Across denominations in the UK, numerous methods for evangelism are Essay

Across denominations in the UK, numerous methods for evangelism are advanced. Critically evaluate the evangelistic methodologies used by a local church forum you have recently visited - Essay Example Paul performed various actions such helping the needy and preaching the gospel in the street to spread the gospel of Christ. The modern church is experiencing a transformation in terms of evangelism. This results from advancements in technology and civilisation. Members of the present generation are obsessed with change, which implies that the church needs to change its approach to evangelism. In the United Kingdom for example, various evangelistic methods are effective in delivering the gospel of Christ to the people. The United Kingdom is among the countries where evangelistic initiates face resistance from the young section of the populace. Evangelists in the United Kingdom are developing evangelistic methods that attract the attention of the young generation in the quest to preach the gospel of Christ. Evangelistic methodologies differ across various denominations. For example, the catholic evangelists use different approaches compared to their Pentecostal counterparts (Medearis, 2011). There are, however, some similarities in the evangelistic methodologies in Christianity. The purpose of evangelism is to inform the society about the word of Christ through action or preaching. The most common evangelistic method in the United Kingdom is the church and street preaching. Other methodologies include home group evangelism, missionary, community service and friendship, prayer as well as Internet evangelisms (Medearis, 2011). This is an evangelistic method where a church member becomes friends with a non-believer and relays the message of salvation to them. The friendship evangelistic methodology is presently the most challenging evangelistic approach in the United Kingdom. Most members ascribed to the friendship evangelistic groups experience problems making friends with non-believers. Majority of people in the United Kingdom are capitalistic in nature, making it difficult for believers to meet non-believers. In addition, most people

Virtual Machine Essay Example | Topics and Well Written Essays - 1500 words

Virtual Machine - Essay Example Virtual machine is a collection of software like JVM (java virtual m/c) that provides run time environment (e.g. data structure support) to user applications. Such software is now referred with the terms virtualization that is running two or more copies of the same operating system or two or more different operating systems and virtual servers. The host software, which provides this capability, is often referred to as a virtual machine monitor or hypervisor. It resides between the hardware and the "guest" operating systems. There are four major conceptual models of Virtual Machines used today and cater for different problem The IBM Model as demonstrated in the IBM S/390 solved the need for a single computer system that could simulate multiple computers with different operating systems. instruction set and maps JVM calls to operating system calls. It simulates a fake CPU that interprets the fake CPU instructions (what is usually referred to as byte code). The most significant feature of the Java Virtual Machine the ability write a program once and execute it with Java Virtual Machines on multiple platforms. The OSI Virtual Machine and the Unix Virtual Machine, represented by the Unix user shell are used to create operating systems and providing services and functions at the operating system level that did not exist in the system hardware. The OSI Virtual Machine model solved the problem of providing services and functions at ... The OSI Virtual Machine model solved the problem of providing services and functions at the operating system level that did not exist in the system hardware. The Unix Virtual Machine model solved series of computer engineering problems by addressing the need for a modular approach to managing the launching and control of Unix processes. The success of the Unix operating systems is to a largely to the versatility and scalability of the Unix process. The History of Virtual Machines Around 1965 the researchers at IBM Yorktown Research center, developed first virtual machine environment, for the IBM System/360 mainframe called VM, which was entirely based in software. Later, IBM developed an implementation of its notion of a virtual machine and added hardware circuits to provide more robust and speedy partitioning between system images. This real world operating system, allows the user to share the resources available on their mainframe computers with many people, thus creating a multiple user environments. . This machine is now known as the IBM System 370 (S/370) and the IBM System 390 (S/390). These machines make use of the IBM VM/ESA operating system and are collectively referred to as IBM's VM lineage. Virtual Machine Research Paper 4 Benefits of running a virtual machine Virtual machine allow user to write applications on one OS and it can be executed on a machine which runs a different OS.One use is to provide multiple users the illusion of having an entire computer. Another advantage is that booting and restarting a virtual machine can be much faster than with a physical machine, since it may be possible to skip tasks such as hardware initialization. Virtual machine allows for testing OS's and requires less

Special Educational Journal Research Paper Essay

Special Educational Journal Research Paper - Essay Example Issues in judgment and evaluation Efficacy of no detention policyFocus on exceptional approaches should be applied for teaching and learning Society should take active participation in the improvement of schools and its practicesChange in the teaching-learning method and the provision of multi-level teaching-learning in different subjects in primary schools should incorporated Approaches to teaching and learning should be different and easy to learn pedagogy should be culturally specific Creativeness should be nourished and development should be cognitiveEmerging needs of the society and education SECONDARY EDUCATION Identification and nurturance of competent ideas in different subject areas in varied classes at different level Ultimate methods of learning to learn new things Integration of skills needed to life should be incorporated into curriculum, textbooks, instructional materials and teaching-learning and evaluation process Identification of suitable grade/class for introduction of second language on the basis of analysis of linguistic situation in the state and or state needs Identification of class/grade/stage at which Hindi/English should be introduced on a compulsory basis as second language and the period for which these should be taught Formulation of State specific plans concerning identification of class/grade in upper primary stage from which third language should be introduced Making curriculum indigenous/culture specific/contextual Developing remedial instruction in different subject areas Development of concepts related to sustainable development and integration in curriculum, textbooks and instructional materials with other subjects and lifePolicy studies in science education... Clark, C. M. (Ed.). (2001). Talking shop: Authentic conversation and teacher learning. New York: Teachers College. Retrieved 15 October 2006, from http://convention.allacademic.com/aera2004/view_paper_info.htmlpub_id=939&part_id1=23267 Cole, A. L., & Knowles, J. G. (2000). Researching teaching: Exploring teacher development through reflex inquiry. Retrieved 15 October 2006, from Hopkins, D., & Stern, D. (1996). International perspectives and policy implications. Teaching and Teacher Education. Retrieved 15 October 2006, from Nuthall, G. A. (2001). The cultural myths and the realities of teaching and learning. In L. Livingstone (Ed.), New Zealand Annual Review of Education, Retrieved 15 October 2006, from Robinson, V. (1998). Methodology and the research-practice gap. Educational Researcher, Retrieved 15 October 2006, from

Theory of the Firm Essay Example | Topics and Well Written Essays - 2750 words

Theory of the Firm - Essay Example Although it is very difficult to suggest which, out of these two is a better structure, but one can clearly identify the merits of each structure. In the U-Form or Unitary form, organizations are broken up into separate departments for each process, for example, separate department for marketing, finance and production. The manager or head of each department reports to the chief executive of the organization, whose function is to co-ordinate the activities of each department, relaying the firm's overall strategy to them and being responsible for inter-departmental communication. Although, this structure is very efficient till the firm is of certain size, but it can lead to inefficiencies as the organization grows. These inefficiencies are: communication difficulties, coordination and control and it become difficult to manage the entire organization from the centre. Another structure which results in the firm being able to overcome these problems is called M-Form or multi-divisional form of internal structure. In this structure, the firm is divided a number of divisions. Each division could be responsible for particular group or group of products or a particular market. The day to day running and even certain long term decision of each division would be the responsibility of the divisional managers. Many people argue that M-Form is better than U-Form structure because it reduces the length of information flows. It also relieves the C.E.O of the coordination activities and he can focus on overall strategic planning. It also increases professional competition between the departments, which lead them to be more efficient. Each department runs as mini firm and try to utilize resources efficiently which increases the efficiency of the entire firm. (Lipsey and Chrystal, 2001) All these benefits that come-out as a result of M-Form structure lead many managers into believing that it is actually better than U-Form structure. But after careful and deep analysis one cannot say that it is good for firms of any size. If this structure is followed by an organization of small size than they would face various problems, such as, it can very bureaucratic with many forms of layers of managers. Managers might pursue goals that conflict with those of shareholders or head office. As a result, some companies in recent years have moved back from M-Form structure to much flatter U-Form structure. So, in the end we can conclude that M-Form is not better than U-Form structure. It is the situation and culture in the firm that is being followed determines which system is going to more useful for the organization and, one cannot say that M-Form is necessarily better than U- Form structure. In the end, we can safely conclude that M-Form or U-Form structure themselves are not the best, but it is the flexibility of the firm which makes any structure good or bad. Some times you need to have a flatter structure, whereas at the other times, decentralization works the best. I recommend that any firm that is governed with flatter and more responsive structure will do much better than the firm with big span of control, as it would make it easier to control the subordinates and keep check and balance on the firm's activities. ESSAY # 2 Structure conduct performance model is used to link various factors in the economic environment that affect the performance of the business. It also links the various

Discuss in Detail Ways in Which Variations in the English Language Reflect the Society They Are Situated in Essay Example for Free

Discuss in Detail Ways in Which Variations in the English Language Reflect the Society They Are Situated in Essay Discuss in detail ways in which variations in the English language reflect the society they are situated in. According to Walt Wolfram, â€Å"Language sows its own seeds of change. Social context gives it the fertile ground to grow and spread.† The global spread of English has inevitably led to the formation of new varieties such as Singlish and Hinglish, which are different in their own ways. The differences among these variations, in terms of lexical choice, structure and even pronunciation, are due to the different context and needs of the societies. These include the economical incentive of English in the society, social groups and their cultural make up. The economic incentive of learning English in the society plays a big role in the type of variation that distinguishes the new Englishes from other varieties. With the affluent and powerful recognizing the importance of English to connect, be a part of the global platform and even acquire well paying jobs, the aspiring middle class, who makes up the majority in any societies, would find it very lucrative to learn English, so as to be associated with them. However, in most societies where English is considered a foreign language, learning it in language school is very expensive and usually is an option for the wealthy. As a result, they would pick up bits and pieces of lexical items from the English language, and use it in their speech, maintaining the structure of their native language. An example would be Hinglish, where â€Å"my head is eating circles, is a direct translation of mera sir chakkar kha raha hai., effectively keeping the structure of Hindi. In India, majority of good Standard English speakers are from the upper class due to the exorbitant fees of the language schools. As such, the variation of English in this case reflects the economical incentives and the income gap in the society, where there is a negative association of the variety due to speakers not being able to afford the education of Standard English. In Text B(i), lexical chain pertaining to negativity is adopted to be referred to code mixed languages. They i nclude, â€Å"gutter- speak†, â€Å"bad† and â€Å"consequence† However, as the use of the variation used by the lower and middle class increase due to the population distribution, it might lead to the acceptance of the dialect in the whole society, then coming up with a more organized and uniform variety that most members of society would understand. This uniformity of the variety reflects the social acceptance of the variation. In Text B(i), semantic field of uniqueness is adopted to

Impacts of Knife Crime

Impacts of Knife Crime Britain is in the grip of a knife crime epidemic. This is the impression one gets from the media: every week seems to bring new stories of stabbing and murder among city youth. But why are these youngsters engaging in such activity? This quote suggests that young people who carry knives do so protection, status and peer pressure. The media also plays a part by reinforcing the idea that everyone else is carrying a weapon. Finally, the quote claims socially excluded young people from dysfunctional families are more likely to use knives. The first part this essay will first give an overview of the labelling approach and social construction theory, it will then go on to consider whether young people are in fact engaging in knife crime because of the above reasons, or whether it is simply a consequence of the labelling process. The labelling theory devotes little effort in explaining why certain individuals begin to engage in deviance. Rather, it stresses the importance of the process through which society defines acts as deviant and the role of negative social reactions in influencing individuals to engage in subsequent acts. The labelling theorists shift their attention away from individuals and their actions and toward the dynamic of social definition that particular acts or actors are deviant. The first labelling theorist was Frank Tannenbaum (1938), he suggested the person who is labelled, subsequently becomes the thing he is being described as. Whether that label be given by those who would punish, or by those who would reform. In either case the emphasis is upon the conduct that is being disapproved of. The harder the criminal justice system works to reform the evil, the greater the evil will grow and the harder it will become to suppress the bad behaviour. He claimed the way out was through a refusal to dramatize the evil. The less said about it the better. The more said about something else, still better.   Taylor et all (1973) reinforced the labelling theory by suggesting that the way a stop will be put to deviant behaviour is: to create a society in which the facts of human diversity, whether personal, organic or social, are not subjected to the power to criminalize.   Sociologist Haword Becker(1963), recognised deviance is not a quality that lies in the behaviour itself but in the interaction between the person who commits an act, and those who respond to it. A good way to demonstrate this point is by referring to the study of opiate use  by the sociologist Alfred Ray Lindesmith, his findings demonstrated how a person becomes aware of their addiction. In essence it is not the drug that makes the person an addict, the addiction is a result of social definition. When others label them as addicts, then the person too comes to define himself as an addict. In other words behaviour is not inherently deviant or normal but is defined and labelled that way. So how does the labelling process work? Erikson (1975), the founder of the labelling theory, describes two main stages to the labelling process. The first stage involves primary deviance, which is the initial criminal act, after which a person may be labelled as deviant or criminal, but does not yet accept this role. So the person does not view himself as a criminal. It is this lack of viewing that separates primary deviance from the next stage, second deviance. Secondary deviance involves a status degradation ceremony This begins by a formal confrontation between the deviant and the officials, as in the criminal trial; this is then followed by an announcement of the verdict, and finally the deviant is assigned with a special role, like a prisoner which redefines his position in society. According to Tannenbaum (1938), formal proceedings signify the dramatization of evil, whereby the act is publically announced and defined as immoral. News of the formal sanction will then spread across the community leading to others also labelling him as deviant. The individual finally accepts the criminal label; their self concept is changed from normal to deviant. According to Lemert, This becomes a mean of defence, attack, or adaption to the problems caused by societal reaction to primary deviation.  This process can also take place in a more subtle fashion as well. For example, the family of deviant may become withdrawn and distance themselves from hi m in disappointment, regardless of whether a formal charge has occurred. Accordingly, the labelling theory suggests: if the individual accepts this negative criminal label that has been applied, they are then more likely to continue engaging in the behaviour that the label was initially meant to control. In other words the label leads the deviant individual to follow a self-fulfilling prophecy conforming to ascribed label, causing them to lead deviant careers. For example, if a person is caught carrying a knife, but is not apprehended or labelled as deviant, that person is more likely to forgo such behaviour in the future. However, if the person is apprehended and labelled as a criminal, then the person is subsequently more likely to change his identity as a rest of the exclusion felt by the individual from normal routines or conventional opportunities, and increased contact with the deviant groups. Having explained the theory, this essay will now interlink the labelling theory with the quote. The quote itself suggests most young people carry knives for: protection, status and peer pressure. The perceived need for protection is compounded by the sense, reinforced by the media coverage of stabbings, that everyone is carrying a weapon, as well as experience of victimisation. In terms of socially excluded young people from dysfunctional families are more likely to engage in knife use. For young people, the transition from childhood to adult can be rather confusing, their adult identity is not yet developed and so they often become bewildered as to their own position within society. George Herbert Mead claimed an individual develops a sense of self through how others perceive them, he coined this as the looking glass self. He suggested as children develop, they become more aware of their own social position and others around them, and subsequently become concerned about the demands and expectations of others and of the larger society. To demonstrate this point, he used a basketball game as an example, to show children, like basketball players, must take into account the roles of all players, as well as consider their own role.  [8]   This symbolic interaction to the study of deviance focuses on the process by which the wider social audience creates deviance and deviants by defining the acts and actors that way. The problem with defining young people as either knife carriers or knife users is that the term knife crime encompasses a very broad range of offences, and makes no distinguish between actual carrying and using. Furthermore, knife crime statistics are equally as difficult to quantify due to lack of clarity. The offences recorded involve sharp instruments these might actually refer to screwdrivers, broken bottles or glass, not a knife. Similarly offences listed as threatening another person with a weapon might involve sticks, rocks or other objects as well as knives. Furthermore certain types of knife may be carried legally if the carrier has a good reason, for example if it is work related, or for religion purposes. So there is some confusion as to who should be labelled when the definition itself is so br oad, a clearer definition is required in order to prevent sensationalised use of the term. If deviance is therefore just a label, where does the label come from? And how does the label come to be applied to specific behaviour and particular individuals? According to the sociologist Howard Becker(1963), moral entrepreneurs are often ones who create the rules about what constitutes deviant or conventional behaviour.  He believes that moral entrepreneurs use their own perspectives on what they believe is right or wrong to establish the rules by which they expect the rest of society to live, usually for their own political agendas. Furthermore, it has been suggested that these rules as to what is right or wrong are not randomly distributed across the social structure, but are instead more likely to apply to the powerless, the disadvantaged, and the poor. Because of existing stereotypes, which portray criminals as members of lower classes, minorities, urban dwellers, and young adults, individuals who belong to such groups are more likely than others to be labelled delinquent.   So the labelling process is a clear case of double standard, one rule for the rich and one for the poor. A perfect example to show this inadequacy is the recent MP expense row, those in power were stealing from the rest of society, yet their power enabled them to put the issues of youth violence, weapon use and gangs at the fore front, sending out sensationalised messages of a broken society  to exploit their own agendas. So the crime of the powerful is somewhat ignored by shifting societies focus on crimes of the middle and lower class. So is the quote correct in assuming knife users are generally from dysfunctional families? A dysfunctional family is one who has very few values or discipline within the household. An interesting theory to incorporate here is the control theory; this is concerned not with why people commit crime, but why so many refrain from doing so. It suggests those children who grow up with parents who exercise fair and consistent discipline are less likely to offend, and more likely to stay committed to conventional definitions of right or wrong behaviour. Those children who typically engage in knife crime or any other crime for that matter are said to come from broken homes, where they have not experienced love or care. Linking this back to the labelling theory, which suggests the powerless, low class are more likely to lead deviant careers, because they lack bonds with society and law. Subsequently, young people who have dysfunctional families within these communities will more likely conform to stereotypes they face. More so, if their parents informally label them as deviant which is very likely in cases of minorities from lower class; because they engage in more objective deviance.  This appraisal from the parent will influence their further delinquency. The quote also suggests the mass media also plays a part in ones decision to carry a knife, but is this true? Does the medias public labelling have an impact on a young persons decision to carry a knife around for protection? The media is one of the most persuasive features of society. The messages and information society receives through the media plays a huge impact on influencing their opinions and understanding. It sends out an image of the world as unrealistically clear-cut and understandable.  The media messages are in fact cleverly selected and edited, in order to offer identifiable values, interest and normative expectations. Stanley Cohen researched the social reaction of the Mods and Rockers disturbance in 1964; he claimed the media created a moral panic by labelling them as folk devils and exaggeration the initial events.  The original incident simply became an opportunity to exploit and enhance the social status of the moral entrepreneurs. In terms of knife crime or any other crime for that matter, the media is able to cultivate in their audience a belief that the larger social environment is dangerous and frightening, for example, when the mail screams that Shock figures reveal no part of Britain is safe as knife violence spreads everywhere, Thugs committing 350 knife assaults EVERYDAY, as blade menace spreads to rural areas, Britain on alert for deadly new knife with exploding tip that freezes victims organs, these are just a few examples to demonstrate the medias exaggeration. In the last headline, the knife was only sold in America, designed to kill sharks and bears, so no risk was being posed in Britain. But these types of sensationalised reports enhance social control, because the frightened audience are easily manipulated and easily accept what the media presents, and knife crime becomes wider and threatening then it actually is. The media has its good elements too; it helps raise knife crime awareness and also brings to the forefront campaigns against knife crime. The bad news is that the huge publicity devoted to raising awareness has the preserve effect of normalising it. The crime reduction charity Nacro, for example, argued: the suggestion that it is in any sense the norm to carry weapons is likely to increase the number of young people who do so, simply because they fear attack and wish to have the means to protect and defend themselves.  Furthermore the Mothers against Murder and aggression Wales found the way knife crime is portrayed in the news gives out the message that all teenagers are armed, which is a frightening concept, Almost everyone carrying a knife does so because they feel they have to protect themselves as everyone else is doing so.  So the media, like the labelling theory, labels certain groups of people, in this case young people, without any proper justification. Furthermore headl ines such as war on young thugs contributes to the concept that for some young people there is a war being waged against them and they be fighting back.  Furthermore the negative connotations of youths, when the vast majority are law-abiding, can add their sense of being under attack. As a consequence these labelled youths may begin to believe stereotypical beliefs surrounding them, or they may think that these beliefs exist based on their learned perception of what people think about criminals; fearing rejection, they may withdraw from interaction with conventional peers. Goffman (1963) suggests labelling can cause the interaction between normal people and stigmatized youth to be uneasy and embarrassing. These awkward experiences are felt by those who bear the stigma as well as those who do not. According to Goffman (1963 the very anticipation of such contacts can lead normals and the stigmatized to arrange life so as to avoid them. Therefore non labelled adolescents and labelled adolescents may tend to avoid one another in order to avoid uncomfortable interaction dynamics. Feeling isolated from the mainstream of society, and being locked within their deviant role, they may seek others similarly labelled to form deviant subcultures.  The deviant subculture will represent a source of social support in which deviant activities are accepted. A social shelter will be provided by the subculture away from those who react negatively towards the deviant status; it will offer alternative values, habits, interests and attitudes. So if an individual is labelled as deviant from society, then that labelled person is increasingly likely to become involved in social groups that consist of social deviants and unconventional others.  Tannenbaum and Becker highlight the role of deviant networks in explaining how public labelling can increase the likelihood of deviance. A final step in the career of a deviant is movement into an organised deviant group. The deviant group provides opportunities that encourage, support and facilitate deviant behaviour. These deviant sub cultures are made up of leaders and followers, solidarity of intention, clarity of purpose. These characteristics may seem positive in an adult world, even necessary for achieving adult identity and self esteem. However this hierarchy proves to be negative in terms of delinquent groups. Those at the top of the hierarchy, the leaders are often given a prestige status, one which would not be given in the mainstream society. With regards to knife crime, these leaders of the gangs side step the risk of being caught carrying a knife, by pressuring the younger member of the gangs to carry them, some as young as seven, this is often referred to as golf caddy. This often leads to an arm race among young people who feel increasingly threatened by peers carrying blades and so carry knives to protect themselves. So as the quote suggested, protection is rightfully a number one motive for knife carriers. Furthermore, young people will carry knives, out of respect, maybe trying to make a name for themselves on the street and gain respect,  so the status which they lack from mainstream society is obtainable within the subculture, To conclude, having gone through the factors within the quote, it seemingly appears that the quote is incorrect. The factors listed within the quote are simply all a consequence of the labelling theory. Society itself is quick to judge and put a label on everything, it was not so long so ago when gun crime was the cause of concern, and now it is knife crime. The term knife crime itself needs a clearer definition, so a distinction can be made between knife use and knife carrying. Furthermore, those who enjoy the power to label need to put an end to class biasness, as the powerless appear disproportionately in official statistics on deviance, which gives an inaccurate account of knife crime. Moving on to the factors themselves, status is something young people crave in order to develop their own adult identity. Once officially labelled through a status degradation ceremonythe individuals criminal status becomes their master status. The peer pressure elements falls into the equation onc e the individual has united with deviant subcultures, as peer pressure is part of the gang culture. The media also plays a big part, by publically labelling certain subcultures as delinquent. So all the factors form one vicious circle, which an individual will have to go through once labelled, This could be avoided, if the courts refused to dramatise the evil by implementing a system whereby minor crimes would not involve formal sentencing and the status degradation ceremony that goes with it. Instead a rehabilitative therapy and out of court settlement could be introduced in order to give young offenders the opportunity to reform and integrate back into society, not excluding them further.

Design of Interventional Biomedical Devices

Design of Interventional Biomedical Devices 1. Neurovascular Catheters and Engineering Design 1. Case Study 1. The following catheter found in the cathlabdigest written by Gill Laroya discusses the advancement of the design of interventional biomedical devices from an engineering perspective and how engineers enhance the design of catheters to prevent problems such as kink. The article discusses areas such as the history of biomedical devices, the materials involved, design challenges and the interface. It discusses a specific example in terms of catheters and their use. If a catheter must travel a long distance within the neurovascular anatomy, the engineer designing the product might decide to incorporate a shaft support component, such as a stainless steel braid in order to enhance the micro catheters kink resistance. The down side of incorporating the stainless steel braid is its ability to travel within tight sections and irregular shaped bends within the neurovascular system. In order to solve this problem a stainless steel coil support is added to the distal end of the catheter, the ad dition of the coil support enhances lateral flexibility and adding hoop strength to even better the kink resistance of the micro catheter. Also, the engineer can add a lubricous hydrophilic coating to the catheter to improve axial and rotational handling of the device and reduce trauma on the walls of the veins and arteries. The study shows us how we can design micro catheters to prevent problems such as kink occurring. Cathlabdigest.com. (2016). The Design of Interventional Devices: An Engineers Perspective | Cath Lab Digest. 2. Neurovascular Catheter Design The following article was posted in Medical Tubing Types by Shana Leonard on December 12, 2014. Form the article it is predicted that by 2020 the neurovascular market will reach $600 million, according to iData Research. A key factor contributing to the growth of this sector is down to the various advancements of the biomedical device. The design goal for minimally invasive surgical devices is to strive towards engineering the smallest possible outside diameter for a micro catheter device without compromising any of the performance characteristics. Designing neurovascular catheters to meet these constraints must take into account the intricate neurovascular anatomy. Mddionline.com. (2016). Key Considerations for Designing Neurovascular Microcatheters | MDDI Medical Device and Diagnostic Industry News Products and Suppliers. According to Steven W. Berhow, president of Rogers, MN-based Biomerics Advanced Catheter, he believes that upon designing neurovascular catheters they must contain the following traits; Good torque within the shaft from the proximal to distal end. Flexibility in the distal portion of the catheter. Kink Resistance. Visibility under fluoroscopy. Low Stretch. High Pressure. Good guidewire movement. These 7 traits stand as basic constraints when it comes to designing intricate, complicated neurovascular minimally invasive devices. Figure 2. Neurovascular Catheter Design.   Mddionline.com. (2016). Key Considerations for Designing Neurovascular Microcatheters | MDDI Medical Device and Diagnostic Industry News Products and Suppliers. 3. Advanced Catheters The first thing you need to know is what an advanced catheter is. So according to Bill Alexander, Director of Business Development at Biomerics Advanced Catheter, an advanced catheter is a minimally invasive medical device that typically consists of a thin walled, braid reinforced tube or shaft with multiple durometers. An advanced catheter has the ability to navigate through the neurovascular anatomy and deliver implants and devices such as coils, heart stents etc. The difference between advanced catheters and traditional catheters can be mainly seen when it comes to manufacturing the product. A little error in the materials used in an advanced catheter can lead to larger errors as the specific wall thickness requirement of an advance catheter are very strict to ensure optimal performance. Characteristics such as pushability, trackability, torqueability and kink resistance are crucial for the advanced catheter design. Traditional catheters and advanced catheters are not mutually exclusive and can be used to benefit each other and improve patient surgical results. (2016). Advanced catheters What you need to know about this growing medical device market. Figure 3 Advanced Catheters and Traditional Catheters.   (2016). Advanced catheters What you need to know about this growing medical device market. Advanced catheters have the ability to incorporate new technologies and have a more complex design than traditional catheters. 2. Human Neurovascular and Cardiovascular Anatomy 1. Cardiovascular System The cardiovascular system consists of the heart and blood vessels along with blood itself. It transports oxygen, nutrients, hormones and more and is powered by the heart. The heart consists of 2 circulatory loops, the pulmonary circulation loop and the systematic circulation loop. The pulmonary circulation transports deoxygenated blood from the right atrium and ventricle to the lungs. The systematic circulation carries oxygenated blood from the left atrium and left ventricle to all around the body. The cardiovascular system consists of blood vessels, coronary circulation (hearts own set of blood vessels), hepatic portal circulation (veins of stomach and intestines) and the blood itself (red blood cells, white blood cells, platelets and plasma). An understanding of the complex network and its physical structures are important when designing non-invasive medical devices. System, C. (2016). Cardiovascular System. InnerBody.   Figure 4 Cardiovascular System. Slideshare.net. (2016). Circulatory system PowerPoint Blood vessels are the road network by which blood transports around the body and returns back to the heart again. This intricate tiny transportation system of blood vessels has a major part to play when engineering advanced catheters and ensuring problems such as kinking dont occur. 2. Structure and Functions of Blood Vessels Blood vessels consist of arteries and veins. Arteries bring blood away from the heart. As the arteries are brought away from the heart they eventually become smaller and are broken down to the smallest arteries called arterioles which further branch into capillaries where gases and nutrients are excreted or exchanged. Veins have a larger structure and bring blood back to the heart again. As can be seen below in figure 4, the cardiovascular circuit can be seen where two main circulatory systems occur. The pulmonary circulatory system and systematic circulatory system. Each providing their own different structural differences that engineers must take into account when designing minimally invasive medical devices. Philschatz.com. (2016). Structure and Function of Blood Vessels  · Anatomy and Physiology. Figure 5 Structure of Blood Vessels. ] Philschatz.com. (2016). The structure of blood vessels can be seen below. The artery and the veins vary in thickness as can be seen from the micrograph in figure 6. From figure 5, it can be seen that Arteries have a thicker Tunica media than Veins but veins have a larger tunica externa than arteries. Figure 6 Arteries vs Veins Structural differences. Philschatz.com. (2016).  Ã‚   Figure 7 Micrograph showing the relevant difference in thickness. Philschatz.com. (2016). As can be seen in figure 6 and 5, vein walls are considerably thinner than Artery walls meaning veins withstand a much lower pressure of blood passing through them. Table 1 Appearance of Arteries and Veins. Philschatz.com. (2016). Arteries Veins General Appearance Thick walls, small lumen Rounded appearance Thin walls, large lumen Flattened appearance Conor Patrick Goold, DME4. 7 3. Shapes of Catheters in the Neurovascular Anatomy 1. Guide Catheters and shapes in the Neurovascular system. The following is an example of a Stryker neurovascular catheter called the DAC catheter. From figure 8, it can be seen that the DAC catheter accesses the distal neurovasculature. It achieves this by providing enhanced stability through a braided shaft and this in turn also provides resistance to ovulation. Preventing shapes such as snaking and reducing friction against the blood vessel walls. Stryker.com. (2016). Neurovascular Intervention DACâ„ ¢ Catheter: Stryker. Figure 8 Catheters, Shapes and Uses. Stryker.com. (2016). Neurovascular Intervention DACâ„ ¢ Catheter: Stryker. 2. Neurovascular Catheters in the Brain. The following images are obtained through a technique that requires the use of a minimally invasive advanced neurovascular catheter. What these images do is they give a visual understanding of the intricate nature in which the catheters must travel within the cardio vascular system. To do this the catheter is guided under x-ray guidance through neurovascular and cardiovascular system. The catheter for this procedure is usually brought to a blood vessel located in the neck and a non-ionic x-ray contrast agent is injected into the blood vessels which then in turn travels through to the brain. Prior to this procedure the catheter is then removed through the groin and the bleeding is stopped through direct manual compression or by using a vascular closure device. Neuroangio.org. (2016). Introductory Brain Angiography | neuroangio.org. Figure 9 ICA Internal Carotid Artery. Neuroangio.org. (2016). Introductory Brain Angiography | neuroangio.org. In order to reach such distances in the neurovascular system, many advanced catheters are used to travel so far. The deployment of a large support catheter through the groin goes first and then a variation of other smaller catheters are deployed through the larger catheter in order to reach the required location and deploy medical devices such as coils and stents. Figure 10. CT scan of Brain. Neuroangio.org. (2016). Introductory Brain Angiography | neuroangio.org. 3. Neurovascular Catheters in the heart. Figure 11 shows the placement of a pacemaker into the heart by the deployment from a minimally invasive advanced catheter. The catheter enters the body through the collar bone on the left hand side of the heart and enters through the veins to place an electronic or mechanical pacemaker into the heart to overcome heart problems such as tachyarrhythmias, which occurs when your heart beats too fast or bradyarrhythmias, which occurs when your heart beats too slow. System, C. (2016). Cardiovascular System. Figure 11 Advanced Catheters in the Heart. System, C. (2016). Cardiovascular System. From figure 11, the C shaped position of the catheter can be seen. A number of issues can occur from an engineering perspective when a catheter must bend into the shape of a C. Kinking can occur at the maximum area of stress and strain. Engineers must design their advanced catheters in order to prevent kink from occurring and so a reinforcement braid is usually added to increase the hoop stresses of the catheter and the addition of this braid also provides better torqueability and pushability of the medical delivery device to allow it to bend to the required positions to deploy a pacemaker in the heart. 4. Research into Existing Test Methods 1. Simple existing Test methods The following is the most basic of test methods implemented by physicians when no Standard test method is available and time is of the essence. This method was applied when surgeons were experiences kinking in catheters when deployed into patients. In order to predetermine kink from happening the physicians used a simple bending technique to test for the kinking limit of catheters. If the catheter kinked, the unit was rendered useless, if not it was determined safe to use. This method is clearly not an optimal solution so further investigation into the kinking limit of catheters had to be researched and developed. Beamer, J. and French, G. (2016). A simple method for testing for the kinking epidural catheter. Figure 12 Simple Test Method No kink LHS and Kinked RHS. Beamer, J. and French, G. (2016). A simple method for testing for the kinking epidural catheter. 1.1 Simple existing test methods The catheter bends around the pin, having a predetermined diameter, D. The diameter can range from a number of different values, 5mm 50mm. The catheter is bent around the template and contacts the template at 2 tangential locations, to generate a curve and predetermine L = D. Figure 13 Kink resistance Test Method. Anon, (2016). 2. Guidance for Industry and FDA Staff Non-Clinical Engineering Tests and Recommended Labelling for Intravascular Stents and Associated Delivery Systems The following FDA guidelines outline the standards to abide by when dealing with stents and associated delivery systems. It details how the content and format of test data should be summarised in a report as well as detailing the test reports and test protocol procedures to carry out. For this test method, a review of the non-clinical engineering section was undertaken focusing on the section B (Stent Dimensions and Functional attributes) of the non-clinical engineering test, part 16. Part 16 gave FDA guidelines in kink resistance. The significance of outlining FDA guidelines for stents which are delivered by advanced catheters, it to prevent kink occurring when the normal body is in motion such as an elbow joint flexing and to ensure that no deformation to the stent occurs. This also applied to the stent delivery system when the physician deploying the stent into the human anatomy as the advanced catheter must be engineered to prevent kink from occurring upon deployment. The recommended outcome to prevent kink from happening, according to the FDA guidance document, is to determine the smallest radius of curvature that the stent can withstand and recover to its original shape and size. The test carried out to determine the smallest radius of curvature must replicate the area to which the stent will be deployed i.e. the femoral arteries. This recommended advice for implementing stents to the human body can be tailored towards the stent delivery systems also i.e. the advanced catheters. Therefore these guidelines will be taken into account when developing a test method to determine the kinking limit of catheters. See appendices for further detail regarding the FDA guidance documents discussed. Fda.gov. (2016). Guidance for Industry and FDA Staff Non-Clinical Engineering Tests and Recommended Labeling for Intravascular Stents and Associated Delivery Systems. 3. Standards and guidelines ProtomedLabs provide a list of standards and regulations that relate to flexibility and kink resistance test methods. Information on the state of the art available testing equipment is provided such as the interventional device testing equipment (IDTE) from MSI which will be discussed further in part 4 of this section (MSI Catheter testing equipment). The ProtomedLabs provide information on flexibility kink resistance regarding applicable standards, related tests and test method descriptions. Applicable standards such as the FDA guidelines discussed in heading 2 above as well as ASTM standard guide for three point bending of balloon expandable vascular stents and stent systems which will be further discussed in section 5 of the literature review. Protomedlabs.com. (2016). Flexibility Kink Resistance Protomed Labs. 4. MSI Catheter testing equipment State of the art interventional device testing equipment (IDTE), compares tests and analyses performance catheters, quantifying the data of each catheter being tested. The PC allows for simple and repeatable tests with instantaneous feedback on design changes of the catheter. The IDTE was designed taking into account several different standards and test regulations such as ISO standard 25539-1 which covers cardiovascular implants endovascular devices and ISO 15539 Cardiovascular implants Endovascular Prostheses. The product is the most state of the art catheter testing equipment available right now and differentiates itself from the rest of the market by having the ability to test catheters in extremely realistic and challenging conditions. MSI. (2016). Catheter Testing MSI. Figure 14. IDTE Test Equipment. MSI. (2016). Catheter Testing MSI. The IDTE has a high temperature range with ambient temperatures of 50oC, a water bath with a temperature accuracy of +/- 2oC. It has auxiliary load cells of 100g and distal load cells of 1kg. It has the ability to test track force which is the force needed to advance a catheter, push efficiency which measures the amount of force being measured from the proximal end to the distal end, flexibility, torqueability a measure of the rotational response, retractability a measure of the amount of force required to withdraw a catheter and the crossability which measures the ability of a catheter to cross the abnormal narrowing of a passage in the body. The machine itself weighs 250kg with a height of 1372mm, width of 1194mm and a depth of 940mm. the output data of each tested is outputted onto a computer where numerical or graphical results can be formulated. MSI. (2016). Catheter Testing MSI. 5. Current Test Methods available to determine Kinking Point 1. ASTM F2606 Standard guide for three-point bending of balloon expandable vascular stents and stent systems The three point bending of stent system guidelines provide a test method that can be used to compare the flexibility of different advanced catheters by comparing load deflection curves and by comparison of calculated slopes of the curves. The test method uses a simple 3 point bending test. The upper single load applier and the two static load supporters as seen below in figure 14 must have a radius of 6.35mm. Another requirement of this test is that both the upper load applier and the two bottom static load supporters must be made of a material with a low friction coefficient so that they do contribute to the results outputted from carrying out this experiment. This test method can also be carried out in a bath of 37oC, which replicates the ambient body temperature and realistic conditions, if this application is necessary, the fixtures can be made from stainless steel or other materials that will not rust. Figure 15 Example of a three point bending test. YouTube. (2017). Catheter Bend Test at Anecto. This test has many benefits as it can many advanced catheters can be used with this method and it is applicable to many different products. It does not cause damage to the product prior to testing and can test the kinking limit along different material junctions. The test method ASTM F2606 uses a tensile tester to output its results to a computer in numerical or graphical form. Instron.us. (2017). ASTM F2606 Three-Point Bending Balloon Expandable Vascular Stents and Stent Systems Instron. 3. BS EN 13868 Catheters test methods for kinking of single lumen catheters and medical tubing This standard test method looks at the kinking of catheters being used for short term or long term uses. The short term use determines the kinking limit of a catheter being used less in than an hour and the long term is above an hour. The tube is defined as being kinked when the flow meter (Labelled 4 in figure 15 below) is outputting a reading 50% lower than the original reading. The original reading is read when the kink tools (Labelled 7) are either 50mm, 100mm or 200mm apart, depending on the users required starting distance. When the kinking tools are being compressed by the tensile tester (Labelled 7) the mass flow rate of the water flowing from the beakers (Labelled 2) will begin to reduce. Once the mass flow rate reduces to 50% of its original the catheter is said to be kinked and the test is complete. The results are outputted to a computer which gives numerical and graphical results. This test method is very beneficial as it is convenient, safe and fit for purpose. Difficulties may arise when using this test method when it comes to the fittings of the flow meter with the different sized catheters. As all catheters vary in sizes, the universal fitting of the flow meter may be difficult to mate with the distal/proximal ends of the various advanced catheters. See Appendices for more detail regarding BS EN 13868 kinking of single lumen catheters. European Standard, (2002). Catheters Test methods for kinking of single lumen catheters and medical tubing. BS EN 13868:2002. Figure 16 Short Term (LHS) and Long Term (RHS) Test methods for kinking single lumen catheters and medical tubings European Standard, (2002). Catheters Test methods for kinking of single lumen catheters and medical tubing. BS EN 13868:2002. 6. Proposed Mathematical Methods for Determining Optimal Test Method significant factors. 1. Analysis of Variance (ANOVA) Testing. The analysis of variance method determines if groups (related or unrelated) are statistically significant to each other. In order to carry out an ANOVA test, a hypothesis must first be determined. A hypothesis is a standard procedure about testing a claim about a property of a population. First a null hypothesis is formed. The Null hypothesis will test the significance of the hypothesis by either rejecting or failing to reject the claim of the null hypothesis. The Null hypothesis will claim that no difference exist between the population and the alternative hypothesis will claim that a difference exists between the populations. The alternative hypothesis will state that one or more of the parameters involved in a population will differ from the null hypothesis. The next step in an ANOVA test is to determine if the null hypothesis should be rejected or is it better to fail to reject the null hypothesis. In order to do so, an understanding of a type 1 and type 2 error is needed. A type 1 error is when the null hypothesis is rejected when in fact it should be accepted. The symbol ÃŽ ± is used to represent a type 1 error. A type 2 error is the mistake of failing to reject the null hypothesis when in fact it is false. The symbol to represent a type 2 error is ÃŽ ². In order to determine when the results are statistically significand and when the null hypothesis should be rejected, then p < ÃŽ ±, therefore the result is statistically significant and the null hypothesis should be rejected. If p > ÃŽ ±, then the null hypothesis should fail to be rejected and the results are statistically insignificant. Lacey, S. (2017). Mathematics for Engineers 402. 2. Analysis of Variance (ANOVA) Examples. To show how the ANOVA method can be applied to the parameters involved in determining the kinking limit of catheters and which factors attribute to the kinking limit the most i.e. which are statistically significant or insignificant, an example where an experiment was undertaken to test the effect of temperature and bar size on the UTS of a weld. The results from the experiment are show below in figure 16 and analysis of variance was carried out in order to determine the level of significance each parameter had on the strength of a weld. Lacey, S. (2017). Mathematics for Engineers 402. Figure 17 Analysis of Variance Example Dr. Sean Lacey, 2016, Mathematics for Engineers 402. Figure 18 Analysis of Variance Example Dr. Sean Lacey, 2016, Mathematics for Engineers 402. Figure 19 Analysis of Variance Example Dr. Sean Lacey, 2016, Mathematics for Engineers 402. Figure 20 Analysis of Variance Example Dr. Sean Lacey, 2016, Mathematics for Engineers 402. 7. Material Properties of Neurovascular Catheters Advanced catheters are engineered to perform an increasing number of minimally invasive surgeries. They must be able to guide their way through the intricate pathways of the neurovascular, cardiovascular and other anatomies. In order to achieve these demands, using ultra small catheters of 0.5 mm, the design must be near perfect and material selection for this design is key. Catheters consists mainly of 3 layers, the liner, the braiding and the outer sheath. They can be made up to lengths ranging from 900mm 1200 mm. the best material for use in catheters are fluoropolymers such as PTFE and FEP due to their biocompatibility and lubricous properties. PTFE is the most lubricous polymer on the market today followed by FEP. The materials can undergo secondary processing steps such as etching and cutting, along with post extrusion expansion such as heat-shrinking. The liner layer mainly is made from PTFE for it lubricity, ability to maintain a thin wall and have a small diameter. The braid reinforcement layer is mainly made from Type 304 or 306 stainless steel. This layer increase is strength and rigidity without kinking the catheter. It increases the rigidity at the proximal end with a smaller pitch between winds and decrease rigidity at the distal end with a larger pitch between winds. This is done to provide greater torque transition from the proximal to distal tip of the catheter. The coil provides a greater kink resistance to the catheter along with reinforcing the catheters liner against ovalization by maximising the hoop stress. The outer sheath is made up of high performance materials such as Pebax, FEP, PTFE, ETFE, polyurethane, polyethylene and nylon. Mddionline.com. (2016). Think Extrusion and Beyond for Optimal Catheter Design | MDDI Medical Device and Diagnostic Industry News Products and Suppliers. Figure 21 Material layers of a Neurovascular Catheter. Mddionline.com. (2016). Think Extrusion and Beyond for Optimal Catheter Design | MDDI Medical Device and Diagnostic Industry News Products and Suppliers.