Biomechanical Engineering

Biomechanical studies suggest that one determinant of abdominal aortic aneurysm (AAA) rupture is related to the stress in the wall. In this regard, a reliable and accurate stress analysis of an in vivo AAA requires a suitable 3D constitutive model. To date, stress analysis conducted on AAA is mainly driven by isotropic tissue models. However, recent biaxial tensile tests performed on AAA tissue samples demonstrate the anisotropic nature of this tissue. The purpose of this work is to study the influence of geometry and material anisotropy on the magnitude and distribution of the peak wall stress in AAAs. Three-dimensional computer models of symmetric and asymmetric AAAs were generated in which the maximum diameter and length of the aneurysm were individually controlled. A five parameter exponential type structural strain-energy function was used to model the anisotropic behavior of the AAA tissue. The anisotropy is determined by the orientation of the collagen fibers (one parameter o...

Human lung undergoes breathing-induced deformation in the form of inhalation and exhalation. Modeling the dynamics is numerically complicated by the lack of information on lung elastic behavior and fluid–structure interactions between air and the tissue. A mathematical method is developed to integrate deformation results from a deformable image registration (DIR) and physics-based modeling approaches in order to represent consistent volumetric lung dynamics. The computational fluid dynamics (CFD) simulation assumes the lung is a poro-elastic medium with spatially distributed elastic property. Simulation is performed on a 3D lung geometry reconstructed from four-dimensional computed tomography (4DCT) dataset of a human subject. The heterogeneous Young’s modulus (YM) is estimated from a linear elastic deformation model with the same lung geometry and 4D lung DIR. The deformation obtained from the CFD is then coupled with the displacement obtained from the 4D lung DIR by means of the T...

The role of arm swing in running has been minimally described, and the contributions of arm motion to lower extremity joint kinematics and external force generation are unknown. These contributions may have implications in the design of musculoskeletal models for computer simulations of running, since previous models have usually not included articulating arm segments. 3D stance phase lower extremity joint angles and ground reaction forces (GRFs) were determined for seven subjects running normally, and running under two conditions of arm restraint. When arm swing was suppressed, the peak vertical GRF decreased by 10–13% bodyweight, and the peak lateral GRF increased by 4–6% bodyweight. Changes in peak joint angles on the order of 1–5 deg were observed for hip flexion, hip adduction, knee flexion, knee adduction, and ankle abduction. The effect sizes (ES) were small to moderate (ES<0.8) for most of the peak GRF differences, but large (ES>0.8) for most of the peak joint angle di...

The biomechanics of skin and underlying tissues plays a fundamental role in the human sense of touch. It governs the mechanics of contact between the skin and an object, the transmission of the mechanical signals through the skin, and their transduction into neural signals by the mechanoreceptors. To better understand the mechanics of touch, it is necessary to establish quantitative relationships between the loads imposed on the skin by an object, the state of stresses/strains at mechanoreceptor locations, and the resulting neural response. Towards this goal, 3-D finite-element models of human and monkey fingertips with realistic external geometries were developed. By computing fingertip model deformations under line loads, it was shown that a multi-layered model was necessary to match previously obtained in vivo data on skin surface displacements. An optimal ratio of elastic moduli of the layers was determined through numerical experiments whose results were matched with empirical ...

La presente investigación muestra el análisis biomecánico asistido por computadora mediante el empleo de simulación en 3D. Se plantea una alternativa de enseñanza que permite optimizar el potencial humano de atletas de alto rendimiento que se desempeñen en disciplinas de artes marciales a través de un sistema de bajo costo que minimiza los tiempos de adiestramiento, entrenamiento y capacitación. La contribución de éste estudio involucra el análisis teórico de los aspectos físicos involucrados en las técnicas de alto grado de dificultad, el estudio se realizó con base a los principios de evolución de los sistemas tecnológicos de TRIZ. Se logra un aprendizaje más sustentado en ciencia y que permite alcanzar avances significativos en menor tiempo y minimiza la ocurrencia de lesiones y accidentes producto de los riesgos involucrados de la práctica de las Artes Marciales Extremas.
Palabras clave: Análisis biomecánico, acrobacia, innovación, TRIZ, simulación.

The formal design, that which is not empirical, has a sequential and iterative structure,which ensures the convergence of the process in functional outcomes. The objective of this paper is to apply the formal design techniques in the sizing of the most important organin a CNC router machine, which is the translation equipment. The classical design methodhas been adopted, which flow is divided into eight chronological steps, from which thestep that involves the manufacture or implementation of the machine is only excluded. 
The translation´s equipment sizing has to be a great deal to a holistic design approach. It means that this organ depends on the other components of the machine, but after acertain point, in the detail design stage, the design philosophy is limited to the translationequipment sizing only.
The factor that highlights the differences between the stages of design, integrated andspecific stage is the dynamic behavior of the machine; in fact, such behavior is reflected inthe machining forces present in the material’s removal process. 
The implementation of a special measuring machine that can determine the behavior of machining forces is crucial for the optimal sizing of the translation equipment. Otherwisethe design process would be based on merely theoretical concepts and in not necessarilyactual estimations. The concept of a measuring machine or a cutting process simulationmachine is implemented in a prototype machine, functional enough to measuring the forces. Once that machining forces are known, which are mentioned as 𝑭 vector, it can be sized in detail, not only the translation equipment CNC router machine, but also to the other organs. At this stage in which the design is specific, components and equipment aredetailed and dimensioned, those which are strictly necessary for the sizing of the translationequipment. The sizing results of such organ consist on an ordered set of criteria, parameters and components, which set together allows fulfilling in an efficient way, the function ofproviding motion to the CNC router machine chains.
In order to quantify the sizing problems and needs, comparative techniques are used insimilar machines and related specific applications. These same techniques are which areimplemented in the validation of the product, with the aim of evaluating whether the result meet the problems and needs established.

Today the use of gadgets and electronic devices has exceeded the limit of the average - average usage usually only in tolerance 30 minutes - 2 hours, now can be more than the time limit that has been specified.
Especially in office workers who spent all day at the work station or work with computers.
With the improvement of the function of his work station as well as devices such as tables and chairs, can add to the comfort and menurangi risk of stress and injury during work.
The addition of an ergonomic devices that support is also needed such as a keyboard and mouse in accordance with the user and also biomekanical anthropometry of the user itself.
the purpose of this journal, would like to invite and give advice to the reader to implement better work station and convenient to apply all ergonomisan

The effect of warfare on hunter-gatherers is a question that has recently come to be a focus of conflict archaeology. One subject that is of particular interest is the identification of weaponry in Southern California. Numerous accounts have been given of club-type weapons and bows used for offense and defense. However, the archaeological evidence remains sparse because of the fragility and multiple uses of these artifacts. This research will analyze the role and impact of these weapons on conflict of Southern California societies. To analyze weaponry, a detailed examination of clubs from previously excavated collections is undertaken in conjunction with an experiment to observe trauma inflicted by the weapons. The experiment consists of wielding clubs on and shooting arrows in a pig carcass, both armored and unarmored, to see the amount of trauma inflicted on the tissue and bone. The clubs and armor are replicas of artifacts represented in primary accounts and museums. A comparison to similar weapons from other cultures (Europeans, Eastern Woodland tribes, and Polynesia) is included for analogy. The hypotheses of this experiment are: If a war club is effective, then the damage to the tissue and bone will be significant, and if armor is effective, then most damage will be dispersed. From the data, a detail of the impact of weapons and the tactics of these societies is determined.

Recent advances in the design and implementation of wearable resistive, capacitive, and optical strain sensors are summarized herein. Wearable and stretchable strain sensors have received extensive research interest due to their applications in personalized healthcare, human motion detection, human–machine interfaces, soft robotics, and beyond. The disconnection of overlapped nanomaterials, reversible opening/closing of microcracks in sensing films, and alteration of the tunneling resistance have been successfully adopted to develop high‐performance resistive‐type sensors. On the other hand, the sensing behavior of capacitive‐type and optical strain sensors is largely governed by their geometrical changes under stretching/releasing cycles. The sensor design parameters, including stretchability, sensitivity, linearity, hysteresis, and dynamic durability, are comprehensively discussed. Finally, the promising applications of wearable strain sensors are highlighted in detail. Although considerable progress has been made so far, wearable strain sensors are still in their prototype stage, and several challenges in the manufacturing of integrated and multifunctional strain sensors should be yet tackled.

This research focuses on the transformation of conflict from its earliest modes to more intensified forms seen in complex societies. Specifically, the focus is on the transition of combat in band level societies to its institutionalization in tribal social structures. One of the challenges in archaeology is in recognizing steps in the evolution of violence in formative and less stratified societies. To achieve this end, the transition of conflict needs to be operationalized. This investigation analyzes the impact of specialized weaponry (i.e. clubs) indicative of the earliest signs of escalating warfare in California. Experiments were conducted in collaboration with forensic scientists and biomechanical engineers in order to derive quantifiable lethality data from traditional war clubs of tribes in Southern California. Weapons were reconstructed from historic accounts and museum specimens, and then tested using biomechanical engineering methods. Test results are discussed in relation to the bioarchaeological record and specific case studies for blunt force trauma in prehistoric California. This comparison allows for the charting of the early development of conflict centered, social organizations.

Femur fracture at the tip of a total hip replacement (THR), commonly known as Vancouver B1 fracture, is mainly treated using rigid metallic bone plates which may result in "stress shielding" leading to bone resorption and implant loosening. To minimize stress shielding, a new carbon fiber (CF)/Flax/Epoxy composite plate has been developed and biomechanically compared to a standard clinical metal plate. For fatigue tests, experiments were done using six artificial femurs cyclically loaded through the femoral head in axial compression for four stages: Stage 1 (intact), stage 2 (after THR insertion), stage 3 (after plate fixation of a simulated Vancouver B1 femoral midshaft fracture gap), and stage 4 (after fracture gap healing). For fracture fixation, one group was fitted with the new CF/Flax/Epoxy plate (n = 3), whereas another group was repaired with a standard clinical metal plate (Zimmer, Warsaw, IN) (n = 3). In addition to axial stiffness measurements, infrared thermogr...

Background: Torque of the maxillary incisors is crucial to occlusal relationship and esthetics and can be influenced by many factors. The aim of this study was to assess the relative influence of the material of the orthodontic appliance (adhesive, bracket, ligature, and wire) on tooth displacements and developed stresses/strains after torque application. Methods: A three-dimensional upper right central incisor with its periodontal ligament (PDL) and alveolus was modeled. A 0.018-in. slot discovery® (Dentaurum, Ispringen, Germany) bracket with a rectangular 0.018 x 0.025-in. wire was generated. The orthodontic appliance varied in the material of its components: adhesive (composite resin or resin-modified glass ionomer cement), bracket (titanium, steel, or ceramic), wire (beta-titanium or steel), and ligature (elastomeric or steel). A total of 24 models were generated, and a palatal root torque of 5° was applied. Afterwards, crown and apex displacement, strains in the PDL, and stresses in the bracket were calculated and analyzed.

Background
Medical equipment donation to low-resource settings is a frequently used strategy to address existing disparities, but there is a paucity of reported experience and evaluation. Challenges such as infrastructure gaps, lack of technological and maintenance capabilities, and non-prioritisation of essential supplies have previously been highlighted. This pragmatic review summarises existing guidelines and literature relevant to surgical and anaesthesia equipment, with recommendations for future initiatives and research.

Methods
Retrospective literature review including both academic and grey literature from 1980 to 2018. We conducted a narrative synthesis to identify key factors that were condensed thematically.

Results
Thirty-three biomedical equipment donation guidelines were identified from governments, WHO, World Bank, academic colleges and non-governmental organisations, and 36 relevant studies in peer-reviewed literature. These highlighted the need to consider all stages of the donation process, including planning, sourcing, transporting, training, maintaining and evaluating equipment donation. Donors were advised to consult national guidelines to ensure equipment was appropriate, desirable and non-costly to both parties. User training and access to biomechanical engineers were suggested as necessary for long-term sustainability. Finally, equitable partnerships between donors and recipients were integral to reducing inappropriate donations and to improve follow-up and evaluation.

Conclusion
There is a paucity of evidence on the causes of success or failure in medical equipment donation, despite its domination of equipment sourcing across many low-resource settings. Equitable partnerships, consultation of policies and guidelines, and careful planning may improve equipment usability and life span. A concerted effort is required to increase awareness of guidelines among health professionals worldwide.

In daily life, people can not be separated from activities that are closely related to subsistence. Human life needs space complete with equipment in accordance with purposes such as lighting equipment, instrument air regulator, seating and other furniture compilation. For that we need a proper study and design so that people can feel comfortable. Seats are fixtures main spatial functions in a simple state can act without regard to the other elements, so the presence of seats in minimum space must exist.
Work chair is one type of chair that is often used, especially when we're working. This study aims to look at the most comfortable seat design used to work, by analyzing the activities undertaken. So that later can be used as a reference design ergonomic chairs, that can support the health of the body and improve the quality of work.
Keywords: Design, Working Chair, Ergonomics.

This article demonstrates the use of hybrid nanofibers to improve the biodegradation rate and biocompatibility of AM50 magnesium alloy. Biodegradable hybrid membrane fiber layers containing nano-hydroxyapatite (nHA) particles and poly(lactide)(PLA) nanofibers were coated layer-by-layer (LbL) on AM50 coupons using a facile single-step air jet spinning (AJS) approach. The corrosion performance of coated and uncoated coupon samples was investigated by means of electrochemical measurements. The results showed that the AJS 3D membrane fiber layers, particularly the hybrid membrane layers containing a small amount of nHA (3 wt.%), induce a higher biocorrosion resistance and effectively decrease the initial degradation rate compared with the neat AM50 coupon samples. The adhesion strength improved highly due to the presence of nHA particles in the AJS layer. Furthermore , the long biodegradation rates of AM50 alloy in Hank's balanced salt solution (HBSS) were significantly controlled by the AJS-coatings. The results showed a higher cytocompatibility for AJS-coatings compared to that for neat Mg alloys. The nanostructured nHA embedded hybrid PLA nanofiber coating can therefore be a suitable coating material for Mg alloy as a potential material for biodegradable metallic orthopedic implants.

This paper proposes a model for low cost design of mhealth solutions. The model presented here is based on RF transmitter and receiver, microcontroller and cellular network integration and uses F-BUS protocol for transmitting and receiving data using a NOKIA 3310 handset. The proposed design aims at eliminating the need of smart-phone dependent costly mhealth solutions. Also, the current paper presents the essential comparative data and statistics to support the concerned proposed design.

Cite: Rajat Kumar and Arvind Rehalia, "Proposed Design of a Low Cost mHealth System," International Journal of Modeling and Optimization vol. 2, no. 1, pp. 15-18, 2012.

Rajat Kumar is with the Bharati Vidyapeeth's College of Engineering, Guru Gobind Singh Indraprastha University , New Delhi , India (e-mail: [email protected]).

Arvind Rehalia is with the Bharati Vidyapeeth's College of Engineering, Guru Gobind Singh Indraprastha University, New Delhi, India (e-mail: [email protected]).