The Desiqn and manufacture of a lightweight cost effective wheelchair for third world countries
Title: The Design and manufacture of a lightweight cost effective wheelchair for a third world context B.A Honours Dissertation Module code: RMH8XA4 Student name: Jason van der Linde Student number: 201371004 University of Johannesburg: Faculty of Art, Design & Architecture Department of Industrial Design Supervisor: Martin Bolton
Anti - Plaqiarism Declaration University of Johannesburg Department of Industrial design Assignment title: Full name: Jason van der Linde Student number: 201371004 Course: Industrial design Supervisor: Martin Bolton Due Date: 12 November 2016 1.
Plagiarism is to present someone else’s ideas as my own.
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Where material written by other people has been used (either from a printed
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I declare that I have written my own sentences and paragraphs throughout my essay and I have credited all the ideas I have gained from other people’s work.
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I declare that this assignment is my own original work.
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I have not allowed, and will not allow, anyone to copy my work with the intention of passing it off as his or her own work.
10. I understand that if someone else submits work that is copied from my own, I may be held liable Signature……………………………………………… Date…………………………………………………
source or from the internet), this has been carefully acknowledged and referenced. I have used the Geneva Convention for citation and referencing. Everything contribution to and quotation from the work of other people in this assignment has been acknowledged through citations and references. 3.
I know that plagiarism is wrong.
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I understand what plagiarism is and am aware of the faculty’s and University’s policy in this regard.
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I know that I would plagiarise if I do not give credit to my sources, or if I copy sentences or paragraphs from a book, article or internet source without proper citation.
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I know that even if I only change the wording slightly, I still plagiarise using someone else’s words without proper citation.
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Table of Contents Anti - Plaqiarism Declaration .........................................................i List of Fiqures ............................................................................. iii List of Annexures ......................................................................... v Acronyms ................................................................................... vi Abstract ..................................................................................... vii Chapter 1: Introduction..................................................................... 1 1.1 Introduction to study ................................................................... 1 1.1.1 Background ................................................................ 1 1.2 Aims, goals and objectives ........................................................... 2 1.3 Problem Statement ...................................................................... 2 1.4 Research Question ....................................................................... 2 Chapter 2: Literature Review ............................................................ 3 2.1 Introduction ................................................................................. 3 2.2 Wheelchairs and how they work? ............................................... 3 2.3 Spinal cord Injuries....................................................................... 4 2.4 Wheelchair components. ............................................................. 5 2.5 Wheelchair Precedents ................................................................ 7 2.6 Perceptions and frustrations faced by wheelchair users ............. 9 2.7 Social barriers faced by wheelchair users. ................................. 10 2.8 Designing wheelchairs third world conditions ........................... 10 2.9 Theoretical Frameworks ............................................................ 11 2.9.1 Human Centered Design: ................................................ 11 2.9.2 Emotional design............................................................. 12 2.9.3 Anthropometrics and Ergonomics .................................. 13 Chapter3: Research Methodology............................................... 14
3.2 Research Design ......................................................................... 14 3.3 Sample Group ............................................................................. 14 3.4 Data Collection and Analysis ...................................................... 17 3.5 Design Process............................................................................ 17 3.6 Ethical Considerations ................................................................ 17 Chapter 4: Data Analysis ................................................................. 18 4.1 Introduction ............................................................................... 18 4.2 Analysing data ............................................................................ 18 4.2.1 Cost.................................................................................. 18 4.2.2 Weight ............................................................................. 20 4.2.4 Wheelchairs available ..................................................... 21 4.2.5 User Preferences in wheelchairs ..................................... 23 4.2.6 Pump action vs manual ................................................... 24 4.2.7 Summary of Findings ....................................................... 25 Chapter 5: Design Process 5.1 Design Process............................................................................ 26 5.2 Design feedback ......................................................................... 27 5.3 User Feedback ............................................................................ 29 5.4 Design Refinement ..................................................................... 29 5.5 Wheelchair Functional Test Prototype....................................... 29 5.7 Standard Components ............................................................... 30 5.8 Manufacturing the Wheelchair .................................................. 31 5.6 Design Finalisation ..................................................................... 33 5.10 Corporate Identity and Branding ............................................. 34 Chapter 6: Conclusion & Recommendations .................................. 36 6.1 Summary of the design Outcome .............................................. 36 6.2 Recommendations for further study.......................................... 37 Sources Consulted ........................................................................... 32
3.1 Research paradigm .................................................................... 14 Page | ii
List of Fiqures Figure 1: Designer unknown, User Guide To Buying A New Wheelchair, 2016. (UN Health Solutions website) .......................................................... 1 Figure 2: Quickie (Designer), Manual Wheelchair, 2015. (Cool Chair Decoration Ideas website 2016) ....................................................................... 3 Figure 3: Designer unknown, Electric wheelchair, 2016. (Mobility Solutions website 2016) ....................................................................................... 3 Figure 4: Designer unknown, Sports wheelchair, 2014. (Whats your problem website 2016) ..................................................................................... 3 Figure 5: Designer unknown, Standing wheelchair, 2011. (Discover your mobility website) ....................................................................................... 3 Figure 6:Visual representation of SCI's, 2016. (Graphic by Author) .............................................................................................................................. 4 Figure 7: Designer unknown, Wheelchair measurements, 1987. (Prosthetics and Orthotics journal 1987) ................................................................ 7 Figure 8: Progeo (design), Casters and footrest, 2015. (Progeo website 2015) ............................................................................................................ 6 Figure 9: Progeo (designer), Push Rims, 2016. (Atoform website 2016) ....................................................................................................................... 6 Figure 10: Progeo (designer), Quick Release mechanism, 2016. (Medical expo website 2016) ................................................................................... 6 Figure 11: Progeo (designer), Push handles and seat, 2016. (Atoform website 2016) ................................................................................................. 6 Figure 12: ROHO (designer), Cushion, 2016. (ROHO website 2016). (Medical expo website 2016) ............................................................................. 6 Figure 13: Progeo (designer), Monocoque Chassy, 2016. (Atoform website 2016) ...................................................................................................... 6 Figure 14: Progeo (designer), Brakes, 2016. (Medical Expo 2016) ................................................................................................................................ 6 Figure 15: Benjamin Hubert (Designer), Layer Go, 2016. (Layer website 2016) ........................................................................................................... 8 Figure 16: Amos Winter, Jake Childs and Jung Tuk (Designers), Leveraged Freedom Chair,2015. (icsid website 2015) .............................................. 8 Figure 17: Designer unknown. Trekinetic wheelchair, 2016. (Trekinetic website 2016)............................................................................................... 9 Figure 18: Carbon Black (Designer), Carbon Black wheelchair,2015. (Carbon Black Website) ..................................................................................... 9 Figure 19: IDEO (designer), Human Centered design Process, 2015. (Human Centered Design Field Guide 2015) ................................................... 12 Figure 20: Participants found in the study, 2016. (Graphic by Author) ....................................................................................................................... 15 Figure 21: Human Centered Design Process, 2016. (Graphic by Author) .................................................................................................................... 16 Figure 22: Medical Aid costs, 2016. (Graphic by Author) ............................................................................................................................................ 19 Figure 23: Designer unknown, Wheelchairs sold at CE Mobility, 2016. (CE Mobility website 2016) .......................................................................... 19 Figure 24: Folding vs Rigid Wheelchairs, 2016. (Graphic by Author)........................................................................................................................... 20 Figure 25: Amos Winter, Jake Childs and Jung Tak (Designers) Leverged Freedom Wheelchair, 2011. (Core 77 website 2011) ............................... 21 Figure 26: Benjamin Hubert (Designer), Layer Go Wheelchair, 2016. (Core 77 website 2016). ................................................................................. 21 Page | iii
Figure 27: Designer unknown, Carbon Black Wheelchair, 2015. (Carbon black Website 2015) ................................................................................. 21 Figure 28: Mike Spindal, Trekinekt Wheelchair, 2008. (Independent website 2015) ................................................................................................. 21 Figure 29: Data analysis of existing wheelchair, 2016. (Graphic by Author) ............................................................................................................... 22 Figure 30: Grit Freedom Chair (Designer), Pump Action Mechanism, 2016. (Grit website 2016) .............................................................................. 24 Figure 31: Initial designs, 2015. (Graphic by Author) .................................................................................................................................................. 26 Figure 32: Kerry persona, 2016. (Graphic by Author) .................................................................................................................................................. 27 Figure 33: Design Feedback, 2016. (Graphic by Author) ............................................................................................................................................. 28 Figure 34: Wheelchair prototype, Johannesburg, 2016. (Photographed by Author) .................................................................................................. 29 Figure 35: CE Mobility manufacturing facility, Johannesburg, 2016. (Photograph by Author) ................................................................................... 30 Figure 36: Front and side profile dimensions, 2016. (Graphic by Author) .................................................................................................................. 30 Figure 37: Stress diagrams on axle,2016. (Graphic by Author from Solidworks) ........................................................................................................ 31 Figure 38: Wheelchair Frame, 2016. (Graphic by Author) ........................................................................................................................................... 32 Figure 39: Front Footrest and Forks, 2016. (Graphic by Author)................................................................................................................................. 32 Figure 40: Side profile of Wheelchair, 2016. (Graphic by Author)............................................................................................................................... 32 Figure 41: Friction Clamps, 2016 (Graphic By Author) ................................................................................................................................................ 32 Figure 42: Axle mount and Riser, 2016. (Graphic by Author) ...................................................................................................................................... 32 Figure 43: Final Wheelchair Design, 2016. (Graphic by Author) .................................................................................................................................. 33 Figure 44: Emerge Logo, 2016. (Graphic by Author) ................................................................................................................................................... 34 Figure 45: Emerge Advert, 2016. (Graphic by Author); ............................................................................................................................................... 35
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List of Annexures Annexure A:
Informed Consent Forms
Annexure B:
Consent Form
Annexure C:
Initial Interviews
Annexure D:
Precedent Review Pack
Annexure E:
Medical Aid Costs
Annexure F:
Boards
Annexure G:
Design Feedback
Annexure H: User Specification Form Annexure H: Annexure I:
Refinement Review Kits
Annexure J:
CNC Bending Brochure.
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Acronyms ADA:
Americans with Disabilities Act
ATW:
All Terrain Wheelchair
CB:
Carbon Black
HCD:
Human Centered Design
LFC:
Leveraged Freedom Chair
MIT:
Massachusetts Institute of Technology
OT:
Occupational Therapist
SCI:
Spinal Cord Injuries
USAID: United states Agency for Interactional Development
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Abstract In this mini dissertation, the research and design of a rigid wheelchair is explored, motivated by the high cost and low weight of imported wheelchairs in relation to what is available in South Africa. Research shows the number of Spinal Cord Injuries (SCI) happening annually are on the rise, particularly in developing countries. Wheelchairs needed for SCI’s are designed to specific user requirements and more often imported from abroad, since locally produced wheelchairs do not achieve the same high standard of quality and durability. By analysing qualitative data from relevant literature and field work, a framework of key issues/themes was developed. The study follows a Human Centered Design (HCD) approach through phenomenological paradigm using qualitative research. Interviews with participants i.e. wheelchair users, occupational therapists, physiotherapists and industrial designers were used as primary sources for this research. A final design was developed through multiple stages of ideation and testing. New manufacturing technologies were considered to streamline the manufacture of wheelchairs and reduce both cost and weight, while making a product which can handle the environmental conditions in third world countries. The aim was to design a quality wheelchair which fits within medical aid cover parameters in order to provide a better quality of life for users.
Keywords: Wheelchair, Human Centered Design, Industrial Design, Mobility, Quality of Life, Durability, Functionality, Cost, Weight, Environmental Condition
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Chapter 1: Introduction 1.1 Introduction to study 1.1.1 Background The design of manual wheelchairs has scarcely evolved over the past decade (Sawatzky 2002: [sp]). Changes made have primarily been in the form of new materials to aid weight reduction, manoeuvrability and transportation (Custom wheelchairs 2005). The aim of a well-designed wheelchair is to provide a better quality of life for users, whom the wheelchair will become an orthosis. Unlike standard hospital wheelchairs, where one size fits all, paraplegic/quadriplegic’s wheelchair are specialised and therefore must be custom made specifically to the measurements of the user’s body (Figure 1). The custom fitting of a wheelchair minimizes the likelihood of injuries and addresses specific needs of the user. Currently, higher end wheelchairs like Tilite (America), Progeo (Italy) and Quickie (America) wheelchairs are all imported into South Africa. These imported chairs are costly, often exceeding the cost covered by medical aids and are better suited to first world environmental conditions. Under these ideal conditions, wheelchairs sustain limited impact on components, vastly different from third world environments where uneven/badly
Figure 1: Designer unknown, User Guide To Buying A New Wheelchair, 2016. (UN Health Solutions website)
constructed road surfaces take their toll on componentry. Wheelchairs currently made in South Africa are designed for cost effectiveness and cannot compare to the quality of imported products (McIntyre 2010: 29). The aim of this study is to design a manual wheelchair more suited to a third world context, using high quality components but at a cost covered by Medical Aids.
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1.2 Aims, goals and objectives It is estimated that the number of people who require wheelchairs will increase by twenty two percent over the next ten years, the greatest need stemming from developing countries (Diseno 2011). This project attempts to redesign and develop a wheelchair more appropriate to the South African market, by developing a product which rivals imported wheelchairs through price, quality and aesthetic appeal. The Human Centered Design (HCD) approach was chosen to better inform technical and ergonomic decision making while user feedback highlighted issues with wheelchairs currently available in South Africa. The improvement in design/quality aims to improve the quality of life for individuals living with disabilities within a local context by making the wheelchairs more easily accessible, cost effective, durable and easily repairable.
anthropometrics and attempt to elevate user’s self-confidence. 1.4 Research Question How can a Human Centered Design approach be used to develop a more appropriate wheelchair suited to a third world context, while addressing the high cost and weight of wheelchairs available?
1.3 Problem Statement The purpose of this study is to examine accessibility of wheelchairs considering price and cover offered by medical aid schemes. This research will aid in the design of a more suitable, lightweight, cost effective solution for third world context, with an emphasis on ergonomics and
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Chapter 2: Literature Review 2.1 Introduction This literature review explores theories relating to Human Centered Design, Emotional Design, Ergonomics and Anthropometrics. Key areas were identified and discussed to develop the basis of a theoretical framework informing the design process. The occurrence of SCI’s emphasised the growing need for wheelchairs, especially in third world countries. A brief explanation of wheelchairs and how they work, helped explore options available. Precedents currently available were considered and discussed to established an understanding of wheelchair design and how the options target different markets. Daily problems faced by users relating to social and environmental barriers would be discussed.
2.2 Wheelchairs and how they work? The Americans with Disabilities Act (ADA) defines a wheelchair as a “manually operated or power-driven device designed primarily for use by an individual with a mobility disability for the main purpose of indoor, or of both indoor and outdoor, locomotion” (What is the definition of a wheelchair under the ADA 2016).
1. Figure 2: Quickie (Designer), Manual Wheelchair, 2015. (Cool Chair Decoration Ideas website 2016) 2. Figure 3: Designer unknown, Electric wheelchair, 2016. (Mobility Solutions website 2016) 3. Figure 4: Designer unknown, Sports wheelchair, 2014. (Whats your problem website 2016) 4. Figure 5: Designer unknown, Standing wheelchair, 2011. (Discover your mobility website)
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Figure 6: Visual representation of SCI's, 2016. (Graphic by Author)
A manual wheelchair (Figure 2) typically consists of two large wheels which are attached to an axle, with two caster wheels near the footrest, a seat and backrest (either moulded or fabric). Each large wheel has a push rim attached made from either metal or plastic (Wheelchairs: Information & Reviews 2016). A wheelchair is operated by pushing the push rims on the outside of either wheel. Electric wheelchairs (Figure 3) are propelled forward by using a motor or battery operated by either a joy stick or buttons. Electronic wheelchairs are able to traverse various terrain with ease, some even capable of climbing stairs. These wheelchairs are very expensive and heavy in comparison to manual options.
There are, however, variations of both manual and electronic wheelchairs available to cater to different user’s needs, these include: Sports wheelchairs (Figure 4) are stable, ultra-lightweight wheelchairs used for playing sports like basketball, rugby, tennis and running marathons. The wheels have a large camber creating a tighter turning circle designed for quick movements. Standing wheelchairs (Figure 5) are designed to support users in a standing position. They give users the option of either a seated manual wheelchair or standing frame. The change from sitting to standing can be achieved manually or through the use of hydraulic pumps.
2.3 Spinal cord Injuries Individuals may require wheelchairs for a number of reasons, these include: amputations, arthritis, back disorders, cerebral palsy, neuromuscular disorders, fibromyalgia and spinal cord injuries. Many of these impairments, however, allow use of a standard medical wheelchair which can be purchased locally without the need for any specialist fitting. Spinal Cord Injuries (SCI), on the other hand, require custom wheelchairs to fit the users body to improve comfort (Custom wheelchairs 2015). Paraplegics and quadriplegics (Figure 6) make up the category of SCI’s. Paraplegics are individuals with T-9 to T-12 spinal injuries, they have complete paralysis from the waist down, however, they retain good trunk control (Paraplegia Page | 4
and Paraplegic 2015). On the other hand, quadriplegics, have C1-C7 spinal Injuries. C1-C4 users are completely paralysed from the neck down, C5-C7 injuries result in paralysis from the chest down allowing upper body movement (Quadriplegia and Quadriplegic 2015). According to the journal article, A global map for traumatic spinal cord injury epidemiology: towards a living data repository for injury prevention, the leading reasons for SCI’s in South Africa are (Cripps, Lee, Wing, Weerts, Mackay, Brown 2011: 495):
30% - Land transport 8% - Falls 5% - Sports/ recreation 61% - Violence/ self-harm 13% - Work related
Developed countries are found to be at lower risk of getting SCI’s from land transport since they have safer cars, better road design, mandatory licensing and training in place, unlike developing countries with poor infrastructure, less regulations, enforcement and poor safety regulations (Cripps, Lee, Wing, Weerts, Mackay, Brown 2011: 495). Globally it is reported that between 2361009 people per million are impaired with SCI’s, unfortunately there is no published
data available for Africa (Cripps, Lee, Wing, Weerts, Mackay, Brown 2011: 495). Research in 2015 estimated around 12 500 new cases of SCI occur every year and there are approximately 240 000-377 000 people currently living with SCI’s in the United states. While no data is available for Africa, McIntyre’s report shows amongst the 5.8 million people living in Kwa-Zulu Natal (KZN), 18 852 need wheelchairs. This means approximately one in every 307 people in KZN need a wheelchair.
2.4 Wheelchair components. “No single chair design is apt to meet all the needs of each individual, but careful thought and attention to detail in prescription preparation can result in a chair that meets most of the needs of the paraplegic” (Wilson 1987: 90). When a paraplegic has a wheelchair ‘set up’ there are various components to be considered, these include: seat, backrest, arms, footrest, leg rests, wheels, tires and casters (Wilson 1986: 104). Seats (Figure 12) play an important role in the comfort and stability of a wheelchair. A narrow seat creates discomfort and increases the risk of
developing pressure sores, whereas, an overly large seat encourages one-sided leaning and promotes scoliosis and increases pressure on one’s posterior (Wilson 1987: 83). The height of a backrest (Figure 11) is dependent on the user and how strong and able their trunk is to support their body. A backrest provides support without obstructing a user’s movement (Wilson 1987: 85). Wheelchairs can either have fixed arm rests or none at all. The arm rests create lateral support and provides space to rest the user’s arms (Wilson 1987: 85). Removable arm rests are often the most popular, they allow extra support without being a permanently fixed component (Figure 11). Standard wheelchairs have 24 inch (609.6mm) rear wheels (Figure 9). The design and manufacture of these wheels have changed over the years with various design options and materials on offer. There are three types of tyres from which to choose from i.e. pneumatic, semi-pneumatic and solid tyres. Both pneumatic and Page | 5
semi-pneumatic tyres allow better shock absorption and are more suited to outdoor use, while solid tyres are best used indoors due to their low shock absorption (Wilson 1987: 86). The casters (Figure 8), the small wheels found on the front of the wheelchair, makes steering possible. Similar to back tyres, casters are available in an array of materials and designs suited to different environments (Wilson 1987: 87) The quick release mechanism (Figure 10) allows users to easily detach wheels from the wheelchair frame. The mechanism works by applying pressure to a stepping rod which is pulled back releasing the lock shaft from the pivot (Aye, Lee, Sim, Wong, Pyae 2013). Hand rims (Figure 6) are circular tubes attached to the rims of the wheelchair and allow users to propel themselves forward. Hand rims can also have additional attachments which allow more grip (Wilson 1987: 86). As with other components, wheelchair users have a variety of options when it comes to choosing cushions. The OT
1. 2. 3. 4. 5. 6. 7.
Figure 7: Progeo (design), Casters and footrest, 2015. (Progeo website 2015) Figure 8: Progeo (designer), Push Rims, 2016. (Atoform website 2016) Figure 9: Progeo (designer), Quick Release mechanism, 2016. (Medical expo website 2016) Figure 10: Progeo (designer), Push handles and seat, 2016. (Atoform website 2016) Figure 11: ROHO (designer), Cushion, 2016. (ROHO website 2016). (Medical expo website 2016) Figure 12: Progeo (designer), Monocoque Chassy, 2016. (Atoform website 2016) Figure 13: Progeo (designer), Brakes, 2016. (Medical Expo 2016)
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would advise the user which options would best suit their needs (Figure 12). Seat cushion selection is dependent on how a user’s body disperses pressure, which helps determine the best type of cushion to be used. Materials options available include foam, gel, fluid and air, with each providing a different feel and comfort level (Wilson 1987: 88). While all these elements make up the componentry required for a wheelchair, there are also important technical details which need to be considered when designing/fitting a wheelchair. Figure 7 indicates the eightpoints OT’s measure when fitting a wheelchair user (Fig 7, dimensions A-H). These technical points differ from user to user as each body shape is different. By changing the dimensions a made to measure wheelchair can be achieved 2.5 Wheelchair Precedents Current wheelchairs with standard shapes models fit the norm and expectation of how a wheelchair should look and function. The four alternate wheelchairs under consideration are: Leveraged Freedom (Figure 16), Layer
Go (Figure 15), Carbon Black (Figure 18) and Trekinekt (Figure 19). Each of these wheelchairs have specific component(s) which makes it unique, i.e. materials or manufacturing processes. The leveraged Freedom Chair (LFC) was designed by MIT students Amos Winter, Jake Childs and Jung Tuk while undertaking their PhD in mechanical engineering (Diseno 2011) (Figure 16). Through research these students discovered evidence indicating an estimated increase in demand of wheelchairs over the next ten years, with the highest demand arising from developing countries (Diseno 2011). The United States Agency for International Development (USAID) estimates around twenty million people in the developing world require a wheelchair (Diseno 2011). With this knowledge, Winter, Childs and Tuk set out to design a wheelchair for users in third world countries. The LFC wheelchair uses technology similar to a mountain bike able to tackle various
Figure 14: Designer unknown, Wheelchair measurements, 1987. (Prosthetics and Orthotics journal 1987)
types of terrain found in Africa (Leveraged Freedom chair 2015). Following their success, the team went about designing a first world version of the LFC (figure 16). This wheelchair uses a pump action system, fixed to the big wheels which sports two handles on either side to propel the user forwards. These handles create more speed/torque in relation to traditional pushing systems (Leveraged Freedom chair 2015). A three-wheel configuration with single front caster optimized the effect of the push handles. This design ensured easier maneuverability over multiple terrains and is better suited to long distance
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travel, often required in third world countries (Diseno 2011).
wheelchair has not been priced yet and will release in late 2016.
The second wheelchair considered was the GO wheelchair (Figure 15), designed by a London based design studio, Layer, which is the first ever 3D printed consumer wheelchair (Morby 2016). The Go wheelchair uses state of the art technology in seat design. A system termed ‘made-to-measure’ creates a virtual model of each user’s body and determines the exact shape and specification required to 3D print a custom seat (Go 2016).
Carbon Black(CB) (Figure 18), option three was designed to be the lightest wheelchair available and is manufactured in the UK. “Carbon Black has been designed to be very minimal so you are seen before your chair. What of the Carbon Black that is seen is very high end, designed with quality, functionality and aesthetics at its heart” (Simplicity the ultimate lightweight wheelchair 2015). A CB wheelchair weighs 5.5kg’s, almost three times lighter than a standard wheelchair (O’hare 2016). To achieve an ultralightweight wheelchair, CB is made entirely from F1 spec carbon fiber (O’hare 2016). Additional benefits of carbon fiber are: incredible strength to weight ratio; absorbs vibrations creating a smoother ride with suspension like qualities; the smooth carbon fiber won’t hurt your hands or leave them dirty after use (Simplicity the ultimate lightweight wheelchair
By using the latest technology, GO wheelchair is designed to help remove stigma’s associated with wheelchairs and create a more human centered product (Go 2016). The wheelchair designed with minimal componentry, alleviates the need for additional attachments such as brakes, instead they are seamlessly incorporated into the axle as a quick release flip handle on either side (Morby 2016). This
Page | 8 1. Figure 16: Benjamin Hubert (Designer), Layer Go, 2016. (Layer website Figure 16: Amos Winter, Jake Childs and Jung Tuk (Designers), Leveraged 2. 2016) Freedom Chair,2015. (icsid website 2015)
2015). However, an ultra-light wheelchair comes with at a premium, costing £7 500 (R140 000) (O’hare 2016). Trekinetic, the last option (Figure 17) for consideration, is a German designed wheelchair created for everyday off road capabilities and has a unique three wheeled configuration, similar to the LFC, which sports three wheels and a Carbon Fiber Bucket seat solution (Wilkins 2008). Trekinetic, however, uses a different orientation to the LFC, with two big wheels in front and a single large caster which sits behind the user. This three-wheel designed enables the user to traverse uneven and rough surfaces with ease (Wilkins 2008) in comparison to other wheelchairs using the standard two caster configuration. The Trekinetic design has enabled user’s to be mobile outdoors and over any terrain (Wilkins 2008). “The Trekinetic is an awful lot faster than a standard wheelchair and a lot better once you get off paved surfaces” (Wilkins 2008).
These four wheelchairs were considered as precedents to explore various aspects to improve the quality of life of a user by creating a wheelchair which can be moulded to an individual user. All four options showcase possibilities which can be achieved with today’s technology. 2.6 Perceptions and frustrations faced by wheelchair users The purpose of this section is to highlight issues wheelchair users face in their daily lives in terms of social barriers. In 1998, Linda L. Pierce a medical professor at the college of Ohio School of Nursing in Toledo published a journal article entitled Barriers to Access: Frustrations of People Who Use a Wheelchair for Full-time Mobility. Pierce wanted to determine what it would be like to fully rely on a wheelchair (Pierce 1998: 121). A sample of four men and five women, all fulltime wheelchair users, participated in one-on-one interviews with Pierce. The interviews showed an overwhelming majority of participants exhibited the same frustrations with: issues of Page | 9 1. Figure 18: Designer unknown. Trekinetic wheelchair, 2016. (Trekinetic website 2016) (icsid website 2015) Figure 18:Chair,2015. Carbon Black (Designer), Carbon Black wheelchair,2015. (Carbon Black Website) 2. Freedom
independence; attitudes of others towards their disabilities and a lack of understanding of their situation (Pierce 1998: 123). One participant felt particularly frustrated by people’s attitudes towards individuals with disabilities and said, “It’s kind of like saying if you are in a wheelchair, then you are all the same because you are in a wheelchair” (Pierce 1998: 122). Pierces study found wheelchair users were particularly frustrated by issues relating to independence and a lack of understanding by society towards individuals with disabilities (Pierce 1998:123). There is a stigma attached to requiring the need for an assistive device (wheelchair), the perception being an individual is not capable of performing everyday tasks because of their disability. Wheelchairs are characterised as “formal, cold and unpleasant” (Herrera 2012: 27), especially from the perspective of users with disabilities. These wheelchair characteristics may play a vital role in the reason society see’s the wheelchair before they perceive the person (Herrera 2012: 28). Ellen Lupton echoes
these thoughts in her book Beautiful users: Designing for people, where she says some users won’t use their medical device as it comes across as being a medical device. Lupton does however believe this is where design comes in, saying, ‘good design can make assistive devices more appealing to users by combining beauty and functionality (Lupton 2014: 81). 2.7 Social barriers faced by wheelchair users. Similar, to Pierce, Patricia Herrera wrote a paper titled; Usage Problems with Social Barriers Faced by Persons with a Wheelchair and Other Aids. In this paper Herrera discusses accessibility issues faced by disabled wheelchair users (Herrera 2012: 24). In 2002, the Pan American Health Organisation found accessibility and mobility to be the biggest issues facing the disabled. In her paper, Herrera identifies barriers faced by two types of wheelchair users, those with chronic pain and those without. In describing these barriers, both groups of wheelchair users faced similar problems, such as “wheelchairs do not
meet the requirements of safety and comfort that users require to meet their needs” (Herrera 2012: 27). As the study, progressed, six usability issues were identified from the participant’s perspective: barriers for a wheelchair (usability and acceptance), creative adaptions, potential use of assistive devices, independence, perception of the body and technical aids and architectural barriers (Herrera 2012: 26-27). Lupton believes, standard wheelchairs require smooth roads, ramps and elevators, they are not designed to travel over anything but ideal conditions (Lupton 2014: 81). 2.8 Designing wheelchairs third world conditions In a journal article entitled Problems, struggles and some success with spinal cord injury in Zimbabwe published by the university of Harare, it was found that wheelchairs designed and manufactured abroad were not suitable both in the use of materials, (which could not withstand the heavy usage) and the types of terrain (rural pathways and tracks) the wheelchairs have to traverse. Tough terrains create issues Page | 10
with the front, used for steering casters (ZIMBABWE READING- 215). Surona Visage, Elsje Scheffler and Marguerite Schneider touch upon this in their reading “Policy implementation in wheelchair service delivery in a rural South African setting�, describing an appropriate wheelchair as being a product that can play a key role in improving quality of life (Visagie, Scheffler & Schneider 2013: 3). In this reading they highlight the same issues as (Zimbabwe reading) stating that current infrastructure found in third world countries is poor with mostly gravel roads, footpaths and little public transport. What is highlighted by many of these authors is, currently, wheelchairs imported from other countries which have appropriate infrastructure in place, are not appropriate for conditions found in third world countries. Even if the wheelchair user lives/works in an urban area where conditions are better, there are still environmental barriers such as buildings not being conducive to wheelchair users.
Not only is the functionality of the imported wheelchairs problematic, they also tend to be costly. June McIntyre in her article Wheelchairs - A human rights issue or a mere Mobility Device? McIntyre highlights the issue of parts when it comes to buying wheelchairs from international companies. Often, local parts do not fit and new parts required must be imported. Not only are parts costly, lead times and delivery for orders placed are lengthy long time, even more so for those in rural settings (McIntyre 2010: 29), where postal services are rare or non-existent. 2.9 Theoretical Frameworks 2.9.1 Human Centered Design: HCD is an approach, which builds a sustainable relationship between a product and a consumer (Elmansy 2015). HCD aims to create a greater interactive experience between systems and humans by using ergonomics (Elmansy 2015). At the start of HCD (Figure 19), one does not know the solution to a given design challenge (The Field Guide to Human-
Centered Design 2015: 21). However, through interaction with individuals and constant progression, a design solution is eventually formulated. HCD is by no means a linear process, but rather includes a lot of back and forth between the various stages (The Field Guide to Human-Centered Design 2015: 11), these stages are: inspiration, ideation and implementation. Inspiration allows better understanding of the individual being designed for and gaining insight into their issues help inform any decision making (The Field Guide to Human-Centered Design 2015: 12). This information is gathered for the ideation stage. During ideation, various concepts are explored to identify solutions addressing relevant issues, refined and progressed into a final design solution (The Field Guide to Human-Centered Design 2015: 12). The final stage of implementation brings the solution to life, establishing how to get the design solution to market, maximizing its impact (The Field Guide to Human-Centered Design 2015: 12).
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2.9.2 Emotional design In Donald A. Normans book Emotional design: Why we love (or hate) everyday things, Norman proposes emotional design as a framework for analysing products in a comprehensive way. Norman considers how products, made up of three different dimensions are interwoven into any design. These dimensions are: visceral; behavioural and reflective (Norman 2003: 4). Norman notes that with these three components interweave emotions and cognition. Visceral dimension is concerned with the initial impact of a product relating to its appearance; the behavioural aspect focuses on how a product is experienced; and finally reflection contemplates individual perception of themselves while using the product (Norman 2003: 3). The goal of emotional design is to bring meaning to products, which otherwise would be seen as mundane (Norman 2003: 6). These beliefs are echoed in the book Design for emotion (Van Gorp, Adams 2012), “Emotions dominate decision making because they trigger and motivate behaviour� (Van Gorp, Adams
Figure 21: IDEO (designer), Human Centered design Process, 2015. (Human Centered Design Field Guide 2015)
2012: 9). Looking at emotion design we are really trying to design for an emotional response increasing the
likelihood users will complete a task (Van Gorp, Adams 2012: 51). Emotional design seeks to create Page | 12
products to satisfy the needs of a target market which are: useful; usable and ultimately desirable (Van Gorp, Adams 2012: 3). “The seductive power of design of certain material and virtual objects can transcend issues of price and performance for buyers and users alike. To many an engineer’s dismay the appearance of a product can sometimes make or break the products market reaction.” (Norman 2003: 111). Understanding visceral, behavioural and reflection dimensions could ensure the design of a product which appeals to users. Users will most likely experience emotion at a visceral and reflection level when first interacting with the product; and behavioural emotion once they have used the product for a prolonged period of time. Therefore, visceral and reflective emotional impacts are important in making a meaningful connection for the user and influencing their decision making when purchasing the product.
2.9.3 Anthropometrics and Ergonomics The Indian Journal of Occupation and Environmental Medicines journal article Ergonomics: A bridge between fundamentals and applied research defines anthropometrics as the study concerned with interactions between human and system, a discipline which aims to optimize the performance between the human and the system (Ghosh, Bagchi, Sen, Bandyopadhyay 2011: 15). Anthropometrics and ergonomics ensures understanding of: body posture; movement; environmental factors and work organisation. Together these aspects determine the health, safety, comfort and performance of a product (Ghosh, Bagchi, Sen, Bandyopadhyay 2011: 15). Using anthropometrics and ergonomics as a framework will ensure a better understanding and how to best design a product, adapted to one’s specific environmental conditions. Since wheelchairs are used up to eleven hours a day, careful consideration of ergonomics play an important role in
designing the product (Sonenblum, Sprigle, Lopez 2011: 1).
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Chapter3: Research Methodology 3.1 Research paradigm A research paradigm is a basic set of beliefs which deals with first principles, creating a world view defined by the researcher (Guba & Lincoln 1994: 106). For the purpose of this study a Phenomenological paradigm was used. The aim of phenomenology is to describe the human experience as it is lived (Creswell 2003: 15). A phenomenological approach will allow greater understanding of what a wheelchair users perceptions of their wheelchair are and issues they face. While using a phenomenological paradigm, the following additional frameworks will be used: Humancentred Design, Emotional Design and Anthropometrics/Ergonomics. These frameworks have been discussed earlier in this paper and will be used as the basis for qualitative research. 3.2 Research Design Qualitative research seeks to make knowledgeable claims and develope various themes from the data collected
(Creswell 2003: 18). It is for this reason a qualitative research methodology was used for data collection, to understand reasons, opinions and motivations relating to manual wheelchair use in South Africa (Creswell 2003: 18). Interviews with medical experts, wheelchair users and design professionals facilitated in the generation of a knowledge base from which ideas could be formulated, allowing preconceived ideas to be laid to rest. 3.3 Sample Group From a medical perspective both Physiotherapists and Occupational Therapists create understanding around issues which exist. The experience and knowledge from medical experts give greater insight into the wheelchair user’s experiences. A better understanding of requirements will be gained through communication with wheelchair users, medical experts as well as designers, in developing patterns and relationships within the research (Creswell 2003: 15). Participants from various professional fields were consulted to gain insight Page | 14
into various facets relating to manual wheelchairs (Figure 20). Two industrial designers currently working for two different wheelchair manufacturers, i.e.: CE Mobility and Shonaquip were consulted. CE Mobility is a Johannesburg based wheelchair design and manufacturing company who do also import high end wheelchairs from abroad. While Shonaquip, a Cape Town Based wheelchair company designs appropriately fitted mobility devices for children and adults, with their primary focus to design and manufacture wheelchairs for rural areas throughout Africa. A focus group of three physiotherapist’s working at the Rehabilitation Centre on Bunting road was created. These physiotherapist’s deal with quadriplegic and paraplegic patients on a daily basis and have a wealth of experience and knowledge in this field. For the purpose of this study it was important to garner information from professionals in more than one medical field i.e. physiotherapists and OT’s. Physiotherapy point of view and during the rehabilitation phase. After which the Occupational Therapist
Figure 22: Participants found in the study, 2016. (Graphic by Author)
would evaluate the patient and recommend an appropriate medical device.
The OT consulted from CE mobility, works directly with wheelchair users in recommending the best mobility Page | 15
devices dependent on their disability. The OT has an excellent understanding of ergonomics and functionality, having dealt with people from different backgrounds with varying levels of wheelchair dependence, over many years. While experts in both the medical and manufacturing sector are vital in gaining a better understanding of technical issues, wheelchairs users are important in further understanding ergonomic and functional considerations and other issues relating to everyday use from a non-medical perspective. 3.3.1 Wheelchair user group Three users were asked to participate in the study. These users, from different socio-economic backgrounds have different wheelchair requirements to suite their individual and environmental needs. Each participant was given a consent form to sign, which outlined the project, and gave permission for relevant information to be assimilated and used (Annexure B). Users would be updated and consulted Figure 23: Human Centered Design Process, 2016. (Graphic by Author)
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during the various stages of the project, their personal opinions established regarding content developed during the entire industrial design process. 3.4 Data Collection and Analysis During the data collection phase, semistructured interviews were conducted. Set question were posed to ascertain opinions relating to aspects of the project. However, these initial interviews became more of a conversation about wheelchairs and experiences. Nicholas Walliman justifies using this method stating that a personal interview “can ensure a high response rate and accurate information� (2011:190). At various stages in the interview pertinent points were elaborated on. All interviews were recorded and transcribed, these transcriptions would later be used in the data analysis to identify common issues or recurring themes/patterns (Annexure C). These patterns would then be used to identify key issues to be addressed in the project.
3.5 Design Process A brief was developed in response to the various themes/issues identified through relevant literature and fieldwork. In Figure 21 the iterative process was documented using a Human Centered Design approach. For the purpose of this project three iterative stages were used which includes design, prototyping, testing and further refinement of concepts who gave feedback after/during each phase were used. Design review packs were completed by participants giving feedback relating to each stage. Involving users, medical experts and designers ensured a USD approach would form a holistic and complete world view. 3.6 Ethical Considerations The ethical approach centred around medical perspectives. The General ethical guidelines for health researchers (2008: 7- 10) provided by the Health and Professionals Council of South Africa was used as a guide to ensure correct ethical processes were used.
These approaches include: informed consent from all participants (See Annexure B); anonymity for all participants where the end user disclosed only information relevant to the project. Participants were informed about their rights and their ability to opt out of the project at any given point. In essence they were not bound to the project in any way. Sensitivities were considered to avoid offending participants while a level of respect and dignity was always maintained. Only adults over the age of 18 were interviewed and to avoid ethical dilemmas, no prototypes were tested by users. Instead, prototypes were assessed from a fundamental understanding of the principles of what does and does not work and was based purely on participant’s opinions.
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Chapter 4: Data Analysis 4.1 Introduction Data was collected and compiled from academic sources, literature reviews and field work findings. Semistructured interviews were conducted during July to August of 2016. These Interviews allowed various design directions to be considered. The analysis which follows, helped identify key issues highlighted by participants. Interviews were conducted with both CE Mobility and Shonaquip and included observations during a walk about of the manufacturing facilities. 4.2 Analysing data The data collected from interviews allowed analysis with regards to: cost, weight, rigid versus folding wheelchair, comparison of current wheelchair available, preferences and pump action versus manual wheelchairs. These areas of discussion have been identified as the key areas where either issues or opportunities arouse facilitating the eventual design of a wheelchair.
4.2.1 Cost Various issues arose during the initial interview process, the most salient being affordability. All users who require wheelchairs face issue’s relating to cost, which determines the type and quality of wheelchair users can purchase. (Physio3: 160-163). Spinal patients require a “very specific wheelchair” (Physio 2: 73-74), customised to their needs. This ‘tailored fit’ comes at a premium cost to users (ID2: 57-58; Physio 2: 90; User1: 17-19) who are highly dependent on their medical aids to fund their wheelchairs. “Ultimately it boils down to cost, cost is a huge issue” (Physio1: 42). Four medical aid companies were consulted to understand disability cover: Discovery health; Bonitas; GEMS (Government Employee Medical Aids Scheme) and Fedhealth. Medical cover (Annexure E) is dependent on the medical aid company and type of plan chosen. “On most medical aids you can replace your wheelchair every 2 years” (Physio1: 37-38), while some medical aids only allow a new chair every two to three years. This requires the wheelchair to be durable enough to last Page | 18
F
for a period of at least two to three years (Pysio1: 41). Medical aids like GEMs and Discovery have very good policies regarding disability cover, offering a higher cover for medical devices. On average, Discovery and GEMS cover R32 800 and R33 850 respectively (Figure 22). Companies like Bonitas and Fedhealth provide a lower cover with the average being R6 862 and R12 650 respectively (Figure 22). To put this into perspective, with cover of R32 800 a wheelchair user would be unable to afford a mid-tier Neon Quickie (imported) wheelchair without any extra’s retailing for R41 000 (Figure23) (CE mobility Q/R Cruiser 2015).
Figure 25: Medical Aid costs, 2016. (Graphic by Author)
Companies like CE Mobility offer cost effective alternative such as the Rollability MK2 for R21 513 (Figure 23) (CE mobility Q/R Cruiser 2015). While this is an alternative, users believe “there is no chair currently made in the country that is worthwhile” (User2: 47-48).
Cost was identified as most important in securing the right type of wheelchair at a price covered by medical aids. While this price of the wheelchair needs to be brought down, the wheelchair must still maintain a high level of durable enough to last two to threeyear period between getting a new wheelchair. Page | 19
Figure 26: Designer unknown, Wheelchairs sold at CE Mobility, 2016. (CE Mobility website 2016)
4.2.2 Weight Another big issue relating to wheelchairs is their weight, “everything is about making it light” (OT: 39-40). Wheelchairs available offer a wide range of materials to choose from including aluminium, steel, Chromemoly, titanium and carbon fibre to name a but few. While completing the user specification form users are able to select any of the specified material options (Annexure H). Choice of materials, however, affect the cost of the wheelchair, where lighter materials command a higher price. Weight of a wheelchair can hugely impact the user depending on the type of disability hey have and their strength. “When I choose a wheelchair it’s about lightness, because I’m a quad and I don’t have full strength. It’s got to be light.” (User1: 62-64). Wheelchairs weighing less, make propulsion easier for users who lack strength in their upper body (User1: 48-49). Users interviewed preferred lighter alternatives to the current options available, this included those who own carbon fibre frames. “It’s light, but it
Figure 27: Folding vs Rigid Wheelchairs, 2016. (Graphic by Author)
could be lighter” (User1: 39). Not only do wheelchair users have to deal with pushing themselves around, but, they also need to be able to lift their wheelchairs when climbing in/out of vehicles. It is important to consider both those using the wheelchair and the individuals assisting the user. Rigid wheelchairs afford the likelihood of designing a lighter product since it offers the possibility of using less components. “the lighter you go the less bolts or screws you want” (OT: 108). “Designers of some of the ‘sports’
chairs, in order to reduce weight, have eliminated the folding mechanism” (Wilson 1987: 82). Having reviewed all feedback from users it was decided, for the purpose of this project, a lightweight wheelchair should be designed by reducing the number of components through the possible use of a modular system.
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4.2.3 Rigid vs Folding
Currently two options of manual wheelchairs are available, folding and rigid (Figure 24). As the name indicates folding wheelchairs fold in half allowing easier storage and transportation while rigid wheelchairs have a single chassis which is unable to be folded. However, rigid frames have less moving parts and can therefore potentially be much lighter. In general, participants believed rigid wheelchairs to be a better option and more beneficial (User2: 77-82; Physio2: 101-103; OT: 84). Ultimately, users should choose the option which best serves their daily needs (Physio3: 157-158). One user preferred using his folding wheelchair while catching taxis purely because he could save money. When using the rigid wheelchair, he was charged double as it couldn’t fold away and took up space of another traveller. (User 3). Rigid wheelchairs offer the opportunity to create a product with “less chance of anything going wrong” (OT: 78) since rigid wheelchairs have far less componentry making the need for repair less likely (Physio 2: 95-96). This
is an important consideration particularly when wheelchairs are imported from abroad and parts could potentially take several weeks to arrive (McIntyre 2010:29). Rigid wheelchairs are also more durable due to the reduction in componentry. Durability is key to users who traverse various environmental condition including the rough terrain found in rural areas (User3: 118-119). To design a wheelchair which meets users’ needs i.e. lightweight and cost effective, the design needs to be a rigid design, this affords many opportunities to achieve the needed results. Users and experts both agreed, a rigid wheelchair design would be most suitable to paraplegics. 4.2.4 Wheelchairs available During the initial interview phase participants were asked to convey their thoughts on four different wheelchairs available in other countries: Leveraged freedom chair (Figure 25), Trekinekt (Figure 26), Carbon Black (figure 27) and Go wheelchair (figure 28). These four designs were singled out for the
1. Figure 28: Amos Winter, Jake Childs and Jung Tak (Designers) Leverged Freedom
Wheelchair, 2011. (Core 77 website 2011)
2. Figure 29: Benjamin Hubert (Designer), Layer Go Wheelchair, 2016. (Core 77 website
2016). 3. Figure 30: Designer unknown, Carbon Black Wheelchair, 2015. (Carbon black Website
2015) 4. Figure 31: Mike Spindal, Trekinekt Wheelchair, 2008. (Independent website 2015)
following reasons: Leverage Freedom chair addresses a pump action alternative for propulsion; Trekinekt’s Page | 21
Figure 32: Data analysis of existing wheelchair, 2016. (Graphic by Author)
wheel orientation moves away from the norm of using front casters and instead provides a three wheeled design made to traverse any terrain; Go wheelchair also breaks away from the conventional
wheelchairs through clean minimalist design while incorporating new manufacturing techniques like 3D scanning and printing (Morby 2016); lastly, Carbon Black is made entirely
from Carbon Fibre in order to create a wheelchair which is as light as possible. Packs containing diagrams of each of the four-wheelchair design were issued Page | 22
to participants to review (annexure D). This information was collated and analysed. In figure 29 participant’s comments were displayed on a page showing positive comments in coloured text and negative aspects in grey. It was deduced while new designs like the GO wheelchair look good on paper users may find the idea of change less comfortable to deal with (Annexure C Physio3: pg2). While wheelchair users accustomed to their mobility device could find such a design visually appealing, being so different may not inspire confidence in users. An issue highlighted when considering wheelchair options was the use of moulded seats which do not allow the use of custom cushions (Annexure C Physio3: pg6). Specialised cushions for patients with spinal injuries is very important. These cushions disperse pressure evenly removing the likelihood of pressure sores. Chairs with built in cushions such as the Leverage Freedom and Trekinekt limit user options and does not allow users to change their cushions as requirements change over time. Moulded chairs are
also considered problematic since they do not fold smaller/down for transportation. Feedback from participants showed preference for wheelchairs with less components (Go wheelchair, Carbon black and Leverage Freedom) which were considered less cumbersome and therefore better alternatives (Trekinekt). Various levels of functionality can be achieved by changing orientation of the three-wheel configuration (Trekinekt and LFC). The Leveraged freedom has a long wheelbase, designed for ease of travel over long distances (Annexure C Physio3: pg2, OT: pg2). However, issues relating to using long wheelbase wheelchair indoors is the lack of manoeuvrability due to the wide turning circle in small areas. The Trekinekt wheelchair has a different wheel orientation, two large spoked rims in front and a large caster trailing behind and sports a short wheelbase which is easy to operate in small spaces (Annexure C Physio3: pg2). The problem with this chair, however, is that by placing the third wheel behind, the wheelchair is no longer tippy. This
means the user can no longer tip themselves backwards balancing on the two large wheels in order to traverse steps or uneven surfaces (Annexure C Physio3: 4; Ot: 4), rendering this chair useful only in perfect conditions. Finally, while certain designs were well received, the context for which they were designed should be taken into account. The majority of these chairs were designed for first world countries and while they look good they may not be durable enough for South Africa conditions. 4.2.5 User Preferences in wheelchairs After a person becomes a quadriplegic/paraplegic they go through a stage of active rehabilitation. During this phase a variety of wheelchairs are offered to them to test and gauge their preferences (Annexure C Physio3: 157-159). During this testing process users are taught about wheelchairs and how to use them optimally (Annexure C Physio3: 163165). Input from physiotherapists assist users to choose the chair best suited to Page | 23
them. The choice of chair is heavily dependent on the user’s personality, their life style (Annexure C Physio3: 173-174), and some users are more confidence levels are higher than others. Wheelchair users can opt for a new chair every two to three years dependent on their medical aid cover, often using their old chairs as a spare (Annexure C OT: 118-120; Physio1: 3738). It takes a number of years to determine exactly what users like/dislike in a wheelchair (Annexure C OT: 54-55; Physio3: 206-208; Physio2: 222-223). These preferences include: centre of gravity (tippy1), which means how easily a chair can be pushed onto its back wheels; length of the chair’s wheelbase (short/long); footrest height; size of casters and also the backrest angle. All these preferences are documented by the OT who fills out a user’s specification form as set out in
Annexure G, these forms are sent to the manufacturer to build a customised wheelchair. After a user has acquired a second/third wheelchair they have determined their preferences and what best suits their needs (Annexure C Physio3: 206-208; OT: 54-55). 4.2.6 Pump action vs manual During a second round of interviews (Annexure G) the pump action wheelchair piqued the interest of users. A pump action wheelchair uses two levers on either side of the big wheels to propel the wheelchair forward through a fixed gear system as seen in figure 30. This system allows more torque and speed to be achieved while exerting less energy (Annexure G User3: 5-7). Considering the above, would a pump action wheelchair make sense in a third world context? To answer this question, users were asked what their thoughts were and whether they believed there was a need for this type
Figure 33: Grit Freedom Chair (Designer), Pump Action Mechanism, 2016. (Grit website 2016)
of wheelchair? The responses were relatively consistent, participants agreed that a pump action would make sense “If you’re in a rural area where
1
Tippy- Refers to the centre of gravity of a wheelchair and how easily it if for users to tip up on their back wheels, casters off the ground
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you need to push for long distances” (Annexure G Physio2: 4-5) (Annexure G Physio3: 37-39; OT: 3-4; User2: 18-21; User3: 19-20). Ultimately it comes down to the environmental conditions users are exposed to, if these conditions included long distances over varying terrains the pump action wheelchair would make sense. However, many believed such a wheelchair would not be desirable in an urban environment (Annexure G Physio2: 8-9; Physio3: 3435; User1: 5-6; OT: 10). “No, in the context of that using a wheelchair indoors you manoeuvre around such small environments over a smooth surface that the pump action wheelchair is not needed.” (Annexure G Physio3: 34-36). Issues other than environmental conditions raised, were: the additional weight (Annexure G User2: 9-10); maintenance required especially where resources aren’t freely available (Annexure G User1: 18-20). Wheelchair users also believed through years of wheelchair use, they had gained enough strength in their arms to propel themselves efficiently (Annexure G User2: 14). ID 2 indicated
this system would create additional complexity to the current project and designing a pump action system should be an entire project of its own. It was concluded that a pump action wheelchair option would increase cost and overall weight and therefore did not fit the purpose of this project.
international and local wheelchair suppliers. The three main issues, cost/weight/ aesthetics, will serve as design parameters which will inform the design process to follow.
4.2.7 Summary of Findings Data gathered through the literature review and participant interviews outlined the key issues, cost, weight and aesthetics of current wheelchairs available to paraplegics. Additional concerns highlighted was the need for access to parts, adjustability and the environmental conditions the wheelchair/users found themselves in. Observations were very insightful and allowed comparison between different manufacturer production processes. Discussions with the OT at CE mobility was important for an artefact analysis on various wheelchairs. Various aspects of different wheelchairs were compared according to weight, material usage, frames types as well as making note of comparisons between Page | 25
Chapter 5: Design Process 5.1 Design Process Precedent boards (Annexure F) were compiled using data collected to obtain a better understanding of products available on the market, while considering shapes and technical componentry. An inspiration page was compiled showcasing products and textures, and a component board was made (Figure 8-14) to break down components and determine which componentry should be designed and those to be bought. Rims and casters to be purchased from companies who specialise in manufacture of such items. Three persona boards were conceptualized, Kerry (Figure 32), Melissa and Kyle. Each represented a different medical aid target market; high, mid-tier or entry level (Annexure F). During the initial design process, multiple design directions were established. To address technical aspects relating to functionality, initial hand drawn sketches were produced in 2D showing front and side views for each design. In addition, 3D drawings
Figure 34: Initial designs, 2015. (Graphic by Author)
were made, further exploring details of 2D drawings (Figure 31). While designing the initial concepts an important aspect was the consideration of use of the wheelchair while the user was in/out of it. This questions, how does the wheelchair disassemble and how do the components sit when disassembled. The design should therefore accommodate the possibility of the Page | 26
user would be transporting their wheelchair. Initial designs explored the possibility of a three-wheeled chair similar to the LFC, using a short wheelbase design to improve maneuverability in tight areas. The issue with a short wheel based design is the center of gravity and how tippy such a chair would be. Where the long wheelbase provides rigidity on either side of the frame. Concepts progressed towards the use of a single, bent-frame design, this would allow less componentry required to connect various components to the wheelchair. 5.2 Design feedback During the design phase of the project each participant was given a design review pack which included different coloured stickers. Each colour represented a different level of appreciation. Through a user-centred design approach the strongest design direction was chosen by analysing participants feedback. Having completed the initial design process, design review packs were compiled and issued to participants to
Figure 35: Kerry persona, 2016. (Graphic by Author)
complete in order to ascertain the design direction. These packs included hand drawn designs with a brief explanation of each design. Four different coloured stickers were used to indicate participant’s favorite designs. The use of four colours was to establish/identify patterns through choices and reasoning. In Addition, a
fifth sticker was used to identify points of interest highlighted by participants (components). In Figure 33 data collected from participant’s feedback regarding design review packs was compiled. Using this information, the preferred design direction was chosen (Annexure G).
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Page | 28 Figure 36: Design Feedback, 2016. (Graphic by Author)
5.3 User Feedback Functionality feedback was predominantly sourced from the OT, physiotherapists and industrial designer since their expert opinions inform feedback when the wheelchair could not be physically tested by users to test the validity of the proposed claims. Wheelchair user’s opinions, were subjective and dependent on their experiences. This design direction was targeted towards to the majority of users’ needs rather than the minority. 5.4 Design Refinement Participant’s feedback pinpointed the favored designs and with this information further refinement was made possible. Hand drawn sketches were used for technical details then developed in CAD to further refine the design to the correct specification/dimensions. CAD offered exploration into different orientations of the frame and the ability to try different shapes and tubing sizes. Components, to be attached to the frame, were then designed. Digital renders were developed to consider both material and color options. Once
again a design review kit was compiled containing renders of the refined design. In this review kit (Annexure J), technical details were shown to participants obtain final thoughts and to iron out issues regarding both technical and aesthetic detailing. 5.5 Wheelchair Functional Test Prototype Using the design direction hand drawn sketches were further refined, then generated and modified in Computer Aided Design (CAD). During the refinement stage tubing sizes and frame shapes were explored. A 1:1 mockup of the design was made to better understand size and proportion of the design. Different component attachments were considered. This mockup made from copper piping (figure 34), was used to replicate the structural composition, but not the final manufacturing processes. The model was used as proof of concept to examine how components would be attached/detached. Users provided beneficial feedback regarding structure and composition. User testing of the physical prototype was not possible due
Figure 37: Wheelchair prototype, Johannesburg, 2016. (Photographed by Author)
to ethical considerations. All information received from participants regarding the functional and technical considerations of the prototype will be used to inform the final design and prototype
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5.7 Standard Components While the frame and various parts of the wheelchair have been designed, not all components needed to be designed. Some components such as a caster, front forks, and rims looked at using components already available on the market. Many companies specialise in the design and manufacture of these components which means users have a far greater variety of options available to them at a reasonable price. With an understand that wheelchair users in third world countries may not have easy access to distributors of rims and tires, the design allows users to use either twenty-four-inch wheelchair or bicycle rims. The rims found on a bicycle undergo the same types of stress as a wheelchair rim, however, bicycle rims and tires are a lot easier to come by in a third world country as many individuals use bicycles as a daily form of transport. Similar to the rims, castors and front forks are dependent on the user’s needs. If a wheelchair user travels over rough terrain found in a rural area they would need larger, more rugged casters Page | 30 1. Figure 38: CE Mobility manufacturing facility, Johannesburg, 2016. (Photograph by Author) 2. Figure 39: Front and side profile dimensions, 2016. (Graphic by Author)
and the right size front forks to fit to the size of these casters. If a user, uses their wheelchair predominantly indoors the may look at smaller caster and front forks. Casters also come in a variety of shapes and sizes for wheelchair users to choose which design suits them. 5.8 Manufacturing the Wheelchair During the CE mobility walk about, ID2 explained how they manufacture their wheelchairs (Figure 35). A radial pipe bender which create the radii found on the frame. Standard sized pipes are bent and matched to meet user specifications. These bent tubes are placed in jigs where workers weld all necessary componentry together, and then send the part manufactured to be powder coated. The use of multiple jigs to dimension each wheelchair makes turnaround time lengthy. A large number of jigs are needed to fit every kind of body shape. For the design of a cost-effective wheelchair an alternate solution to using multiple jigs was required. The answer to this dilemma presented itself in the form of the J.NEU Freeform Computer Numerical Control (CNC) Pipe Bender (Annexure J). The
freeform pipe bender allows complex shapes to be bent from a single tube by using CAD (Figure 36) files to determine specifications for each frame. By using machinery which works directly from CAD files, the necessity for jigs was eliminated, reducing manufacturing time, personnel and the overall cost of the product. The other benefit of using a CAD based system is the change in dimensions from user to user can be done manually with the overall design adjusting itself accordingly. Aside from the technical aspects wheelchairs users can customize their wheelchair by choosing from an array of powder coating colours to finish off their wheelchair. Powder coating components seals and protects components from the elements as well as adding visual aesthetics to the wheelchair. Powder coating is a preferential option which offers a more durable finish to spray painting which could chip/peel if bumped against surfaces. While asking users to test prototypes was not an option, Solidworks Xpress
Figure 40: Stress diagrams on axle,2016. (Graphic by Author from Solidworks)
Analysis Wizard was used to run stress tests simulations (Figure 37)(Annexure K) to check for any technical/structural issues which could arise. These simulations exposed potential areas of Page | 31
weakness in the design and allowed for modifications to component to be made then retested to ensure weakness in those areas were addressed. The component put through this simulation process was the axle which would have the most stress applied to it. For the simulation test, a weight of 80kg’s was used to see the level of stress on the axle. Figure 37 shows two designs, the one with two columns closer (Stress test 1) to each other and the other with columns wider (Stress test 2) apart. The design with columns closer together showed an increase in stress on the weld points, increasing the distance between these columns reduced the stress significantly, as the force applied was better distributed. It would be ideal for users to test the wheelchair, since this was not possible CAD simulation gives an indication of potential areas of weakness which can only be proven through rigorous component testing. 5.9 Custom Fit By using a Free Form CNC bending machine to manufacture the frame the design of a custom fit wheelchair Figure 41: Wheelchair Frame, 2016. (Graphic by Author) Figure 42: Front Footrest and Forks, 2016. (Graphic by Author) Figure 43: Side profile of Wheelchair, 2016. (Graphic by Author) Figure 44: Friction Clamps, 2016 (Graphic By Author) Figure 45: Axle mount and Riser, 2016. (Graphic by Author)
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required by paraplegics can be achieved. Engineers simply require user specifications (side and front profile) (Figure 36) to modify the fit of the wheelchair to each user. This permits the design to be changed quickly to suit any individual’s body shape and size. The frame is designed to user specifications and the height of the axle is fabricated to the exact height specifications required. 5.6 Design Finalisation Figure 38 – 42 shows the components which make up the final design. The components highlighted were designed for overall functionality of the wheelchair and include, the: frame; axle; frame mount; riser; friction clamp; backrest; sideguards; footrest and front forks. The frame (Figure 38) designed from a single piece of tubing was designed in such a way to allow the axle, seat, backrest and footrest to be attached/detached with ease. The design of the frame is similar to current wheelchairs but enables easy disassembly and transportation. The radius’ at the front of the frame was increased to create a sweeping profile. The use of round ensures effortless attachment of parts to the frame. Figure 46: Final Wheelchair Design, 2016. (Graphic by Author)
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The axle (Figure 42) has been designed with two columns in the center to ensure even distribution of weight. A previous option explored using a single column created issues relating to structural integrity, too much stress was placed on the welding points. The frame mount (Figure 42) is welded onto the axle and enables the axle to be fixed to the frame. This mount can be loosened so the part can be adjusted on the frame. This component’s secondary function is to keep the side guards in place. The side guards (Figure) slot into the mount and can easily be attached/detached. The side guard’s act as protection for user’s against dirty or damage from the rims. The seat (Figure 40) is attached to the frame mount and a riser (Figure 42) found towards the front of the frame permits the rigid seat to be secured onto the frame.
Finally, the front forks have been designed with longevity in mind. Most wheelchairs available have these components welded on, which can cause weakness, since parts can crack/fracture when placed under stress. For this reason, the front forks were designed as separate components which can be adjusted on the frame. These separate parts are designed to be stronger and more durable and should the component get damaged it can easily be replaced at a lower cost than a wheelchair with component welded on.
5.10 Corporate Identity and Branding Currently the trend in brand identities of companies which sell medical devices, includes words relating to disabilities and use of the disabled sign in their logos. The corporate identity for this product seeks to create a market presence as a brand distancing itself from the norm expected from a wheelchair company. The chosen brand name ‘Emerge’
The backrest (Figure 41) was designed to fold down making the wheelchair more compact when required. A slight tapper on the bottom of the backrest enables folding. The shape of the backrest can be moulded to specific user needs, i.e. specified height and width. Two friction clamps have been used to hold the backrest in place. These clamps form part of the backrest and clamp onto the frame with a stopper at an angle specified by the user. Figure 47: Emerge Logo, 2016. (Graphic by Author)
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means to become visible, apparent or prominent; to move out of or away from something and become visible. The idea of becoming visible is important as the design of the wheelchair seeks to instill confidence in users by letting society see the user before they see the wheelchair. The ‘Emerge’ logo incorporates the use of wheelchair users image set behind the logo Figure 44. In Figure 45 is an advert using existing wheelchairs on the market (Images compiled from various sources), with images showing small parts of the wheelchairs and sections of the user’s body. The idea is the user becomes visible and ‘emerges’ and is therefore the focal point in the design of this wheelchair.
Figure 48: Emerge Advert, 2016. (Graphic by Author);
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Chapter 6: Conclusion & Recommendations 6.1 Summary of the design Outcome While top of the range wheelchairs are being imported into the South African market, the large majority of paraplegics have issues affording the high cost associated to these wheelchairs. There are however, wheelchair manufacturers in South Africa but user do not believe these wheelchairs live up to the quality and standard required in a third world context. Interviews with medical professionals, designers and wheelchair users created an understanding building onto the knowledge base found in literature review. Three main areas of concern identified through participant feedback were cost, weight and aesthetics. The cost and weight factors of the wheelchair work hand in hand with one another. The lighter the wheelchair purchased the higher the cost, lighter materials costing more. Affordable wheelchair inevitably weigh more. Wheelchairs are generally perceived as being medical devices,
wheelchair aesthetics perpetuate this view. In answer to the research question in chapter one, a HCD approach has enabled a greater understanding of the cost and weight dilemma and how to address it. The Emerge wheelchair seeks to remove the stigma associated with the wheelchair. By using a rigid wheelchair as appose to a folding wheelchair excess componentry can be removed, reducing the overall weight of the wheelchair. The design of a single bent frame decreases turnaround time and labor requirements of manufacture and assembly reducing the overall cost. The single bent frame adds to the structural integrity and durability of the design as It means there are no welded connections where parts can fail. The wheelchair was designed to accommodate wheelchair users in various medical aid brackets. By using the same clean/minimalist design and changing the materials, various medical aid brackets can be catered for. Users are able to upgrade components such Page | 36
as the wheels, casters and front forks to improve in weight reduction. Having considered these issues the wheelchair seeks to improve the quality of life of the user. 6.2 Recommendations for further study For future development of this project physical user testing is imperative as it would allow users to pin point issues which may not be evident without physically testing the wheelchair. It is also recommended that further prototypes be manufactured and put through rigorous real world tests as opposed to simulations, to ensure strength and durability of components. Various alternate materials should be tested in urban and rural environments to ensure a lightweight and
robust wheelchair strong enough to last users the two to three-year period before requiring a new wheelchair. Existing components such as rims and castes currently being manufactured could be considered in an alternate study to suit the design aesthetics and durability required in third world context to create a completely rounded design.
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