use is made of electric lines only for the connection cable between the ultrasonic vibrating element 10 and the operation section B, it is possible to make a diameter of the insertion section A small and thus the flexibility of the insertion section A can be maintained. In this case, the patient can swallow the insertion section A easily and the operation of the insertion section A in the body cavity can be made easy. Moreover, since the rotation variation of the ultrasonic vibrating element due to the kinks of the flexible shaft can be reduced, the scanning operation of the ultrasonic vibrating element 10 can be made accurate and stable as shown in FIG. 5. As a result, good clinical images with no distortion can be obtained. Further, since the brush noise of the electric motor is not generated in the signal transmission line 44, good clinical images with no flicker can be obtained. Moreover, since it is not necessary to use the mechanical members such as D.C. motor 6, gear box 7, and potentiometer 9, the operation section B arranged outside the body cavity can be made small.

FIG. 6A is a perspective view showing a construction of the ultrasonic motor according to the invention. In this embodiment, the ultrasonic motor comprises a stator member 71 for generating a bending vibration due to the ultrasonic wave, and a rotor member 72 arranged in contact with the stator member 71. The stator member 71 comprises a metal ring 73 and a piezoelectric ceramic element 74. Then, the stator member 71 is vibrated in a longitudinal direction by applying a voltage with high frequency over 20 KHz to the piezoelectric ceramic element 74. This vibration of the metal ring 73 proceeds in a circumferential direction, and thus the rotor member 72 is rotated in an inverse direction with respect to the circumferential direction mentioned above. In this embodiment, use is made of the metal ring 73 made of Ni 36%-Fe 64% alloy and the rotor member 71 made of aluminum alloy, and Al.sub.2 O.sub.3 layer is arranged on the rotor member 71 opposite to the metal ring 73. Since a contact surface 75 of the rotor member 72 is constructed by a flange-shape spring vibrating in the longitudinal direction, the vibration of the stator 71 in the longitudinal direction can be absorbed preferably. Positions of electrodes A and B are shifted by .lambda./4 as shown in FIG. 6B. An electrode S observes a resonance state of the bending vibration generated from electrodes A and B respectively. FIG. 7 shows a block diagram illustrating a circuit construction of the ultrasonic motor shown in FIG. 4.

FIG. 8 is a schematic view showing a second embodiment of the probe of the ultrasonic endoscope according to the invention. In this embodiment, an endoscope 111 comprises an operation section 112 in which various operation members are arranged, a drive section 113 for driving the ultrasonic vibrating element, and an insertion section 114. A distal hard portion 116 is arranged via a flexible portion 115 at a distal end of the insertion section 114. The operation section 112 has a universal code 117 and a connector 118 is arranged at a distal end of the universal code 117. The connector 118 is to be connected to a light source unit, and thus one end portion of a light guide 119 is projected.

In this embodiment, various members such as light guide, image guide, forceps channel, air supply channel are arranged inside the insertion section 114, and thus an object in the body cavity can be observed by an eyepiece arranged in the operation section 112. This construction is widely known in a field of the endoscope, and thus detail explanations are omitted here. Further, an operation knob 121 for bending the flexible portion 115 is arranged in the operation section 112, and the distal end of the insertion section 114 can be moved in the body cavity at will by operating the operation knob 121. Moreover, an opening 122 of the forceps is arranged in the drive section 113.

An ultrasonic vibrating element 123 is arranged in the distal hard portion 116 of the insertion section 114, and a distal end of the rotation shaft extended in the insertion section 114 is secured to the ultrasonic vibrating element 123. This rotation shaft is extended toward the drive section 113 and is rotated by an ultrasonic motor arranged in the drive section 113. On the other hand, cables connected to the ultrasonic vibrating element 123 are extended in the rotation shaft and further in the universal code 117. Further, these cables are introduced to a connector 125 through a code 124 divided from the universal code 117, and the connector 125 is to be connected to an ultrasonic observation device. Moreover, an amplifier 126 for the repeating operation is arranged in the middle of the code 124. A balloon 127 is detachably arranged outside the distal hard portion 116 as shown in the dotted line, and the balloon 127 is expanded by means of waters so as not to reduce the energy of ultrasonic wave in the body cavity.

FIG. 9 is a cross sectional view showing the drive section 113 of the second embodiment shown in FIG. 8. In this embodiment, a rotation shaft 131 connected to the ultrasonic vibrating element 123 is constructed by a flexible and cylindrical tube, and a cable 132 connected electrically to the ultrasonic vibrating element 123 is inserted and extended in the rotation shaft 131. The rotation shaft 131 is secured to a sleeve 133 which is rotatably secured to a base 135 via a bearing 134. A supporting member 136 is fixed to the base 135, and the sleeve 133 is also rotatably secured to the supporting member 136 via a bearing 137. An ultrasonic motor 138 is arranged between the base 135 and the sleeve 133. That is to say, a ring-shaped stator 138a is secured to the base 135, and a rotor 138b cooperative with the stator 138a is secured to the sleeve 133. Moreover, a rotation position detector 139 is secured to the base 135 so as to detect a mark arranged on the rotor 138b at a position opposite to the base 135. In this manner, a rotation position of the sleeve 133 i.e. the rotation shaft 131 is detected. Further, flanges 140 and 141 are fixed to the sleeve 133, and a receiving amplifier 142 is arranged between the flanges 140 and 141. The cable 132 is connected to the receiving amplifier 142 so as to amplify the signal supplied from the ultrasonic vibrating element 123. The signal amplified by the receiving amplifier 142 is supplied to a rotary contact box 144 through a cable 143 arranged in the sleeve 133 and is further supplied to a cable 145 through for example a slip ring contact.

The stator 138a of the ultrasonic motor 138 has electrodes divided into a few parts, a ring-shaped piezoelectric elements and a ring-shaped elastic member, but in FIG. 9 all members are shown as the stator. When a driving voltage having a predetermined phase is applied to the piezoelectric element, the piezoelectric element is vibrated and the elastic member is also vibrated as a wave, and then the rotor 138b brought into contact with the elastic member is rotated. Since the rotor 138b is secured to the sleeve 133 which is secured to the rotation shaft 131, the rotation shaft 131 is rotated and thus the ultrasonic vibrating element 123 connected to the distal end of the rotation shaft 131 is also rotated.

In this manner, if use is made of the ultrasonic motor 138, and the stator 138a and the rotor 138b are arranged coaxially to the rotation shaft 131, a dimension of the whole drive section can be made small. Moreover, since the rotor 138b is directly connected to the rotation shaft, it is not necessary to use power supply mechanisms such as gear, timing belt, a total amount of mechanisms to be used can be reduced. Further, since mechanisms of the ultrasonic motor are not arranged on an axis of the rotation shaft, the cable can be arranged in the rotation shaft easily and the rotary contact box 144 can be arranged on the axis of the rotation shaft. Therefore, the construction can be simplified.

The present invention is not limited to the second embodiment mentioned above, but various modifications are possible. For example, in the second embodiment mentioned above, the stator and the rotor have the ring-shape, but it is possible to use a circular plate stator and rotor each having a hole at its center. Further, as shown in FIG. 10, use may be made of the ultrasonic motor wherein a cylindrical stator 152 comprising electrodes, piezoelectric element and elastic member is secured to an inner surface of a cylinder 151 and a rotor 153 having a sleeve shape is inserted into the cylindrical stator 152. Further, as shown in FIG. 11, use may be made of the ultrasonic motor wherein a stator 155 is secured to an outer surface of a sleeve 154 connected to the rotation shaft, and cylinders 156 divided into two parts are arranged around the stator 155 to rotate the sleeve 154.

FIG. 12 is a cross sectional view showing a third embodiment of the probe according to the invention. In this embodiment, a numeral 201 is an insertion section for being inserted into the body cavity, and an ultrasonic scanning head 203 is arranged in a distal end portion 202 of the insertion section 201. The ultrasonic head 203 comprises a cylindrical cover 204 projected from the distal end portion 202 in an axis direction of the insertion section 201. One end of the cover 204 is connected to an outer surface of the distal end portion 202, and the other end of the cover 204 is closed by a tip wall portion 205. Moreover, an ultrasonic vibrating element 206 for transmitting and receiving the ultrasonic wave is accommodated in an inner space of the cover 204.

A tubular rotation shaft 208 is projected integrally from a supporting member 207 for covering the ultrasonic vibrating element 206, and the rotation shaft 208 is introduced into a hole 209 arranged in a tip surface of the distal end portion 202. In the hole 209, ball bearings 210 and 211 are arranged to support the rotation shaft 208 rotatably, and inner lathes 210a and 211a of the ball bearings 210 and 211 are screwed in an outer surface of the rotation shaft 208 to be rotated integrally with the rotation shaft 208.

Moreover, a signal cable 213 for transmitting and receiving a signal supplied from the ultrasonic vibrating element 206 is inserted into the rotation shaft 208 and a protection tube 212 connected to the rotation shaft 208, and the signal cable 213 is connected to an ultrasonic transmitting and receiving device not shown arranged at a proximal end of the insertion section 201.

In the hole 209 of the distal end portion 202, an ultrasonic motor 214 having a ring shape for rotating the ultrasonic vibrating element 20 is installed. The ultrasonic motor 214 comprises an ultrasonic vibrator 215 having a ring shape. In the hole 209, the ultrasonic vibrator 215 is arranged between the ball bearings 210 and 211, and is arranged coaxially with respect to the rotation shaft 208. Then, one end surface of the ultrasonic vibrator 215 is coaxially brought into contact with the inner lathe 210a of the ball bearing 210 positioned at a side of the ultrasonic vibrating element 206, and the ultrasonic vibrator 215 is connected to an operation section of the ultrasonic motor 201 through a d