Patent Description:
<CIT> relates to an ultrasound imaging assembly including a housing having a longitudinal axis, a proximal end, and a distal ending defining a receptacle.

<CIT> relates to a system for imaging a vessel of a patient comprising an elongated sheath with proximal and distal ends.

<CIT> relates to a fixing sleeve that is fitted outward on a connecting portion between a connecting pipe and a treatment tool inserting tube for fixation of the connecting portion comprises a cylindrical sleeve body, an arc-shaped portion, and a projection portion.

<CIT> relates to a catheter comprising a sheath to be inserted into a living body, including a tubular reinforcement layer of at least one layer, which is formed with a spiral slit, a termination end of the spiral slit, and a slit termination portion.

In the related art, as an example of a diagnostic imaging catheter that obtains a tomographic image of a blood vessel or the like, a catheter that obtains an image by an intra vascular ultra sound (IVUS) has been known. PTL <NUM> discloses a diagnostic imaging catheter of this type. PTL <NUM> describes an ultrasound transducer as a signal transmission and reception member, which is mounted on a terminal housing as a housing.

The housing on which the signal transmission and reception member is mounted is made of a hard and hard-to-deform material in order to stabilize a rotation axis of the transmission and reception member with respect to rotation of a drive shaft. On the other hand, the housing is required to have followability for easily moving forward along a bent blood vessel shape.

An object of the present disclosure is to provide a diagnostic imaging catheter including a housing capable of improving followability to a blood vessel shape.

A diagnostic imaging catheter according to a first aspect of the present disclosure includes: a diagnostic imaging catheter according to claim <NUM>.

As one embodiment of the present disclosure, a side surface of the housing includes a support surface that supports the transmission and reception member, and in an upper side view of the housing as viewed from a support surface side, the inclined portion is formed on the side surface of the housing located on at least one side of the transmission and reception member.

As one embodiment of the present disclosure, a side surface of the housing includes a support surface that supports the transmission and reception member, and the inclined portion is formed at a position of the side surface of the housing on a back side of the support surface.

As one embodiment of the present disclosure, a back side of the support surface of the side surface of the housing is defined by a peripheral surface.

As one embodiment of the present disclosure, a proximal protrusion portion protruding toward an inner surface of the sheath from the transmission and reception member supported by the support surface is provided on a proximal side of the side surface of the housing with respect to the support surface.

As one embodiment of the present disclosure, a distal protrusion portion protruding toward an inner surface of the sheath from the transmission and reception member supported by the support surface is provided on a distal side of the side surface of the housing with respect to the support surface.

As one embodiment of the present disclosure, an angle of the inclined portion with respect to the central axis line increases toward the distal side.

The transmission and reception member is an ultrasound transducer capable of transmitting and receiving ultrasound on a ultrasound transmission and reception surface, and a distal end surface of the ultrasound transducer is formed of a convex curved surface.

According to the present disclosure, it is possible to provide a diagnostic imaging catheter including a housing capable of improving followability to a blood vessel shape.

Hereinafter, an embodiment of a diagnostic imaging catheter according to the present disclosure will be described with reference to the drawings. In the drawings, common members and portions are denoted by the same reference numerals. Hereinafter, for convenience of description, in the diagnostic imaging catheter according to the present disclosure, a longitudinal direction of the diagnostic imaging catheter is referred to as a "longitudinal direction A". In addition, in the longitudinal direction A of the diagnostic imaging catheter, a side on which the diagnostic imaging catheter is inserted into a living body is referred to as a "distal side", and a side opposite thereto is referred to as a "proximal side". In addition, a direction from the proximal side toward the distal side of the diagnostic imaging catheter according to the present disclosure may be simply referred to as an "insertion direction A1". In addition, a direction from the distal side to the proximal side of a diagnostic imaging catheter <NUM> may be simply referred to as a "removal direction A2".

First, an example of a diagnostic imaging system to which the diagnostic imaging catheter according to the present disclosure can be applied will be described. <FIG> is a diagram showing a diagnostic imaging system <NUM> including the diagnostic imaging catheter <NUM> as an embodiment of the present disclosure.

The diagnostic imaging system <NUM> includes the diagnostic imaging catheter <NUM> and a diagnostic imaging apparatus <NUM>. <FIG> shows a state in which the diagnostic imaging catheter <NUM> is connected to the diagnostic imaging apparatus <NUM>. <FIG> is a cross-sectional view showing a cross section parallel to the longitudinal direction A at a distal end portion that is an end portion on the distal side of the diagnostic imaging catheter <NUM>. <FIG> is an upper side view of a vicinity of an imaging core portion <NUM> of the diagnostic imaging catheter <NUM>. <FIG> is a horizontal side view of the vicinity of the imaging core portion <NUM> of the diagnostic imaging catheter <NUM>. <FIG> is a perspective view of the vicinity of the imaging core portion <NUM> of the diagnostic imaging catheter <NUM>. In <FIG>, a sheath <NUM> is omitted.

The diagnostic imaging catheter <NUM> of the present embodiment can be applied to IVUS. As shown in <FIG>, the diagnostic imaging catheter <NUM> is driven by being connected to the diagnostic imaging apparatus <NUM>. More specifically, the diagnostic imaging catheter <NUM> of the present embodiment is connected to a drive unit 120a of the diagnostic imaging apparatus <NUM>.

As shown in <FIG>, the diagnostic imaging catheter <NUM> includes an insertion portion 1a and an operation portion 1b. The insertion portion 1a is a portion of the diagnostic imaging catheter <NUM> that is inserted into the living body and used. The operation portion 1b is a portion of the diagnostic imaging catheter <NUM> that is operated outside the living body in a state where the insertion portion 1a is inserted into the living body. In the diagnostic imaging catheter <NUM> of the present embodiment, a portion on the distal side of a distal side connector <NUM> (see <FIG>) described later is the insertion portion 1a, and a portion on the proximal side from the distal side connector <NUM> is the operation portion 1b.

As shown in <FIG> and <FIG>, the insertion portion 1a includes the imaging core portion <NUM>, a drive shaft <NUM>, a signal line <NUM>, and a sheath <NUM>. The imaging core portion <NUM> is coupled to the distal side of the drive shaft <NUM>. The sheath <NUM> is inserted into the living body and used (see <FIG>). The imaging core portion <NUM>, the drive shaft <NUM>, and the signal line <NUM> are located in the sheath <NUM> and are inserted into the living body together with the sheath <NUM> and used (see <FIG>).

As shown in <FIG>, the operation portion 1b includes an inner tube member <NUM> and an outer tube member <NUM>. The inner tube member <NUM> holds an end portion on the proximal side of the drive shaft <NUM>. The outer tube member <NUM> holds an end portion on the proximal side of the sheath <NUM>. When the inner tube member <NUM> moves in a central axis direction in the outer tube member <NUM>, the imaging core portion <NUM>, the drive shaft <NUM>, and the signal line <NUM> shown in <FIG> can move in the sheath <NUM> in the longitudinal direction A. The drive shaft <NUM> and the signal line <NUM> extend not only in a region of the insertion portion 1a but also in a region of the operation portion 1b in the longitudinal direction A through the inside of the inner tube member <NUM> and the outer tube member <NUM>.

As shown in <FIG>, the imaging core portion <NUM> is located in the sheath <NUM> inserted into the living body. The imaging core portion <NUM> of the present embodiment includes a transmission and reception member <NUM> capable of transmitting and receiving a signal, a housing <NUM> holding the transmission and reception member <NUM>, and a contrast marker <NUM>.

The transmission and reception member <NUM> of the present embodiment is an ultrasound transducer 11a capable of transmitting and receiving an ultrasonic signal. Hereinafter, the ultrasound transducer 11a as the transmission and reception member <NUM> will be described as an example, but the transmission and reception member <NUM> is not limited to the ultrasound transducer 11a, and may be, for example, an optical element capable of transmitting and receiving an optical signal. An example of the optical element capable of transmitting and receiving the optical signal includes a ball lens that is provided at a distal end of an optical fiber and has a lens function of condensing light and a reflection function of reflecting light.

The ultrasound transducer 11a as the transmission and reception member <NUM> of the present embodiment includes a piezoelectric element <NUM>, a support member <NUM>, and an acoustic matching member <NUM>.

Specifically, the piezoelectric element <NUM> includes a flat piezoelectric body, a first electrode laminated on at least one side in a thickness direction of the piezoelectric body, and a second electrode laminated on at least the other side in the thickness direction of the piezoelectric body. Hereinafter, for convenience of description, a side on which an ultrasound transmission and reception surface 11a1 capable of transmitting and receiving ultrasound of the ultrasound transducer 11a is located in the thickness direction of the piezoelectric body is referred to as a "front surface side", and a side opposite to the ultrasound transmission and reception surface 11a1 of the ultrasound transducer 11a in the thickness direction of the piezoelectric body is referred to as a "back surface side".

The piezoelectric body of the piezoelectric element <NUM> is formed of, for example, a piezoelectric ceramic sheet. An example of a material of the piezoelectric ceramic sheet includes a piezoelectric ceramic material such as lead zirconate titanate (PZT) and lithium niobate. The piezoelectric body may be formed of crystal instead of the piezoelectric ceramic material.

The first electrode and the second electrode of the piezoelectric element <NUM> can be formed, for example, by laminating electrode layers on both sides in the thickness direction of the piezoelectric body by an ion plating method, a vapor deposition method, or a sputtering method using a mask material. Examples of a material of the first electrode and the second electrode include metals such as silver, chromium, copper, nickel, and gold, and laminates of these metals.

The first electrode is laminated only on the front surface side of the piezoelectric body. The second electrode is laminated on the back surface side of the piezoelectric body, and a part of the second electrode is folded back to the front surface side of the piezoelectric body. That is, the second electrode of the present embodiment is a folded-back electrode. However, the first electrode and the second electrode may not be folded-back electrodes. In addition, the second electrode may not be a folded-back electrode, and the first electrode may be a folded-back electrode in which a part of the first electrode is folded back to the back surface side to form the second electrode.

The support member <NUM> supports the piezoelectric element <NUM> from the back surface side of the piezoelectric element. Specifically, the support member <NUM> is laminated on the piezoelectric element <NUM> to cover an entire region of the back surface side of the piezoelectric element <NUM>. Thus, the ultrasound from the piezoelectric element <NUM> that is noise can be absorbed. That is, the support member <NUM> of the present embodiment is a sound absorbing layer that absorbs the ultrasound of the piezoelectric element <NUM>.

The sound absorbing layer as the support member <NUM> can be formed by a method of bonding a sheet material forming the sound absorbing layer to the piezoelectric element <NUM>, a method of applying and curing a liquid sound absorbing material forming the sound absorbing layer, or the like. An example of a material of the support member <NUM> includes an epoxy resin in which rubber and a metal powder such as tungsten powder are dispersed.

The acoustic matching member <NUM> is laminated to cover the front surface side of the piezoelectric element <NUM>. More specifically, the acoustic matching member <NUM> of the present embodiment is laminated to cover the entire region of the front surface side of the piezoelectric element <NUM> except for a portion of the piezoelectric element <NUM> to which the signal line <NUM> is connected to the first electrode and the second electrode. By providing the acoustic matching member <NUM>, propagation efficiency of the ultrasound to an object can be enhanced. That is, the acoustic matching member <NUM> of the present embodiment is an acoustic matching layer that enhances the propagation efficiency of the ultrasound.

The acoustic matching layer as the acoustic matching member <NUM> can be formed by a method of bonding a sheet material forming the acoustic matching layer to the piezoelectric element <NUM>, a method of applying and curing a liquid acoustic matching material forming the acoustic matching layer, or the like. An example of the material of the acoustic matching member <NUM> includes a resin material such as the epoxy resin. Further, the acoustic matching member <NUM> may be a laminated body of resin layers made of the resin material.

The ultrasound transmission and reception surface 11a1 of the ultrasound transducer 11a as the transmission and reception member <NUM> of the present embodiment is a surface of the ultrasound transducer 11a. That is, in the ultrasound transducer 11a of the present embodiment, the planar ultrasound transmission and reception surface 11a1 is defined by the acoustic matching member <NUM>.

Further, the ultrasound transducer 11a as the transmission and reception member <NUM> of the present embodiment has an elliptical outer shape in a plan view as viewed in the thickness direction of the piezoelectric body, that is, in a plan view of the ultrasound transmission and reception surface 11a1. Details thereof will be described later.

As shown in <FIG>, the housing <NUM> holds the ultrasound transducer 11a as the transmission and reception member <NUM> in the sheath <NUM>. The proximal side of the housing <NUM> is connected to the drive shaft <NUM>. As shown in <FIG>, a side surface of the housing <NUM> that faces a radial direction B of the sheath <NUM> includes an inclined portion <NUM> that is inclined to approach a central axis line O of the drive shaft <NUM> toward the distal side until reaching the distal end. The "side surface of the housing" is a surface of the housing that faces the radial direction B of the sheath, and means a surface that constitutes an entire region around the sheath in the radial direction B. The side surface of the housing <NUM> of the present embodiment includes a support surface 12a that supports the ultrasound transducer 11a serving as the transmission and reception member <NUM>. The side surface of the housing <NUM> will be described in detail later.

The housing <NUM> of the present embodiment includes a main body portion 12b, a distal end portion 12c, and a proximal end portion 12d. The main body portion 12b includes the above support surface 12a. The distal end portion 12c is located on the distal side of the main body portion 12b and includes a distal end. The proximal end portion 12d is located on the proximal side of the main body portion 12b, and is connected to the contrast marker <NUM>. Each portion of the housing <NUM> will be described in detail later.

The housing <NUM> can be made of, for example, a resin such as polycarbonate. The housing <NUM> is formed by, for example, injection molding of the resin material. The housing <NUM> may be made of metal. Such a housing <NUM> can be made of, for example, stainless steel, gold-plated stainless steel, a platinum iridium alloy, and a platinum zirconia alloy. In addition, such a housing <NUM> is formed by cutting from a metal ingot, metallic powder injection molding (MIM), or the like. Further, the housing <NUM> may be made of ceramics prepared by firing zirconia or the like.

The contrast marker <NUM> has a substantially cylindrical outer shape, and is connected to the proximal end portion 12d of the housing <NUM> at the distal side. In the present embodiment, in a state where the proximal end portion 12d of the housing <NUM> is inserted into the contrast marker <NUM>, the housing <NUM> and the contrast marker <NUM> are bonded to each other by an adhesive or the like. However, a connection configuration between the housing <NUM> and the contrast marker <NUM> is not limited to the above configuration. The contrast marker <NUM> can be, for example, a metal coil or a metal pipe having high X-ray impermeableness such as platinum, gold, iridium, and tungsten.

As shown in <FIG>, for example, an absorbing member <NUM> formed of the same material as that of the support member <NUM> described above is disposed inside the substantially cylindrical contrast marker <NUM> of the present embodiment. Since the inside of the contrast marker <NUM> is filled with such an absorbing member <NUM>, it is possible to prevent the ultrasound from being transmitted from the ultrasound transducer 11a serving as the transmission and reception member <NUM> toward a portion different from a target portion. Further, it is possible to prevent the ultrasound transducer 11a serving as the transmission and reception member <NUM> from receiving the ultrasound reflected at a portion different from the target portion.

The imaging core portion <NUM> of the present embodiment includes the contrast marker <NUM> on the proximal side of the housing <NUM>, and may also be an imaging core portion without the contrast marker <NUM>. That is, the proximal end portion 12d of the housing <NUM> may be connected to the drive shaft <NUM>, which will be described later, without the contrast marker <NUM>. When the imaging core portion without the contrast marker <NUM> is formed in this way, the housing <NUM> itself may be formed of a material having a contrast property, such as metal, a resin containing a material having high X-ray impermeableness, or ceramics.

The drive shaft <NUM> is rotatable around the central axis line O in the sheath <NUM>. The imaging core portion <NUM> described above is attached to the drive shaft <NUM> in the sheath <NUM>. Therefore, the drive shaft <NUM> rotates the imaging core portion <NUM> around the central axis line O in the sheath <NUM>. More specifically, the drive shaft <NUM> rotates around the central axis line O in the sheath to rotate the transmission and reception member <NUM>, the housing <NUM>, and the contrast marker <NUM> connected thereto around the central axis line O. A power source for rotating the drive shaft <NUM> is a motor <NUM> (see <FIG>) of the diagnostic imaging apparatus <NUM> to be described later.

The drive shaft <NUM> is formed of a tubular body having flexibility. The signal line <NUM> connected to the ultrasound transducer 11a as the transmission and reception member <NUM> is disposed inside the drive shaft <NUM>. The drive shaft <NUM> is, for example, a multi-layer coil having different winding directions around an axis. Examples of a material of the coil include the stainless steel and a nickeltitanium (Ni-Ti) alloy. By providing such a drive shaft <NUM>, even if two electric signal lines are formed of a double spiral twisted pair cable as the signal line <NUM>, the shielding property can be improved and an influence of noise generated from the electric signal line can be reduced.

The drive shaft <NUM> extends through the inside of the inner tube member <NUM> and the outer tube member <NUM> to a hub <NUM> to be described later. The hub <NUM> is located at the proximal end portion of the inner tube member <NUM>. That is, the drive shaft <NUM> extends from the distal end portion of the insertion portion 1a to the proximal end portion of the operation portion 1b in the longitudinal direction A.

The signal line <NUM> extends into the drive shaft <NUM>, and electrically or optically connects the transmission and reception member <NUM> and the diagnostic imaging apparatus <NUM>. The signal line <NUM> of the present embodiment is an electric signal line that electrically connects the ultrasound transducer 11a serving as the transmission and reception member <NUM> and the diagnostic imaging apparatus <NUM>. Similarly to the drive shaft <NUM>, the electric signal line as the signal line <NUM> of the present embodiment extends from the distal end portion of the insertion portion 1a to the proximal end portion of the operation portion 1b in the longitudinal direction A. A plurality of (two in the present embodiment) electric signal lines are provided as the signal line <NUM> of the present embodiment, and are respectively connected to the first electrode and the second electrode of the ultrasound transducer 11a described above. The plurality of electric signal lines as the signal line <NUM> are, for example, a twisted pair cable in which the two electric signal lines are twisted.

The signal line <NUM> of the present embodiment is an electric signal line. Alternatively, in a case of a configuration in which the transmission and reception member <NUM> can transmit and receive an optical signal, the signal line <NUM> may be, for example, an optical fiber line.

As shown in <FIG>, the sheath <NUM> defines a first hollow portion 41a and a second hollow portion 41b. The imaging core portion <NUM>, the drive shaft <NUM>, and the signal line <NUM> are accommodated in the first hollow portion 41a. The imaging core portion <NUM>, the drive shaft <NUM>, and the signal line <NUM> can move forward and backward in the longitudinal direction A in the first hollow portion 41a. A guide wire W can be inserted into the second hollow portion 41b. In the present embodiment, a tubular guide wire insertion portion 40b that defines the second hollow portion 41b is located to be substantially parallel to the distal end portion of a tubular main body portion 40a that defines the first hollow portion 41a. The main body portion 40a and the guide wire insertion portion 40b can be formed by joining different tube members by thermal fusion or the like, and the present disclosure is not limited to such a forming method.

The main body portion 40a is provided with a marker portion <NUM> that has X-ray contrast properties and is formed of a material impermeable to X-rays. The guide wire insertion portion 40b is also provided with a marker portion <NUM> having X-ray contrast properties. The marker portions <NUM> and <NUM> can be, for example, a metal coil or a metal pipe having high X-ray impermeableness such as platinum, gold, iridium, and tungsten.

In a range in which the ultrasound transducer 11a as the transmission and reception member <NUM> moves in the longitudinal direction A of the sheath <NUM>, a window portion <NUM> in which ultrasound permeability is higher than that at other portions is provided. More specifically, the window portion <NUM> of the present embodiment is provided in the main body portion 40a of the sheath <NUM>.

The window portion <NUM> of the main body portion 40a and the guide wire insertion portion 40b are made of a material having flexibility, and the material is not particularly limited. Examples of the material include various thermoplastic elastomers such as polyethylene, styrene, polyolefin, polyurethane, polyester, polyamide, polyimide, polybutadiene, trans-polyisoprene, fluorine rubber, and chlorinated polyethylene, and polymer alloys, polymer blends, laminates, and the like that combine one or more of these substances can also be used.

The proximal side of the window portion <NUM> of the main body portion 40a includes a reinforced portion reinforced by a material having higher rigidity than the window portion <NUM>. The reinforced portion is formed by, for example, disposing a reinforcing member, in which a metal wire made of the stainless steel or the like is braided in a mesh shape, in a tubular member having flexibility such as a resin. The tubular member may be formed of the same material as that of the window portion <NUM>.

It is preferable to dispose a hydrophilic lubricating coating layer that exhibits lubricity when wet on an outer surface of the sheath <NUM>.

A communication hole <NUM> that communicates the inside with the outside of the first hollow portion 41a is formed in the distal end portion of the main body portion 40a of the sheath <NUM>. During priming, gas in the main body portion 40a can be discharged through the communication hole <NUM>.

As shown in <FIG>, the inner tube member <NUM> includes an inner tube <NUM> and the hub <NUM>. The inner tube <NUM> is inserted into the outer tube member <NUM> to be movable forward and backward. The hub <NUM> is provided on the proximal side of the inner tube <NUM>.

As shown in <FIG>, the outer tube member <NUM> includes an outer tube <NUM>, the distal side connector <NUM>, and a proximal side connector <NUM>. The outer tube <NUM> is located on an outer side in the radial direction (the same direction as the radial direction B of the sheath <NUM>) of the inner tube <NUM>, and the inner tube <NUM> moves forward and backward in the outer tube <NUM>. The distal side connector <NUM> connects the proximal end portion of the main body portion 40a of the sheath <NUM> and the distal end portion of the outer tube <NUM>. The proximal side connector <NUM> is provided at the proximal end portion of the outer tube <NUM>, and accommodates the inner tube <NUM> in the outer tube <NUM>.

The drive shaft <NUM> and the signal line <NUM> described above extend from the first hollow portion 41a of the main body portion 40a of the sheath <NUM> to the hub <NUM> located at the proximal end portion of the inner tube member <NUM> through the inside of the outer tube member <NUM> connected to the proximal side of the main body portion 40a and the inside of the inner tube member <NUM> a portion of which is inserted into the outer tube member <NUM>.

The imaging core portion <NUM> described above is integrally coupled to the inner tube member <NUM> via the drive shaft <NUM>. Therefore, when the inner tube member <NUM> is pushed in the insertion direction A1, the inner tube member <NUM> is pushed into the outer tube member <NUM> in the insertion direction A1. When the inner tube member <NUM> is pushed into the outer tube member <NUM> in the insertion direction A1, the imaging core portion <NUM> coupled to the inner tube member <NUM> via the drive shaft <NUM> moves in the main body portion 40a of the sheath <NUM> in the insertion direction A1. Conversely, when the inner tube member <NUM> is pulled in the removal direction A2, the inner tube member <NUM> is pulled out in the removal direction A2 from the inside of the outer tube member <NUM>. When the inner tube member <NUM> is pulled out in the removal direction A2 from the inside of the outer tube member <NUM>, the imaging core portion <NUM> coupled to the inner tube member <NUM> via the drive shaft <NUM> moves in the removal direction A2 inside the main body portion 40a of the sheath <NUM>.

A connector portion mechanically and electrically connected to the diagnostic imaging apparatus <NUM> is provided at a proximal end of the hub <NUM> of the inner tube member <NUM>. That is, the diagnostic imaging catheter <NUM> is mechanically and electrically connected to the diagnostic imaging apparatus <NUM> by the connector portion provided on the hub <NUM> of the inner tube member <NUM>. More specifically, the electric signal line as the signal line <NUM> of the diagnostic imaging catheter <NUM> extends from the ultrasound transducer 11a to the connector portion of the hub <NUM>. The electric signal line as the signal line <NUM> electrically connects the ultrasound transducer 11a and the diagnostic imaging apparatus <NUM> in a state where the connector portion of the hub <NUM> is connected to the diagnostic imaging apparatus <NUM>. A reception signal in the ultrasound transducer 11a is transmitted to the diagnostic imaging apparatus <NUM> via the connector portion of the hub <NUM>, subjected to predetermined processing, and displayed as an image.

As shown in <FIG>, the diagnostic imaging apparatus <NUM> includes the motor <NUM>, which is the power source for rotating the drive shaft <NUM>, and a motor <NUM>, which is a power source for moving the drive shaft <NUM> in the longitudinal direction A. A rotational movement of the motor <NUM> is converted into an axial movement by a ball screw <NUM> connected to the motor <NUM>.

More specifically, the diagnostic imaging apparatus <NUM> of the present embodiment includes the drive unit 120a, a control device 120b, and a monitor 120c. The control device 120b is electrically connected to the drive unit 120a by wire or wirelessly. The monitor 120c can display an image generated by the control device 120b based on a reception signal received from the diagnostic imaging catheter <NUM>. The motor <NUM>, the motor <NUM>, and the ball screw <NUM> described above of the present embodiment are provided in the drive unit 120a. An operation of the drive unit 120a is controlled by the control device 120b. The control device 120b may be a processor including a CPU and a memory.

The diagnostic imaging apparatus <NUM> is not limited to the configuration shown in the present embodiment, and may further include, for example, an external input unit such as a keyboard.

<FIG> is an in-use state diagram showing a state in which the diagnostic imaging catheter <NUM> of the present embodiment is inserted into a blood vessel BV. Hereinafter, a feature of the housing <NUM> of the imaging core portion <NUM> of the diagnostic imaging catheter <NUM> will be described with reference to <FIG>.

As shown in <FIG>, the sheath <NUM> of the diagnostic imaging catheter <NUM> is inserted into the living body and used. As described above, the imaging core portion <NUM> and the drive shaft <NUM> are accommodated in the sheath <NUM>, and the imaging core portion <NUM> and the drive shaft <NUM> are inserted into the living body together with the sheath <NUM> and used.

Here, as shown in <FIG>, the side surface of the housing <NUM> that faces the radial direction B of the sheath <NUM> includes the inclined portion <NUM> that is inclined to approach the central axis line O of the drive shaft <NUM> toward the distal side until reaching the distal end. The inclined portion <NUM> extends from the proximal side of a distal end 11a2 of the ultrasound transducer 11a as the transmission and reception member <NUM> to the distal side of the distal end 11a2 of the ultrasound transducer 11a as the transmission and reception member <NUM>.

By providing such an inclined portion <NUM> on the side surface of the housing <NUM>, it is possible to improve followability to a blood vessel shape. Therefore, even in a bent blood vessel shape as shown in <FIG>, since the housing <NUM> of the present embodiment includes the inclined portion <NUM> on the side surface, the housing <NUM> is easily brought into surface contact with an inner surface of the sheath <NUM> extending along the bent blood vessel shape. As a result, the housing <NUM> moves easily forward and backward along an inner wall of the blood vessel BV (see <FIG>).

More specifically, the housing <NUM> of the present embodiment includes the main body portion 12b, the distal end portion 12c, and the proximal end portion 12d. A substantially elliptical columnar recess is formed in the main body portion 12b. The ultrasound transducer 11a as the transmission and reception member <NUM> is held by the housing <NUM> with the back surface side on which the support member <NUM> is disposed accommodated in the recess and the ultrasound transducer 11a being supported on a bottom surface of the recess. Therefore, the support surface 12a of the transmission and reception member <NUM> of the housing <NUM> of the present embodiment is the bottom surface of the recess.

The ultrasound transducer 11a of the present embodiment is bonded to the housing <NUM> by an adhesive or the like in a state of being accommodated in the recess. As shown in <FIG>, a through-hole 12b1 penetrating to the outside is formed in the vicinity of the bottom surface of the recess formed in the main body portion 12b of the housing <NUM>. An excess adhesive that adheres the ultrasound transducer 11a and the housing <NUM> leaks to the outside through the through-hole 12b1. Therefore, it is possible to prevent the adhesive from leaking from a side wall of the recess to the front surface side of the ultrasound transducer 11a. Therefore, it is possible to prevent the adhesive from adhering to the ultrasound transmission and reception surface 11a1 of the ultrasound transducer 11a.

As shown in <FIG>, in an upper side view of the housing <NUM> as viewed from a support surface 12a side, the inclined portion <NUM> is formed on side surfaces of the housing <NUM> located on both sides of the transmission and reception member <NUM>. By providing such an inclined portion <NUM>, the followability of the housing <NUM> to the blood vessel shape can be improved. The upper side view of the housing <NUM> as viewed from the support surface 12a side (see <FIG>) means a side view of the housing <NUM> as viewed from the support surface 12a side in the radial direction B of the sheath <NUM>. Hereinafter, the upper side view of the housing <NUM> as viewed from the support surface 12a side will be simply referred to as "the upper side view of the housing <NUM>".

In the present embodiment, in the upper side view of the housing <NUM> (see <FIG>), the inclined portion <NUM> is formed on the side surfaces of the housing <NUM> located on the both sides of the transmission and reception member <NUM>. However, the present disclosure is not limited to this configuration. In the upper side view (see <FIG>) of the housing <NUM>, the inclined portion <NUM> may be formed on the side surface of the housing <NUM> located at least on one side of the transmission and reception member <NUM>. However, from a viewpoint of improving the followability of the housing <NUM> to the blood vessel shape, as in the present embodiment, it is preferable that the inclined portion <NUM> is formed on the side surfaces of the housing <NUM> located on the both sides of the transmission and reception member <NUM> in the upper side view (see <FIG>) of the housing <NUM>.

Further, in the present embodiment, the inclined portion <NUM> is also formed at a position of the side surface of the housing <NUM> on a back side of the support surface 12a. Specifically, in a horizontal side view of the housing <NUM> shown in <FIG>, the inclined portion <NUM> is formed at the position of the side surface of the housing <NUM> on the back side of the support surface 12a. By providing such an inclined portion <NUM>, the followability of the housing <NUM> to the blood vessel shape can be improved. The horizontal side view (see <FIG>) of the housing <NUM> means a side view as viewed from a viewpoint in which the support surface 12a of the housing <NUM> appears linear in the radial direction B of the sheath <NUM>. In the present embodiment, as shown in <FIG>, in the horizontal side view of the housing <NUM>, not only the support surface 12a but also the ultrasound transmission and reception surface 11a1 of the ultrasound transducer 11a as the transmission and reception member <NUM> is also linearly seen.

As described above, the inclined portion <NUM> is provided on the side surface of the housing <NUM> of the present embodiment at positions on both sides of the ultrasound transducer 11a as the transmission and reception member <NUM> in the upper side view (see <FIG>) of the housing <NUM>. Further, on the side surface of the housing <NUM> of the present embodiment, the inclined portion <NUM> is provided at a position on the back side of the support surface 12a in the horizontal side view (see <FIG>) of the housing <NUM>.

Further, in the present embodiment, the inclined portion <NUM> is formed in the whole circumferential region from the position on one side of the side surface of the housing <NUM> on which the ultrasound transducer 11a is interposed in the upper side view (see <FIG>) of the housing <NUM> to the position on the other side on which the ultrasound transducer 11a is interposed in the upper side view (see <FIG>) of the housing <NUM> through the position on the back side of the support surface 12a in the horizontal side view (see <FIG>) of the housing <NUM>. In this way, the followability of the housing <NUM> to the blood vessel shape can be further improved.

An angle of the inclined portion <NUM> with respect to the central axis line O of the drive shaft <NUM> is preferably increased toward the distal side in the side view of the housing <NUM> (see <FIG>). Specifically, in the side views shown in <FIG>, the inclined portion <NUM> of the present embodiment includes a proximal inclined portion 71a and a distal inclined portion 71b in which the angle of the inclined portion <NUM> with respect to the central axis line O of the drive shaft <NUM> is larger than that of the proximal inclined portion 71a. The proximal inclined portion 71a extends substantially linearly in the side views of the housing <NUM> (see <FIG>). The proximal inclined portion 71a extends over the proximal side and the distal side of the distal end 11a2 of the transmission and reception member <NUM>. The distal inclined portion 71b is convexly curved and extends in the side view (see <FIG>) of the housing <NUM>. The distal inclined portion 71b is continuous with the distal end of the proximal inclined portion 71a and extends to a distal end surface 12e of the housing <NUM>.

The distal end surface 12e of the housing <NUM> is a flat surface orthogonal to the central axis line O of the drive shaft <NUM>, but the present disclosure is not limited to this, and for example, may be a curved surface that projects convexly to the distal side. Further, the inclined portion <NUM> on the side surface of the housing <NUM> includes by the proximal inclined portion 71a linearly extending and the distal inclined portion 71b convexly curved in the side views (see <FIG>). However, the present disclosure is not limited to this configuration. For example, in the side views (see <FIG>), the inclined portion may be curved and extend such that the angle of the drive shaft <NUM> with respect to the central axis line O gradually increases toward the distal side.

Further, the inclined portion <NUM> of the present embodiment is formed from the main body portion 12b of the housing <NUM> to the distal end portion 12c. More specifically, the inclined portion <NUM> of the present embodiment is formed only on the distal side of a proximal end 11a3 of the transmission and reception member <NUM>, and is not formed on the proximal side from the proximal end 11a3 of the transmission and reception member <NUM>. That is, the inclined portion <NUM> on the side surface of the housing <NUM> of the present embodiment is not formed on the proximal end portion 12d of the housing <NUM>. However, the inclined portion may extend from the distal end of the housing <NUM> to the proximal side of the proximal end 11a3 of the transmission and reception member <NUM>.

In the side surface of the housing <NUM> of the present embodiment, the back side of the support surface 12a is defined by a peripheral surface. More specifically, in the side surface of the housing <NUM> of the present embodiment, the back side of the support surface 12a is defined by the peripheral surface along an inner peripheral surface of the sheath <NUM>. Therefore, the housing <NUM> is easily brought into surface contact with the inner surface of the sheath <NUM>, the inner surface of the sheath <NUM> is not easily damaged, the housing <NUM> is less likely to be caught in the inner surface of the sheath <NUM>, and the followability of the housing <NUM> to the blood vessel shape can be enhanced. Further, as described above, in the present embodiment, the inclined portion <NUM> is formed in the whole circumferential region from the position on one side of the side surface of the housing <NUM> on which the ultrasound transducer 11a is interposed in the upper side view (see <FIG>) of the housing <NUM> to the position on the other side on which the ultrasound transducer 11a is interposed in the upper side view (see <FIG>) of the housing <NUM> through the position on the back side of the support surface 12a in the horizontal side view (see <FIG>) of the housing <NUM>. That is, in the side surface of the housing <NUM> of the present embodiment, the back side of the support surface 12a is the peripheral surface, on which the inclined portion <NUM> is formed. Therefore, the followability of the housing <NUM> to the blood vessel shape can be further improved.

In other words, the distal end portion 12c of the housing <NUM> of the present embodiment has a substantially truncated conical outer shape. The side surface of the distal end portion 12c is a tapered surface that decreases in diameter from the proximal side toward the distal side. A part of the tapered surface of the distal end portion 12c extends continuously in the main body portion 12b, and the inclined portion <NUM> is formed on the side surface of the housing <NUM> by extending to the proximal side of the distal end 11a2 of the ultrasound transducer 11a as the transmission and reception member <NUM>.

In other words, the housing <NUM> of the present embodiment includes the main body portion 12b including the support surface 12a that supports the transmission and reception member <NUM>, and the distal end portion 12c located on the distal side of the main body portion 12b and including the distal end. The side surface of the housing <NUM> extends over the main body portion 12b and the distal end portion 12c, and includes a peripheral surface portion formed by the peripheral surface along the inner surface of the sheath <NUM>. The peripheral surface portion is formed by the above inclined portion <NUM> that approaches the central axis line O of the drive shaft <NUM> from the proximal side toward the distal side.

Further, as shown in <FIG>, a proximal protrusion portion 17a protruding toward the inner surface of the sheath <NUM> from the transmission and reception member <NUM> supported by the support surface 12a is provided on the proximal side of the side surface of the housing <NUM> with respect to the support surface 12a. With such a configuration, when the imaging core portion <NUM> moves forward and backward in the sheath <NUM>, it is possible to prevent the ultrasound transmission and reception surface 11a1 of the ultrasound transducer 11a from abutting against the inner surface of the sheath <NUM>. Therefore, the ultrasound transmission and reception surface 11a1 of the ultrasound transducer 11a is less likely to be damaged.

Further, as shown in <FIG>, a distal protrusion portion 17b protruding toward the inner surface of the sheath <NUM> from the transmission and reception member <NUM> supported by the support surface 12a is provided on the distal side of the side surface of the housing <NUM> with respect to the support surface 12a. With such a configuration, when the imaging core portion <NUM> moves forward and backward in the sheath <NUM>, it is possible to prevent the ultrasound transmission and reception surface 11a1 of the ultrasound transducer 11a from abutting against the inner surface of the sheath <NUM>. Therefore, the ultrasound transmission and reception surface 11a1 of the ultrasound transducer 11a is less likely to be damaged.

Further, as shown in <FIG>, the distal protrusion portion 17b protrudes further toward the inner surface of the sheath <NUM> than the proximal protrusion portion 17a. With such a configuration, when the imaging core portion <NUM> moves forward and backward in the sheath <NUM>, it is possible to further prevent the ultrasound transmission and reception surface 11a1 of the ultrasound transducer 11a from abutting against the inner surface of the sheath <NUM>. Therefore, the ultrasound transmission and reception surface 11a1 of the ultrasound transducer 11a is less likely to be damaged.

Further, the distal protrusion portion 17b of the present embodiment is inclined so as to approach the central axis line O of the drive shaft <NUM> toward the distal side in the horizontal side view (see <FIG>) of the housing <NUM>. Further, in the horizontal side view (see <FIG>) of the housing <NUM>, the angle of the distal protrusion portion 17b with respect to the central axis line O of the drive shaft <NUM> increases toward the distal side, and extends to the distal end surface 12e of the housing <NUM>. By providing such a distal protrusion portion 17b, it is possible to further improve the followability of the housing <NUM> to the blood vessel shape.

Here, the transmission and reception member <NUM> of the present embodiment is the ultrasound transducer 11a capable of transmitting and receiving the ultrasound on the ultrasound transmission and reception surface 11a1. A distal end surface 11a4 including the distal end 11a2 of the ultrasound transducer 11a is preferably formed of a convex curved surface. The ultrasound transducer 11a of the present embodiment has an elliptical outer shape in a front view of the ultrasound transmission and reception surface 11a1. However, the present disclosure is not limited to this configuration. For example, the ultrasound transducer may be an ultrasound transducer having an outer shape such as a circular shape in a front view of the ultrasound transmission and reception surface, a substantially quadrangular shape in which only the distal end surface is a convex curved surface in the front view of the ultrasound transmission and reception surface, or the like. However, in consideration of a convergence performance of the ultrasound transducer 11a, the outer shape of the ultrasound transmission and reception surface 11a1 is preferably the elliptical shape or the circular shape, and particularly preferably the circular shape.

When a small piezoelectric element <NUM> (see <FIG>) capable of being inserted into the living body is used as in the present embodiment, it is preferable to increase an area of the ultrasound transmission and reception surface 11a1 of the ultrasound transducer 11a to implement a high output of the ultrasound. Therefore, in the upper side view (see <FIG>) of the housing <NUM>, the side surfaces of the housing <NUM> on the both sides of the ultrasound transducer 11a as the transmission and reception member <NUM> are likely to be located close to the inner surface of the sheath <NUM>.

As described above, the distal end surface 11a4 of the ultrasound transducer 11a is formed of the convex curved surface, and the inclined portion <NUM> is provided along the curved surface of the distal end surface 11a4 of the ultrasound transducer 11a on the side surface of the housing <NUM> on the both sides of the ultrasound transducer 11a in the upper side view (see <FIG>) of the housing <NUM>. Therefore, it is possible to further improve the followability of the housing <NUM> to the blood vessel shape. Further, when the outer shape of the ultrasound transmission and reception surface 11a1 is the elliptical shape or the circular shape, the convergence performance of the ultrasound transducer 11a can also be improved. <FIG> is a diagram showing a modification of the ultrasound transducer 11a described above. In an ultrasound transducer 211a shown in <FIG>, an outer shape of an ultrasound transmission and reception surface 211a1 is an elliptical shape. However, a part of the ultrasound transducer 211a on the proximal side of a piezoelectric element <NUM> is located at a position not overlapping the ultrasound transmission and reception surface 211a1 in a front view of the ultrasound transmission and reception surface 211a1. A contact portion of the first electrode and the second electrode to which the signal line <NUM> is electrically connected is provided in the portion not overlapping the ultrasound transmission and reception surface 211a1 in the piezoelectric element <NUM>. According to the ultrasound transducer 211a shown in <FIG>, the convergence performance of the ultrasound from the ultrasound transmission and reception surface 211a1 can be enhanced as compared with the ultrasound transducer 11a described above.

The diagnostic imaging catheter according to the present disclosure is not limited to the specific configuration specified in the above embodiment, and various modifications and changes can be made without departing from the scope of the claims. The imaging core portion <NUM> of the above embodiment includes only the ultrasound transducer 11a capable of transmitting and receiving the ultrasonic signal as the transmission and reception member <NUM>. However, the present disclosure is not limited to this configuration. The transmission and reception member <NUM> may be, for example, an optical element that can transmit and receive the optical signal and that enables optical coherence tomography (abbreviated as "OCT").

Claim 1:
A diagnostic imaging catheter (<NUM>) comprising:
a sheath (<NUM>) configured to be inserted into a living body;
a drive shaft (<NUM>) rotatable in the sheath (<NUM>); and
an imaging core portion (<NUM>) attached to the drive shaft (<NUM>) in the sheath (<NUM>), wherein
the imaging core portion (<NUM>) includes:
a transmission and reception member (<NUM>) capable of transmitting and receiving a signal; and
a housing (<NUM>) holding the transmission and reception member (<NUM>),
wherein a side surface of the housing (<NUM>) that faces a radial direction (B) of the sheath (<NUM>) includes an inclined portion (<NUM>) that is inclined to approach a central axis line (O) of the drive shaft (<NUM>) toward a distal side until reaching a distal end,
wherein the inclined portion (<NUM>) extends from a proximal side of a distal end (11a2) of the transmission and reception member (<NUM>) to a distal side of the distal end (11a2) of the transmission and reception member (<NUM>),
wherein the transmission and reception member (<NUM>) are an ultrasound transducer (11a) capable of transmitting and receiving ultrasound on a ultrasound transmission and reception surface, and
wherein a distal end surface (11a4) of the ultrasound transducer (11a) is formed of a convex curved surface,
characterized in that the ultrasound transducer (11a) as the transmission and reception member (<NUM>) is held by the housing (<NUM>) with a back surface side on which a support member (<NUM>) is disposed accommodated in a recess and the ultrasound transducer (11a) is supported on a bottom surface of the recess.