Browsing by Subject "Micromanipulation"

Now showing 1 - 3 of 3

Open Access
Design of a novel MRI compatible manipulator for image guided prostate interventions
(IEEE, 2005-02) Krieger, A.; Susil, R. C.; Ménard, C.; Coleman, J. A.; Fichtinger, G.; Atalar, Ergin; Whitcomb, L. L.
This paper reports a novel remotely actuated manipulator for access to prostate tissue under magnetic resonance imaging guidance (APT-MRI) device, designed for use in a standard high-field MRI scanner. The device provides three-dimensional MRI guided needle placement with millimeter accuracy under physician control. Procedures enabled by this device include MRI guided needle biopsy, fiducial marker placements, and therapy delivery. Its compact size allows for use in both standard cylindrical and open configuration MRI scanners. Preliminary in vivo canine experiments and first clinical trials are reported.
Open Access
Generation of phospholipid vesicle-nanotube networks and transport of molecules therein
(2011) Jesorka, A.; Stepanyants, N.; Zhang H.; Ortmen, B.; Hakonen, B.; Orwar O.
We describe micromanipulation and microinjection procedures for the fabrication of soft-matter networks consisting of lipid bilayer nanotubes and surface-immobilized vesicles. These biomimetic membrane systems feature unique structural flexibility and expandability and, unlike solid-state microfluidic and nanofluidic devices prepared by top-down fabrication, they allow network designs with dynamic control over individual containers and interconnecting conduits. The fabrication is founded on self-assembly of phospholipid molecules, followed by micromanipulation operations, such as membrane electroporation and microinjection, to effect shape transformations of the membrane and create a series of interconnected compartments. Size and geometry of the network can be chosen according to its desired function. Membrane composition is controlled mainly during the self-assembly step, whereas the interior contents of individual containers is defined through a sequence of microneedle injections. Networks cannot be fabricated with other currently available methods of giant unilamellar vesicle preparation (large unilamellar vesicle fusion or electroformation). Described in detail are also three transport modes, which are suitable for moving water-soluble or membrane-bound small molecules, polymers, DNA, proteins and nanoparticles within the networks. The fabrication protocol requires ∼90 min, provided all necessary preparations are made in advance. The transport studies require an additional 60-120 min, depending on the transport regime. © 2011 Nature America, Inc. All rights reserved.
Open Access
Manipulation of particles using inertial microfluidics and viscoelastic fluids
(2018-03) Asghari, Mohammad
Recent years have witnessed an elevated trend in using miniaturized and labon- a-chip systems in biomedical devices due to numerous advantages including minimal sample/reagent consumption, portability, and superior performance. One of the key challenges within these microsystems is to precisely manipulate and order bio-particles. Various techniques have been introduced to accomplish this mission. Inertial microfluidics enables lateral migration of particles and cells in laminar flow regime due to the velocity gradient effect in moderate Reynolds number. Moreover, viscoelastic fluids exploit intrinsic elastic property of the fluids to transfer particles and cells across laminar ow streamlines. Both methods utilize inherent properties of fluids alleviating any external force field inducer. This dissertation elucidates inertial and viscoelastic effects on particles and cells motion and investigates some unexplored migration behaviors. For inertial migration study, a new fabrication method termed tape'n roll is introduced enabling to study migration in both 2D and 3D structures. To better unravel the covert mechanism of migration, computational model is applied. For viscoelastic behavior study, focusing of particles inside three different viscoelastic fluids in a straight glass capillary tube is scrutinized through optical system and image processing.