Systems and methods for making and using an imaging core of an intravascular ultrasound imaging system

An imaging assembly for an intravascular ultrasound system, the imaging assembly comprising:

• a guidewire configured and arranged for insertion into the vasculature of a patient;
• an imaging core configured and arranged for coupling to the guidewire, the imaging core comprising
• a body having a proximal end, a distal end, and defining a lumen extending along a longitudinal length of the body, the lumen configured and arranged to receive the guidewire,
• a rotary unit disposed in the body and rotatable in response to a magnetic field generated external to the imaging assembly, the rotary unit comprising a rotatable magnet, a tilted reflective surface, and a sonolucent material all configured and arranged to rotate at the same rotational velocity, wherein the tilted reflective surface is disposed at one end of a longitudinal length of the magnet and a sonolucent material is disposed over the reflective tilted surface, and
• at least one fixed transducer positioned at the proximal end of the body, the at least one transducer configured and arranged for transforming applied electrical signals to acoustic signals and also for transforming received echo signals to electrical signals;
• and
• at least one transducer conductor electrically coupled to the at least one transducer and in electrical communication with a pulse generator configured and arranged for providing electric signals to the at least one transducer.

An imaging assembly for an intravascular ultrasound system, the imaging assembly comprising:

• a catheter having a longitudinal length, a distal end, and a proximal end, the catheter defining a lumen extending along the longitudinal length of the catheter from the proximal end to the distal end, the catheter configured and arranged for insertion into the vasculature of a patient;
• an imaging core with a longitudinal length that is substantially less than the longitudinal length of the catheter, the imaging core configured and arranged for being disposed in a distal end of the lumen, the imaging core comprising
• at least one transducer configured and arranged for transforming applied electrical signals to acoustic signals and also for transforming received echo signals to electrical signals,
• a transformer comprising a rotating component and a stationary component spaced apart from one another, wherein the rotating component is coupled to the at least one transducer and is configured and arranged to rotate the at least one transducer, and
• a magnet configured and arranged to be driven to rotate by a magnetic field generated external to the catheter, wherein the magnet is coupled to, or disposed on, at least one of the rotating component of the transformer or the at least one transducer;
• and
• at least one transducer conductor electrically coupled to the stationary component of the transformer and extending to the proximal end of the catheter.

A method for imaging a patient using an intravascular ultrasound imaging system, the method comprising:

• inserting a catheter into patient vasculature, the catheter comprising an imaging core disposed in a lumen defined in the catheter, the imaging core electrically coupled to a control module by at least one transducer conductor, the imaging core having a longitudinal axis and comprising at least one fixed transducer and a magnet that rotates by application of a magnetic field generated external to the catheter, wherein the transducer emits acoustic signals directed at a tilted reflected surface configured and arranged to rotate with the magnet;
• extending the imaging core out from a distal end of the catheter so that the imaging core remains coupled to the control module via the at least one transducer conductor;
• transmitting at least one electrical signal from the control module to the at least one transducer;
• generating a magnetic field to cause the magnet to rotate;
• transmitting at least one acoustic signal from the at least one transducer to patient tissue via reflection from the reflective surface of the magnet;
• receiving at least one echo signal from a tissue-boundary between adjacent imaged patient tissue by the imaging core;
• and
• transmitting at least one transformed echo signal from the at least one transducer to the control module for processing.