Apparatus and methods for low-cost intravascular ultrasound imaging and for crossing severe vascular occlusions

An apparatus for advancing an intravascular device through a severe obstruction in a blood vessel comprising:

• a catheter having proximal and distal ends and a tip at the distal end;
• ultrasound emitting and receiving means mounted to the tip for transmitting ultrasound pulses and receiving echoes;
• an ablation means mounted to the tip;
• the catheter having sufficient torsional stiffness and longitudinal flexibility to enable it to be manually advanced through, and its distal end controllably rotated within, the blood vessel solely by manual rotation of the proximal portion of the catheter;
• angle encoding means associated with the proximal end of the catheter for detecting changes in the angular position of the catheter;
• electronic means associated with the angle encoding means and the transducer for generating and transmitting an electrical signal to the transducer solely in response to rotation of the catheter;
• means for processing echo signals to generate a graphic image of the vessel;
• and
• manually triggerable means for generating and transmitting radiofrequency energy to the ablation electrode.

An apparatus for advancing through a severe obstruction in a blood vessel, comprising:

• a catheter having a proximal end, a distal end, and a longitudinal axis, the catheter being configured with sufficient torsional stiffness and longitudinal flexibility to be manually advanced through the blood vessel, the proximal end having a proximal portion configured to be manipulated by a user, the distal end being controllably rotatable within the blood vessel by manual rotation of the proximal portion of the catheter, the distal end having a distal tip, the catheter comprising:
• an ultrasound transducer mounted to the tip and arranged to transmit ultrasound pulses in the distal direction and receive echo signals from media in the blood vessel distal of the distal tip;
• a radiofrequency ablation electrode mounted to the tip and arranged to emit radiofrequency ablation energy in the distal direction to ablate media in the blood vessel distal of the distal tip;
• circuitry and software configured to receive the echo signals and configured to process the echo signals to create and display an image of the blood vessel;
• manually accountable circuitry configured to generate and transmit radiofrequency energy to the ablation electrode,
• wherein the distal tip of the catheter can be positioned, rotated and actuated to ablate the obstruction distally of the distal tip entirely under manual control;
• an angle encoder connected to the catheter and configured to detect changes in the angular position of the catheter;
• and
• circuitry and software operatively associated with the angle encoder and the ultrasound transducer and configured to generate and transmit an electrical signal to the transducer to activate the transducer only in response to detection of changes in the angular position of the catheter.