Laser-activated shape memory polymer microactuator for thrombus removal following ischemic stroke: preliminary in vitro analysis
- 5 December 2005
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Journal of Selected Topics in Quantum Electronics
- Vol. 11 (4), 892-901
- https://doi.org/10.1109/jstqe.2005.857748
Abstract
Due to the narrow (3-h) treatment window for effective use of the thrombolytic drug recombinant tissue-type plasminogen activator (rt-PA), there is a need to develop alternative treatments for ischemic stroke. We are developing an intravascular device for mechanical thrombus removal using shape memory polymer (SMP). We propose to deliver the SMP microactuator in its secondary straight rod form (length=4 cm, diameter=350 /spl mu/m) through a catheter distal to the vascular occlusion. The microactuator, which is mounted on the end of an optical fiber, is then transformed into its primary corkscrew shape by laser heating (diode laser, /spl lambda/=800 nm) above its soft-phase glass transition temperature (T/sub gs/=55/spl deg/C). Once deployed, the microactuator is retracted, and the captured thrombus is removed to restore blood flow. The SMP is doped with indocyanine green (ICG) dye to increase absorption of the laser light. Successful deployment of the microactuator depends on the optical properties of the ICG-doped SMP, as well as the optical coupling efficiency of the interface between the optical fiber and the SMP. Spectrophotometry, thermal imaging, and computer simulation aided the initial design effort and continue to be useful tools for optimization of the dye concentration and laser power. Thermomechanical testing was performed to characterize the elastic modulus of the SMP. We have demonstrated laser activation of the SMP microactuator in air at room temperature, suggesting this concept is a promising therapeutic alternative to rt-PA.Keywords
This publication has 14 references indexed in Scilit:
- Effect of fluoride prophylactic agents on the mechanical properties of nickel-titanium-based orthodontic wiresAmerican Journal of Orthodontics and Dentofacial Orthopedics, 2005
- MERCI 1Stroke, 2004
- Beyond tissue plasminogen activator: Mechanical intervention in acute strokeAnnals of Emergency Medicine, 2003
- Early stroke treatment associated with better outcomeNeurology, 2000
- Recombinant Tissue-Type Plasminogen Activator (Alteplase) for Ischemic Stroke 3 to 5 Hours After Symptom OnsetJAMA, 1999
- Intra-arterial Prourokinase for Acute Ischemic StrokeJAMA, 1999
- Optical Properties of Whole BloodLasers in Medical Science, 1998
- PROACT: A Phase II Randomized Trial of Recombinant Pro-Urokinase by Direct Arterial Delivery in Acute Middle Cerebral Artery StrokeStroke, 1998
- Tissue Plasminogen Activator for Acute Ischemic StrokeNew England Journal of Medicine, 1995
- Overview of Bioheat TransferPublished by Springer Science and Business Media LLC ,1995