The Western Lowland Gorilla Essays - Mammals Of Africa, Gorillas

The Western Lowland Gorilla: The Western Lowland Gorilla: A comparison with humans and a critique of methods of study. By Fokren Masters For thousands of years, men and women have strived to explain the why of their existence. To discover the reasons for how we act the way we do and what this knowledge can do to impact the way we live our lives in this complex society that we have created. One of the ways that science has begun to shed light on the inner workings of the human condition is through Primatology. Built from the words Primate which refers to a group of animals closely related to humans and logos which is a Greek word meaning ?the study of' Primatology's goals include more than simply to amass data on the primate species. Rather a Primatologist observes data about primates in an effort to understand the primate species under their study and to relate that data back to the human condition so that we can learn more about ourselves through our evolutionary cousins. In recent years, Primatologists have done much research on all aspects of the life of the western lowland Gorilla, known scientifically as: gorilla gorilla gorilla (Fay, 1989). In this paper I will compare these primates, more precisely classified as great apes, to humans in an attempt to illuminate both differences and similarities between the two species. More specifically, I will focus on the social structure of the western lowland Gorilla, describing how these predominantly gentle creatures live in a society similar to that of humans in many ways. Finally, in my conclusion I will explore the methods that Primatologists use to study primates such as the western lowland Gorilla and whether those methods are biased towards or against the Gorillas. However, I cannot draw indelible conclusions about these subjects as I have had no time studying these animals in the field and have only the observations and writings of others from which to draw my data and form opinions. The most common of the Gorilla species, there are approximately ten thousand to thirty five thousand western lowland Gorillas in the wild and five hundred and fifty individuals in captivity worldwide. They are found in Nigeria, Cameroon, Gabon, Congo, Central African Republic and Zaire in increasingly shrinking habitats due to the incessant encroachment of human populations. Western lowland gorillas are covered with black or brown-gray fur with black skin on chests, palms, and faces. Red heads are common in Camaroon gorillas especially. Males develop a silver back as they mature this is not unlike the tendency for many human males to develop gray hair as they mature as well. The main difference being that only Gorilla males develop silver backs whereas in humans both males and females alike tend to lose their hair coloring with age. Unlike humans, which are bipedal, walking on two legs, Gorillas are quadrupedal, they walk on all fours with the soles of their feet flat on the ground with the knuckles of the hands curled and planted on the ground (Schaller, 1963). Although they are mainly quadrupedal, gorillas can travel bipedally but generally no farther than approximately six meters (Schaller, 1963). This upright stance is used most often used for chest beating, to observe something of interest, or to reach an object (Schaller, 1963). Gorillas recognize each other by their faces and body shapes. Each gorilla has a unique nose print which researchers can use to identify animals in the field (Schaller, 1963). This is very much like humans who recognize each other almost exclusively by visual identification of the facial features. Gorillas sleep about 13 hours each night and rest for several hours at midday. They build new sleeping nests every night by bending nearby plants into a springy platform, usually on the ground or in low trees. When not resting, they spend most of their time looking for food and eating it. Despite their fearsome size (three hundred to five hundred pounds for males and one hundred fifty to two hundred fifty pounds for females) and large canine teeth the western lowland gorilla is an herbivore. They consume over two hundred types of leaves, tubers, flowers, and fruit, supplemented with fungus and some types of insects. Gorillas do

What Is a Sample PARCC Essay Response Grade?

What Is a Sample PARCC Essay Response Grade?A sample parcc essay response grade is necessary when attempting to win a PARCC essay test. It is a great way to determine if you are truly qualified to take the exam or if it is time to seek additional education. If you are attending a community college or university, then you should already have a copy of your parcc essay grade. If you are attending a private college or university, then you may have to write your own sample response.A sample response should include all of the topics that you will be required to answer on the test. While you may need to write answers for other sections, it is recommended that you write all of the answers in your sample response. The best approach is to prepare multiple sample responses that will assist you to successfully answer the question.The best way to avoid wasted time on the actual PARCC test is to learn as much as you can about the subject at hand before you write the sample essay. You should caref ully plan your response, word for word, and take every opportunity to review the text for mistakes and to prepare to answer each question. The right writing style is important to use for your response essay, and you should stick to it. You will need to take advantage of every opportunity to apply what you have learned. When working on a sample essay, it is best to start with the points that you feel most confident with, or you will spend most of your time correcting the mistakes that you make.If you are given the opportunity to write a sample parcc essay response and fail to respond in a timely manner, you will likely lose the opportunity to be taken on the next test. This would be a great mistake, and you should not attempt to pass the test by writing a poor essay. However, it is possible to have several good responses in a shorter amount of time than the exact amount of time that you actually spend writing the response.You should take a positive approach when you write your respon se. Do not make a mistake and waste the test or effort of others. Be concise, avoid any grammatical or spelling errors, and consider the idea of 'Word for Word.' If you do this, you will have an easier time understanding the questions and finding the best words to use in your essay.You may also need to prepare for the actual test by reviewing or memorizing your responses to the main topics on the PARCC testing. You should read the test and evaluate your work so that you do not make any mistakes and will be ready to write a sample response that is appropriate to the test. If you are unable to sit down and study for the exam, then the exam itself can be used as a review of your response. This is especially important if you do not like the format of the actual testing or find the way that you answer to be cumbersome. Although you may want to take an alternative, it is still best to use the actual PARCC testing as a means to gaining practical experience and to help you become familiar w ith the format of the test.Before you begin writing your response, you should also review the sample response and learn how to make the best use of the format of the parcc exam. Doing this will help you better understand the exam and the style of the questions that you will be asked to answer. While it is a great way to improve your chances for success on the exam, it is not always necessary to have a sample parcc essay response grade.

Controlling vapours from an open tank along the path includes (select

Controlling vapours from an open tank along the path includes (select Controlling vapours from an open tank along the path includes (select all that apply): – Assignment Example Controlling vapors from an open tank "along the path" includes (select all that apply Problem The main idea of the business was to establish a strategy that will ensure that there is stability of the business even if there are instances of substitutes or entrants of new companies into the industry. That will ensure that the business gains brand royals that will ensure that there is smooth running of the business. There is also an attempt to ensure that the quality of products is maximized so as to reduce the bargaining of customers. Problem 2 The best customer experience I had was when I was in a supermarket that sold wrapped sandwiches. The wrapping was in an attractive package that was eye capturing. I did not expect that I would ever find sandwiches that had been wrapped in such a manner. The packaging was attractive far much than my expectations and that is the first thing that caught my sight and that made me to be attracted to the product. The product stands out as my best because I was able to get a product that surpassed my expectations. I was also able to get a thing that was of a high product and equally attractive and that made me to be excited about the whole thing. The worst thing customer product experience that I have ever had is after I purchased a local juice from the streets. The juice was packed in a good manner; however, the taste did not match the packaging. I expected the drink to b awesome but that turned out to be contrary to my expectations. The product counts to be the worst because I was not able to gather the satisfaction that I expected (Gietzmann, 1996). Part 3 It would be hard for the company to succeed without any scientific proof. This is because the patients or customers would not want to try out on anything that has not been scientifically proven. People would prefer scientific approval of the products that they use. The product’s cost is reasonable because it is easily affordable for the consumers or customers. The annual quantity can be estimated by forecasting based on the market estimates that are available for the substitute products (Furlong, 1997). The marketing strategy that can be applied can vary based on the approach that is proffered. The company can use the pricing strategy. That can involve a low penetration cost that is backed by high low levels of advertising. That would ensure that the consumers are attracted to the company products by the low prices. The other strategy could be the use of high prices and high levels of advertising. The high prices would compensate for the high advertising costs that are incurred by the company. The company should not rush into manufacturing because the amount investment could end up as a loss if the products are not approved. If I was the CEO of the company, I would first await for the approving of the product before I go ahead with manufacturing. References Furlong, W. (1997). Marketing concepts. New York, free state. Gietzmann, (1996). Customer satisfaction and privilege. Marketing Research (December): 409- 429.

The 12 Best Journalism Schools

The 12 Best Journalism Schools SAT / ACT Prep Online Guides and Tips When you have a niche interest like journalism, it can be difficult to find reliable information on the strength of undergraduate programs. To help you get your college search going, we’ve rounded up a list of the best journalism schools out there for aspiring writers, editors, and reporters. Ranking Criteria for Top Journalism Schools College ranking lists can be really helpful if you’re just starting your college search- they’re great if you want to get a general idea of what schools are out there and whether they fit your interests and criteria. The danger comes with using them as the be-all, end-all source of info about college quality- ranking organizations all use different methods for coming up with these lists, and they’re not always transparent about the process. Although this ranking list should also just be used as a jumping-off point, I want to be much more transparent about the process used to compile this list of best journalism schools. First, I started by searching for colleges and universities that have a dedicated journalism major for undergraduates. After that, I took these major criteria into account: School Reputation- Journalism has grown increasingly interdisciplinary as communications and media have changed with technological advances. It’s important that undergraduate students have access to other strong departments within the school as well, so I considered the general reputation of the school when compiling this list. Graduate School Reputation- Although I only listed schools here if they had a dedicated undergraduate program, schools got points if they had a well-regarded graduate department in journalism or communications. Undergraduate students studying journalism will often benefit from faculty and resources from the graduate program. Career Preparation- Journalism is a field where it’s super important to get plenty of hands-on experience before jumping into a career. I looked for schools where students were getting plenty of prep working in the field (e.g. internship opportunities at local or national newspapers or news stations). Class Options- A reputation for providing a strong foundational knowledge is important, but interesting, unique classes are definitely a plus. Journalism classes in more niche subject areas may also signal a creative faculty with greater resources to spare. Alumni- When departments have many notable alumni, that signals a strong alumni network and a strong journalism program. This boosts the reputation of the school and may help out when you’re starting to look for jobs. The Best Journalism Schools The caveats I listed for ranking lists above continue to apply here: although this list was compiled in a transparent (albeit unscientific) way, you should use it primarily as a jumping-off point for your own research. I encourage you to focus less on the strict order of rankings (which is pretty subjective to begin with) and more on the individual characteristics of each school. #1: Northwestern University Journalism is one of the most popular majors at Northwestern, and for good reason. There are many programs in place to ensure that students are well-prepared for careers as journalists. Some of these programs include: The Journalism Residency Program- Students spend time working as reporters or public relations specialists at media outlets across the country (and sometimes even internationally). The Media on the Hill Program- Students serve as mobile journalists and quickly update info on events in DC. Medill Justice Program- Students examine potentially wrongful convictions and look into criminal justice issues. Special courses offered through the school include interesting electives like â€Å"The Googlization of America† and â€Å"Journalism in a Networked World.† Finally, Northwestern hosts one of the top graduate journalism programs in the country in addition to an awesome creative writing program. #2: University of Missouri- Columbia (Mizzou) Mizzou is a large public university that’s well known for its undergraduate and graduate journalism programs. There are over 30 different interest areas (i.e. concentrations) available to undergraduate journalism students, including ones like â€Å"Entrepreneurial Journalism† and â€Å"Magazine Publishing and Management.† If none of the existing interest areas meet your needs, you have the option to design your own. Hands-on opportunities in real-media labs are available to students in each interest area. There are also quite a few relevant student groups on campus, including ones like the Association for Women in Sports Media and the Student Society of News Design. #3: Boston University BU is a well-ranked school in a bustling college town- the area around the school (never mind the school itself) comes with a lot of opportunity. The school itself- which has produced 24 Pulitzer Prize winners- combines a liberal arts background with plenty of pre-professional training in the field. Undergrads have many different focus areas to choose from, including Online Journalism and Magazine Journalism. Students often intern at prestigious Boston-area news organizations like the Boston Globe. Finally, BU boasts a strong journalism master's program, which indicates access to plenty of awesome faculty and other resources. Living in a hub like Boston opens up a lot of professional opportunities. #4: Syracuse University One of the best universities in upstate NY, Syracuse offers eight different undergrad programs in journalism and communications, including Broadcast Digital Journalism and Newspaper Online Journalism. The school maintains several industry partnerships with major communications companies, leading to professional/networking opportunities. Special programs include the SULA Semester (Syracuse University Los Angeles), where students spend a summer living and working in LA. #5: UT Austin Journalism is a popular major at UT Austin, but there are also many helpful supporting departments, including Communication Media Studies and Digital Communication. Journalism at UT Austin- which boasts 18 Pulitzer Prize winning alumni- emphasizes digital skills training for all its students. The school's Specialty Communications Career Services Center helps journalism students find internships and jobs. There are also many relevant student groups on campus, including University of Texas Hispanic Journalists and ORANGE Magazine (UT’s student magazine). #6: NYU NYU is a highly-ranked school in general (with a highly-ranked creative writing program to boot). Journalism students at NYU choose between two undergraduate tracks: Journalism and Media Criticism. Both programs focus on professional ethics, the cultural politics of media, the social role of the journalist, and the importance of craft. Students are required to double-major in one additional field of study. This is great if you want a more liberal arts spin to your education, but not so great if you’re sure you just want to focus on journalism. New York City is a great place to study journalism- there are so many prestigious media outlets with headquarters there- but if you have international ambitions, you might be interested in NYU's Journalism Abroad Program: students study and work in Ghana, Czech Republic, China, and England. #7: Arizona State University ASU is a huge public university in a large city with a lot of opportunity for hands-on experience. The Walter Cronkite School of Journalism and Mass Communication offers three bachelor's degree options: Journalism and Mass Communication, Mass Communication and Media Studies, and Sports Journalism. Students get training in live newsrooms under professional journalists. ASU’s PBS station- which reaches 1.9 million households- is also used as a teaching tool for students at the journalism school. At such a large school you'll be sure to find an equally large selection of student groups. Some relevant groups include the Fashion Journalists Club, the National Association of Black Journalists, and the Cronkite Cut. Phoenix is more of a metropolis than you might realize- and the area comes with some extra perks. #8: American University American University is located in DC, a perfect spot for aspiring journalists to get work experience (especially if you're interested in politics). In addition to the standard bachelor's degree program, American offers a unique joint BA/MA program. Undergraduate students choose from one of two tracks: Broadcast or Print Journalism. Investigative journalism workshops and practicums are an important part of the program. Other programs offered at the school include communication studies, film media arts, and public communication- all disciplines that play well with journalism. #9: Emerson College Emerson is located in Boston, just blocks from the state house. The program really strives to be proactive in embracing technological advances in the field- it adopted a new multimedia curriculum in 2011. Aside from journalism, other popular majors at Emerson include film, marketing, and digital communication. The college boasts several award-winning on-campus media outlets (including newspapers and radio stations). There is a wide array of interesting student groups, including Captured Emotion (dedicated to documentary and nonfiction work), spec (a group dedicated to the art of screenwriting), and Wax on Felt (a student record company). #10: Ohio University Ohio University offers its students a combination of a liberal arts + professional degree. Its mission statement says the school is committed to providing an education in professional ethics, critical thinking, and responsibility. There's a strong emphasis on the importance of media training while studying journalism. Student media groups on campus include The Post (a daily newspaper), Backdrop (a lifestyle magazine), and the interActvist (a progressive magazine). Bonus Schools These schools didn't meet the criteria to make the list above, but they still make great options for students who are interested in entering the field. Just because they didn't make the official list doesn't mean these schools aren't great places for aspiring journalists! UCLA UCLA doesn’t offer a dedicated undergraduate journalism degree- instead, undergrads can major in â€Å"Communication Studies,† which is much more broad (but still very applicable). Students can take courses in up to 12 different departments. The Communications Studies curriculum includes hands-on field study courses for students' junior and senior years which sounds like a great way to get relevant experience. Columbia Columbia also doesn't have an undergrad journalism major, but you are able to take courses through their top-rated graduate program. Since it's in New York, it comes with the same location advantages of NYU- not to mention that it's a top-ranked Ivy League school with a great creative writing program. How to Choose the Right School Like I mentioned earlier, the rank itself will matter less than whether the school offers everything you’re looking for in a journalism program. Follow these tips to figure out which of the best journalism schools listed above might be the best match for you. Check Out the Curriculum If you have special interests (or even if you don’t), you’ll want to check out the core classes and the available electives for each program. Different schools may also offer various concentrations or tracks within their journalism degree program- if that’s the case, explore those different options. You don’t have to get excited about each and every course (especially when it comes to foundational or required courses), but you want to look for a school whose curriculum is aligned with your own interests. Learn More About Relevant Student Groups When pursuing a degree in journalism, it’s super important to get professional experience as a student- this will help prepare you for your job search. Is there a specific type of media that you’re very excited to work in outside of your classes? Is there a particular subject you’re passionate about working on? Student-run media is the place to do this. Some of these schools have more limited student media options than others. This may not be a problem if a program already has a group you’re interested in, but if not, you might want to check out other programs. Do Your Research on the Faculty The people who will actually be teaching you will make a huge difference in how much you get out of your education. Check out the type of work that they do- many top profs in journalism programs have achieved some serious professional success. You may also want to check out their ratings on ratemyprofessor.com, but remember that students are less likely to leave reviews if they’re generally satisfied with the instructor- you get sort of a skewed perspective with the site, as you do with any ratings platform. Think More About the School in General A journalism program is (usually) only a part of whatever school you attend- your overall experience will also depend on the school more generally. What’s the student body like? Where is the school located? What’s the housing situation? If you aren’t happy with these (very important) aspects of student life at a school, chances are you won’t be happy in the journalism program. To figure out what you should prioritize when looking for a college or university, check out our guide to choosing where to go to college. Finally, keep in mind that it's possible to pursue journalism at almost any school, regardless of whether it has a formal program. The most important thing is that you find opportunities to gain professional experience. You can do this by working at campus media outlets (like newspapers, magazines, or websites) or by seeking work off-campus as a student writer. What's Next? If you're thinking about becoming a journalist, you might also want to check out the top-ranked creative writing programs. Like I mentioned earlier in this article, you don't necessarily need a dedicated journalism program to enter the field. Getting into any top program means top grades, high ACT/SAT scores, and awesome extracurriculars. Check out our guides on those topics before reading more about the college application timeline. Want to improve your SAT score by 160 points or your ACT score by 4 points? We've written a guide for each test about the top 5 strategies you must be using to have a shot at improving your score. Download it for free now:

Health information Assignment Example | Topics and Well Written Essays - 250 words

Health information - Assignment Example Which of the Patients’ Bill of Rights afforded under Title II of HIPAA did Sally violate? Sally violated the rights of John as she was supposed to call him on his personal number that he had recorded in the health information form. Again, she ought to have ensured that she delivered the message to the right person and in that case John. It is inappropriate for Sally to inform Holly of any information relating to the period when the work release form is available. It is due to the fact that Holly should be contacted only in cases of emergency and not her contacting the healthcare facility. Giving the patient’s information without his authority would amount to lack of consideration of the autonomy principle. John was involved in an automobile accident and was taken to the Emergency Department byambulance for treatment. The physician in the ED contacted Dr. Moodey’s office for information regarding John’s health as he was unconscious and unable to give a medical history. Dr. Moodey’s office was not able to contact Holly. In cases of emergency where Holly is unavailable, there is the secondary option that serves as John’s brother. Valez is the person that the hospital needs to contact as the patient provides authorization to contact him as his second option during emergency cases. Match the procedural step for the HIPAA rules in regards to privacy/release of information to the purpose of the procedural step. (pg. 291) Type the letter from the Procedural Steps in the blank to the left of the

Applied Experience Paper Term Example | Topics and Well Written Essays - 1000 words

Applied Experience - Term Paper Example They also discover various aspects of people feeling certain response on a particular issue (Brittany, 2010). The learning from different aspects of psychology has had a deep impact on my life. Due to my education in this field, I have developed a better understanding of people and scenarios at every stage of life. To explore the different dimensions of the psychology and their application in the real life, I have participated in group psychotherapy of the adolescents, who had been displaying aggressive attitude in their everyday life. Since group therapy is about making people understand that they are not the only one who is suffering from the same circumstances, there are other people as well who are also going through same circumstances (DRB Alternatives. Inc, 2010). Group therapy is successful because the members of the groups share personal issues that they are facing (Weinberg, 2000). In a group therapy, people interact with individuals who are in either a state of emotion, or ahead, or those people who have recovered from their problem. Through this, the members of the group become a source of support and strength for each other. Moreover, because of their common experience, the participants understand each other’s situation, and therefore, they can develop a better relationship with each other. Psychotherapy In the setting that I experienced, there were altogether six adolescents and the therapist. The issue that they had on hand to deal with was increased aggression in their personalities. All these children had complained that against their own will, with the passage of time, they were developing an aggressive personality. Once the participants started discussing their family backgrounds, their life experiences and the relationship of their parents with each other, I discovered that most of the participants had previously experienced aggression in their lives to some extent. If they had not experienced it, then they had a broken family and/or w ere brought up by a single parent. While I was sitting in the setting and was listening to the experiences of the adolescents, the concept that was running in my mind was Bandura’s Experiments (Myers, 2008). In these experiments, the researcher has proved that children have exceptionally high level of observation starting from their birth. Therefore, their learning through observation is very strong. Thus, they imitate everything they see, if not immediately then possibly at some other time, but they do imitate the observed behaviour. From the explanation of the adolescents during the therapy, it was evident that out of six, four of them had someone in the family that was very aggressive, because of which they also developed a habit that keeps getting stronger by the day. The interesting part that I found about these participants is that almost every child has at least one of the parents who are aggressive in front of the children. At this point, the other theory that I have observed in my daily life is that children usually idealize their parents and tend to copy them in most of the situations where they can. They tend to do whatever their parents do in front of them, either in person or in similar settings. However, the rest of the two adolescents who were complaining about the aggression had not witnessed aggressive attitude by their parents. They were the brought up

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.