scholarly journals Intravital Microreflectometry of Individual Pial Vessels and Capillary Region of Rat

1994 ◽  
Vol 14 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Manabu Watanabe ◽  
Noboru Harada ◽  
Hiroaki Kosaka ◽  
Takeshi Shiga
Keyword(s):  
Oxygen Saturation ◽  
Oxygen Transport ◽  
Progressive Reduction ◽  
Slight Tendency ◽  
Pial Vessels ◽  
Brain Surface ◽  
The Difference ◽  
Spontaneously Breathing ◽  
The Brain

A microscopic reflectance spectrophotometer was constructed to obtain the spectra of single pial vessels and of a region containing only capillaries (capillary region). The difference in the oxygen saturation (So2) of hemoglobin between the regional arteriole and venule [R(A – V)] and that between the regional arteriole or capillaries [R(A – C)] were calculated. The reduction of cytochrome aa3 was also estimated in the capillary region. This method was applied to the brain surface of spontaneously breathing rats subjected to hypoxic and anemic hypoxia. On decreasing the inhaled O2 from 100 to 15%, elevation of R(A – V) and R(A – C) with slight arteriolar dilatation (though statistically not significant) was observed. Below 10% O2 (especially at 4 and 3% O2), the R(A – V) and R(A – C) decreased in spite of significant arteriolar dilatation with progressive reduction of cytochrome aa3, indicating suppression of oxygen transport to mitochondria. In the case of hemodilution down to 37% hematocrit (Ht), elevation of R(A – V) and R(A – C) occurred with a slight tendency toward arteriolar dilatation. Below 32% Ht, the R(A – V) decreased but the R(A – C) remained steady, while reduction of cytochrome aa3 progressed. Altogether, the So2 in the capillary region decreased and the reduction of cytochrome aa3 progressed with the decline of arteriolar O2 supply in both hypoxic and anemic hypoxia.

scholarly journals Modeling of Brain Shift Phenomenon for Different Craniotomies and Solid Models

2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
Alvaro Valencia ◽  
Benjamin Blas ◽  
Jaime H. Ortega
Keyword(s):  
Elastic Solid ◽  
Brain Parenchyma ◽  
Solid Model ◽  
Elastic Model ◽  
Brain Shift ◽  
Healthy Human ◽  
Brain Surface ◽  
Solid Models ◽  
The Difference ◽  
The Brain

This study investigates the effects of different solid models on predictions of brain shift for three craniotomies. We created a generic 3D brain model based on healthy human brain and modeled the brain parenchyma as single continuum and constrained by a practically rigid skull. We have used elastic model, hyperelastic 1st, 2nd, and 3rd Ogden models, and hyperelastic Mooney-Rivlin with 2- and 5-parameter models. A pressure on the brain surface at craniotomy region was applied to load the model. The models were solved with the finite elements package ANSYS. The predictions on stress and displacements were compared for three different craniotomies. The difference between the predictions of elastic solid model and a hyperelastic Ogden solid model of maximum brain displacement and maximum effective stress is relevant.

Analytical Electron Microscopy (AEM) of Meningeal Cells Exposed to Particulate Cobalt During Studies of Experimental Epilepsy

1982 ◽  
Vol 40 ◽  
pp. 186-187
Author(s):  
R.G. Frederickson ◽  
R.G. Ulrich ◽  
J.L. Culberson
Keyword(s):  
Electron Microscopy ◽  
Analytical Electron Microscopy ◽  
Experimental Epilepsy ◽  
Metallic Cobalt ◽  
Experimental Animals ◽  
X Ray ◽  
Brain Surface ◽  
Meningeal Cells ◽  
Analytical Electron ◽  
The Brain

Metallic cobalt acts as an epileptogenic agent when placed on the brain surface of some experimental animals. The mechanism by which this substance produces abnormal neuronal discharge is unknown. One potentially useful approach to this problem is to study the cellular and extracellular distribution of elemental cobalt in the meninges and adjacent cerebral cortex. Since it is possible to demonstrate the morphological localization and distribution of heavy metals, such as cobalt, by correlative x-ray analysis and electron microscopy (i.e., by AEM), we are using AEM to locate and identify elemental cobalt in phagocytic meningeal cells of young 80-day postnatal opossums following a subdural injection of cobalt particles.

A new technique for the mapping of oxygen tension on the brain surface

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S543-S543
Author(s):  
Satoshi Kimura ◽  
Keigo Matsumoto ◽  
Yoshio Imahori ◽  
Katsuyoshi Mineura ◽  
Toshiyuki Itoh
Keyword(s):  
Oxygen Tension ◽  
New Technique ◽  
Brain Surface ◽  
A New Technique ◽  
The Brain

Frontier concept of rabi chip for intelligent humanoid

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Preecha Yupapin ◽  
Amiri I. S. ◽  
Ali J. ◽  
Ponsuwancharoen N. ◽  
Youplao P.
Keyword(s):  
Human Brain ◽  
Brain Function ◽  
Rabi Oscillation ◽  
Liquid Core ◽  
Brain Surface ◽  
Dipole Oscillation ◽  
On Chip ◽  
The Brain ◽  
Robotic Applications ◽  
Atom System

The sequence of the human brain can be configured by the originated strongly coupling fields to a pair of the ionic substances(bio-cells) within the microtubules. From which the dipole oscillation begins and transports by the strong trapped force, which is known as a tweezer. The tweezers are the trapped polaritons, which are the electrical charges with information. They will be collected on the brain surface and transport via the liquid core guide wave, which is the mixture of blood content and water. The oscillation frequency is called the Rabi frequency, is formed by the two-level atom system. Our aim will manipulate the Rabi oscillation by an on-chip device, where the quantum outputs may help to form the realistic human brain function for humanoid robotic applications.

scholarly journals Practical application of synthetic head models in real ballistic cases

2021 ◽  
Author(s):  
F. Riva ◽  
T. Fracasso ◽  
A. Guerra ◽  
P. Genet
Keyword(s):  
Soft Tissues ◽  
Spherical Model ◽  
Brain Parenchyma ◽  
Human Bone ◽  
Shape Model ◽  
The Difference ◽  
Open Shape ◽  
The Brain ◽  
Synthetic Models ◽  
Representative Material

AbstractIn shooting crimes, ballistics tests are often recommended in order to reproduce the wound characteristics of the involved persons. For this purpose, several “simulants” can be used. However, despite the efforts in the research of “surrogates” in the field of forensic ballistic, the development of synthetic models needs still to be improved through a validation process based on specific real caseworks. This study has been triggered by the findings observed during the autopsy performed on two victims killed in the same shooting incident, with similar wounding characteristics; namely two retained head shots with ricochet against the interior wall of the skull; both projectiles have been recovered during the autopsies after migration in the brain parenchyma. The thickness of the different tissues and structures along the bullets trajectories as well as the incident angles between the bullets paths and the skull walls have been measured and reproduced during the assemblage of the synthetic head models. Two different types of models (“open shape” and “spherical”) have been assembled using leather, polyurethane and gelatine to simulate respectively skin, bone and soft tissues. Six shots have been performed in total. The results of the models have been compared to the findings of post-mortem computed tomography (PMCT) and the autopsy findings.Out of the six shots, two perforated the models and four were retained. When the projectile was retained, the use of both models allowed reproducing the wounds characteristics observed on both victims in terms of penetration and ricochet behaviour. However, the projectiles recovered from the models showed less deformation than the bullets collected during the autopsies. The “open shape” model allowed a better controlling on the shooting parameters than the “spherical” model. Finally, the difference in bullet deformation could be caused by the choice of the bone simulant, which might under-represent either the strength or the density of the human bone. In our opinion, it would be worth to develop a new, more representative material for ballistic which simulates the human bone.

scholarly journals Non-Stationary Model of Cerebral Oxygen Transport with Unknown Sources

Mathematics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 910
Author(s):  
Andrey Kovtanyuk ◽  
Alexander Chebotarev ◽  
Varvara Turova ◽  
Irina Sidorenko ◽  
Renée Lampe
Keyword(s):  
Inverse Problem ◽  
Oxygen Transport ◽  
Model Parameters ◽  
Cerebral Oxygen ◽  
System Of Equations ◽  
Blood Oxygen ◽  
Stationary Model ◽  
Average Oxygen Concentration ◽  
The Right ◽  
The Brain

An inverse problem for a system of equations modeling oxygen transport in the brain is studied. The problem consists of finding the right-hand side of the equation for the blood oxygen transport, which is a linear combination of given functionals describing the average oxygen concentration in the neighborhoods of the ends of arterioles and venules. The overdetermination condition is determined by the values of these functionals evaluated on the solution. The unique solvability of the problem is proven without any smallness assumptions on the model parameters.

scholarly journals Fast Nonsupervised 3D Registration of PET and MR Images of the Brain

1994 ◽  
Vol 14 (5) ◽  
pp. 749-762 ◽  
Author(s):  
Jean-François Mangin ◽  
Vincent Frouin ◽  
Isabelle Bloch ◽  
Bernard Bendriem ◽  
Jaime Lopez-Krahe
Keyword(s):  
Three Dimensional ◽  
Magnetic Resonance Images ◽  
Surface Matching ◽  
3D Registration ◽  
Matching Algorithm ◽  
Distance Map ◽  
Brain Surface ◽  
Discrete Surfaces ◽  
Positron Emission ◽  
The Brain

We propose a fully nonsupervised methodology dedicated to the fast registration of positron emission tomography (PET) and magnetic resonance images of the brain. First, discrete representations of the surfaces of interest (head or brain surface) are automatically extracted from both images. Then, a shape-independent surface-matching algorithm gives a rigid body transformation, which allows the transfer of information between both modalities. A three-dimensional (3D) extension of the chamfer-matching principle makes up the core of this surface-matching algorithm. The optimal transformation is inferred from the minimization of a quadratic generalized distance between discrete surfaces, taking into account between-modality differences in the localization of the segmented surfaces. The minimization process is efficiently performed via the precomputation of a 3D distance map. Validation studies using a dedicated brain-shaped phantom have shown that the maximum registration error was of the order of the PET pixel size (2 mm) for the wide variety of tested configurations. The software is routinely used today in a clinical context by the physicians of the Service Hospitalier Frédéric Joliot (>150 registrations performed). The entire registration process requires ∼5 min on a conventional workstation.

Psychiatry’s “Chemical Imbalance” Fraud: Who Killed Rebecca Riley?

2008 ◽  
Vol 10 (2) ◽  
pp. 96-108 ◽  
Author(s):  
Fred A. Baughman
Keyword(s):  
The United States ◽  
Diagnosis And Treatment ◽  
Normal Person ◽  
Organic Disease ◽  
Health Care Fraud ◽  
Department Of Health ◽  
Congressional Hearing ◽  
The Difference ◽  
Chemical Imbalance ◽  
The Brain

All physicians attend medical school and learn of (a) all things physically normal; anatomy, physiology, and chemistry, (b) all things physically abnormal; pathology, disease, and (c) how to tell the difference. Diagnosis is the first obligation of every physician to every patient, and must precede treatment. Diagnosis first asks, “Is there a physical abnormality (physical abnormality = disorder = disease), yes or no?” Patients with no abnormality (no physical abnormality = no disorder = no disease = normal) are referred to as having “no evidence or disease” (NED) or “no organic disease” (NOD). Their problems may be psychological or psychiatric, but they are not medical or surgical. In patients found to have an abnormality, diagnosis now asks, “Which disease?” Psychiatrists are the only physicians who do not perform physical diagnosis. The absence of disease is determined for them by other physicians, usually referring physicians. In 1948 the previously conjoint specialty of neuropsychiatry was divided into neurology—responsible for the diagnosis and treatment or physical/organic disease of the nervous system—and psychiatry—responsible for the treatment of emotional and psychological problems, none of them due to organic diseases. Nor did psychiatry object to this scientific division of labor at the time. However, in the 1950s, with the advent of psychotropic drugs, psychiatry, increasingly in league with the pharmaceutical industry, began referring to psychological diagnoses as disorders/diseases/chemical imbalances of the brain, albeit with no proof or science. In a congressional hearing in 1970, psychiatrists and federal officials, including the Food and Drug Administration and the Department of Health, Education, and Welfare, represented hyperkinetic disorder (HKD) to be a disorder/disease of the brain leading to the appropriation of millions of dollars for research, diagnosis and treatment into the drug treatment of school children said to have the new disease HKD. HKD became ADD, then ADHD, a disorder/disease/chemical imbalance always in need of a “chemical balancer”—a pill. Without proof of an abnormality/disorder/disease, the ADHD epidemic grew from 150,000 in 1970 to 6 million to 7 million today, the most common childhood diagnosis in the United States, a multi-billion dollar industry, and a model for all 374 DSM–IV psychological/psychiatric diagnoses—none of them actual diseases. As such, psychiatry is not a legitimate branch of medicine deserving scientific-fiscal parity; rather, collectively, it is the greatest health care fraud in history. Every time a so-called chemical imbalance is diagnosed, a patient’s right to informed consent has been abrogated. Every time a medically normal person is treated with a psychotropic chemical balancer—a pill—their first and only abnormality is the iatrogenic intoxication: poisoning.

Development of a New Image-Guided Neuronavigation System: Mixed-Reality Projection Mapping Is Accurate and Feasible

2021 ◽  
Author(s):  
Tsukasa Koike ◽  
Taichi Kin ◽  
Shota Tanaka ◽  
Katsuya Sato ◽  
Tatsuya Uchida ◽  
...  
Keyword(s):  
Image Processing ◽  
Mixed Reality ◽  
Improve Patient Safety ◽  
Projection Mapping ◽  
Normalized Mutual Information ◽  
Image Guided ◽  
Brain Surface ◽  
Initial Surgery ◽  
Position And Orientation ◽  
The Brain

Abstract BACKGROUND Image-guided systems improve the safety, functional outcome, and overall survival of neurosurgery but require extensive equipment. OBJECTIVE To develop an image-guided surgery system that combines the brain surface photographic texture (BSP-T) captured during surgery with 3-dimensional computer graphics (3DCG) using projection mapping. METHODS Patients who underwent initial surgery with brain tumors were prospectively enrolled. The texture of the 3DCG (3DCG-T) was obtained from 3DCG under similar conditions as those when capturing the brain surface photographs. The position and orientation at the time of 3DCG-T acquisition were used as the reference. The correct position and orientation of the BSP-T were obtained by aligning the BSP-T with the 3DCG-T using normalized mutual information. The BSP-T was combined with and displayed on the 3DCG using projection mapping. This mixed-reality projection mapping (MRPM) was used prospectively in 15 patients (mean age 46.6 yr, 6 males). The difference between the centerlines of surface blood vessels on the BSP-T and 3DCG constituted the target registration error (TRE) and was measured in 16 fields of the craniotomy area. We also measured the time required for image processing. RESULTS The TRE was measured at 158 locations in the 15 patients, with an average of 1.19 ± 0.14 mm (mean ± standard error). The average image processing time was 16.58 min. CONCLUSION Our MRPM method does not require extensive equipment while presenting information of patients’ anatomy together with medical images in the same coordinate system. It has the potential to improve patient safety.

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