BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a tube unit system such as an ultrasound imaging catheter system for displaying the sectional view of a tubular cavity or determining blood stream with the aid of an inserting part provided with a tube and inserted into the body cavity such as a blood vessel or a vein or an endoscope system for visual observation of the inside of a tubular cavity. 
     2. Description of the Related Art 
     The ultrasound imaging catheter system so adapted as to effect display of the sectional view of a tubular cavity by inserting into the body cavity a catheter provided at the leading end side of a rotary drive shaft thereof with an ultrasound transducer has been heretofore known. 
     This ultrasound imaging catheter system is readied for use by having a connector of the catheter in a sterilized state inserted into a connecting part of an external drive device, i.e. an unsterilized part serving to rotate the drive shaft. Once the connector is joined to the external drive device, therefore, the part of the connector brought into contact with the external drive device is fated to be contaminated. For the purpose of precluding the possibility that the operator&#39;s hands will be contaminated by the part of the connector, therefore, the connector and the external drive device which are in a connected state are not allowed to be separated from each other until the manipulation of the catheter is completed. 
     When the catheter is manipulated in various ways while the connector of the catheter is kept in connection with the external drive device, however, the body of machine or operator possibly rides on the connected parts of the ultrasound imaging catheter and the external drive device and, as a result, brings the problem of compelling the ultrasound imaging catheter to sustain breakage besides the possibility that the delicate operation of the catheter will be obstructed. 
     When the ultrasound imaging catheter is to be used, it must be first connected to the external drive device and then given a trial run intended to confirm normal operation before it is inserted into the body cavity. When the ultrasound imaging catheter in use is designed for the self-guiding operation which relies on the operator&#39;s application of torque to the catheter to produce a motion of the catheter to the neighborhood of the affected part without requiring use of a guide wire, therefore, since this catheter cannot be operated while it is kept in connection with the external drive device, the operator has no alternative but to remove the connector of the catheter from the external drive device subsequently to the confirmation of the normal operation mentioned above and then proceed to operate the catheter. As a means to prevent the operator s hands from being contaminated in this case, the method of covering the connector with a sterilized cap may be used. This method, however, has the problem of entailing a complicated work which is fated to urge deliberation. 
     SUMMARY OF THE INVENTION 
     It is an object of this invention to provide a tube unit system which, by means of a sterilized part interposed between the connector of such a tube unit as a catheter and the external unit, prevents the part of the connector from contamination and keeps intact the sterilized state of the tube unit such as the catheter and facilitate separation of the two connected parts. 
     One aspect of this invention is directed to a tube unit system which comprises 
     a tube unit provided with an inserting part possessed of a tube to be inserted into a body cavity and a connector disposed on the handle side of the inserting part; 
     an outer unit provided with a connecting part for connection to the connector of the tube unit; and 
     an adapter intended for interposition between the connector and the connecting part and already subjected to a purifying treatment as by sterilization, the adapter being arbitrarily attachable to and detachable from the connector and the connecting part. 
     In accordance with this invention, the part of the connector of the tube unit can be prevented from contamination and, as a result, the sterilized state of the tube unit can be kept intact by causing the adapter which has undergone the purifying treatment as by sterilization to be interposed between the tube unit and the external unit. Consequently, the operator while using the catheter is enabled to attach tube unit to and detach it from the external unit catheter and promote prevention of the tube unit from breakage. 
     Another aspect of this invention is directed to a device for protecting an article which has undergone a purifying treatment against a contaminated article, which comprises 
     a bag already subjected to a purifying treatment as by sterilization and provided with a hole; and 
     an adapter provided with a hollow body and a retaining part adapted to be held manually by the operator and already subjected to a purifying treatment as by sterilization; 
     the bag being enabled to be fixed to the adapter in such manner that the hole thereof will be located at the center of the hollow body. 
     Still another aspect of this invention is directed to method for visually observing the appearance of the body cavity of a given patient by means of the ultrasound imaging catheter, which method comprises 
     a step of covering an external drive device for driving the ultrasound imaging catheter with a bag subjected to a purifying treatment as by sterilization; 
     a step of connecting an adapter subjected to a purifying treatment as by sterilization to the connecting part of the external drive device; 
     a step of connecting a connector of an ultrasound imaging catheter subjected to a purifying treatment as by sterilization through the medium of the adapter to the external drive device; and 
     a step of setting the external drive device operating. 
     The objects, characteristics, and special features of this invention other than those set forth above will become apparent from the description to be given herein below with reference to preferred embodiments illustrated in the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a whole side view illustrating an ultrasound imaging catheter system as the first preferred embodiment of this invention, 
     FIG. 2 is a cross section illustrating in a disassembled state the essential part of connected parts of the ultrasound imaging catheter shown in FIG.  1  and an external drive device, 
     FIG. 3 is a perspective view illustrating in a disassembled state a connecting part of the external drive device, an adapter, a sterilized bag, and a cap shown in FIG. 2, 
     FIG. 4 is a cross section taken through FIG. 3 along the line IV—IV, 
     FIG. 5 is a cross section illustrating the state in which an adapter is inserted into the connecting part of the external drive device, 
     FIG. 6 is a cross section illustrating the state in which he connector of the catheter is inserted through the medium of the adapter into the external drive device, 
     FIG.  7 A-FIG. 7C are cross sections intended as specimens to aid in describing the manner in which a flap of a lock part is gradually deforming toward the inside diameter in consequence of the rotation of the adapter, 
     FIG. 8 is a cross section illustrating the state in which the connector and the adapter are perfectly fixed in tight adhesion by the lock part, 
     FIG. 9 is a cross section illustrating in a disassembled state the essential part of connected parts of an ultrasound imaging catheter of an ultrasound imaging catheter system as the second embodiment of this invention and the external drive device, 
     FIG. 10 is a perspective view illustrating in a disassembled state a connecting part of the external drive device and an adapter shown in FIG. 9, 
     FIG. 11 is a cross section taken through FIG. 10 along the line XI—XI, 
     FIG. 12 is a cross section illustrating the state in which the adapter is inserted into the connecting part of the external drive device, 
     FIG. 13 is a cross section illustrating the state in which the connector of the catheter is connected through the medium of the adapter to the external drive device, 
     FIG.  14 A-FIG. 14C are cross sections intended as specimens to aid in describing the manner in which the flap of the lock part is gradually deforming toward the inside diameter in consequence of the rotation of the adapter, and 
     FIG. 15 is a cross section illustrating the state in which the connector and the adapter are perfectly fixed in tight adhesion by the lock part. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The embodiments of this invention will be described below with reference to the accompanying drawings. 
     FIG. 1 is a whole side view illustrating an ultrasound imaging catheter system as the first preferred embodiment of this invention. An ultrasound imaging catheter system  10  illustrated in FIG. 1 comprises an ultrasound imaging catheter  1  as a tube unit provided with an inserting part to be inserted into the body cavity and a connector  5  disposed at the trailing end part thereof, an external drive device  6  as an external unit, an adapter  7 , and a sterilized bag  8 . Then, the inserting part mentioned above comprises a sheath  2  as an external tube, a drive shaft (not shown) inserted in the sheath  2  and adapted to transmit a mechanical driving force from the basal end side to the leading end side, and an ultrasound transducer (not shown) fixed at the leading end part of the drive shaft. 
     FIG. 2 is a cross section illustrating in a disassembled state the essential part of connected parts of the ultrasound imaging catheter shown in FIG.  1  and an external drive device. On the connector  5 , a pair of keys  50  are integrally formed in such a manner as to protrude from the outer peripheral part thereof and an insulator  51  formed of an elastomer such as, for example, natural rubber or synthetic resin and vested with elasticity is disposed on the outer peripheral part thereof as illustrated in FIG.  2 . Further, inside the connector  5 , a female electric contact point  52  and a connector side mechanical joint  53  are coaxially and rotatably mounted. 
     The external drive device  6  is provided with a motor (not shown) for rotating the drive shaft mentioned above and a connecting part  20  for removably connecting the connector  5  of the catheter  1  and the adapter  7 . This connecting part  20  is provided therein with a male electric contact point  62  and an external drive device side mechanical joint  63 . 
     FIG. 3 is a perspective view illustrating in a disassembled state the connecting part of the external drive device, adapter, sterilized bag, and cap shown in FIG.  2 . The connecting part  20 , as illustrated in FIG. 3, is provided with a tubular part  21  assuming a substantially tubular shape and a flange part  22  formed at the terminal part of the tubular part  21 . On the outer peripheral part of the hollow tubular part  21  of the connecting part  20 , a cam groove  23  of a shape closely similar to the letter L and formed of an axial direction part  24  and a peripheral direction part  25  is formed. A protuberance  70  which will be specifically described herein below is adapted to be moved along the cam groove  23 . 
     FIG. 4 is a cross section taken through FIG. 3 along the line IV—IV. Large-diameter parts  210  and small-diameter parts  211  are alternately formed three each on the circumference on the inner side at the catheter side leading end of the tubular part  21  of the connecting part  20  as illustrated in FIG.  4 . 
     On the outer peripheral side of the connecting part  20 , a slide member  30  is mounted slidably in the axial direction as illustrated in FIG.  2 . This slide member  30  is provided with a tubular part  31  contacting the outer peripheral part of the connecting part  20 , a finger grip part  32  fixed to one end of the tubular part  31 , and a spring  33  for urging the slide member  30  toward the flange part  22  of the connecting part  20 . On the lateral side of the tubular part  31 , a fixing member  35  formed of a ball plunger is screwed in the radial direction. This fixing member  35  is provided with a tubular body having a male thread formed on the outer peripheral surface thereof, a ball retained inside the tubular body in such a manner as to attain protrusion over a prescribed distance from the leading edge thereof, and a spring member for urging the ball toward the leading end of the tubular body. 
     The adapter  7  is integrally composed of an insertion hole part  71  for allowing insertion of a connector therein, a handle part  72 , an insertion shaft part  74  for insertion into the drive device, and a neck part  75 . This insertion shaft part  74  assumes a tubular shape. In this insertion shaft part, the protuberance  70  and the lock part  73  mentioned above are integrally formed. A flange part  751  is formed on the insertion shaft part  74  side of the neck part  75 . This flange part  751  has a structure such that it may be interlocked between the fixing member  35  and an end face  34  of the tubular part  31 . 
     The insertion hole part  71  is provided with an insertion hole  710 , a key groove  711 , and an engaging part  712  and is adapted to admit the basal end side of the connector  5  of the ultrasound imaging catheter  1 . The connector  5  is led in through the insertion hole  710  so as to ensure conformity of the key  50  thereof with the key groove  711  and is driven in as far as the engaging part  712 . 
     The handle part  72  is formed in a noncircular cross section such as a starlike cross section or a roughly elliptic cross section such that the operator may take easy grip thereof. By moving the protuberance  70  along the cam groove  23  by means of this handle part  72 , the adapter  7  in its entirely is enabled to be rotated easily and moved in the axial direction easily. 
     The lock parts  73 , in the present embodiment, are formed one each at three places on the circumference  3 . They each comprise a one-side flap  730  and a roughly spherically shaped projecting part  731  thrust toward the outside of the insertion shaft part  74 . The flaps are formed in the same direction. 
     The adapter  7  is so constructed that when the insertion shaft part  74  of the adapter  7  is inserted into the connecting part  20  of the external drive device  6 , the top part of the lock part  73  of the adapter  7  is positioned more on the inner side than the large-diameter part  210  of the tubular part  21  of the connecting part  20  and more on the outer side than the small-diameter part  211  and, as a result, the protuberance  731  is depressed by the small-diameter part  211 . The inner surface of the small-diameter part  211  has a concave cross section approximately conforming in radius of curvature with the outer surface of the protuberance  731 . The top part of the protuberance  70  of the adapter  7  is likewise so formed as to be positioned more on the inner side than the large-diameter part  210  of the tubular part  21  of the connecting part  20 . Owing to the provision of the groove in the top part of the large-diameter part  210 , the top part of the protuberance  70  is allowed to become larger on the outer side than the large-diameter part  210 . 
     The lock part  73  enables the connector  5  of the ultrasound imaging catheter  1  to contact intimately the adapter  7  and the connecting part  20  and consequently prevents the vibration generated by the exertion of the drive torque on the external drive device  6  from being transmitted to the ultrasound imaging catheter  1 . As a result, the ultrasound imaging catheter  1  is improved in performance and the operator is enabled to relieve the feeling of discomfort and fatigue. 
     The sterilized bag  8  is a preliminarily sterilized slender bag made of a transparent or translucent polymer such as, for example, vinyl chloride or polyethylene. It has a hole  81  of a small diameter formed in the terminal end, namely on the bottom side, thereof for the purpose of permitting insertion of the connector  5  therethrough. After a cap  83  has been used in conjunction with the adapter  7  to have the terminal end side of the sterilized bag  8  nipped therebetween, rivets  84  are inserted through fitting holes  831 ,  721 , and  82  and fixed. The rivets  84  are only required to be such that when they are driven home, the leading end parts thereof may be spread out and enabled to fix the cap  83  and the adapter  7 . By connecting the sterilized bag  8  integrally or removably to the adapter  7  as described above, the situation that the external drive device accidentally smears the catheter or the operator&#39;s hand can be infallibly prevented. 
     A cover  61  of the external drive device  6  is provided with a small-diameter part  610  and consequently enabled to retain the spring  33  inside the external drive device  6 . 
     Now, the method for operating the ultrasound imaging catheter system  10  according to this invention and the function thereof will be described. 
     For a start, the system is to be prepared for the operation. First, the external drive device  6  is wholly inserted in the sterilized bag  8  to which the adapter  7  is fitted by the use of the cap  83  and the rivets  84 . The adapter  7 , the cap  83 , the rivets  84  and the sterilized bag  8  are used herein as nearly sterilized (or perfectly sterilized occasionally). Then, the adapter  7  is pushed in so that the protuberance  70  thereof may be laid along the longitudinal direction of the axial direction part  24  of the cam groove  23  formed in the connecting part  20  of the external drive device  6 . 
     The adapter  7 , with the flange part  751  thereof forcing the ball of the fixing member  35  backward toward the exterior, is pushed in until a seating surface  740  formed on the adapter collides or verges on colliding with the end face  34  of the tubular part  31  of the sliding member  30  as illustrated in FIG.  5 . When the flange part  751  is pushed in to this position, the ball of the fixing member  35  is returned by the force of a spring and caused to fix the adapter  7 . Thus, the adapter  7  is inserted into the connecting part  20  of the external drive device  6  and, by the fact that the flange part  751  is interlocked between the fixing member  35  and the end face  34  of the tubular part  31 , is fixed with proper retaining power. At this time, the protuberance  70  of the adapter  7  is positioned exactly at the end part in the longitudinal direction of the axial direction part  24  of the cam groove  23 . It is permissible to keep the adapter  7  and the sterilized bag  8  separated initially and cause them to join at this time. The positioning completes the preparation. Incidentally, at this time, the protuberance  731  of the adapter  7  is at such a position that it may neither touch the inner surface of the large-diameter part  210  formed at the entrance to the connecting part  20  or nor succumb to the depressing force exerted by the large-diameter part  210  (FIG.  5  and FIG. 7A refer). 
     Subsequently, the connector  5  of the ultrasound imaging catheter  1  is inserted, with the key  50  kept in alignment with the key groove  711 , into the insertion hole part  71  of the adapter  7  as far as the engaging part  712  as illustrated in FIG.  6 . At this time, the inner face of the flap  730  of the lock part  73  is positioned just the outer side of the insulator  51  of the connector  5 . Immediately before this time, the female electric contact point  52  of the connector  5  and the male electric contact point  62  of the external drive device contact each other and the mechanical joints  53  and  63  thereof establish mechanical contact. 
     Since the diameter of the insulator  51  is slightly smaller than the inside diameter of the insertion hole  710 , the insulator  51  and the insertion hole  710  remain in light contact with each other. Thus, the connector and the adapter  7  in the state illustrated in FIG. 6 can be easily released and coupled. 
     Then, to connect and fix the connector  5  of the ultrasound imaging catheter  1 , the handle part  72  of the adapter  7 , as held in the state illustrated in FIG. 6, is rotated by 45 degrees clockwise in the direction of the external drive device  6 . At this time, the protuberance  70  is moved along the peripheral direction part  25  of the cam groove  23  till the end part of the groove. The connector  5  rotates under slight contact pressure in conjunction with the adapter  7 . Gradually, the protuberance  731  collides with the small-diameter part  211  formed at the entrance to the connecting part  20  and the flap  730  begins bending toward the inner side of the adapter  7 . As a result, the inner face of the flap  730  begins encroaching on the insulator  51  (FIG. 7B refers). The angle of rotation in this case is preferred to be in the range of 30 degrees-90 degrees. If this angle is unduly large, the excess will possibly twist the bag and inflict breakage thereon. 
     When the protuberance  731  of the lock part  73  almost reaches the center of the small-diameter part  211  as illustrated in FIG. 8, the connector  5  is completely fixed by the flap  730  in intimate contact with the adapter  7  (FIG.  7 C and FIG. 8 refer). 
     The adapter  7  and the connecting part  20  are clamped with even force in three directions by the protuberance  731 . And they are prevented from wavering. They are, however, allowed to move in the axial direction (excepting when the protuberance  70  is positioned inside the peripheral direction part  25  of the cam groove  23 ) or to move in the circumferential direction because at least either of them is formed of a material with a low coefficient of sliding friction (such as, for example, polyphenylenesulfide, polyacetal or tetrafluoroethylene resin, optionally reinforced with glass fibers). 
     The ultrasound imaging catheter  1  is set operating when the motor of the external drive device  6  in the ensuant state is actuated. 
     Now, the method for withdrawing the ultrasound imaging catheter  1  from the external drive device  6  will be described below. 
     The motor of the external drive device  6  is stopped and the handle part  72  of the adapter  7  is rotated counterclockwise in the direction of the external drive device  6 . The protuberance  70  of the adapter  7  is moved along the peripheral direction part  25  of the cam groove  23  from the end part of the groove to the intersection with the axial direction part  24 . Since the protuberance  731  is thus moved to the position opposite the inner face of the large-diameter part  210  formed at the entrance to the connecting part  20 , the flap  730  is returned to the home position and relieved of the state locked to the connector  5  (in the state illustrated in FIG.  6 ). 
     Subsequently, the finger grip part  32  of the slide member  30  is moved toward the catheter against the urging force of the spring  33 . As a result, the end face  34  of the slide member  30  or the end face  36  of the finger grip part  32  evenly depresses the adapter  7  and the adapter  7  is moved in conjunction with the connector  5  toward the catheter. At the same time, the electric contact and the mechanical contact are broken. At this time, the ultrasound imaging catheter  1  can be easily withdrawn from the adapter  7 . Incidentally, the adapter  7  escapes this release owing to the fixing member  35 . 
     The connector  5 , as surmised from the construction described above, is exposed to unsterilized parts (the male electric contact point  62  of the external drive device  6  and the mechanical joint  63 ) in the interior thereof. Since the connector  5  has a sufficiently small opening part and is positioned in deep recess from the opening part, the possibility of the operator touching a contaminated part is nil even when the connector  5  is once connected to the external drive device  6  and then made to release it. So long as the adapter  7  is sterilized, therefore, the sterilized state of the ultrasound imaging catheter  1  can be retained even when the connector is connected again to the external drive device  6  through the medium of the adapter  7 . As a result, the ultrasound imaging catheter can be released from or coupled with the external drive device while the catheter system is in use. At various steps of the operation of the catheter, therefore, the joints between the ultrasound imaging catheter and the external drive device can avoid the situation of exposing themselves to an external attack, with the result that the ultrasound imaging catheter will be prevented from breakage. After the confirmation of the operation of the catheter, the connector of the catheter may be removed from the external drive device without interrupting the catheter operation. 
     FIG. 9 is a cross section illustrating in a disassembled state the essential part of the connecting part of the ultrasound imaging catheter and the external drive device in the ultrasound imaging catheter system as the second embodiment of this invention, FIG. 10 is a perspective view illustrating in a disassembled state the connecting part of the external drive device and the adapter shown in FIG. 9, and FIG. 11 is a cross section taken through FIG. 10 along the line XI—XI. 
     In the second embodiment, one hole is opened at the terminal end, namely on the bottom side, of a sterilized bag  8   a . Then, the sterilized bag  8   a  can be easily fitted to an adapter  7   a  by inserting the neck part  75  of the adapter  7   a  into the hole on the terminal end side of the sterilized bag  8  and fixing it to the bag with a rubber band or a double-face adhesive tape. 
     The lock parts  73   a  of the adapter  7   a  are formed one each at four places on the circumference and the flaps  730  thereof have their directions changed alternately so as to preclude otherwise possible deterioration of rigidity (FIG. 10 refers). On the inner side of the catheter side leading end of a tubular part  21   a  of a connecting part  20   a , large-diameter  210   a  and small-diameter parts  211   a  are alternately formed each at four places on the circumference. Then, on the outer peripheral part of the tubular part  21   a , a cam groove  23   a  of a shape closely similar to the letter L and formed of an axial direction part  24  and a peripheral direction part  25   a  is formed. The peripheral direction part  25   a  is formed in the range of about 45 degrees on the circumferential direction. 
     Incidentally, the cam groove  23  of the connecting part  20   a  and the protuberance  70  of the adapter  7   a  are integrally formed so as to be symmetrized also in the diametric direction. They are omitted from the diagram for the sake of simplicity. 
     Since the second embodiment is identical with the first embodiment described above, like parts are denoted by like reference numerals and are omitted from the following description. 
     The present ultrasound imaging catheter system is operated in almost the same manner as in that of the first embodiment described above. FIG. 12 is a cross section illustrating the state in which the adapter is inserted into the connecting part of the external drive device, FIG. 13 is a cross section illustrating the state in which the connector of the catheter is inserted through the medium of the adapter into the external drive device, FIG.  14 A-FIG. 14C are specimen cross sections as aids in describing the manner in which the flaps of the lock part are gradually bent toward the inner side in consequence of the rotation of the adapter, and FIG. 15 is a cross section illustrating the state in which the connector and the adapter are perfectly fixed in intimate contact by the lock part. 
     To put this ultrasound imaging catheter system to use, the adapter  7   a  is pushed in so as to move the protuberance  70  thereof along the longitudinal direction of the axial direction part  24  of the cam groove  23   a  formed in the connecting part  20   a  of the external drive device  6 , the connector  5  of the ultrasound imaging catheter  1  is inserted into the insertion hole part  71  of the adapter  7   a , and the handle part  72  of the adapter  7   a  is rotated from the state illustrated in FIG. 13 by 45 degrees clockwise in the direction of the external drive device  6  as illustrated in FIG.  14 A-FIG.  14 C. As a result, the adapter  7   a  and the connecting part  20   a  are clamped with even force in four directions by the protuberances  731 . 
     Since the connector  5  and the external drive device  6  are likewise connected through the medium of the sterilized adapter  7   a  in accordance with the second embodiment, the part of the connector of the ultrasound imaging catheter can be prevented from contamination and consequently the ultrasound imaging catheter can retain the sterilized state thereof in the same manner as in the first embodiment described above. As a result, the ultrasound imaging catheter can be released from and coupled with the external drive device without interrupting the operation of the system, the insertion of the catheter into the blood vessel can be facilitated, and the ultrasound imaging catheter can be prevented from breakage. 
     It is obvious that this invention is not limited to the particular embodiments shown and described above but may be variously changed and modified without departing from the technical concept of this invention. 
     For example, the lock parts  73 ,  73   a  of the adapters  7 ,  7   a  may be provided one each at one place on the circumference. The rotation of the protuberances  70  along the peripheral direction parts  25 ,  25   a  of the cam grooves  23 ,  23   a  may be produced counterclockwise instead relative to the external drive device. The cam grooves  23 ,  23   a  do not need to have a shape closely similar to the letter L as mentioned above. The number of protuberances  70  of the adapters  7 ,  7   a  may be one or in a suitably selected plurality. The spring  33  may be omitted. The lock mechanism is arbitrarily selected so long as it serves as a means for pressing the lock parts  73 ,  73   a  fast against the connector  5 . Optionally, it may be so constructed as to obviate the necessity for a cam groove. 
     If the ultrasound imaging catheter is not possessed of an electronic scan type rotary drive mechanism, for example, it tolerates the absence of such a lock mechanism as described above. The connector  5 , the insertion hole part  71 , the connecting part  20 , etc. may not be in a tubular shape. 
     The embodiments, cited above, have depicted the ultrasound imaging catheter system. Optionally, this invention can be applied to the endoscope system, for example, which is intended to attain internal observation of the tubular cavity. 
     This application is based on Application No. 10-053564 filed in Japan, the contents of which are herein incorporated by way of reference.
An ultrasound imaging catheter system 10 comprises an ultrasound imaging catheter 1 provided with a connector 5 positioned on the handle side thereof, an external drive device 6 provided with a connecting part 20 for connection to the connector 5 of the ultrasound imaging catheter 1, and an adapter 7 interposed between the connector 5 and the connecting part 20 and having undergone a purifying treatment such as sterilization, the adapter 7 being removable relative to the connector 5 of the ultrasound imaging catheter 1 and the connecting part 20 of the external drive device 6. The construction prevents the connector 5 part of the ultrasound imaging catheter 1 from contamination and allows it to retain a sterilized state thereof and enables the ultrasound imaging catheter 1 to be attached to and detached from the external drive device 6 without interrupting the operation.