16 research outputs found
Haptic guidance improves the visuo-manual tracking of trajectories
BACKGROUND: Learning to perform new movements is usually achieved by
following visual demonstrations. Haptic guidance by a force feedback device is
a recent and original technology which provides additional proprioceptive cues
during visuo-motor learning tasks. The effects of two types of haptic
guidances-control in position (HGP) or in force (HGF)-on visuo-manual tracking
("following") of trajectories are still under debate. METHODOLOGY/PRINCIPALS
FINDINGS: Three training techniques of haptic guidance (HGP, HGF or control
condition, NHG, without haptic guidance) were evaluated in two experiments.
Movements produced by adults were assessed in terms of shapes (dynamic time
warping) and kinematics criteria (number of velocity peaks and mean velocity)
before and after the training sessions. CONCLUSION/SIGNIFICANCE: These results
show that the addition of haptic information, probably encoded in force
coordinates, play a crucial role on the visuo-manual tracking of new
trajectories
03:45 PM Abstract No. 368 Changes in ph and not temperature significantly contributes to cell death during IRE performed at low-voltage and high pulse numbers
04:03 PM Abstract No. 428 Electroporation enhances delivery and effectiveness of sorafenib nanoparticles for the treatment of colorectal cancer
Abstract No. 469 Improved intra-arterial tumor targeting using an omniphobic oil in a pig model
Cytoskeletal Remodeling and Gap Junction Translocation Mediates Blood–Brain Barrier Disruption by Non-invasive Low-Voltage Pulsed Electric Fields
High-voltage pulsed electric fields (HV-PEF) delivered with invasive needle electrodes for electroporation applications is known to induce off-target blood–brain barrier (BBB) disruption. In this study, we sought to determine the feasibility of minimally invasive PEF application to produce BBB disruption in rat brain and identify the putative mechanisms mediating the effect. We observed dose-dependent presence of Evans Blue (EB) dye in rat brain when PEF were delivered with a skull mounted electrode used for neurostimulation application. Maximum region of dye uptake was observed while using 1500 V, 100 pulses, 100 µs and 10 Hz. Results of computational models suggested that the region of BBB disruption was occurring at thresholds of 63 V/cm or higher; well below intensity levels for electroporation. In vitro experiments recapitulating this effect with human umbilical vein endothelial cells (HUVEC) demonstrated cellular alterations that underlie BBB manifests at low-voltage high-pulse conditions without affecting cell viability or proliferation. Morphological changes in HUVECs due to PEF were accompanied by disruption of actin cytoskeleton, loss of tight junction protein—ZO-1 and VE-Cadherin at cell junctions and partial translocation into the cytoplasm. Uptake of propidium iodide (PI) in PEF treated conditions is less than 1% and 2.5% of total number of cells in high voltage (HV) and low-voltage (LV) groups, respectively, implying that BBB disruption to be independent of electroporation under these conditions. 3-D microfabricated blood vessel permeability was found to increase significantly following PEF treatment and confirmed with correlative cytoskeletal changes and loss of tight junction proteins. Finally, we show that the rat brain model can be scaled to human brains with a similar effect on BBB disruption characterized by electric field strength (EFS) threshold and using a combination of two bilateral HD electrode configurations