Intravascular ultrasonic imaging probe and methods of using same

An ultrasonic imaging probe comprising:

• housing means for holding an ultrasonic transducer;
• and
• torque cable means coupled to said housing means for transferring rotational motion in a predetermined rotation direction to said housing means;
• said torque cable means including an inner subcable and an outer subcable concentrically surrounding said inner subcable, said inner and outer subcables being formed of wires helically wound in opposite directions to provide means tending to radially expand and contract said inner and outer subcables, respectively, in response to rotation in said predetermined direction, whereby an essentially rigid union between said inner and outer subcables is effected to transfer torque to said housing means,
• said torque cable means also including means for increasing longitudinal stiffness of said torque cable means, wherein said means for increasing longitudinal stiffness of said torque cable means includes a polymer impregnated within interstices of adjacent windings of said helically wound inner and outer subcables.

An ultrasonic imaging probe comprising:

• housing means for holding an ultrasonic transducer;
• and
• torque cable means coupled to said housing means for transferring rotational motion in a predetermined rotation direction to said housing means;
• said torque cable means including an inner subcable and an outer subcable concentrically surrounding said inner subcable, said inner and outer subcables being formed of wires helically wound in opposite directions to provide means tending to radially expand and contract said inner and outer subcables, respectively, in response to rotation in said predetermined direction, whereby an essentially rigid union between said inner and outer subcables is effected to transfer torque to said housing means,
• said torque cable means also including means for increasing longitudinal stiffness of said torque cable means, wherein said means for increasing longitudinal stiffness of said torque cable means includes at least one synthetic fiber having proximal and distal ends fixed to respective proximal and distal ends of said torque cable means.

A medical probe comprising:

• a distally located element;
• a helically wound wire torque cable coupled to said distally located element and having relatively minimum strength longitudinally yet relatively maximum strength torsionally for transferring rotational motion to said element in a predetermined rotation direction;
• and
• longitudinal strengthening means associated with said torque cable for increasing said relatively minimum longitudinal strength, wherein said longitudinal strengthening means includes at least one synthetic fiber fixedly attached at each of its ends to a respective end of said torque cable and extending within said torque cable between said fixedly attached ends thereof.

An ultrasonic imaging system for obtaining real time images of a vessel in a patient's vascular system comprising:

• a guide catheter defining a catheter lumen and adapted to being inserted into a vessel of a patient's vascular system;
• ultrasonic imaging probe means adapted to being inserted within said catheter lumen for producing acoustical signals in response to an electrical stimulus and for generating electrical signals in response to receiving echoes of said produced acoustical signals returning from the vessel;
• motive means for providing rotational drive to said imaging probe means to rotate the same in a predetermined rotation directing;
• an ultrasonic transceiver coupled to said probe means including (i) transmitter means for generating said electrical stimulus and (ii) receiver means for receiving and interpreting said electrical signals produced by said probe means at a rate that is asynchronous relative to said generated electrical stimulus;
• and
• electrical cabling which establishes electrical communication between said ultrasonic transceiver and said probe means for supplying said electrical stimulus to said probe means and for transmitting said electrical signals to said ultrasonic transceiver.

A method for ultrasonically imaging a portion of a vessel in a patient's vascular system comprising the sequential steps of:

• percutaneously inserting a guide wire within the vessel to be imaged;
• telescopically advancing a guide catheter having (i) a guide sheath with a distally located region which minimally attenuates and/or reflects ultrasonic energy, and (ii) a removable inner sleeve member such that said region is adjacent to the vessel portion to be imaged;
• withdrawing said guide wire and said inner sleeve member from said guide sheath;
• inserting an ultrasonic imaging probe within said guide sheath so that an ultrasonic transducer means associated with said probe is aligned with said distally located region which minimally attenuates and/or reflects ultrasonic energy;
• and then
• operating said transducer means to obtain ultrasonic images of said vessel portion.

A method for ultrasonically imaging a portion of a vessel in a patient's vascular system comprising the sequential steps of:

• percutaneously inserting and positioning a flexible guide wire within a preselected vessel of a patient's vascular system to be imaged;
• telescopically advancing a guide catheter over said guide wire and positioning a distal region of the same adjacent a portion of said preselected vessel to be imaged;
• withdrawing said guide wire from said guide catheter;
• and then
• inserting an ultrasonic imaging probe into said guide catheter and operating said probe to obtain an ultrasonic image of said preselected vessel portion;
• wherein
• said step of advancing a guide catheter includes using a guide catheter having a removable inner tubular sleeve member sized so as to be capable of being telescopically advanced over said positioned guide wire;
• and wherein
• said step of withdrawing said guide wire includes withdrawing said inner tubular sleeve member.

An ultrasonic imaging probe comprising:

• a flexible wound wire torque cable defining an interior space between its proximal and distal ends;
• an ultrasonic transducer carried at said distal end said torque cable;
• electrical cabling disposed within said defined interior space of said torque cable and operatively connected to said ultrasonic transducer at said distal end thereof;
• and
• at least one fiber having a length substantially coextensive with said torque cable, said fiber being disposed within said defined interior space and having each of its ends fixed to a respective proximal and distal ends of said torque cable.

An ultrasonic imaging system for obtaining real time images of a vessel in a patient's vascular system comprising:

• an ultrasonic imaging probe having an ultrasonic transducer at a distal end thereof which produces acoustical signals in response to an electrical stimulus and generates electrical signals in response to receiving echoes of said produced acoustical signals returning from the vessel;
• a rotational drive element coupled to the ultrasonic imaging probe to rotate the same in a predetermined rotation direction;
• an ultrasonic transceiver coupled operatively to said ultrasonic transducer and including (i) a transmitter which generates said electrical stimulus, and (ii) a receiver which receives said electrical signals produced by said ultrasonic transducer and interprets said received electrical signals at a rate which is asynchronous relative to said generated electrical stimulus;
• and
• electrical cabling which establishes electrical communication between said ultrasonic transceiver and said ultrasonic transducer for supplying said electrical stimulus to said ultrasonic transducer and for transmitting said electrical signals to said ultrasonic transceiver.