Biomechanical Modeling of Human Finger

2013 ◽  
Vol 430 ◽  
pp. 217-221
Author(s):  
Panaitescu Liess Radu

Many of the studies in the biomechanics of the human body made globally focused primarily on hand-arm. This segment of the human body is considered a "gateway" of vibrations to other parts of the body or to internal organs. A long-term exposure to these mechanical vibration (caused by vibrating hand equipment: drill, grinder, etc.) affects the soft tissues and may lead to a dangerous syndrome, that is particularly vibration white finger (VWF), which is narrowing of blood vessels, a phenomenon that in time and untreated can even cause gangrene. This article focuses on a dynamic model with three degrees of freedom of the human finger. Some dynamic characteristics, such as centre of gravity, stiffness and damping, using both a rigid body structure system and computer simulations can be determined after measuring the vibrations.

2015 ◽  
Vol 801 ◽  
pp. 295-299
Author(s):  
Daniela Mariana Barbu ◽  
Mihaela Ioana Baritz

In the human body, vibrations are generated by internal or external sources. Because of the soft tissues, bones, joints, internal organs and also because of its anatomical particularities components in general, the human body is a complex vibratory system. The vibrations from external sources can be transmitted to the human body when it is positioned in different manners: standing, sitting, recumbent and moving or at work. The effect of vibration on the human body is related to the natural frequency of affected parts in the human body. This paper studies the dynamic characteristics of a human body system in a vibration environment and sets limits to which the balance is affected. The main result is a multi degrees of freedom lumped parameter model. The model provides an analytical tool for human body dynamics research. The relative displacements of human parts are evaluated, which can be a basis for the assessment of vibration risk and setting limits for keeping human balance.


2019 ◽  
Vol 65 (3) ◽  
Author(s):  
Aleksandra Słojewska ◽  
Izabela Gutowska

Introduction: Food is a carrier of many pollutants nowadays. For cadmium and dioxins, it is the main source of these compounds in the general population. Hence, the aim of this work was to collect data on the health effects associated with exposure to cadmium and dioxins which get into the human body through food.Materials and methods: A literature review was conducted by searching the scientific Medline database (PubMed) and Google Scholar.Results: Health effects associated with a long-term exposure to low doses of cadmium and dioxins may be nonspecific and are rarely attributed to food sources. These may cause disorders affecting hormonal balance, kidney function, lipid metabolism, fertility, cognitive function, bone mineralization, and susceptibility to diseases and allergies. These compounds may also lead to cancer development.Conclusions: The general population faces the problem of longterm exposure to small doses of these substances due to their accumulation in the body, even if their amounts do not exceed the relevant standards. The health effects of this type of exposure may be significantly delayed and are not likely to be attributed to the consumption of contaminated food. Consumers wishing to reduce the amounts of these compounds delivered to the body should limit the consumption of grilled and smoked products, and should also opt for organic food.


Author(s):  
Cristóbal Pera

ABSTRACTIf the human body is really a fabric, should surgeons be considered architects, as some surgeons describe themselves today? The author raises and analyzes this question, and he concludes that vsurgeons cannot be considered as such: the architect is the creator of his work —fabric or building—, but the surgeon is not the creator of this complex biological fabric —vulnerable and subject to deterioration and with an expiration date— which is the human body. This body is the object upon which his hands and instruments operate. The surgeon cures and heals wounds, immobilizes and aligns fractured bones in order to facilitate their good and timely repair, and cuts open the body’s surface in order to reach its internal organs. He also explores the body with his hands or instruments, destroys and reconstructs its ailing parts, substitutes vital organs taken from a donor’s foreign body, designs devices or prostheses, and replaces body parts, such as arteries and joints, that are damaged or worn out. In today’s culture, dominated by the desire to perfect the body, other surgeons keep retouching its aging façade, looking for an iconic and timeless beauty. This longing can drive, sometimes, to surgical madness. The surgeon is not capable of putting into motion, from scratch, a biological fabric such as the human body. Thus, he can’t create the subject of his work in the way that an architect can create a building. In contrast, the surgeon restores the body’s deteriorated or damaged parts and modifies the appearance of the body’s façade.RESUMEN¿Si el cuerpo humano fuera realmente una fábrica, podría el cirujano ser considerado su arquitecto, como algunos se pregonan en estos tiempos? Esta es la cuestión planteada por el autor y, a tenor de lo discurrido, su respuesta es negativa: porque así como el arquitecto es el artífice de su obra —fábrica o edificio— el cirujano no es el artífice de la complejísima fábrica biológica —vulnerable, deteriorable y caducable— que es el cuerpo humano, la cual le es dada como objeto de las acciones de sus manos y de sus instrumentos. El cirujano cura y restaña sus heridas, alinea e inmoviliza sus huesos fracturados para que su reparación llegue a buen término, penetra por sus orificios naturales o dibuja sobre la superficie corporal incisiones que le permitan llegar a sus entrañas, las explora con sus manos o mediante instrumentos, destruye y reconstruye sus partes enfermas, sustituye órganos vitales que no le ayudan a vivir por los extraídos de cuerpos donantes, y concibe, diseña y hace fabricar artefactos o prótesis, como recambio fragmentos corporales deteriorados o desgastados, como arterias o articulaciones. Otros cirujanos, en la predominante cultura de la modificación del cuerpo, retocan una y otra vez su fachada envejecida ineludiblemente por el paso del tiempo, empeñados en la búsqueda incesante de una belleza icónica y mediática e intemporal, una pretensión que puede conducir, y a veces conduce, al desvarío quirúrgico. En definitiva, el cirujano es incapaz de poner de pie, ex novo, una fábrica biológica como la del cuerpo humano y, por lo tanto, no puede ser su artífice, como lo es el arquitecto de su edificio. A lo sumo, es el restaurador de sus entrañas deterioradas y el modificador de su fachada, de su apariencia.


1982 ◽  
Vol 63 (1) ◽  
pp. 58-61
Author(s):  
I. M. Raskin ◽  
J. S. Zimmerman

Free sale of vitamin preparations with high activity, insufficient scientific development of the consequences of excessive intake of vitamins, the spread of superficial knowledge about vitamins among the population have led to numerous facts of the adverse effect of certain vitamins on the human body. It turned out that unjustifiably long-term intake of large doses of one of the vitamins can cause a deficiency in the body of another vitamin, cause the development of hypovitaminosis. The complex interaction of vitamins in the human body is due to the presence, they have metabolic and functional connections.


2014 ◽  
Vol 955-959 ◽  
pp. 1397-1404 ◽  
Author(s):  
Li Na Shi ◽  
Xun Xu ◽  
Xiao Yan Dou ◽  
Xu Dong Zhao

PM2.5 is one of the most important components in air pollution. It is also the focus of the most closely watched at home and abroad. Based on its small size, complex components, and strongenvironmental activity, it can be used as a carrier for chemicals, heavy metals, bacteria, toxins and carcinogens into the body. Then, as a result, it will affect Human Body Health. Heavy metals are important components of PM2.5, and the long-term accumulation of heavy metals in PM2.5 poses a great threat on human health and the environment. This paper reviewed the sources, distribution methods,chemical form, detection methods, disposal way, research progress of heavy metals in PM2.5. As a result, it provided a reference for in-depth study on the future.


2019 ◽  
Vol 24 (3) ◽  
pp. 592-599
Author(s):  
Hamid Gheibollahi ◽  
Masoud Masih-Tehrani ◽  
Mohammadmehdi Niroobakhsh

In this study, adding a headrest to the conventional vehicle driver seat is investigated to improve the driver comfort and decrease the driver damages. For this purpose, a conventional biomechanical human body model of wholebody vibrations is provided and modified by adding a head degree of freedom to the body model and a headrest to the seat model. The basic model is in the sitting posture, lumped parameters and has nine DOFs for the human body, on contrary to the proposed model which has ten DOFs. The new human body DOF is the twisting motion of the head and neck. This new DOF is generated because of headrest adding to the driver’s seat. To determine the head discomforts, the Seat to Head (STH) indexes are studied in two directions: horizontal and vertical. The Genetic Algorithm (GA) is used to optimize the STH in different directions. The optimization variables are stiffness and damping parameters of the driver’s seat which are 12 for the basic model and are 16 for a new seat. The integer programming is used for time reduction. The results show that new seat (equipped by headrest) has very better STH in both directions.


Author(s):  
Svitlana Тymchik ◽  
Оleksandr Bryksin ◽  
Eugenia Omelyanchuk

In the modern world with the advent of devices that facilitate work (computer, technical equipment) has decreased sharply motor activity of people compared to previous decades. This, in the end, leads to a decrease in human functionality, as well as various diseases. Today, purely physical work does not play a significant role, it is replaced by mental. Intellectual work dramatically reduces the efficiency of the body. Lack of human energy expenditure leads to inconsistencies in the functioning of individual systems (muscular, skeletal, respiratory, cardiovascular) and the body as a whole with the environment, as well as reduced immunity and impaired metabolism. Exercise affects all muscle groups, joints, ligaments, which become strong, increase muscle volume, elasticity, strength and rate of contraction. Increased muscle activity forces the heart, lungs and other organs and systems of our body to work with additional load, thereby increasing the functional capabilities of man, his resistance to adverse environmental influences. Regular exercise primarily affects the musculoskeletal system, muscles. When you exercise, the muscles generate heat, to which the body responds by increased sweating. During exercise, blood flow increases: the blood brings oxygen and nutrients to the muscles, which in the process of life break down, releasing energy. When movements in the muscles additionally open reserve capillaries, the amount of circulating blood increases significantly, which causes an improvement in metabolism. In response to the reaction of the human body to exercise, the first place is occupied by the influence of the cerebral cortex on the regulation of the functions of the basic systems: there is a change in the cardiorespiratory system, gas exchange, metabolism, and others. Exercises enhance the functional restructuring of all parts of the musculoskeletal system, cardiovascular and other systems, improve tissue metabolism. Under the influence of moderate physical activity increases the efficiency of the heart, hemoglobin and red blood cell count, increases the phagocytic function of the blood. Improves the function and structure of the internal organs, improves chemical processing and promotion of food in the intestine. The combined activity of muscles and internal organs is regulated by the nervous system, the function of which is also improved by regular exercise. If the muscles do not work - their nutrition deteriorates, volume and strength decrease, elasticity and resilience decrease, they become weak, sluggish. Restrictions in movement (hypodynamia), passive lifestyle lead to various pre-pathological and pathological changes in the human body. So, the American doctors, having deprived volunteers of movements by imposing of high plaster and having kept to them a normal diet, were convinced that in 40 days at them muscle atrophy began and fat has accumulated. At the same time increased the reactivity of the cardiovascular system and decreased basal metabolism. However, during the next 4 weeks, when the subjects began to move actively (with the same diet), the above phenomena were eliminated, the muscles were strengthened and hypertrophied. Thus, due to physical exertion, recovery was possible both in functional and structural terms. Exercise has a multifaceted effect on the human body, increasing its resistance to adverse environmental influences. For example, physically trained people have better tolerance to oxygen starvation than untrained people. High ability to work at increase of body temperature over 38 ° C during physical exertions is noted. It has been noticed that radiologists who exercise have a lower degree of influence of penetrating radiation on the morphological composition of the blood. Animal experiments have shown that regular muscle training slows the development of malignant tumors. Regular exercise in physical education promotes good health and affects the various physiological adaptations of the neuromuscular, cardiovascular and respiratory systems of the human body. Types of physical activities are considered: aerobic, anaerobic, interval and hypoxic physical activities.


2018 ◽  
Vol 21 (2) ◽  
pp. 101-105
Author(s):  
Alexander B. Krivosheev ◽  
L. A Khvan ◽  
D. N Bobokhidze ◽  
I. A Krivosheeva ◽  
D. V Morozov ◽  
...  

A brief review of literature on the problem of argyria is presented. Hyperpigmentation of the skin in 10-20% of cases has an iatrogenic cause. Hyperpigmentation of the skin can form on the background of taking non-steroidal anti-inflammatory drugs, amiodarone, cytostatics, antimalarials, etc. Systemic deposition of silver in various organs and tissues is known as generalized argyria. The disease is caused by the prolonged use of compounds containing silver (lapis pencil, silver nitrate, etc.). Clinically, generalized arginia is characterized by the gradual appearance of ashy-bluish coloration of the skin of open areas of the body (face, neck) and nail plates of the phalanges of the hands. The period from the moment of the beginning of reception of preparations of silver and before occurrence of the first dermatological changes varies on the average from 1 year to 5 years. Generalized argiria is a rare disease. This is due to the limited use of silver drugs in clinical practice, as well as the improvement of technological processes in pharmacological production. The patient’s own observation with generalized arginia formed against the background of the long-term administration of the drug Argovit-S, whose silver content is 0.75-0.85 mg/ml, is analyzed. The patient took the drug alone as a food supplement for 25 years. The diagnosis of generalized arginia is verified clinically, but is confirmed necessarily in the course of histological examination. It is shown that argyria is not only the iatrogenic cause of skin hyperpigmentation, but a serious risk factor for the manifestation and progression of liver cirrhosis. Patients with generalized arginia should undergo a comprehensive examination in order to verify the serious pathology of internal organs.


2019 ◽  
Vol 3 (3) ◽  
pp. 1-4
Author(s):  
Radosław Drozd ◽  

Two cases with the dramatic course of secondary hyperparathyroidism in patients with chronic kidney disease on long-term dialysis. Has anything possible been done in management of these patients? Complications associated with impaired bone mineralization among patients with chronic kidney disease on long-term dialysis are observed frequently with an array of pathologic processes being found. Kidney osteodystrophy may be associated with either increased or decreased (adynamic bone disease, osteomalacia, aluminum-induced osteopenia) bone metabolism, as well as mixed forms related to the B2 microglobulin amyloidosis. Differential diagnosis of various types of osteopathy is difficult and is usually based on the histologic assessment of the bone biopsy. The most typical bone complication in patients with impaired kidney function is osetodistophy with increased bone metabolism, caused by secondary hyperparathyroidism clinically manifesting as osteitis fibrosa. High serum levels of PTH induce osteoclast and osteoblast activity. Early changes, with characteristic increase in the woven osteoid suggesting early, increased osteoplastic bone resorption may be found in a significant percentage of patients with GFR>60ml/min/1,73m2 of the body surface. Lower values of the GFR are associated with both faster bone synthesis and more active resorption with progressive increase in the intraosseous fibrosis and decreased bone mineralization. As the abnormalities progress, which is especially marked in patients on long-term dialysis, a rage of clinical symptoms, such as: severe bone and joint pain, bone deformation, pathological fractures, especially in the spinal region, calcifications of the soft tissues and vessels, including heart valves and lungs. In children, the most common abnormality is growth impairment. In some patient’s skin calcifications, with subsequent necrosis, due to increased calcium deposition in small and medium arteries. The diagnosis is based on the typical clinical picture, biochemical parameters (calcium and phosphate ratio, parathormone levels, characteristic radiologic charges and sometimes, bone histology. Prevention and treatment of these complications includes effective dialysis, appropriate low-phosphate diet with limitation of the protein supply to the 0.8g/kg of the body mass, adequate calcium and active Vitamin D3 supply, introduction of the phosphate binding medications (sevelamer or lantan) as well as calcimimetic use (substances activating parathyroid gland calcium receptors inhibiting both its up-regulation and PTH secretion). In the severe cases, with insufficient effect of the treatment described above, parathyroidectomy is required after close ultrasound and scintigraphy-based assessment of these glands. However, even such treatment may be insufficient in some cases, as presented below.


Robotica ◽  
2001 ◽  
Vol 19 (6) ◽  
pp. 601-610 ◽  
Author(s):  
Jihong Lee ◽  
Insoo Ha

In this paper we propose a set of techniques for a real-time motion capture of a human body. The proposed motion capture system is based on low cost accelerometers, and is capable of identifying the body configuration by extracting gravity-related terms from the sensor data. One sensor unit is composed of 3 accelerometers arranged orthogonally to each other, and is capable of identifying 2 rotating angles of joints with 2 degrees of freedom. A geometric fusion technique is applied to cope with the uncertainty of sensor data. A practical calibration technique is also proposed to handle errors in aligning the sensing axis to the coordination axis. In the case where motion acceleration is not negligible compared with gravity acceleration, a compensation technique to extract gravity acceleration from the sensor data is proposed. Experimental results not only for individual techniques but also for human motion capturing with graphics are included.


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