A Pneumatic-based Mechanism for Inserting a Flexible Microprobe into the Brain

2022 ◽  
pp. 1-20
Author(s):  
Naser Sharafkhani ◽  
Abbas Kouzani ◽  
Scott D. Adams ◽  
John M. Long ◽  
Julius O. Orwa
Keyword(s):  
Tissue Damage ◽  
Tensile Force ◽  
Compressive Force ◽  
Neural Tissue ◽  
Brain Penetration ◽  
Critical Buckling Force ◽  
Penetration Force ◽  
Insertion Mechanism ◽  
The Brain ◽  
Premature Removal

Abstract Insertion of flexible microprobes into the brain requires withstanding the compressive penetration force by the microprobes. To aid the insertion of the microprobes, most of the existing approaches employ pushing mechanisms to provide temporary stiffness increase for the microprobes to prevent buckling during insertion into the brain. However, increasing the microprobe stiffness may result in acute neural tissue damage during insertion. Moreover, any late or premature removal of the temporary stiffness after insertion may lead to further tissue damage due to brain micromotion, or inaccuracy in the microprobe positioning. In this study, a novel pneumatic-based insertion mechanism is proposed which simultaneously pulls and pushes a flexible microprobe towards the brain. As part of the brain penetration force in the proposed mechanism is supplied by the tensile force, the applied compressive force, which the microprobe must withstand during insertion, is lower compared to the existing approaches. Therefore, the microprobes with a critical buckling force less than the brain penetration force can be inserted into the brain without buckling. Since there is no need for temporary stiffness increment, the neural tissue damage during the microprobe insertion will be much lower compared to the existing insertion approaches. The pneumatic-based insertion mechanism is modelled analytically to investigate the effects of the microprobe configuration and the applied air pressure on the applied tensile and compressive forces to the microprobe. Next, finite element modelling is conducted, and its analysis results not only validate the analytical results but also confirm the efficiency of the mechanism.

scholarly journals Enhanced resolution of histochemical distribution of glucose-6-phosphate dehydrogenase activity in rat neural tissue by use of a semipermeable membrane.

1991 ◽  
Vol 39 (7) ◽  
pp. 937-943 ◽  
Author(s):  
M A Philbert ◽  
C M Beiswanger ◽  
T L Roscoe ◽  
D K Waters ◽  
H E Lowndes
Keyword(s):  
Vestibular Nucleus ◽  
Neural Tissue ◽  
Semipermeable Membrane ◽  
G6pd Activity ◽  
Ependymal Cells ◽  
Regional Localization ◽  
Enhanced Resolution ◽  
Membrane Technique ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
The Brain

We examined the histochemical distribution of glucose-6-phosphate dehydrogenase (G6PD) activity in neural tissue using different diffusion barriers. Although polyvinyl alcohol and agar overlays permitted regional localization of G6PD, a semipermeable membrane revealed cellular differences in G6PD activity within populations of neurons. Distribution of G6PD activity in selected regions of the nervous system was examined using the membrane technique. White matter usually exhibited strong G6PD activity. The neuronal somata of the dorsal root ganglia (L4-L6) and anterior horns of the spinal lumbar enlargement demonstrated a variation in activity which was independent of somal size. Satellite cells showed intense activity when the membrane technique was used. Hippocampal pyramidal and granular cells of the dentate gyrus exhibited moderate, uniform G6PD activity, but only weak activity was seen in hippocampal and dentate molecular layers. High levels of activity were observed in the vascular endothelial cells of the brain, spinal cord, and choroid plexus, and in the ependymal cells of the spinal central canal and ventricles of the brain. The superior vestibular nucleus appeared to have little G6PD activity in either the neuron cell bodies or the surrounding parenchyma. The use of a semipermeable membrane for localization of G6PD activity in neural tissues permits enhanced resolution of neuron elements and may provide a more accurate assessment of G6PD activity in histological preparations.

Genetic Ablation of Transcription Repressor Bach1 Reduces Neural Tissue Damage and Improves Locomotor Function after Spinal Cord Injury in Mice

2009 ◽  
Vol 26 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Haruo Kanno ◽  
Hiroshi Ozawa ◽  
Yoshihiro Dohi ◽  
Akira Sekiguchi ◽  
Kazuhiko Igarashi ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Tissue Damage ◽  
Neural Tissue ◽  
Locomotor Function ◽  
Genetic Ablation ◽  
Cord Injury

scholarly journals Novel Design and Position Control Strategy of a Soft Robot Arm

Robotics ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 72 ◽  
Author(s):  
Alaa Al-Ibadi ◽  
Samia Nefti-Meziani ◽  
Steve Davis ◽  
Theo Theodoridis
Keyword(s):  
Position Control ◽  
Control Strategies ◽  
Tensile Force ◽  
Compressive Force ◽  
Soft Robot ◽  
Robot Arm ◽  
Bending Actuator ◽  
Muscle Actuators ◽  
Novel Design ◽  
Bending Behaviour

This article presents a novel design of a continuum arm, which has the ability to extend and bend efficiently. Numerous designs and experiments have been done to different dimensions on both types of McKibben pneumatic muscle actuators (PMA) in order to study their performances. The contraction and extension behaviour have been illustrated with single contractor actuators and single extensor actuators, respectively. The tensile force for the contractor actuator and the compressive force for the extensor PMA are thoroughly explained and compared. Furthermore, the bending behaviour has been explained for a single extensor PMA, multi extensor actuators and multi contractor actuators. A two-section continuum arm has been implemented from both types of actuators to achieve multiple operations. Then, a novel construction is proposed to achieve efficient bending behaviour of a single contraction PMA. This novel design of a bending-actuator has been used to modify the presented continuum arm. Two different position control strategies are presented, arising from the results of the modified soft robot arm experiment. A cascaded position control is applied to control the position of the end effector of the soft arm at no load by efficiently controlling the pressure of all the actuators in the continuum arm. A new algorithm is then proposed by distributing the x, y and z-axis to the actuators and applying an effective closed-loop position control to the proposed arm at different load conditions.

Analysis of Jib Strength and Broken Jib Accident of High Pedestal Jib Crane from the Perspective of Mechanics

2012 ◽  
Vol 164 ◽  
pp. 322-325 ◽  
Author(s):  
Qing Dun Zeng ◽  
Fang Liu
Keyword(s):  
Finite Element ◽  
Working Conditions ◽  
Tensile Force ◽  
Compressive Force ◽  
Guangdong Province ◽  
Solid Model ◽  
Finite Element Software ◽  
Actual Working

According to an example of the broken jib accident of a high pedestal jib crane (HM2564) in a Shipyard Co., Ltd. in Guangdong province, this paper used a finite element software ANSYS to establish a solid model for the jib frame of the crane, calculated the stresses of jib system under various actual working conditions and checked the strengths. Simultaneously, the reasons of broken jib were quantitatively analyzed from the perspective of mechanics. The results show that the strengths of the jib system meet the requirements of safe use under all kinds of working conditions, but the related hoistman incorrectly operated the facility, cables can’t be winded normally in pulleys, thus resulting in that the tensile force of a cable was directly applied on the main jib by pulley spindle and the failure of the jib frame occurred under heavy compressive force of lifting cables.

Ventricular and Cerebrospinal Fluid System

2017 ◽  
pp. 409-434
Author(s):  
Eduardo E. Benarroch ◽  
Jeremy K. Cutsforth-Gregory ◽  
Kelly D. Flemming
Keyword(s):  
Cerebrospinal Fluid ◽  
Neural Tissue ◽  
Local Environment ◽  
System P ◽  
Neurologic Disorders ◽  
Unique System ◽  
The Central Nervous System ◽  
Protective Structures ◽  
And Function ◽  
The Brain

The meninges, ventricular system, subarachnoid space, and cerebrospinal fluid (CSF) constitute a functionally unique system that has an important role in maintaining a stable environment within which the central nervous system can function. The membranes that constitute the meninges serve as supportive and protective structures for neural tissue. The CSF itself provides a cushioning effect during rapid movement of the head and mechanical buoyancy to the brain. In addition to providing a pathway for the removal of brain metabolites, it functions as a chemical reservoir that protects the local environment of the brain from changes that may occur in the blood, thus ensuring the brain’s continued undisturbed performance. The CSF system is present at the supratentorial, posterior fossa, and spinal levels. Because of this extensive anatomical distribution and function, pathologic alterations of the CSF system can occur in many neurologic disorders.

scholarly journals Development of an LDL Receptor-Targeted Peptide Susceptible to Facilitate the Brain Access of Diagnostic or Therapeutic Agents

Biology ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 161
Author(s):  
Séverine André ◽  
Lionel Larbanoix ◽  
Sébastien Verteneuil ◽  
Dimitri Stanicki ◽  
Denis Nonclercq ◽  
...  
Keyword(s):  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Therapeutic Agents ◽  
In Vivo Studies ◽  
Phage Display Technology ◽  
Brain Penetration ◽  
Wide Range ◽  
The Brain

Blood-brain barrier (BBB) crossing and brain penetration are really challenging for the delivery of therapeutic agents and imaging probes. The development of new crossing strategies is needed, and a wide range of approaches (invasive or not) have been proposed so far. The receptor-mediated transcytosis is an attractive mechanism, allowing the non-invasive penetration of the BBB. Among available targets, the low-density lipoprotein (LDL) receptor (LDLR) shows favorable characteristics mainly because of the lysosome-bypassed pathway of LDL delivery to the brain, allowing an intact discharge of the carried ligand to the brain targets. The phage display technology was employed to identify a dodecapeptide targeted to the extracellular domain of LDLR (ED-LDLR). This peptide was able to bind the ED-LDLR in the presence of natural ligands and dissociated at acidic pH and in the absence of calcium, in a similar manner as the LDL. In vitro, our peptide was endocytosed by endothelial cells through the caveolae-dependent pathway, proper to the LDLR route in BBB, suggesting the prevention of its lysosomal degradation. The in vivo studies performed by magnetic resonance imaging and fluorescent lifetime imaging suggested the brain penetration of this ED-LDLR-targeted peptide.

scholarly journals Repositioning N-Acetylcysteine (NAC): NAC-Loaded Electrospun Drug Delivery Scaffolding for Potential Neural Tissue Engineering Application

Pharmaceutics ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 934
Author(s):  
Gillian D. Mahumane ◽  
Pradeep Kumar ◽  
Viness Pillay ◽  
Yahya E. Choonara
Keyword(s):  
Cell Viability ◽  
Engineering Application ◽  
Neural Tissue ◽  
Modern Medicine ◽  
Burst Release ◽  
Tissue Engineering Application ◽  
Glioblastoma Multiform ◽  
Pheochromocytoma Pc12 ◽  
The Brain

Traumatic brain injury (TBI) presents a serious challenge for modern medicine due to the poor regenerative capabilities of the brain, complex pathophysiology, and lack of effective treatment for TBI to date. Tissue-engineered scaffolds have shown some experimental success in vivo; unfortunately, none have yielded consummate results of clinical efficacy. N-acetylcysteine has shown neuroprotective potential. To this end, we developed a N-acetylcysteine (NAC)-loaded poly(lactic-co-glycolic acid) (PLGA) electrospun system for potential neural tissue application for TBI. Scanning electron microscopy showed nanofiber diameters ranging 72–542 nm and 124–592 nm for NAC-free and NAC-loaded PLGA nanofibers, respectively. NAC loading was obtained at 28%, and drug entrapment efficacy was obtained at 84%. A biphasic NAC release pattern that featured an initial burst release (13.9%) stage and a later sustained release stage was noted, thus enabling the prolonged replenishing of NAC and drastically improving cell viability and proliferation. This was evidenced by a significantly higher cell viability and proliferation on NAC-loaded nanofibers for rat pheochromocytoma (PC12) and human glioblastoma multiform (A172) cell lines in comparison to PLGA-only nanofibers. The increased cell viability and cell proliferation on NAC-loaded nanofiber substantiates for the repositioning of NAC as a pharmacological agent in neural tissue regeneration applications.

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