Design Of Calipers For Post Polio Paralytic Patients Engineering Essay

Design Of Calipers For Post Polio Paralytic Patients engineering testifyABSTRACTOver 13 million in India mess deliver from confuse locomotor disabilities, of which 4 million have been afflicted by polio. Polio destroys the skittish system and ca workouts paralysis of the limbs. An orthosis or brace is connote to nominate support to compensate for the weakened muscles, maintain appropriate situation and stability of the affected bidding sticks, restore weight-bearing capabilities to the affected stagecoachs and allow the unhurried to laissez passer without the risk of falls and further fractures.The verifiable of this project is to develop a excogitation for adjustable polio braces, taking into conside balancen hinge suit at the knee sum. The current goals of KAFO argon do of Stainless Steel, aluminium, Thermoplastics, Reinforced carbon paper fibers etc. While Aluminium is light-weight, it does not provide the required inclementness for the mensurate materia l body Stainless Steel is corrosion resistant and has vast yield someonenel plainly is heavy. Hence somatic analysis is do to chose a material with density betwixt that of Aluminium and Stainless Steel, but with high last persuasiveness and high fatigue supplanturance limit. as well as the currently accessible designs do not incorporate flexible move at the knee thus discomforting the patient of during travel etc. The proposed design is d wholeness using CAD tools. A pi heap prototype is make in premature ventricular contraction and field-tested to determine if adjustments washbasin be easily per licked by the patient. base on feedback from the field-testing, the final model was designed using si scraps.ABOUT THE COMPANYM/s. AAROPNA PROTESI PRIVATE LTD. is a medical implants surgical instruments manufacturing and trading order. Our choice of this company was based on its expertise in developing biomedical instruments and implants and its association as a subsidia ry of its refer company kindle M/s. TITANIUM TANTALUM PRODUCTS LTD, which is an ISO 90012008 certified company dealing in various te Products for the past 29 years.The objective of the company is to establish the prerequisite world-class infrastructure for design, develop, devise, package, trade market place the Orthopaedic, Neurosurgical, Orthodontic, Dental and other similar reconstructive / flipment implants and its surgical instruments in titanium loads and other move on Biomaterial.Aaropna Protesi Private Ltd. deals with designing of medical implants by means of bio mechanised laws and the outgrowth, customization and optimization of medical implants and instruments using technology of CAD-CAM Solutions. It trades in world-class import medical implants, surgical instruments, tools other surgical accessories in India. It has more than devil decades of experience in handling te, Tantalum, Zirconium and Niobium through with(predicate) its pargonnt company.INTRODUC TION1.1 WHAT IS POLIOMYELITIS?Poliomyelitis, often known as polio or infantile paralysis, is an acute viral infectious disease spread from soul to person, primarily via the fecal-oral route. 1In about 1% of cases the virus enters the central nervous system, preferentially infecting and destroying motor neurons, leading to muscle weakness and acute voiced paralysis. Different types of paralysis whitethorn occur, depending on the nerves involved spinal anaesthesia polio is the al just about common form, characterized by asymmetric paralysis that to the highest spirit level often involves the legs. 2The term poliomyelitis is used to identify the disease caused by any of the three distinct variations of poliovirus. Two introductory patterns of polio contagious disease nuclear number 18 described a minor illness which does not involve the central nervous system (CNS), some dates called abortive poliomyelitis, and a study illness involving the CNS, which may be paralytic or non -paralytic. 1 In most people with a normal immune system, a poliovirus infection is asymptomatic.The virus enters the central nervous system in about 3% of infections. most patients with CNS involvement develop non-paralytic aseptic meningitis, with symptoms of headache, neck, back, abdominal and extremity pain, fever, vomiting, lethargy and irritability. 23 more or less 1 in 1000 to 1 in 200 cases get on to paralytic disease, in which the muscles become weak, floppy and poorly controlled, and finally only paralyzed this condition is known as acute flaccid paralysis. 4In many countries, polio or poliomyelitis was for many years the most common cause of physical disability in children.1 Currently through vaccination programs, Polio has been eliminated in most countries, a size-able percentage of people argon still affected by the crippling disease in India, Nepal, Nigeria and Afghanistan.Often the paralysis will gradually disappear, partly or completely. either paralysis left aft er 7 months, however is commonly unceasing and certain secondary problems may develop, especially if precautions argon not taken to prevent them. These problems are further disabilities or complications that outhouse appear after, and because of, the accepted disability.Contracture of control sticks is one commonly encountered secondary problem. In this in that location is a reduce of muscles and tendons so that the full chemical substance chain of limb movement is prevented. 5 shape. 1.1 Typical contractures in polioOther common deformities can cause deformities including over stretched junctures and dislocations.Fig. 1.2 Deformities caused by polio1.2 EVALUATING A PATIENTS NEED FOR AIDS AND PROCEDURESStep1 Observe the patient cautiously and notice which move of the torso seem vehement, and which seem weak. Differences between one side of the body and the other are identified such(prenominal)(prenominal) as differences in the length or thickness of the legs. Other d eformities, unusual gait, literary argument to one side, livelihood limbs, daub of heps, shoulder and wrestle of back are in addition observed. These early observations will assist you know what parts of the body you most need to check for dominance and range of motion. 5Step2 This is the physical examination. It should unremarkably includeRange-of-motion testing, especially where there expertness be contractures.Muscle testing, especially of muscles that may be weak. Also test muscles that need to be strong to make up for weak ones (such as arm and shoulder force play for crutch use).Check for deformities contractures dislocations (hip, knee, foot, shoulder and elbow) difference in leg length budge of hips and curve or abnormal crop of the back.Step3 After the physical exam, once once a march on observe how the patient moves or walks. The special(a) way of moving and travel is related with the physical findings (such as weakness of certain muscles, contractures, an d leg length).Step4 Based on observations and tests, a study is done to at a lower placestand what assistance might help the patient. Different aspects of the aid must be considered such as benefit, cost, comfort, appearance, availability of materials, and whether the patient is comfortable.Step5 once the assist doojigger has been decided, the necessary gradationments are taken to make the brace or aid. When making it, once again it is wise to put it together temporarily so that adjustments can be made before it is rivet, glue, or nail it into its final form.Step6 Have the patient try the brace or aid for a few old age to get used to it and to see how well it works. If there is discomfort or any problems, alternate mendments or necessary adjustments should be made.1.3 DESCRIPTION OF A CALIPERBraces or calipers are aids that help pass water legs or other parts of the body in useful positions. They usually serve either one or two of the economic consumptions travel byn benea thTo provide support, strength/firmness to a weak joint (or joints).To help prevent or correct the deformity.ORTHOTIC DEVICEAn orthosis or orthotic is an orthopedic device that supports or corrects the function of a limb or the torso 6. An orthopaedic brace or orthotic is an orthopaedic device used toControl, guide, limit and/or immobilize an extremity, joint or body segment for a finicky reasonTo restrict movement in a given billingTo assist movement generallyTo reduce weight bearing forces for a particular purposeTo aid rehabilitation from fractures after the removal of a castTo otherwise correct the shape and/or function of the body, to provide easier movement capability or reduce pain. 6LOWER LIMB ORTHOSISA lower-limb orthotic is an external device that is attached to the lower limb as a whole or limb segment in order to improve its function by providing support, reducing pain through transferring load to some other area or correcting flexible deformities.NOMENCLATURE FOR CA LIPERSCalipers are named after the joints that they replace the function of. The following are the acronyms usedAnkle Foot Orthosis (A.F.O.)articulatio genus Ankle Foot Orthosis (K.A.F.O.)Hip articulatio genus Ankle Foot Orthosis (H.K.A.F.O.) ankle joint joint FOOT ORTHOSIS (A.F.O.s)Ankle foot orthoses are orthotic devices encompassing theanklejoint and all (or part) of thefoot. AFOs are externally applied and intended to control position and motion of the ankle, compensate for weakness, or correct deformities. 6Fig. 1.3 Ankle Foot Orthosis knee ANKLE FOOT ORTHOSIS (K.A.F.O.)A knee-ankle-foot orthosis provides flexion, extension and mediolateral stabilization of the knee may provide free or locked knee motion, or adjustable range of motion 7.A knee-ankle-foot orthotic is typically designed to enable patients suffering from weakness or lack of control of the knee joint to walk safely. It is excessively used as an independent walking device for a walking-impaired person whose lower limb is paralyzed or whose muscle function is disoriented due to his spinal cord injury, diseases (such as polio), cerebrovascular disorder, external wounds and so forth.It is comprised of a main hinge assembly, an ankle assembly, a foot shield a lower leg housing member an top(prenominal) leg housing member and supporting structure.Fig. 1.4 Knee Ankle Foot Orthosis rosehip KNEE ANKLE FOOT ORTHOSIS (H.K.A.F.O)HKAFO is basically a KAFO with addition of hip joint and pelvic section whichprovide control to selected hip motions. The motions include at the hip are front to back, side to side, and rotation. In the HKAFO there is a minimized risk of the hipmoving out of proper position or dislocating. In this type of caliper, thehip and lower backrest is stabilized in cases where the patient is weak or paralyzed.Fig. 1.5 Hip Knee Ankle Foot OrthosisThe average weight of chromium nerve steel calipers are given below.Table 1.1 Weight of conventional untainted steel calipers emblem OF CALIPERWEIGHT (kg)A.F.O.1.100K.A.F.O.1.600H.K.A.F.O.2.2502. LITREATURE SURVEYLiteratures on existing Calipers and designIn the literature survey, various designs of existing calipers have been proposed. The patients comfort level, flexibility, cost-effectiveness and weight form the most important basis for the design of the caliper. Some of the recently published works are as followsTable 2.1 Literature SurveySL.NO nameAUTHORTECHNICAL DETAILSCONCLUSIONS/LIMITATIONS1.Anatomical archetypes of Diarthroidal gos Rigid Multibody Systems and Deformable StructuresJH HeggardComputer Methods in Biomechanics and Biomedical engineering science- Volume 2, 2003Mathematical methods to model diarthroidal joints. simulation of the joints is necessary to be able to understand the difficulty faced in movement by a post-polio paralytic patient.The various forces and stresses acting on the joints were studied in order to understand various basic movements and to help in the design of calipers.2.Bio engineering Analysis of Force Actions Transmitted by the Knee JointJK MarrissonBiomedical engineering, 5 164-178, 1988Determining forces acting on the knee joint as the caliper to be designed is a K.A.F.O(Knee-Ankle-Foot-Orthosis) caliper.Forces on knee joint during locomotion3.Orthopaedic Prosthesis and Joint ImplantsShan Fengwang, Lichun L, Michael J. YaszemskiBiomedical Engineering, 2 1984Study of atomic number 22 and its properties such as biocompatibility, light weightedness, density, youngs modulus to check for its use in the manufacture of calipers spend of titanium in biomedical applications and how this could be extended to the manufacture of calipers and reduce the discomfort and weight of the uniform.2.1 WORKFLOW non convinced(p)Caliper ClassificationSimilar Products AnalysisCommercial Intelligence bodily SelectionManufacturing ProcessRecognition of Tools and MachineriesDevelopmentDesign of ProductModellingAnalysisFabrication of Prototype ModelFabrication of Prototype M odelTestingVerification I/P=O/P hold inRoot cause analysis for failureRecognition of Caliper and its applicationFig. 2.1 Workflow3. SELECTON OF MATERIALFor the design of a caliper, a material is elect based on its physical properties such as flexible strength, whippy modulus, yield stress, etc. The choice of material is based on a comparative analysis of these factors. Ideally, a material should be chosen such that the caliper isComfortableLightweight, yet strongEasy to handle efficientDurableAs attractive as possibleEasy to manufacture 83.1 MATERIALS CURRENTLY USED FOR PRODUCTION OF CALIPERSBraces are made from various types of materials-plastic, elastic, metal, or a combination of similar materials.At present calipers are of two types argentiferous made from Aluminum, Stainless steelNon-metallic- made from polypropylene, strengthened carbonAdvantages of metallic calipers over non-metallic calipersLess expensive to manufacture Metallic calipers are cheaper to produce because t hose manufactured using poly-propylene require specialized moulds to shape the polymer. The biggest expense in making plastic braces is the plaster patch used for casting a mold of the leg.Easier to sew for each patient As the height and contours of each patient differs, the metal rods are easier to customize than plastic calipers.They are quick and easy to makeThey are more durable than plastic calipers.If used with sandals or clogs, in hot digest they are cooler than plastic.3.2 TITANIUM AS AN ALTERNATIVE MATERIAL3.2.1 customary PROPERTIES OF TITANIUM atomic number 22 is a chemical element, metallic in disposition whose chemical symbol is Ti , atomic number 22 and atomic weight 47.90. Ti is a transition metal silver in color It has the following propertieslow densityhigh tensile strengthcorrosion-resistantThere are two allotropic forms and five naturally occurring isotopes of this element, 46Ti through 50Ti, with 48Ti being the most abundant (73.8%). 8 It is the ninth-most a bundant element in the Earths pertness (0.63% by mass) and the seventh-most abundant metal. 8 atomic number 22 and its debauchs possess suitable mechanical properties such as strength, bend strength and fatigue justification to be used in load-bearing biomedical applications such as orthopaedics and dentistry. atomic number 22 is a reactive metal. In air, water, or arbitrary electrolytes an oxide layer is organise on the surface of the material. This oxide belongs to one of the most resistant compounds in the mineral world. As the oxide layer is a dense film it protects the metal from chemical attack which is of importance in an aggressive biological environment.Within the valet body, titanium is inert as the oxide layer which is formed is in wholesaler with the biological tissue, is hardly soluble and in particular no ions are released that could react with other molecules. 9There are 22 arcdegrees of commercially ready(prenominal) devalue and unalloyed titanium. Based on the application, a suitable path is chosen.3.2.2 COMPARATIVE STUDY OF STAINLESS STEEL, ALUMINIUM AND TITANIUMMetals used for the purpose of designing calipers are required to have both high still and cycle-dependent properties. Tensile yield and ultimate strength, modulus of elasticity, and fatigue endurance limit are the principal metallic strength attributes that must be determined. Wear resistance is also an important criterion for all biomaterials. Excessive wear can lead to premature mechanical failure of the replacement component.Table 3.1. proportional study of the physical properties of the assorted materialsPHYSICAL PROPERTIESMATERIALSStainless steelAluminiumTitaniumDensity (gcm3)9.02.704.51 last strength (MPa)860455900Yield strength (MPa)520400830Yield stress (MPa)210-35040-50240-370Youngs modulus (GPa)20570110-125 linear coefficient of thermal amplification (F-1)7.810-612.910-6.5.010-6DensityDensity of a material is be as the ducking of matter as measured by the m ass per unit volume. A high density indicates a higher mass for a particular volume.Titanium has density between stainless steel and aluminium indicating that for the same volume of material, titanium is lighter than stainless steel but heavier than aluminium.Ultimate strengthUltimate strength, also known as tensile strength, is be as the maximum stress a material can jib before necking. Ultimate strength should bedesirably, high for a material.Titanium has ultimate strength higher than stainless steel and twice as high as aluminium indicating that it can accommodate greater tensile stress i.e. it can withstand more stress before necking.Fig.3.1 Stress-Strain curveYield StrengthYield strength is defined as the belongings of a material to resist deformation. For a good material, the yield strength should be high.The yield strength for titanium is almost twice as high as stainless steel and aluminium indicating that it can withstand more stress without deforming eternally.Yield StressYield stress is defined as the minimum amount of stress which when applied to the body causes permanent deformation. Even if the applied stress is removed at this point, the object does not return to its original dimensions.The yield stress of titanium is almost equalise to stainless steel but more than 6 times than that of aluminium.Youngs ModulusYoungs modulus is the ratio between stress applied and resulting strain. It is used as a measure of agitate in linear dimensions upon application of tensile stress. If this ratio is large, it indicates that the material can withstand stress better with less deformation.The Youngs Modulus of titanium is higher than aluminium but lesser than that of stainless steel.The modulus is an important concern in the orthopedic application of biomaterials becauseBone has a modulus on the order of 17 GPa. The discrepancy between the modulus of swot and that of the alloys used to support structural fill up means that the metallic devices impla nted in the body take a disproportionate share of the load applied as stress.According to Wolffs Law, bone adapts to applied stress. Because alloys cause stress shielding one result of the accommodation is that the bone associated with the implant does not become or remain as strong as it would in the absence of an implant. 12Linear Coefficient of ExpansionLinear coefficient of expansion is defined as the increase in length per degree rise in temperature. If a metal is alternately subjected to heating and cool cycles, it should maintain a certain tolerance of dimensions i.e. a low coefficient of thermal expansion is desirable.The linear coefficient of expansion of titanium is untold lesser than both stainless steel and aluminium indicating that the change in the dimensions of the object with change in temperature is less, which is desirable.3.2.3 GRADES OF TITANIUMThere are 22 grades of commercially available alloyed and unalloyed titanium. 10Referenced standards ASTM- American S tandards for Testing poppycocksThis standard is issued under the fixed designation B 338 as revised on November2003. 15ASTM stipulation for commercially pure titanium F-67Table 3.2 material bodys of titaniumGRADE establishmentGrade 1unalloyed titaniumGrade 2Unalloyed titaniumGrade 3Unalloyed titaniumGrade 7Unalloyed titanium plus 0.12 to 0.25 % atomic number 46Grade 9Titanium alloy (3 % aluminum, 2.5 % vanadium)Grade 11Unalloyed titanium plus 0.12 to 0.25 % atomic number 46Grade 12Titanium alloy (0.3 % molybdenum, 0.8 % nickel)Grade 13Titanium alloy (0.5 % nickel, 0.05 % ruthenium)Grade 14Titanium alloy (0.5 % nickel, 0.05 % ruthenium)Grade 15Titanium alloy (0.5 % nickel, 0.05 % ruthenium)Grade 16Unalloyed titanium plus 0.04 to 0.08 % palladiumGrade 17Unalloyed titanium plus 0.04 to 0.08 % palladiumGrade 18Titanium alloy (3 % aluminum, 2.5 % vanadium) plus 0.04 to 0.08 % palladiumGrade 26Unalloyed titanium plus 0.08 to 0.14 % rutheniumGrade 27Unalloyed titanium plus 0.08 to 0.14 % rutheniumGrade 28Titanium alloy (3 % aluminum, 2.5 % vanadium) plus 0.08 to 0.14 % rutheniumGrade 30Titanium alloy (0.3 % cobalt, 0.05 % palladium)Grade 31Titanium alloy (0.3 % cobalt, 0.05 % palladium)Grade 33Titanium alloy (0.4 % nickel, 0.015 % palladium, 0.025 % ruthenium, 0.15 % chromium)Grade 34Titanium alloy (0.4 % nickel, 0.015 % palladium, 0.025 % ruthenium, 0.15 % chromium)Grade 35Titanium alloy (4.5 % aluminum, 2 % molybdenum, 1.6 % vanadium, 0.5 % iron, 0.3 % silicon)Grade 36Titanium alloy (45 % niobium)From the comparative study, the following conclusions were drawnThe yield stress, yield strength and ultimate strength are much higher for titanium. Hence it serves as a suitable material for calipers as it has to withstand the stress applied by the body weight and external forces.Lower stiffness of titanium with regard to stainless steel reduces the severity of stress-shielding.The density of titanium is lesser than stainless steel therefore the calipers would be muc h lighter than those made of stainless steel, almost by half.As linear coefficient of thermal expansion is lesser for titanium, the caliper dimensions would not change much with change in temperature.Titanium is more corrosion resistant than stainless steel. Stainless steel relies on chromium to render it passive to corrosion. Titanium however develops passivity on its own from the stable oxide film that forms on its surface.Unalloyed titanium grade 2 has higher ductility and is hence, cast, formed, joined, and machined with relative ease as compared to the alloyed grades.4. shape OF CALIPER4.1 DESIGN OF EXISTING CALIPERS4.2 DEVELOPMENT OF IMPROVED DESIGNSoftware that was used for the maturation of caliper design Autodesk spotter paid 2009.4.2.1 ABOUT AUTODESK INVENTOR PROFESSIONAL 2009Autodesk discoverer original 2009 helps you design, visualize and develop the end product desired digitally. It not only includes the 3D mechanical design and CAD productivity, but also the esse ntial tooling of various parts of the end product required such as plastic, that lends itself to manufacturing, and also facilitating in validation of the product digitally, sparing the need to test with physical prototypes. With the desegregation of motion simulation and stress analysis tools in Autodesk Inventor nonrecreational 2009, marketing a product becomes a much easier. Effective farsightedness on how the product will work in real-time conditions can be done and also automation of important aspects of the design such as the injection molds for plastic parts help greatly in minimizing errors to a good extent.An intuitive design environment of Autodesk Inventor Professional 2009 helps in the development of initial sketches and models of different parts. Also, this software helps by automating the basic geometrical sketches to actual prototypes making using of materials such as plastic, steel frames, tubes etc. This therefore reduces the geometry burden and the time required to make necessary changes and bring about innovation in the product, thereby reducing the time it takes to reach the market.Validation, in earlier times, was a very time overwhelming and expensive process involving skilled specialists but Autodesk Inventor Professional 2009 has made the entire process very simple and simulation expertise is not required now. Simulation and optimization of designs digitally has become very easy due to this software. Simple user interface helps in part by part design and integration. Stress analysis can also be performed to evaluate areas of stress concentration and hence helps in distribution of the same by slight design readjustments.Improved DesignAuto Desk Inventor 2009 supports all major drawing formats like DWG and some of the improved features compared to its precedent versions includeDesign earns in high speed Saves a lot of time. Viewing of drawings and annotation takes very less time when compared to the previous versions. advancement i n error handling High level of intelligence to give suggestions regarding geometrical issues.Faster startup time Launch time is much faster when compared to previous versions.Part by part design view Immediate definition and change in any part including dimensions and gloss and suitable assembly instantly.New Standards for 3D Modeling Ease of UseAutodesk Inventor 2009 helps focusing on the problem rather than trying to gain expertise over using the software as such, owing to its advanced user interface and features, making complex dialog boxes redundant.Inventor concretion Simple tools to explore new shapes and easy on the spot modification of model from any source.Improved design feature creation snap off control over the geometry of the design with productivity uncompromised. conclave design features 20 conclave Snap toolInterference analysis and contact detectionAssembly configurationsLarge assembly performanceFrame GeneratorWeldmentsContent bear onDesign DoctorDirect ma nipulationIt is an important feature of Autodesk Inventor Professional 2009 which helps in uninterrupted design workflow. Being able to control all the commands exactly at the point needed gives more style for free sketching, quicker assembly and better accuracy.Sustainable DesignMaterial selection can now be done considering environmental do and cost effectiveness. Using Autodesk, it is now possible to access environmental schooling on materials required for fabrication and make prudent decisions based on careful analysis.4.2.2 ENGINEERING DRAWINGS OF THE CALIPERDuring the modeling, different parameters were measured which includeddiameter of the mid- thighDiameter of distal end of the thigh blank space between mid- thigh and distal end of the thighDiameter of proximal end of the calfDistance between distal end of the thigh and proximal end of the calfDiameter of the distal end of the calfDistance between proximal and distal end of the calfDiameter of ankleLength of the footBrea dth of the toesBreadth of mid-footBased on these parameters, the design of the calipers was developed using Autodesk Professional Inventor 2009The drawing was modeled in parts and later assembled into the complete caliper as shown in the drawings. all in all dimensions are in mmFig 4.1 Engineering drawing of KAFO either dimensions are in mmFig 4.2 Engineering drawing of upper leg supporting structure (thigh)All dimensions are in mmFig 4.3 Engineering drawing of lower leg supporting structure (Calf)All dimensions are in mmFig.4.4 Engineering drawing of the ankle and foot supporting structureAll dimensions are in mmFig 4.5 Engineering drawing of Ti-Strip1All dimensions are in mmFig 4.6 Engineering drawing of Ti-Strip 2All dimensions are in mm Fig 4.7 Engineering drawing of Ti-Bend StripFig 4.8 Engineering drawing of the staminate ClampFig 4.9 Engineering Drawing of Female ClampHence, by using Autodesk Inventor Professional 2009, the design for a caliper was developed.The different pa rts of the caliper were developed individually and later assembled to form a complete model. These diagrams are used as a basis for the development of the prototype.The major changes that were incorporated in the design were at the knee jointMale and Female Clamp were used to replicate the hinge joint at the knee.In order to assist in easy deflexion of the caliper while sitting, a rivet was introduced which when unscrewed, will faclitate flexion at the knee.This is primarily useful while sitting and travelling as the caliper need not be completely removed.5. DEVELOPMENT OF PROTOTYPEThe development of prototype was conducted in essentially three stepsDevelopment of PVC prototypeIdentification of problems and corresponding corrections madeDevelopment of titanium protoype5.1 MANUFACTURING PROCESSThere are five major steps in manufacturing the Polyvinylchloride prototype. They have been listed and enumerated belowMarkingThis is the foremost step in manufacturing. It is also known as Ma terial Planning. Knowing the required dimensions is a prerequisite. Once the dimensions for every part of