Microfabricated therapeutic actuators and release mechanisms therefor

US6059815A · kind A · utility

Assignee

• The Regents of the University of California · US

Inventors

• Abraham P. Lee · Irvine, US
• Joseph P. Fitch · Livermore, US
• Daniel L. Schumann · Concord, US
• Luiz B. Da Silva · Danville, US
• William J. Benett · Livermore, US
• Peter Krulevitch · Pleasanton, US

Key dates

• Filing date: Apr 28, 1998
• Grant date: May 9, 2000
• Expiry date: Apr 28, 2018

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61B2017/12077
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

Microfabricated therapeutic actuators are fabricated using a shape memory polymer (SMP), a polyurethane-based material that undergoes a phase transformation at a specified temperature (Tg). At a temperature above temperature Tg material is soft and can be easily reshaped into another configuration. As the temperature is lowered below temperature Tg the new shape is fixed and locked in as long as the material stays below temperature Tg. Upon reheating the material to a temperature above Tg, the material will return to its original shape. By the use of such SMP material, SMP microtubing can be used as a retaining/release actuator for the delivery of material, such as embolic coils, for example, through catheters into aneurysms, for example. The microtubing can be manufactured in various sizes and the phase change temperature Tg is determinate for an intended temperature target and intended use. The SMP microtubing can be positioned around or within an end of a deposit material. Various heating arrangements can be utilized with the SMP release mechanism, and the SMP microtubing can include a metallic coating for enhanced light absorption.