Image diagnosis catheter
An image diagnosis catheter is disclosed, which includes: a sheath inserted into a living body; an ultrasound vibrator capable of transmitting and receiving ultrasound in the sheath; a housing holding the ultrasound vibrator in the sheath; and a drive shaft attached to a proximal side of the housing and rotatable in the sheath, in which an ultrasound transmitting/receiving surface of the ultrasound vibrator facing a radial direction of the sheath is inclined with respect to an extension direction of the sheath such that a distal end of the ultrasound transmitting/receiving surface is closer to an inner peripheral surface of the sheath than a proximal end of the ultrasound transmitting/receiving surface, and the housing does not block a distal side of the ultrasound vibrator in an in-plane direction of the ultrasound transmitting/receiving surface.
1 . An image diagnosis catheter comprising:
an elongated sheath configured to be inserted into a living body;
an imaging core unit disposed in the sheath;
a drive shaft attached to a proximal end of the imaging core unit and disposed in the sheath;
the imaging core unit including:
an ultrasound vibrator that includes an ultrasound transmitting/receiving surface, a back surface opposed to the ultrasound transmitting/receiving surface, and a distal end surface substantially orthogonal to the ultrasound transmitting/receiving surface, the ultrasound vibrator configured to transmit ultrasound from the ultrasound transmitting/receiving surface mainly toward a radial direction of the sheath orthogonal to an extension direction of the sheath; and
a backing member that supports the back surface of the ultrasound vibrator and is configured to absorb a partial ultrasound transmitted from the ultrasound vibrator;
a housing configured to hold the ultrasound vibrator in the sheath;
wherein the drive shaft is movable with the imaging core unit in the sheath along the extension direction of the sheath and rotatable with the imaging core unit in the sheath around an axis of the sheath; and
the backing member includes a distal cover portion covering the distal end surface of the ultrasound vibrator, and a distal end of the housing does not cover the distal end surface of the ultrasound vibrator.
2 . The image diagnosis catheter according to claim 1 , wherein the housing is positioned distal to the distal end of the ultrasound vibrator and only on a back surface side of the ultrasound transmitting/receiving surface of the ultrasound vibrator.
3 . The image diagnosis catheter according to claim 1 , wherein the housing includes a proximal tubular portion disposed coaxially with the drive shaft and a protruding portion distally protruding from the proximal tubular portion and positioned on a back surface side of the ultrasound transmitting/receiving surface of the ultrasound vibrator.
4 . The image diagnosis catheter according to claim 3 , the protruding portion is positioned below a central axis of the proximal tubular portion in a case where a side faced by the ultrasound transmitting/receiving surface is an upper side and a lower side is opposite to the upper side.
5 . The image diagnosis catheter according to claim 1 ,
wherein the ultrasound vibrator includes a side end surface substantially orthogonal to an ultrasound transmitting/receiving surface, the side end surface facing in a direction orthogonal to the extension direction of the sheath,
wherein the housing does not cover the side end surface of the ultrasound vibrator.
6 . The image diagnosis catheter according to claim 1 ,
wherein the housing portion includes a concave plate portion extending along the extension direction of the sheath with being concaved outwardly in the radial direction of the sheath,
wherein the concave plate portion includes end surfaces on both sides of the concave plate portion, the end surfaces facing parallel to the ultrasound transmitting/receiving surface,
wherein the backing member further includes:
a main body portion disposed in a concave portion formed by the concave plate portion, and
a flange portion protruding from the main body portion and supported by the end surfaces of the concave plate portion in a circumferential direction of the sheath.
7 . The image diagnosis catheter according to claim 1 , the distal cover portion of the backing member includes a convex curved surface toward a distal direction.