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Background research
Artificial limbs (arms and legs) or the prostheses are intended to perform the degree of the normal function to the amputees. The mechanical devices enable the amputees to walk or to continue using the hand(s) as normal. According to research, artificial limbs date back in 600 BC when armorers created the first prostheses using cumbersome and inflexible iron. Artificial hands intricate imitations of the real hands. Amputees themselves started making their limps after losing such parts. Research shows some amputees lost arms and legs during civil wars and accidents.
Indeed, the twentieth century has seen significant advances in prosthetic limps. Modern prostheses are designed with strong and lightweight materials such plastics compared to ancient wood and iron-made structures. The new plastic, better pigments, and sophisticated procedures create fairly realistic looking skin as well (Buxton 54).
Hypotheses
The project is purposed design and build of prostheses. According to the evolution of prostheses: these structures dates back from first beginning to the present sophisticated times. An amputee at the present feels that prostheses are part of their body as the initial organs. With precision molding, real human fur (hair), and hand-painted veins. The most exciting advancement of the project is the development of myoelectric prosthetic limbs. In this project, electric signals from the limb muscles initiate the movement of the prostheses. Computers are employed to fix these artificial limbs to amputees (Engineering 87). About 85% of the prostheses use CAD to design the models of the patient’s limbs that are used to prepare a mold from which the new limb is shaped. The use of laser guided measuring and fitting is as well employed. The project is hypothesized to produce prostheses that guarantee excellent performance and comfort of the amputees (Gray 98).
Impact
The fundamental goal of rehabilitation of amputation is the optimum restoration of function. The designer, physician, and prosthetist who perform the prosthetic procedure integrate marketing and scientific data to ensure important, cost-effective decisions. Patient comfort is an important factor that influences the functional status they ultimately achieve. A study of veterans and non-veterans with amputations confirmed that the fit and comfort of these prostheses, avoidance of sores and blisters were the fundamental functional features of the structures (Encyclopedia of Health 43). The absence of fatigue and pain during walking is the impact that every amputee and the society would feel comfortable with.
Amputations of artificial limbs have remarkable impact on the engineering, societal and economic goals. Amputation provides a reasonable solution for loss of a limb. Economically, it helps eliminate the use of hand bikes for those with lower limb problems. Research shows that artificial limbs could be used by an athlete in times of competitions (Paralympic competitions), a societal and individual benefit for the competitors.
Also, body-powered prostheses use voluntary opening or voluntary closing control of terminal devices for holding and manipulating objects. However, amputation could bring detrimental consequences on the quality of life of the patient. Use of prosthetic limbs remediates these deficits (Naik 456). In upper limb amputation, dramatic improvement of manipulation capabilities of the amputee is enhanced. In lower limb amputation, the degree of mobility offered by prostheses is critical to the functional outcome. The level of mobility is a function of biomechanical features of the prostheses.
Goals of the project
The aim of this project is to design and build an artificial limp intended to fit into a lost or damaged limp of a patient. In the project, the importance of fitting prostheses in amputees is appreciated. To build an artificial limb that comes as similar as possible to being as real, useful, and comfortable as the natural limb. How to make an artificial leg is viewed as simple and vital exercise in a bid to rescue damaged limps in the society (Singh 82).
Design
A typical prosthetic device includes a custom fitted socket, knee cuffs and belt, an internal structure referred to as pylon, prosthetic socks, and in some cases, realistic looking skin. The prophetic device must be lightweight, usually plastic. Its socket is made from polypropylene. Newest development of artificial limbs involves the use of carbon fiber to make a lightweight pylon. The feet have traditionally been achieved of wood and rubber. Polyethylene, polypropylene, acrylics, and polyurethane are as well employed in this structure. The socks are made from soft and strong fabrics. The physical appearance of the limp is fundamental to the amputee as the majority is covered with a polyurethane foam cover designed to match the shape of the patient’s sound limb. Artificial skin covers the foam to match the skin color of the patient. Figure 1 below shows the elements used in the design and building of the artificial limb (Hanson 206).
Figure 1. Elements of artificial limb
Unlike dentures and eyeglasses that are mass-produced, prosthetic limbs are prescribed by the doctor after consulting the amputee, the physician, and the prosthetist. Accuracy and detailed attention are vital in the manufacture of limbs. The prosthetist evaluates and takes a digital reading of the residual limb before the real fabrication process starts. The relevant body segment length is measured to determine the location of bones and tendons in the remaining limb. A plaster cast of the stump is build using the impressions and the measurements. Afterward, a thermoplastic sheet is vacuum-formed around the plastic cast to make a test socket. The plastic sheet is heated and placed in a vacuum chamber. As the air is rejected (sucked) out of the chamber, the plastic adheres to the cast assuming its shape. The permanent socket is formed in similar way (Artificial Parts 23)
In the fabrication of the prostheses, Plastic pieces such as soft-foam are used as liners or padding are usually made using plastic forming methods – vacuum forming, injecting molding, and extruding. Titanium and aluminum made pylons are die-casted in which liquid metal is forced into the steel die of the proper shape (Ulloth 241). Wooden pieces are planned, sawed, and drilled, and various components are assembled using bolts, adhesives, and laminating materials. The entire limb is assembled using tools such as screw driver and torque wrench (Pal 56). The permanent socket is fixed to the patient with competing custom-made limb attached. Figure 2 below shows complete artificially made limb.
Figure 2. A typical artificial limb; the foam membrane is covered with an artificial skin that match with the natural skin color of the patient.
Rationale of the project
The purpose of designing and building an artificial limb project is to provide a patient with comfortable life with the replacement of their damaged limb. After the amputation process, rehabilitation follows the fitting of the prostheses onto the patient’s body. The patient learns special exercises that strengthen their muscles in moving the device (Perry 73).
At times, amputees are advised to clean the prostheses parts including the socks. The project is intended to teach patients on how to cope with challenges associated with amputation. An amputee fitted with an artificial arm should learn to use the arm and the device. For instance, the amputee learns how to use the fingers in pressing and holding objects just like a natural hand. If the amputee is fitted with an artificial leg, they must learn to walk up and down the hill, how to fall and get up safely, how to get into and out of a bed or in and out of a car as well as jumping and jogging on them.
Evaluation of the project
Inevitable challenges during the implementation of the project included thin assembling materials, poor time planning, as well as the lack of specific standards for the design. Some materials such as polypropylene are not locally available and are expensive to purchase. Also, the method used is perhaps sophisticated. Producing a perfect design of prostheses that resemble a natural limb requires highly précised procedure and accuracy of measurements. Producing unproportioned prostheses means useless efforts are put into practice (Terminal Research Reports on Artificial Limbs 135).
In the design of the prostheses, no specific standards guide the building process. According to international manufacturers, international standards organization of Europe standards is referred as the datum of designing artificial limbs. The standards could be confusing and unrealistic in this case: different designs could result if the standards are not considered. The complex method used to construct prostheses include vacuum forming, injecting molding, and extruding, process that requires high degree of accuracy. Otherwise, poorly molded and irregularly fitted prostheses would be manufactured.
Time framing is a fundamental factor in molding a perfect design of the prostheses. Poor results of the project could be associated with time miscalculations. Weak prostheses result from wrongly followed procedures, wrong type of materials used in the assembly, as well as the poorly designed timeframe. Little of these challenges were noted during the implementation of the project. When the limbs failed to satisfy the ultimate design, improvements on the same were made.
Modifications
There is vast room for modification of an artificial limb, a sophisticated device yet preferably simple in design. The device must be designed easy for the amputee to learn how to use, do some repair or replacement if needed, be comfortable to put on and take off, easily adjustable, stronger and more lightweight, look real (natural), and be easy to wash. For instance, the advent of computer microprocessors and robotics in modern prostheses return the patients to the lifestyle they were accustomed before the amputation rather than just providing basic functionality or a pleasing appearance. The artificial limbs have silicone covers and can mimic the function of a natural limb.
Software that superimposes a grid on the CAT scan to indicate the extent of pressure the tissues can handle with minimum pain has been developed. By viewing the model on a computer platform, it is easy to design a socket that reduces the displaced soft tissue. Pressure-sensitive foot works excellently well in this model as pressure transducers in the feet convey signals to electrodes set in the stump. The nerves receive and interpret the signals correctly. The amputees can walk comfortably on the devices as they can feel the ground and make the appropriate gait adjustment (Thomas 152).
Work cited
Artificial Parts, Practical Lives Modern Histories of Prosthetics. New York, NY: the New York University Press, 2002. Print.
Buxton, Daniel. Applied Human Aesthetic in Artificial Limb Design: Research Design Development Study: Masters Industrial Design Development Study: [a Thesis Submitted in Partial Fulfilment of the Requirements for the Degree of Master of Design]. , 2005. Print.
Encyclopedia of Health. New York: Marshall Cavendish, 2010. Print.
Engineering. London: Office for Advertisements and Publication, 1866. Print.
Gray, Susan H. Artificial Limbs. Ann Arbor, MI: Cherry Lake Pub, 2009. Internet resource.
Hanson, Matt. The Science Behind the Fiction: the Building Sci-Fi Moviescapes. Burlington, Mass: Focal Press, 2005. Print.
Naik, Ganesh R, and Yina Guo. Emerging Theory and Practice in Neuroprosthetics. , 2014. Internet resource.
Pal, Subrata. The design of Artificial Human Joints & Organs. , 2013. Internet resource.
Perry, Heather R. Recycling the Disabled: Army, Medicine, and Modernity in Wwi Germany. New York, NY: Manchester University Press, 2014. Print.
Singh, Mandeep. Introduction to Biomedical Instrumentation. New Delhi: PHI Learning, 2010. Print.
Terminal Research Reports on Artificial Limbs: CoveringPeriod, 1 April 1945. Through 30 June 1947. Washington, 1947. Print.
Thomas, Michael. Design, the Implementation, and the Evaluation of Virtual Learning Environments. Hershey, PA: Information Science Reference, 2012. Print.
Ulloth, Dana R. Communication Technology: A Survey. Lanham: University Press of America, 1992. Print.
