초록 ▼

Laser catheter delivery system for controlled ablation of atheroma, combining laser angioplasty and intra-arterial ultrasonic imaging. In laser ablation of atheroma, dosage and directing of the laser light beam represent critical problems, since accurate removal of the atheroma is required without d

Laser catheter delivery system for controlled ablation of atheroma, combining laser angioplasty and intra-arterial ultrasonic imaging. In laser ablation of atheroma, dosage and directing of the laser light beam represent critical problems, since accurate removal of the atheroma is required without damaging of the arterial wall. The present system comprise a combined laser and ultrasound catheter composed of apparatus for emitting a laser beam in an artery towards an atheroma for ablation of the atheroma an optical fiber assembly for feeding laser light from a laser to the emitting apparatus an ultrasound transducer for intra-arterial imaging of tissue structures like the atheroma, the vessel wall and surrounding tissue, by emitting a pulsed ultrasound beam towards the tissue structures and also arranged to receive backscattered ultrasound from the tissue structures beam directing apparatus arranged to direct the ultrasound beam towards the tissue structures and also arranged so that the laser beam can be brought into for practical purposes any of the directions the ultrasound beam can assume for imaging, so that the laser beam can be steered towards a portion of the ultrasound image indicating a portion of an atheroma to ablate that portion of the atheroma receive circuits adapted to receive and process the backscattered ultrasound for imaging of the tissue structures, and apparatus for analysing the ultrasound image, either manually or automatically, to determine the presence of atheroma so that the image can be used to direct the laser beam towards the regions in the ultrasound image which have been determined to represent a portion of an atheroma and determine the intensity and the dosage of the laser beam for accurate ablation of that portion of the atheroma.

대표청구항 ▼

An intra-arterial laser angioplasty catheter, comprising: an elongated catheter tube for intra-arterial insertion and extension to an angioplasty site and having a distal end for operative disposition proximate the angioplasty site; optical fiber means extending along and within said tube for transm

An intra-arterial laser angioplasty catheter, comprising: an elongated catheter tube for intra-arterial insertion and extension to an angioplasty site and having a distal end for operative disposition proximate the angioplasty site; optical fiber means extending along and within said tube for transmitting laser irradiation to the distal end of the catheter tube for selective tissue ablation; ultrasound transducer means proximate the distal end of said tube for emitting a pulsed ultrasound beam toward tissue at the angioplasty site and for receiving ultrasound reflections of said emitted beam to thereby provide intra-arterial imaging of tissue structures; means proximate the distal end of said tube for directing said laser irradiation from the catheter in a first direction and for directing said emitted ultrasound beam from the catheter in a second direction, said first and second directions having a fixed angular relation therebetween; and means operable for rotating said directing means relative to said catheter tube so as to concurrently selectively vary said first and second directions while maintaining said fixed angular relation therebetween and thereby selectively steer said emitted ultrasound beam and laser irradiation toward tissue structures for imaging and ablation, respectively, thereof, whereby said intra-arterial imaging enables steering of said laser irradiation by selective rotation of said directing means to guidedly direct the laser irradiation for intra-arterial tissue ablation in accordance with the imaging provided by said ultrasound beam.