UNIVERSITATEA TEHNICĂ GHEORGHE ASACHI DIN IAȘI în cotutelă cu TECHNISCHE UNIVERSITÄT DRESDEN Fakultät Maschinenwesen, Institut für Textilmaschinen und

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2 UNIVERSITATEA TEHNICĂ GHEORGHE ASACHI DIN IAȘI în cotutelă cu TECHNISCHE UNIVERSITÄT DRESDEN Fakultät Maschinenwesen, Institut für Textilmaschinen und Textile Hochleistungswerkstofftechnik RESEARCHES ON THE IMPLEMENTATION OF NEW DIGITAL METHODS FOR THE DEVELOPMENT OF TEXTILE PRODUCTS FOR PEOPLE WITH LOCOMOTOR DISABILITIES - abstract - CERCETĂRI PRIVIND IMPLEMENTAREA UNOR NOI METODE DIGITALE ÎN DEZVOLTAREA PRODUSELOR TEXTILE PENTRU PERSOANE CU DIZABILITĂȚI LOCOMOTORII - rezumat teză doctorat- Doctorand: Ing. Bianca ALUCULESEI Conducători de doctorat: Prof. Dr. Ing. Antonela CURTEZA Prof. Dr. Ing. habil. Sybille KRZYWINSKI IAȘI,

3 Cuprins / Contents Rezumat teză doctorat Introducere Obiectivele cercetării Partea experimentală Rezultate și concluzii Contribuția tezei Cercetări viitoare... 9 Abstract Chapter 1: Introduction to the research Introduction Research objective Challenges in the researched area Objectives and structure of the work Chapter 2: Disabilities: Definitions and clothing needs Disability Clothing for persons with special needs Needs and demands of wheelchair users regarding clothing Chapter 3: Garment design methods for wheelchair users - a literature review Anthropometric measurements Measurement techniques for wheelchair users Traditional method Three dimensional scanning procedure Kinematic body model Computer-aided design systems Conventional garment construction for wheelchair users D virtual prototyping of garments for wheelchair users Chapter 4: Methodology establishment in current research Research design, procedure and participants Three-dimensional scanning procedure Scanning procedure for a wheelchair user Body posture simulation using a kinematic template model Chapter 5: Virtual pattern making for wheelchair users D-to-2D virtual prototyping Fit simulation for the tight-fitting trouser model D-3D virtual prototyping

4 The construction of basic trouser patterns and fit simulation Modification of the basic trouser patterns Fit simulation of the modified basic trousers Designing a pair of trousers for a man wheelchair-user Conclusions Chapter 6: General conclusions and future work Results of the experimental studies Contribution of the thesis Future work References - selection List of published papers Awards

5 Rezumat teză doctorat 1. Introducere În industria confecțiilor, odată cu evoluția tehnologiilor, activitatea de proiectare a trecut de la etapa manuală la cea computerizată. Sistemele CAD utilizate pentru proiectarea formelor tiparelor produselor de îmbrăcăminte au module care permit proiectarea plană (2D), proiectarea 3D și simularea în spațiul virtual a interacțiunii produs vestimentar- corp uman [1]. Evoluția modulelor care permit proiectarea directă 3D a tiparelor produselor de îmbrăcăminte folosindu-se de manechinul corpului uman a devenit o soluție inovativă pentru activitatea de design a produselor de îmbrăcăminte, în special cea destinată persoanelor cu anumite dizabilități. Dizabilitatea reprezintă incapacitatea sau limitarea de a efectua anumite activități legate de acțiunile normale din viața de zi cu zi. Dizabilitatea poate rezulta din anumite deficiențe care pot proveni dintr-o serie de probleme fizice, cognitive, mentale, intelectuale, senzoriale sau mentale. Leziunea coloanei vertebrale reprezintă o leziune a coloanei sau a nervilor care poate afecta abilitățile motorii sau senzoriale ale unei persoane. Paraplegia rezultă dintr-o leziune a măduvei spinării [2] și se referă la o deficiență sau o pierdere a funcții motorii și/sau senzoriale la nivelul toracic (T2-T12), lombar (L1-L5) sau sacral (S1-S5) ale măduvei spinării [3]. Produsele de îmbrăcăminte destinate persoanelor cu dizabilități trebuie să răspundă la anumite nevoi speciale impuse de postura corpului, limitarea libertății de mișcare și a duratei mari de ședere în scaunul cu rotile. 2. Obiectivele cercetării Industria de textile și confecții se află abia la începutul etapei de conștientizare a nevoilor persoanelor cu dizabilități. La nivel European există firme de confecții care realizează produse vestimentare destinate acestei categorii de purtător, dar în România nu există încă asemenea producători. Activitatea de cercetare pentru elaborarea tezei de doctorat cu titlul Cercetări privind implementarea unor noi metode digitale în dezvoltarea produselor textile pentru persoane cu dizabilități locomotorii, s-a orientat spre identificarea și analiza nevoilor și cerințelor persoanelor care stau în scaunul cu rotile în ceea ce privește produsele vestimentare și s-au propus soluții de proiectare a acestor produse, perfect adaptate particularităților lor (postură și limitarea activității de mișcare). Persoanele paraplegice reprezintă 1% din populația Europei, aproape opt milioane de oameni [4], și sunt un grup de purtători care au necesități și nevoi specifice și din punct de vedere vestimentar. În proiectarea și fabricația produselor de îmbrăcăminte destinate acestei grupe de purtători trebuie să se țină cont de postura particulară a corpului și de durata mare de timp petrecută în scaunul cu rotile. Limitarea posibilității de mișcare a persoanelor care stau în scaunul cu rotile ridică probleme la îmbrăcarea- dezbrăcarea produselor cu sprijin în talie pantaloni. Principalul obiectiv al acestui studiu de cercetare a fost proiectarea 3D a unui model de pantaloni, cu module 3D ale sistemelor CAD, folosind manechinul virtual corespunzător poziției șezânde a purtătorului paraplegic. În proiectarea tiparelor produselor de îmbrăcăminte prin metoda geometrică se folosesc informații despre forma și dimensiunile corpului și ale modelului produsului de îmbrăcăminte 4

6 dorit. Măsurarea dimensiunilor corpului uman se poate face prin metode directe (metode de contact) și metode indirecte (metode fără contact).informațiile despre forma și dimensiunile corpului uman (persoane paraplegice) necesare scopului tezei de doctorat sunt obținute prin scanare 3D. Scanarea s-a realizat folosind un scanner de mână și un scanner fix. Pentru rezolvarea obiectivului tezei a fost necesară animarea unui corp cinematic într-un mediu virtual, cu anumite mișcări și poziții. Animația unui corp 3D într-un mediu virtual poate oferi informații despre forma corpului în anumite mișcări sau poziții. Prin realizarea animației virtuale, s-au obținut diferite poziții dinamice ale corpului 3D. În etapa următoare s-a proiectat un model de pantaloni folosind modulul 3D de proiectare al sistemului CAD, potrivit dimensiunilor corpului și posturii acestuia pentru persoane care stau în scaun cu rotile. După desfășurarea tiparelor, s-au obținut formele 2D ale reperelor de produs și apoi s-a verificat modul de potrivire al modelului creat cu manechinul virtual al purtătorului. Motivul alegerii pantalonilor pentru această cercetare a fost interesul pentru rezolvarea problemelor pe care un utilizator de scaun cu rotile le are cu acest articol de îmbrăcăminte. În comparație cu un produs pentru partea superioară a corpului, pantalonii necesită o modificare mai complexa pentru a rezolva problemele de ajustare a produsului în poziția șezândă. Prin simularea în spațiul virtual al prototipului elaborat se verifică corespondența dimensională produs vestimentar- corp uman și echilibrul produsului pe corp. 3. Partea experimentală Partea experimentală a cercetării a fost efectuată la Universitatea Tehnică din Dresden, Institutul pentru utilaje textile și tehnologii pentru materiale textile performante (ITM), Germania. Protocolul de scanare pentru persoane care stau în scaun cu rotile (utilizarea scannerului fix și mobil) s-a elaborat prin sesiuni succesive de scanarea a 2 persoane: 2 femei (25 și 62 de ani, în poziție ortostatica, persoane care nu au probleme cu poziția și postura corpului. Scanarea s-a realizat cu scanerul manual MHT Artec și scanerul zsnapper de la Vialux. Suprafețele mesh ale corpului s-au editat cu programul GeomagicStudio. După elaborarea protocolului de scanare acesta a fost utilizat pentru scanarea unui bărbat paraplegic, cu vârsta de 54 de ani. Imaginea 3D a subiectului masculin paraplegic a fost utilizată ca suport pentru obținerea informațiilor (postură și mărimi antropometrice) în proiectarea virtuală reperelor unui model de pantaloni. Figura 1: Schema poziționării dispozitivelor în procesul de scanare Figura 2: Procedura de scanare pentru peroana paraplegică Figura 3: Corpul virtual obținut înainte și după procesarea suprafeței de mesh În activitatea de proiectarea virtuală 3D se utilizează corpuri în poziție ortostatică. Pentru a putea realiza proiectarea unui model de pantaloni a fost necesar să se elaboreze un corp virtual, 5

7 care poate avea diferite poziții dinamice (elaborarea acestui corp s-a realizat în programul 3ds Max, prin prelucrarea imaginii unui corp scanat în poziție ortostatică cu un șablon cinematic. (Figura 4). Corpul 3D cinematic a fost animat pentru a obține diferite poziții dinamice ale corpului, cu diferite unghiuri între coapsă și gambă (Figura 5). Cu programul DesignConcept -Lectra s-a proiectat 3D un model de pantaloni, pentru o anumită postură a corpului (trunchiul înclinat cu 130 și unghiul dintre axa coapsei cu cea a gambei de 130 (Figura 6). Modelele au fost aplatizate și analizate în continuare în procesul de proiectare 3D (Figura 7). Figura 4: Model cinematic obținut prin fuziunea de date scanate cu un template cinematic Figura 5: Diferite poziții ale parții de jos a trunchiului pentru corpul cinematic obținut Figura 6: Model pantalon 3D Figura 7: Repere 2D aplatizate Simularea modului de așezare al prototipului de pantaloni pe manechinul virtual s-a realizat folosind sistemul Lectra- Modaris V8R1. Forma 2D a reperelor modelului proiectat a fost analizată pentru o anumită poziție dinamică a corpului, corespunzătoare poziției unei persoane paraplegice. În această poziție s-a constatat ca lungimea turului este insuficientă, de aceea se impune o majorare a lungimii acestei linii de contur (Figura 8). Figura 8: Simularea virtuală a tiparelor obținute din aplatizarea modelului 3D Figura 9: Simularea virtuală a tiparelor de baza ale modelului de pantalon Analizând modul de așezare al pantalonului pe mijlocul feței, se observă ca lungimea pantalonului pe linia sa de mijloc este prea mare (pantalonul formează pliuri, care determină senzația de disconfort). În zona genunchilor, modelul de pantaloni necesită o suplimentare pentru a asigura confortul la purtare (acest lucru se observă din analiza hărții tensiunilor dezvoltate în produs la îmbrăcarea pe corp). În continuare un modelul de pantaloni 2D este proiectat pentru 6

8 mărimea 42, iar simularea virtuală a modului de așezare a fost făcută pe aceeași poziție dinamică pe care a fost construit și modelul de pantaloni 3D (Figura 9). Analizând harta tensiunilor dezvoltate în produs la îmbrăcarea pe corp (spațiu virtual) se stabilesc care sunt prelucrările care trebuie aplicate reperelor de produs: scurtarea lungimii pantalonilor pe linia de mijloc față, majorarea lungimii liniei turului (spate) și eliminarea pliurilor de la spatele pantalonilor. Formele reperelor modelului proiectat au fost modificate și noul prototip a fost verificat în spațiul virtual. (Figura 10-11). Noul prototip are o așezare mai bună pe corp, mai ales în zona taliei. Faldul care se formează la nivelul taliei are o adâncime mică și acesta poate fi eliminat prin modul de finisare a terminației superioare a pantalonilor (bandă elastică). Numărul de pliuri de la partea posterioară a produsului s-a redus considerabil. Figura 10: Modificarea tiparului de bază a pantalonilor Figura 11: Simularea virtuală a modelului de pantalon modificat Figura 12: Modelul de pantaloni pentru bărbați modificat Figura 13: Persoană paraplegică purtînd modelul de pantaloni modificat Folosind dimensiunile manechinului scanat al persoanei paraplegice, un model de pantaloni bărbătești mărimea 52 a fost proiectat și modificat. Etapele de modelare care au fost aplicate reperelor primului prototip virtual au fost folosite și pentru modelul de pantaloni pentru bărbați (Figura 12). Modelul nou creat a fost încercat de către utilizatorul de scaun cu rotile (Figura 13). 7

9 4. Rezultate și concluzii Pentru atingerea obiectivului tezei a fost necesar să se studieze informațiile existente în literatura de specialitate (rezultate ale unor cercetări anterioare) privind forma, funcționalitatea produselor vestimentare și caracteristicile materiilor prime care sunt recomandate a fi folosite pentru fabricarea unor produse destinate persoanelor paraplegice (ca de exemplu pantaloni). Cercetările antropometrice desfășurate ca urmare cerințelor industriei de confecții, standardele existente, sunt valabile pentru persoane considerate normale. Pentru persoane paraplegice nu există rezultate ale unor cercetări antropometrice sau standarde. În prima parte a capitolului 4 se descrie o procedură de scanare a corpului paraplegic elaborată prin teste succesive de scanare. Scanarea s-a realizat cu scanerul manual MHT Artec și scanerul zsnapper de la Vialux, rezultînd un protocol de scanare al unei persoane paraplegice. În a doua parte a capitolului, s-au proiectat diferite poziții dinamice ale corpului uman folosind un corp cinematic, care s-au utilizat mai departe în construcția modelului de pantaloni 3D. S-a demonstrat utiliatea unui corp cinematic pentru a obține diferite poziții dinamice al corpului pâna la cea specifică unui utilizato de scaun cu rotile. În capitolul 5 se descrie metodologia de proiectare 3D al unui model de pantaloni (prototip), cu siluetă ajustată și apoi este analizat modul de așezare al produsului pe corp. Forma reperelor produsului proiectat a fost modificată pentru a asigura confort la purtarea de către o persoană paraplegică (metoda 2D-to-3D). Prin simularea virtuală s-a verificat echilibrul produsului pe corp, respectiv corespondența dimensională produs vestimentar- corp uman, s-au stabilit dacă mai sunt de introdus alte modificări și în final s-a validat soluția de proiectare elaborată. 5. Contribuția tezei În urma cercetărilor și concluziilor prezentei teze, principalele contribuții pentru cercetarea designului îmbrăcămintei 3D sunt: - stadiul actual al cercetărilor antropometrice ("state of art") pentru persoane care stau în scaun cu rotile (țara noastră și pe plan mondial) - analiza problemelor medicale și sociale ale utilizatorilor de scaune cu rotile, - studiul cerințelor și nevoilor vestimentare pentru persoane care stau în scaun cu rotile, - utilitatea folosirii modulelor 3D ale sistemelor CAD pentru proiectarea formei reperelor din structura unui produs vestimentar, - elaborarea unui protocol de scanare al persoanelor care stau în scaun cu rotile, - proiectarea unui șablon cinematic în diferite poziții dinamice până la obținerea unei imagini cât mai fidele a unui corp paraplegic în postura lui obișnuită, care se poate utiliza în proiectarea 3D a unui model de pantaloni, - elaborarea unei metode de proiectare 3D a unui model de pantaloni, cu siluetă semiajustată pentru persoane paraplegice. 8

10 6. Cercetări viitoare Prin metodele dezvoltate descrise în această teză pot fi elaborate direcții de cercetare ulterioară: - pentru metoda de scanare, se poate stabili un protocol specific în funcție de categoria de dizabilitate a persoanei care să permită acuratețe în obținerea informațiilor necesare unor studii avansate de antropometrie, - protocolul de cercetare se poate aplica și pentru proiectarea 3D a altor categorii de produse destinate persoanelor paraplegice, - stabilirea unor structuri optime de straturi, caracteristici de țesături/ materii prime și materiale care sunt potrivite pentru fabricația produselor destinate persoanelor paraplegice, - elaborarea unor soluții de modelare tehnică a reperelor de pantaloni pe partea anterioară sau posterioară, în corelație cu proprietățile de elasticitate, desime, rigiditate ale materialului folosit la fabricarea produsului în scopul asigurării confortului la purtare. 9

11 Abstract Chapter 1: Introduction to the research 1.1 Introduction Disability represents the incapacity or limitation to perform certain activities or behaviours connected with every-day life normal actions. The disability may result from certain impairments, which can originate from a series of physical, cognitive, mental, intellectual, sensory or mental issues. Disabled people represent 15% of the world s population and across EU the disability is about 10% from the whole population, with a big probability of going up in the next years [1]. In Romania at the end of 2018 there were reported 812,594 disabled people, almost 4% from the entire population [2]. It can be understand that regarding the disability aspect, this important and numerous group of people are in high demand of personalized and functional products on the market. Regarding the clothing products, disabilities often lead to special functional requirements, which increase the necessity of physical and psychological comfort. Most of the garments for disabled people that exist now on the market don t have fabrics adapted to the individual s medical problems and also, the products don t have a suitable pattern construction for the atypical body, posture or movements of the wearer. It is necessary a bigger attention upon the research and development of functional clothing for disabled people in order to improve the functionality, attractiveness, ease in use and affordability of the clothing products. 1.2 Research objective Challenges in the researched area In order to develop a customized product that can fulfil the necessities of a target market is necessary an extensive research about the characteristics of the studied group, especially when this includes people with a variety of physical abilities. A market research in this matter can be more complex and challenging because of the variety of needs and characteristics of the disabled persons. Clothing needs of the people that are living with a sort of disability are not being met; there is an absence of appropriate clothing which hinder this group of people in having normal social activities and relationships, jobs or everyday life activities [3,4]. The variety of disabilities which have special design requirements for clothing is big and each one needs to be studied carefully. The present research was focused on the persons who suffer from paraplegia and are using a wheelchair for the locomotion process. The wheelchair users are very sensitive to the clothes they are wearing regarding functional and design characteristics. They have to take into account every time their health problems (e.g. skin fragility) and the fitting of the clothes on their body which is most of the times problematic due to their body shape and sitting. The main attributes the wheelchair users are searching for in clothing are the functionality, attractiveness, ease in use, affordability and safety Objectives and structure of the work The main objective of this research activity consists in implementing 3D CAD technologies in designing trousers for wheelchair users. The design of any type of garment has at the base information about the shape and dimensions of the body of the wearer. There are two 10

12 methods of human body measuring: direct methods (contact methods) and indirect methods (noncontact methods). For this research the indirect method 3D scanning- was used for better understanding the shape and dimensions of a wheelchair users s body. Multiple scans trials were done using a hand-held scanner and a whole-body scanner. The research was developed further with the animation of a kinematic body model. The animation of a 3D body in a virtual environment can give information about the body shape in certain movements or positions. By doing the virtual animation, different 3D body models in several positions were obtained, from standing to sitting. Further, 3D-to-2D and 2D-to-3D prototyping was used to create a trouser model that can fit to the shape and dimensions of a wheelchair user. 3D virtual simulation was applied to test the applicability of the pattern modifications and in the end a trouser prototype was designed and tried-on. The reason for choosing the trousers for this research was the interest in solving the problems a wheelchair user has while sitting with this piece of garment. In comparison with a garment for the upper part of the body, the trousers are involving some problems that require more complex pattern modification to solve the fitting issues. The thesis is structured in six Chapters: - Chapter 1 and 2, with the introductive part and the analysis of paraplegic people regarding their disability and their clothing needs; - In Chapter 3, it is gathered information about the functional clothing for paraplegic people and the existing literature on measuring techniques, virtual body animation, scanning procedures and 2D or 3D prototyping of clothing for wheelchair users; - Chapter 4, the experimental data of this research regarding the scanning procedure and 3D body animation; - Chapter 5, with the 3D-to-2D and 2D-to-3D trouser prototyping, and - Chapter 6 with the general conclusions, the thesis contribution in the domain and the future possible research regarding the thesis subject. Chapter 2: Disabilities: Definitions and clothing needs 2.1. Disability Disability is defined from the context of health experience, by the International Classification of Impairments, Disabilities, and Handicaps (Geneva 1980), as a limited participation in daily living activities that can come from a physical or psychological impairment [5]. Taking to another level of understanding, with the development of International Classification of Functioning, Disability and Health (Geneva 2001), the World Health Organization takes the meaning of disability to a wider caption, covering impairments, activity limitations, and participation restrictions [6], putting together aspects of both health aspects and the social model problems. The medical aspect of disability refers directly to the health problems of an individual which can be caused by different diseases, traumas or other causes, while the social model takes disability into a section of a socially created problem which takes it further into a problem of integration of individuals into society. In conclusion, disability embodies more than one medical attribute, but a complex set of environmental factors [7] Clothing for persons with special needs Clothing for disabled people should follow the next requirements [16,39]: 11

13 - to match the disability and keep the handicap under control by adequate patterns and fasteners posture matching, adequacy to joint mobility, - to encourage independence in movement while wearing, the independence while using the fasteners and ensure a high level of comfort and safety ease of use, wear /tear resistance, - to have an easy maintenance with fabrics easy to wash and iron - repellence / stain -resistance, - to be made from fabrics that will not chafe or irritate the skin and assure good thermal isolation - moisture management, perspiration control, thermal insulation, - the fabric should be from natural fibres or treated with antibacterial solvents antimicrobial/bacterial requirements, and - to provide a certain psychological comfort and self-confidence of the person wearing it Needs and demands of wheelchair users regarding clothing Paraplegia refers to an impairment or loss of motor and/or sensory function in thoracic (T2-T12), lumbar (L1-L5), or sacral (S1-S5) segments of the spinal cord [10]. It can affect the functions of the trunk, legs and some of the pelvic organs but the upper part of the body and the arms are not affected. It can be caused by damaging the spinal cord in accidents, in appearance of tumours, tuberculosis, and transverse myelitis or it can have hereditary provenience. Wheelchair users represent 1% of European population, nearly eight million people. Because of their permanently or semi-permanently sitting position, the contact area has to carry their body weight during long periods. The absence of muscle tone in their legs and the lack of activity are reducing the natural body cushioning, it decreases the size in circumference of the legs with a possible increase of the upper part of the body and makes their circulatory system less efficient. The nerve spine being damaged, there is an absence of sensory feedback which makes their skin tissue especially vulnerable to oedemas and ulcerations. Because of the prolonged time in sitting position or even the incontinence problems, the moisture on the affected areas increases which makes the skin even more sensitive. There are many aspects to understand that wheelchair users are in a need of adaptive clothing [11]. Different aspects of the comfort that can be treated are thermal isolation and permeability, tactile factors, usability, fitting, or hypoallergenic agents [16,6,42]. Chapter 3: Garment design methods for wheelchair users - a literature review 3.1. Anthropometric measurements The design of any type of garment product must be based on information about the shape and dimensions of the body of the wearer. Anthropometry represents the study of measuring the dimensions of the human body [13]. There are two methods of human body measuring: direct methods (contact methods) and indirect methods (non-contact methods) [44,46,47]: contact methods: traditional measuring tools non-contact methods: scanning or photogrammetry 12

14 3.2. Measurement techniques for wheelchair users Traditional method Anthropometric measurements of wheelchair users are used for designing their occupational environments and products. Many of the existing studies in the literature regarding their anthropometry are being done for the design of living, public or workplaces, with the purpose of eliminating harmful and uncomfortable positions. The accessibility demands and the special design recommendations are also being analysed [67,68,69,70]. Ergonomic studies for wheelchair users are not enough to be used for the garment construction area, as the ergonomic measurements are more related to the environment where the person is living. For the garment construction, the measurements need to be taken directly on the body, but in this case, with the person sitting in the wheelchair Three dimensional scanning procedure Regarding the scanning procedure for wheelchair users, there are a couple of studies where are analysed, most of the times on healthy peoples: how to obtain a useful 3D body model in the sitting position, the necessary equipment and the scanning procedure that a disabled person can follow. There is a certain interest to acquire an accurate 3D body model in a sitting position for garment prototyping, as in the past years the industry for customized products tends to develop, being more aware of the demands and necessities of disabled peoples. For scanning the sitting position, several methods have been tested regarding the necessary equipment, the scanning procedure or the posture of the body for the optimal gathering of the scanning data [89,90,91] Kinematic body model An interesting approach in observing the changes in a human body in the sitting position would be the animation of a kinematic body model in 3D programs. The field of application of virtual human models is diverse. The adaption and individualization of human models can be applied in areas like [96,97]: ergonomics, entertainment industry (e.g. film and video production, games, sports), medical rehabilitation, product design (e.g. automotive industry, virtual clothing construction and fitting), training through interactive simulation, and providing knowledge (e.g., museums, airports, websites). A kinematic body model is the result of merging a scan data with a template model in body animation programs with the help of defined landmarks. Within these animation programs, the body motions can be controlled and it can be analysed the change of the body shape in different motions [98,99] Computer-aided design systems Garment CAD technology represents the use of computer technology in designing garment products [28]. Based on the importance of CAD technology in the garment industry, the CAD technology was strongly studied until these days, much of research being made on garment modelling and simulation, garment design, garment grading, as well as the existing of available 13

15 3D CAD systems for the clothing industry [119,120,121,122,123,124]. All of these reviews are gathering information about virtual prototyping process, which can be approached from a 2D-to- 3D and 3D-to-2D technique. The 2D design techniques are based on several sizing rules, using the measurements of the standard body, and the conventional garment design method. The garment industry is based on 2D patterns for product manufacturing but more recently the 3D virtual fit simulation started to get into attention. The virtual fitting on 3D body models would be an important step for the clothing industry to reduce the number of prototypes in garment development [119,129]. The basic 2D patterns can be designed and later assembled through a virtual sewing procedure to produce realistic draping simulation on a 3D mannequin [130,131,132]. 3D virtual garment construction is a technique for the garment development that requires the application of innovative CAD solutions. The objective of virtual prototyping is the integration of garment characteristics, pattern cuts and fabric properties, to check the fitting on a virtual body model [32]. In the 3D environment it is possible to modify the shape of the garments and to apply certain fabric properties. 3D-to-2D technique is based on the development of 3D human body measurements and modelling, 3D garment design on virtual body models, 3D garment simulation, and 2D pattern generation from the designed 3D garment model [119,120] Conventional garment construction for wheelchair users In the process of creating customized garments for wheelchair users there are many dimensional changes compared to a basic model that must be considered. There are several studies focused on the pattern modifications for the lower and upper garments for this type of clothing. Analysing these studies, the garments for the lower part of the body usually need adaptation in length and waist area, the crotch was shortened in front and lengthened in the back side, while for the waist there were added some extra darts to equilibrate the difference between the hip area and the waistline in the sitting position [39]. Other modification necessary to apply were the extension of the pants in length and width, knee-line reposition, and widening the sitting crotch area [21]. Besides the pattern modification, the placement of the opening systems was reconsidered, by adding special plackets on the sides, zippers to detach the crotch area or elastic bands on the waist to facilitate the dressing and undressing [147,148]. Detachable legs in sections or tight-fitting bottoms were also considered, with the usage of soft and water absorbent knitted fabrics, fabrics made from a mix of synthetic and natural fibres, softer material at the backside and flat and smooth seems [12]. The garments for the upper part of the body usually needed to have reinforced back sleeves, longer back, shortened front, large armholes, the full sleeves without cuffs and the centre front with placket easy to utilize. The elbow area needed more lightness by using darts and pleats. There is still needed a special attention on the placement of opening systems [42,89,147,148]. Besides the analysis of regular clothes, protective textiles also caught the attention, protective pads or diapers for incontinence, protective clothing for wind and rain being also important [41,147,149] D virtual prototyping of garments for wheelchair users For the research on virtual prototyping of garments for paraplegic people a series of studies were made using 2D-to-3D technique. All researches were made using OptiTex 3D [89,91,95]. The patterns [21] for basic trousers and blouse for a standing position were designed 14

16 and virtually simulated on a sitting body model. After this, according to the virtual measured dimensions from the sitting body, the patterns were modelled and the new ones were virtually simulated. The proposed modifications of the basic patterns were a first step to understand the garment construction for a sitting position but the procedure is cumbersome and requires a different approach. In [23] study were designed three garments for wheelchair users: a jacket, a dress and a pair of trousers. The virtual prototype of the garments was made based on the virtual measurements taken on the scan body of the disabled persons. After this, the virtual fit simulation of the designed models was carried out for a standing and a sitting position. Doing this comparison between the virtual fittings, it was possible to see what modifications are necessary for the garments for a sitting position. The presented literature on 3D scanning and virtual prototyping of garments for wheelchair-users helped to have a basic idea about individualized functional garments from the ergonomic point of view and to understand better the functional and aesthetical needs of paraplegic people. There is still need for the improvement of the scanning procedure for the sitting position, in order to obtain more data from the sitting area. This would be helpful in obtaining better 3D body models for accurate virtual measurements and virtual prototyping of garments. The virtual prototyping of the garments would be less time consuming if the 2D-3D technique would be transformed to a 3D-2D technique, as it would be easier to see, from the beginning, the necessary dimensional modifications for the basic patterns. Therefore, the major lack of dimensional data for wheelchair users, necessary for the garment construction, was the starting point of this research. The scanning procedure and the virtual garment prototyping are proposed to be analysed in this research in order to obtain improved results for this matter. Chapter 4: Methodology establishment in current research 4.1. Research design, procedure and participants With reference to the needs and demands of paraplegic people regarding clothing, in this part of research was analysed the 3D scanning procedure and some computer simulation techniques to see the possibility of using a kinematic body model in the virtual garment prototype dedicated to wheelchair users. All investigations were carried out at TU Dresden, Institute of Textile Machinery and High Performance Material Technology (ITM), Germany. The scanning procedure of the selected persons (two healthy and one paraplegic), was performed using the handheld MHT scanner form Artec [45] and the body scanner zsnapper cart from Vialux [46]. Both scanners were used for the scanning procedure in order to analyse the capacities these technologies have in obtaining good scan data for virtual body models. The editing of the mesh surfaces of the obtained scanned data was made in GeomagicStudio program from 3D Systems [47]. The scanned image of the body was imported and animated in 3dsMax program from Autodesk [48] with the purpose of obtaining different positions of the lower part of the body. This entire procedure was important in the research area of trousers design for the sitting position that can offer suitable ergonomic comfort for the wheelchair users. The 3D scanning procedure was made on three participants, two healthy females, age 25 and 62 and one paraplegic male, age 54. The need of using healthy people in the first place was 15

17 necessary for the establishment of the scanning procedure for the sitting position and to select devices that could help in the scanning process. The trials with the healthy participants helped to understand better the usability and efficiency, both of the handheld and whole body scanner, the methodology needed to be applied in order to obtain better data and better time managing, and necessary devices possible to use in the scanning procedure of sitting position Three-dimensional scanning procedure The starting point of the scanning procedure for the sitting position was to test the usability and efficiency of Artec MHT handheld scanner to catch data from such a problematic body posture. The tested person had to sit on a normal chair without a backseat, with the legs fixed on the ground and bend knees. The arms had to be bended up from the elbow area so that they don t appear in the scan data for the lower part of the body. The scanned person had to wear tight-fitting clothing for obtaining a realistic shape of the body. It was necessary to pinpoint white clay markers on different locations of the body (Figure 4.1) in order to merge multiple scanning in the next steps of data processing. The position being defined, multiple scan trials were done starting from different sides and angles in order to see the best scanning procedure for obtaining optimal data. The multiple scan trials revealed that it is difficult to scan a large area of the body with a handheld scanner without obtaining overlapping images or double mesh layers that would hinder the achievement of realistic and correct scan data. Because of that, it has been decided to scan one leg to obtain better data for analyzing the missing parts in sitting posture. The scan data was achieved and edited in ArtecStudio (Figure 4.2). The result is a polygonal model that was saved as an.obj file for further mesh editing in GeomagicStudio (Figure 4.3). The mesh editing process consisted in filling the missing holes, smoothening the mesh surface and erasing the unnecessary parts. After the mesh processing, the leg was mirrored to have a full lower part of the body that can be further used in 3D environments (Figure 4.4). Figure 4.1: Scanning with Artec MHT handheld scanner Figure 4.2: Obtained and edited scan data in ArtecStudio Figure 4.3: Obtained virtual body model before mesh processing in GeomagicStudio Figure 4.4: Obtained virtual body model after mesh processing Based on the gained experience from the scanning procedure using a normal chair and knowing what the difficult parts to scan are, the idea was to develop a special chair for better results. The chair was made from transparent Plexiglas that can allow for the scanner light beams to reach the back side of the thighs and buttocks. Only a small area from the centre of the chair table, that is made from a thicker Plexiglas used to fix the leg of the chair, doesn t allow for the scanner to take data. The design included also a seat-back useful in sustaining the 16

18 paraplegic s body during the scanning procedure. Knowing that the scanning time with zsnapper scanner takes less than one minute for the entire body, the designed chair was fixed on a plate that could be set on the turntable of Vialux equipment. The scanner cart was positioned to catch data from the rotating chair and the hand scanner was placed on the ground at 50 cm distance from the backside of the turntable, with the angular field of view towards the buttocks. Both scanners were turned on in the same time, Vialux scanner catching data from the entire body and Artec scanner from the lower part of the body (Figure 4.6). The person had to sit on the chair with the legs placed on the turntable, leaned on the back seat and hands raised up above the back of the neck. The subject had to wear light colored clothes and clay markers were fixed on the body with the scope of merging together the data from both scanners (Figure 4.5). The obtained scan data were further processed in ArtecStudio and GeomagicStudio. Figure 4.5: Scheme for scanner positioning in the scanning procedure Figure 4.6: Scanning procedure with ArtecMHT and VialuxzSnapper cart The body scanner form Vialux proved to have difficulties to catch data from the areas where the light beams couldn t reach directly. There were missing parts from the top of the thighs, back legs and buttocks. The MHTArtec scanner successfully catches data from the buttocks side. The processing of the data was made in ArtecStudio. The two scans were aligned by fixing a set of point pairs between them (Figure 4.7). The result of the alignment (Figure 4.8) shows that the scanning method is accurate in catching data with the same precision with two different scanners in the same time. An.obj file was saved for further mesh processing in GeomagicStudio. The fusion method between two scan data obtained with two different scanners proved to be not only feasible but also made it possible to obtain a 3D body model in the sitting posture with less missing areas from the buttocks and back area of the thighs (Figure 4.9). With the help of these new existing scanned areas, the buttocks can be more easily repaired to follow a realistic body shape of the sitting posture (Figure 4.10). Figure 4.7: Fusion between Figure 4.8: Figure 4.9: Obtained 3D body Figure 4.10: Obtained virtual 17

19 the scans obtained from Vialux and Artec scanners Alignment result between the two scans model in GeomagicStudio body model after mesh processing 4.3. Scanning procedure for a wheelchair user The method established in this research proved to be efficient in obtaining data and lowtime consuming. The first purpose was to establish a better method by which data from the lower part of the body in sitting posture can be obtained. The second purpose was to obtain a good timing while scanning so that a disabled person wouldn t be kept for a long time in a special position. If the first trial with the handheld scanner gave an overall view of what capturing data from the sitting posture involves, the procedure of capturing data with both scanners proved to be an important step in the development of proper equipment possible to use in this case. Having the developed special chair and knowing from previous trials what is the best technique to catch data in a short time, it was possible to make a scan trial with a wheelchair user, in order to test the usability of the new chair in this special case, and the possibility to scan the paraplegic user (Figure 4.11). The first step was to see if a wheelchair user can transfer himself from his chair to the turntable. The maneuver did not bring any problem as long as the chair is stable; he can move by himself easily and fast. The second step was to see if a paraplegic person can maintain the established posture for the scanning period, sit leaned against the seat back and keep the hands over the back of the neck. Having the seat back of the chair to support him, the posture that he had to maintain for less than one minute did not create any problems to him. Because of the incapacity to maintain his legs in a proper position for the scanning process, it was necessary to use a tape to keep them in a fixed position (Figure 4.11). The procedure being established, he had to wear tight-fitting and light colored clothes to obtain a proper shape of the body during the scanning procedure. The scan data obtained with Vialux, and Artec scanners were merged together and saved for the mesh repairing process in Geomagic (Figure 4.12). After the mesh processing, a 3D body model in the polygonal phase of a paraplegic person was obtained (Figure 4.13). Figure 4.11: Scanning procedure for a wheelchair user Figure 4.12: Obtained 3D body model in GeomagicStudio Figure 4.13: Obtained virtual body model after mesh processing 18

20 The effectiveness of Artec and Vialux scanners used in the same time proved to be a first step in gathering more data from the buttocks and thighs area. The possibility of merging multiple scan data in one single 3D model using ArtecStudio was also important for the final result. In the end, GeomagicStudio proved to have important tools for easy and quick mesh processing. The faced problems in the body scanning for the sitting posture could not be yet fully solved, but the idea of the transparent chair and the combination of multiple scanners is an important step in gathering scan data in a more efficient way Body posture simulation using a kinematic template model The objective of the virtual body simulation for this research was to analyse the possibility to obtain a sitting 3D body model that could be used for the virtual development of garments. The virtual prototyping of garments nowadays offers the opportunity to design comfortable and functional clothing but the majority of the CAD systems are using, for the pattern design and fit simulation, virtual body models with a standard body shape in standing posture. One of the objectives of this research was to obtain a realistic virtual body model in sitting posture, leaded to the possibility of using the 3D animation programs that can allow obtaining different postures of a scan data from standard posture. In this part of research were achieved different body postures of the lower part of the body, going from the standing position, passing through different positioning angles, and ending with the sitting position. In order to obtain an animable kinematic body model 1, a scan data of a female person size 42 (Figure 4.14) was merged together with a kinematic template model 2 developed in a previous research [25] in 3dsMax program (Figure 4.15). Figure 4.14: Female scan image size 42 Figure 4.15: Kinematic template 1 used name for further explanations in this research regarding the merged data between the scan and the kinematic template 2 the template represents the designed kinematic human model in 3dsMax consisting of a skeleton, muscle system and surface mesh 19

21 The entire procedure of adapting the kinematic template model to the scan object was applied several times, with different scans in different sizes and different adjustment techniques, so that an optimal kinematic body model can be obtained to be used further in the animation process (Figure 4.16). From a variety of position sequences, a couple of them, with different bending angles, were selected to be used further in the study of garment construction for the sitting position. Figure 4.16: Motion sequence of the kinematic body model The selected bent positions of the lower part of the body were converted to EditablePatch, which gives a smoother geometry for the mesh edges, and exported as.obj file for 3DDesignConcept from Lectra (Figure 4.17). The exported positions were further used to study the possibility of 3D construction of trousers. It can be seen that for the sitting position there is no additional support for the sitting area that could offer a realistic body shape in this particular case. Figure 4.17: Sequence of different positions for the lower part of the body in 3D DesignConcept Chapter 5: Virtual pattern making for wheelchair users Over time, the clothing industry has switched from conventional pattern making on paper to the CAD pattern making. As early mentioned, the clothing computer design systems can include three integrated parts: 2D pattern designing, 3D garment construction and virtual try-on for clothing simulation [49]. With the development of 3D CAD technologies, the idea of 20

22 designing a garment directly on a 3D body model comes as an innovative solution for garment construction for people with certain disabilities. Few studies are analysing the 3D garment construction for people with scoliosis [145,171,172]. When it comes to the virtual prototyping of clothing for wheelchair users, the current literature is based on 2D-to-3D technique [89,91,94,95]. All these studies approached the idea of garment-fitting for the wheelchair-users by implementing CAD systems in the experimental methods regarding pattern modification. With the purpose of finding an improved solution for the pattern modification, necessary to apply for obtaining a good fitting of the garments on the body in a sitting posture, a 3D-to-2D technique is described in the following chapter. The attempt to find a standard procedure for the pattern modifications for trousers designed for wheelchair-users was also an objective in this part of research D-to-2D virtual prototyping The 3D-to-2D technique involves the construction of the garment directly on a virtual body model in the 3D environment and then the 2D pattern pieces are generated by flattening the created regions. First, construction lines defining the garment s shape are drawn on the virtual body model, then, 3D patterns are generated in accordance with the drawn regions. The obtained 3D pattern pieces are flattened into 2D patterns by applying a meshing process through a mathematic algorithm, and finally the 2D patterns are ready to be used in the creation of the garment model. The garment product that comes out from the 3D-to-2D technique follows the silhouette and the measurements implemented in the 3D body model. In this way, the phase of modifying a basic model in several steps until it matches the silhouette of the person is eliminated and the time is reduced for the product development. A 3D virtual construction of a tight-fitting trouser model was made using DesignConcept from Lectra [54]. A tight-fitting garment follows closely the contour of the body. In order to find a proper posture to obtain 2D patterns by applying the flattening procedure, many bending angles for the knee and trunk area were analysed. Three different postures with different bending degrees for the knees and trunk are detailed in Figure 5.1. First, the curves were drawn to define the trouser model, secondly, the patterns were obtained by creating the mesh regions according to the boundaries defined by the curves, and in the end the regions were flattened and 2D patterns were obtained. It can be seen that a big bending degree doesn t allow to obtain good 2D patterns for the front side hip and back knee area, as the software cannot transform the same dimensional surface from 3D to 2D (Figure 5.1 a. and b.). A posture with a lower bending degree is more appropriate to obtain good 2D patterns (Figure 5.1 c.). Taking into account the results from the pattern development with different bending angles, a posture with 90 trunk bending and 110 knee bending was chosen to create a tightfitting trouser prototype (Figure 5.2). It was kept the same bending degree in the trunk area as in the sitting posture but the in the front hip area were the flattening procedure failed, the region was divided in four. The bending degree for the knee was increased from the 90 in the sitting posture to 110 to allow the designing of a pattern to define the back of the knee. The flattening procedure was successful for each 3D pattern. The patterns for the front side hip were merged together to avoid an unnecessary seam line. The 2D pieces were converted in.dxf files and printed for sewing the trouser prototype which was tried-on by a person to check the fitting on the body. 21

23 a. b. c. Figure 5.1: Tight-fitting trouser model on: a - Posture with 90 knee and trunk bending degree, b knee bending degree and 90 trunk bending degree, and c knee bending degree and 100 trunk bending degree Considering the functionality demands of paraplegics for the comfort of garment products, it would be necessary to avoid thick and hard seams, especially in areas exposed to high levels of pressure, like back and buttocks, which can lead to pressure sores and skin wounds. Knowing this problem, it was necessary to design a new tight-fitting trouser model by reducing the seam areas in the patterns for the buttocks and thighs (Figure 5.3). The bending degree for the trunk area was raised to from 90 to 130 and for the knees from 110 to 130. The new posture was chosen to design the 3D trouser model with less seam lines and to make the flattening procedure feasible for obtaining good 2D patterns. Creating a trouser model with less seam lines on the first posture with 90 and 110 bending degree was not practicable to obtain good 2D patterns from the flattening procedure as the curvature level of the body was too big. a. b. c. d. Figure 5.2: Tight-fitting trouser model on a defined bent posture a - 90 trunk bending and 110 knee bending, b designed trouser model, c 2D patterns and d modified patterns The new tight-fitting trouser model has for the back side only two patterns, being divided only on the knee area, where the fabric needs to be reduced. The front side has three patterns, being necessary to create a dividing area for the knee, where the fabric needs to have a bigger allowance. 22

24 a. b. c. Figure 5.3: Tight-fitting trouser model with less seam line areas on a defined bent posture a trunk bending and 130 knee bending, b designed trouser model, and c - 2D flattened patterns Making a comparison with the first patterns, there can be seen that even if the bending degree was smaller, there were still obtained the necessary modifications for the interest areas, buttocks, crotch and knees. The unnecessary seam lines were in this way excluded and the information about the dimensional change for the specific areas still obtained Fit simulation for the tight-fitting trouser model With the purpose to verify the fitting of the patterns obtained from 3D-to-2D technique, it was done further a virtual fit simulation on a 3D body model. For the obtained 2D patterns in the 3D-to-2D methodology, the virtual fit simulation was done, in this part of research, using ModarisV8R1 program. For the trouser simulation on the mannequin, an interactive prepositioning of the patterns was necessary (Figure 5.4). There can be seen from the fit simulation (Figure 5.5) that the patterns from the back side don t fit in a good way. The reason is that in the 3D-2D flattening procedure the mesh surface in the curved area can suffer some modifications because of the inaccuracies in flattening such curved pattern pieces. The differences between the 3D surface and 2D surface can vary accordingly to the level of the curvature. Figure 5.4: Interactive preposition of the patterns Figure 5.5: Simulated trousers 23

25 In order to see if an ease value would solve the problem for the 3D trouser model in the virtual simulation process, the 2D patterns were modified further by increasing the width. The patterns were modified following the dimensions of a basic trouser size 42 ( ) 3, with the waist girth of 80 cm, knee girth of 25 cm and the trouser hem width of 22 cm. Figure 5.6: Virtual simulation of the modified 3D trouser model with fabric ease distribution The modified patterns were stitched together in Modaris and after this exported in Modaris 3D. The seam lines were defined, the same fabric was chosen and after the preposition of the patterns, from the Assembly command bar the Simulate process was applied. Although there was obtained a better fit, the knee line was properly situated and the ease distribution showed a good fitting for comfort, but the problem with the back side was still not solved (Figure 5.6). That means the missing part from the flattened pattern for the back side could not be corrected only by modifying the ease in width of the 3D model. Analysing the functional traits of the obtained 2D patterns it can be seen that the trousers for the bent posture needs the following modifications for a better fitting on the body: - a bigger back crotch length to cover properly the back side, so, it was necessary to measure the back crotch length for this position to be used in the pattern construction process, - the length for the front crotch had to be shortened to offer a proper fitting in the waist line, - the fabric from the back knee area had to be reduced to avoid the excess of folds that could bother the skin, and - the fabric for the front knee needed more allowance to offer a good comfort in the sitting posture. Although it offers good information about the pattern modification, the 3D-to-2D technique cannot be used without modifications to obtain directly tight-fitting trousers for a bent position because of the flattening process error. Therefore, the fitting traits from the 3D trouser model were further analysed to see if there is a possibility to obtain customized loose-fitting trousers by applying the modifications resulted from the 3D-to-2D technique D-3D virtual prototyping As stated before, 2D-to-3D virtual prototyping involves the 3D simulation of 2D designed patterns. In this manner, the patterns are designed at the beginning in the conventional body height, 96 - breast girth, hip girth 24

26 way in CAD programs and after this are imported in the 3D simulation programs. A 2D basic trouser model was designed following the pattern construction specifications of size 42. The patterns were further modified following the changes from the flattened patterns of the 3D trouser model. The fitting, of both the basic trouser and the modified one, was analysed for the bent posture The construction of basic trouser patterns and fit simulation Figure 5.7: Front and back basic patterns for women trousers (size 42) The 2D construction of the basic patterns for the women trousers size 42 (the size of the scan data that was used to obtain in the animation program different positions of the lower part of the body) was done following the measurements for the construction of ladies' outerwear based on the DOB size charts of the DOB - Verband, Cologne Edition 1995, using Modaris program from Lectra. The needed line segments, curves or circles were calculated using the specific mathematical formulations from the construction specifications chart, defining body dimensions like inseam or side-seam length, crotch length, waist or hip line etc. After completing the entire network of necessary lines for the patterns, the front and back pieces were extracted (Figure 5.7) and used further for the virtual fit simulation. To verify the correctness of the obtained 2D basic patterns, the virtual fit simulation was done on the standing posture obtained in 3dsMax (Figure 5.8). The fitting result showed that the obtained trouser model was suitable for the standing posture. Next, the fit simulation of the basic trouser was made on the bent position with a bending angle in the knees and trunk area of 130. From the virtual fit result (Figure 5.9) it can be seen that a basic trouser, in a bent position of the body, suffers some fit modifications. The back side of the body remains uncovered and the front waist line of the trousers goes upper than the natural waist line. In the back side of the knees some extra folds are appearing. All of these aspects would cause discomfort for a wheelchair user that spends all time sitting. 25

27 Figure 5.8: Fit simulation of basic trousers on a standing position front, side and back views Figure 5.9: Fit simulation of basic trousers on a bent position with 130 bending degree for the knees and trunk front, side and back views Modification of the basic trouser patterns According to the results from the fit simulation it was concluded that the basic patterns must be modified in the back area by extending the crotch. Next, the fitting traits from the 3D trouser model were analysed to see if there is a possibility to obtain customized loose-fitting trousers by applying the modifications resulted from the 3D-to-2D technique. The basic patterns were further modified following the changes from the flattened patterns of the 3D trouser model. For the back side pattern, the dimension of the crotch length was increased with 4 cm and the dart was closed to avoid unnecessary seam lines. The pattern was divided in the knee area to reduce the fabric for the knee back line with 6 cm. For the front side pattern, the crotch length was reduced with 8 cm and for the knee area it was given allowance by creating two darts of 1.5 cm. The procedure that was done to transform the patterns for the basic trousers followed logical and calculated steps. The new model of trousers combines the traits of a loose-fitting trouser with the shape and dimensional characteristics from the tight-fitting trouser model (Figure 5.10 and 5.11). 26

28 Figure 5.10: Back view for the three pattern models Figure 5.11: Front views for the three pattern models Fit simulation of the modified basic trousers To verify the correctness of the modified trouser model it was necessary to make also a virtual fit simulation. Analysing the obtained fit result (Figure 5.12), it can be seen that the new trouser model had a good fitting for the waist area. The back side was covered and the front waist line had a good position to offer comfort for the bent body position. The small fold that appears in the back waistline can be adjusted with an elastic waist band that in the simulation process was not designed. The modification of the pattern in the back knee area reduced the number of fabric folds. From the fabric ease distribution (Figure 5.13) it can be seen that the trouser has a good fitting degree. The part of the waistline and crotch area with an ease allowance of cm is offering balance for the trouser to fit on the body. Going down from the crotch area, the ease allowance increases, offering comfort to the body. Figure 5.12: Fit simulation of the modified basic trouser Figure 5.13: Fabric ease distribution for the modified basic trouser 27

29 5.4. Designing a pair of trousers for a man wheelchair-user The next step was to take a basic trouser model for men and to apply the pattern modifications which were made in the case of the women trousers. By comparing the obtained body measurements for the wheelchair user for the hip area with the size chart SizeGermany of the dimensional specifications for clothing designed for men, a basic trouser model size 52 (Figure 5.14) was created and further modified (Figure 5.15) so that the prototype can be tried-on by the wheelchair-user. Taking measurements of the body of the wheelchair user, it was concluded that the knee line has to be lowered with 3 cm for a better fitting on the body. Figure 5.14: Back and front patterns for a man trouser model, size 52 Figure 5.15: Modified patterns for the men trouser model So, on size 52 patterns, the length of the basic trouser was lowered with 3 cm from the knees down. The obtained patterns were further printed, prepared for sewing and then try on by the wheelchair user (Figure 5.16, Figure 5.17). For the trouser prototype it was chosen a zipper with the same length as the front crotch, so that the dressing process can be easier. For the waistband it was chosen an elastic tape to fix the trouser on the body and to prevent the slipping when the person has to move from the chair. According to the discussions with the wheelchair-user, the trouser prototype was fitting in a good way, following his demands regarding fit comfort. Because of the conformation of his body, with a more prominent belly, he said he prefers the front waist lower with 2 cm, but it was not a big inconvenient for him. This aspect cannot be valid for all the wheelchair-users, as it depends on their particular preferences and body morphology. The back was fully covered, and the knee line was fitting well, with reduced folds for the back knee. The fact that the trousers were loosefitting was from his point of view a good aspect, as it can hide the deformity of the atrophied legs. 28

30 Figure 5.16: Modified trouser prototype size 52 Figure 5.17: Wheelchair-user wearing the modified trouser model size 52 When it comes to the used fabric, the person said he prefers and uses for daily living, jeans trousers made from 100% cotton, as it lets his skin to breath properly and the fabric has a lower elasticity level to help him move when he grab his legs from one side to another. 29