Photoacoustic removal of occlusions from blood vessels

US6428531B1 · kind B1 · utility

Assignees

• The Regents of the University of California · US
• Endovasix, Inc. · US

Inventors

• Steven R. Visuri · Livermore, US
• Luiz B. Da Silva · Danville, US
• Peter M. Celliers · Berkeley, US
• Richard London · Lenzburg, CH
• Duncan J. Maitland · College Station, US
• Victor C. Esch · San Francisco, US

Key dates

• Filing date: Jun 27, 2000
• Grant date: Aug 6, 2002
• Expiry date: Jun 27, 2020

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61B2018/2211
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

Partial or total occlusions of fluid passages within the human body are removed by positioning an array of optical fibers in the passage and directing treatment radiation pulses along the fibers, one at a time, to generate a shock wave and hydrodynamics flows that strike and emulsify the occlusions. A preferred application is the removal of blood clots (thrombin and embolic) from small cerebral vessels to reverse the effects of an ischemic stroke. The operating parameters and techniques are chosen to minimize the amount of heating of the fragile cerebral vessel walls occurring during this photo acoustic treatment. One such technique is the optical monitoring of the existence of hydrodynamics flow generating vapor bubbles when they are expected to occur and stopping the heat generating pulses propagated along an optical fiber that is not generating such bubbles.