DESIGN AND FABRICATION OF ELECTRIC WHEELCHAIR AND MODIFICATION OF

SUITABLE TWO WHEELER FOR PARAPLEGICS

PRASANT PARAMATMUNI

NETTUR TECHNICAL TRAINING FOUNDATION, BANGALORE, INDIA

Paramatmuni_prasanth@yahoo.com

ABSTRACT

Over 90% of paraplegics in India come from the low income or lower middle

class income group. Since there is no social security system in India and the

Government Medical institutions cannot keep patients with spinal injuries in the

hospital for any length of time, they are sent home after the intital treatment.

Electric wheelchairs would have helped them be more independent and help

them function as an integral part of society. This project involved developing a

low cost electric wheelchair which is capable of withstanding the rigors of the

road and modifying a two wheeler available in the market so that the electric

wheelchair will be integral part of the two wheeler enabling the paraplegic person

to ride the road. The Project involved making an electric wheelchair which

combines as an intergral part of a two wheeler so that he/she can just attach

his/her wheechair to the road going vehicle without getting off of his wheelchair.

Thus making him completely independent of any external help. Hence the project

involved the deisgn of the electric wheelchair having constraints on basis of size

of the kinetic Honda withoug major component modification of the kinetic. The

wheelchair also has to be guided into the kinetic and then locked in position so

that it will be an intergral part of it. The project focused on lowering cost for the

fabrication part so that if it is manufatured on a large scale, the overall price of

the entire unit will be low enabling those physically handicapped people who are

cash strapped to purchase the unit.

INTRODUCTION

DISABILITY is the term which is in use from many

decades now. As per Oxford Etymology, “DISABILITY”

is used in many contexts viz, it was a sport in 1650’s

with the name “CAP IN HAND”, it was used in horse

races in 1750’s, in 1870’s it is “Any race or competition

in which the chances of the competitors are sought to

be equalized by giving an advantage to the less

efficient or imposing a disadvantage upon the more

efficient.” Finally, the first use of handicap to designate

mental or physical impairment is recorded in a 1915

photo caption: The Handicapped Child. From 1915 the

word “DISABILITY/HANDICAP” has become the brand name for the people who

are physically or mentally challenged.

“Disabilities is an umbrella term, covering impairments, activity limitations, and

participation restrictions. An impairment is a problem in body function or

structure; an activity limitation is a difficulty encountered by an individual in

executing a task or action; while a participation restriction is a problem

experienced by an individual in involvement in life situations. Thus disability is a

complex phenomenon, reflecting an interaction between features of a person’s

body and features of the society in which he or she lives”

—World Health Organization

TYPES OF DISABILITIES:

Disability is caused by impairments to various subsystems of the body - these

can be broadly sorted into the following categories.

1. Physical Disability

2. Sensory Disability

a. Visual Impairment

b. Hearing Impairment

c. Olfactory and gustatory Impairment

d. Somatosensory Impairment

e. Balance Disorder

3. Intellectual Disability

4. Mental health and emotional disabilities

5. Developmental Disability

6. Nonvisible Disability

Physical Disability

Sensory Disability

PURPOSE OF THE STUDY:

People who are affected by paraplegia, accidents, muscular dystrophy and

genetic defects from loss of sensory function of the lower extremities.

According to survey conducted by NDTV there are about 17 million

physically handicapped people in India.

A survey conducted by OXFAM trust, the Indian arm of OXFAM

international says that most of the disabled people in India live below the

poverty line or are part of the lower middle class of society.

Over 90% of paraplegics in India come from the low income or lower

middle class income group. Since there is no social security system in

India and the Government Medical institutions cannot keep patients with

spinal injuries in the hospital for any length of time, they are sent home

after initial treatment. These paraplegics, left to fend for themselves,

develop bed sores and ultimately die in the prime of their youth.

Electric wheelchairs are not currently being manufactured or marketed in

India.

The only electric wheelchairs available in India are imported from

countries like UK, China etc.

Cost is one of the major factors which deter people from purchasing these

wheelchairs as they sell for a premium of 1.3-1.8 lacks for the basic

versions.

These wheelchairs have been designed to be driven on flat surfaces

unlike most of the surfaces in India.

OBJECTIVE: (PROBLEM DEFINITION & SCOPE)

1. This project aims at developing a low cost electric wheelchair which

is capable of withstanding the rigors of the road and modifying a two wheeler

available in the market so that electric wheelchair will be an integral part of

the two wheeler enabling the paraplegic person to ride on the road.

2. The Project involves making an electric wheelchair which combines

an integral part of a two wheeler so that he can just attach his wheelchair to

the road going vehicle without getting off of his wheelchair. Thus making him

completely independent of any external help. The project will be focused on

lowering cost for fabrication part so that if it is manufactured on a large scale,

the overall price of the entire unit will be low enabling those physically

handicapped people who are cash strapped to purchase the unit .

UNDERSTANDING PARAPLEGIA

Paraplegia:

When a person suffers a spinal cord injury, information traveling along the spinal

nerves below the level of injury, will be either completely or partially cur off from

the brain, resulting in Quadriplegia (Tetraplegia) or Paraplegia.

The body will still be trying to send messages

from below the level of injury to the brain known

as sensory messages, and the brain will still be

trying to send messages downwards to the

muscles in the body, known as motor messages.

These messages however will be blocked by the

damage in the spinal cord at the level of injury.

Nerves joining the spinal cord above the level of

injury will be unaffected and continue to work as

normal.

Paraplegia is when the level of injury occurs

below the first thoracic of leg movement, to

complete paralysis of the legs and abdomen up to the nipple line. Paraplegia is

an impairment in motor and/or sensory function of the lower extremities. It is

usually the result of spinal cord injury or a congenital condition such as spina

bifida which affects the neural elements of the spinal canal. The area of the

spinal canal which is affected in paraplegia is either the thoracic, lumbar or sacral

regions. Paraplegics have full use of their arm and hands.

Causes:The cause range from trauma (actual spinal cord injury: transaction or

compression of the cord, usually by bone fragments from vertebral fractures) to

tumors (chronic compression of the cord), myelitis transversa and multiple

sclerosis.

Peripheral nervous system:

Rarer is the type which is caused by damage to the nerves supplying the legs.

This form of damage is not usually symmetrical and would not cause paraplegia,

but polyneuropathy may cause paraplegia if motor fibers are affected. While in

theory the arms should also be affected, the fibers that supply the legs are longer

and hence more vulnerable to damage.

Complications:

Due to decreased movement and loss of the ability to run, paraplegia may cause

numerous medical complications, many of which can be prevented with vigilant

self care. These include pressure sores (decubitus), thrombosis and pneumonia.

Physiotherapy and various assistive technologies, such as standing frame, may

aid in preventing these complications.

Problems faced by paraplegics:

People with paraplegia encounter many challenges in their everyday lives.

Primarily, mobility problems cause them difficulties in engaging in gainful

employment or going to school. These problems also restrict their participation in

the community.

Mobility & Movement

Full head and neck movement with normal muscle strength. Normal shoulder

movement. Full use of arms, wrists and fingers.

Complete paralysis of lower body and legs. Upper body strength will vary

depending on level of injury, but the lower level, the stronger the upper body

strength and balance.

A T4 cord injured person will have good strength in the chest muscles; however

this will get progressively weaker the higher up the injury.

Sympathetic nervous system may be compromised, possibility of Autonomic

Dysreflexia.

May use an electric wheelchair for long distance independent travel or uneven

outdoor surfaces. A manual wheelchair may be used for everyday living, with the

ability to go over uneven ground for short distances.

Ability to transfer independently from bed to chair, and chair to car. Car transfers

may need assistance depending on upper body strength.

Ability to drive a car adapted with hand controls. Assistance may be required to

load wheelchair into car.

Ability to feed self independently during mealtimes.

Respiratory System

Ability to breathe normal, although respiration capacity and endurance may be

compromised.

Personal Care

Should be independent in personal care as long as no other factors are involved,

i.e., additional injuries, severe spasticity etc.

Domestic Care

Partial domestic assistance is required, such as heavy household cleaning and

home maintenance.

Ability to prepare complex meals and general household duties independently.

Communication

Normal communication skills apply.

CURRENTLY AVAILABLE DESIGNS OF WHEELCHAIRS AND THREE WHEELERS FOR

PARAPLEGICS

INTRODUCTION TO WHEELCHAIRS:

As wheelchair is a wheeled mobility device in

which the user sits. The devise is propelled either

manually (by turning the wheels by the hand) or via various automated systems.

Wheelchairs are used by people for whom walking is difficult or impossible due to

illness (mental or physical), injury or disability. People with both sitting and

walking disability often need to use a wheelbench. The earliest record of the

wheelchair in England dates from the 1670s [Oxford English Dictionary, (2 nd Ed.),

1989, Vol. XX., p.203], and in continental Europe this technology dates back to

the German Renaissance.

TYPES OF WHEELCHAIRS:

A basic standard manual wheelchair incorporates a sear and back, two small

front (caster) wheels and two large wheels, one on each side and a foot rest.

Wheelchairs are often variations on this basic design, but there are many types

of wheelchairs, and they are often highly customized for the individual user’s

needs. The sear size (width and depth), sear-to-floor height, footrests/leg rests,

front caster outriggers, adjustable backrests, controls and many other features

can be customized on, or added to , many basic models, while some users, often

those with specialized needs, may have wheelchairs custom-built.

Various optional accessories are available, such as anti-tip bars or wheels, safety

belts, adjustable backrests, tilt and/or recline features, extra support for limbs or

neck, mounts or carrying devices for crutches, walkers or oxygen tanks, drink

holders, and clothing protectors.

MANUAL WHEELCHAIRS

MANUAL TRANSIT WHEELCHAIRS

ELECTRIC WHEELCHAIRS

STAND-UPBARIATRIC WHEECHAIRSPORTS WHEECHAIR

Advantages and Disadvantages of Current Design of Wheelchairs

Manual wheelchairs do in fact have benefits over their electric counterparts that

one may not imagine. They are lightweight whereas the electric ones are heavy.

This may be a significant selling point for those people who lack body strength

necessary for some chairs. They are simpler to maneuver and even thought the

electric power chairs can move by themselves there is the chance that perhaps

the battery may die. One of the major advantages of the manual chair is that it

can go virtually anywhere. A person in the wheelchair should not be concerned

with whether the terrain is uneven or bumpy as they would if they had a power

chair.

The major disadvantage of the manual

wheelchairs is person have to do with ones

upper body. Although the exercise may be

good for the people who push themselves

over a period of time the same motion

continually can eventually bead to injury.

Another disadvantage of a manual chair is

that the tires will need to be inflated

BEACH WHEECHAIRELECTRIC SCOOTER

regularly. A variety of factors much be properly considered prior to a person

choosing between a power chair and a manual version. The manual chairs may

not come with all the fancy accessories that the power wheelchairs tend to offer

for the handicapped individuals however they can be cheaper and a bit more

efficient than their bulky power chairs alternatives.

Trikes and Tricycles for Paraplegics

CONCEPTUALIZATION:

BASIC ARCHITECTURE

CONCEPT 1CONCEPT 2

CONCEPT 3

CONCEPT 4

CONCEPT 4a CONCEPT 4b

ERGONOMIC DETAILS We know that Ergonomics (or human factors) is the scientific discipline

concerned with the understanding of interactions among humans and other

elements of a system, and the profession that applies theory, principles, data and

methods to design in order to optimize human well-being and overall system

performance.

As our study is focused on handling of elderly people & patients in

hospitals during shifting from one mobility aid (wheelchair, stretcher)to another,

we considered Ergonomics involved &Indian Public Health Standards for design

of proposed concept.

As per Indian Public Standards every Hospital should have Barrier free

access environment for easy access to non-ambulant (Wheelchair, stretcher),

semi ambulant visually disabled & elderly persons as per Govt. of India

guidelines.

Below fig. shows Anthropometric data of wheelchair user related to uses within

easy reach.

ANTHROPOMETRY DATAHuman dimensions are considered for both male and female and 95 percentile

for stature, maximum body breadth relaxed,

Hip95th percentile

406 mm (combined)

Maximum body breadth relaxed

95th percentile619 mm (combined)

Stature95th percentile

1771 mm (combined)

DETAIL DESIGN:

Major parts of the wheelchair:

Frame: The final frame design is as shown above

Hob motor: Hob motors have been used to run the electric wheelchair due to

its compactness and efficiency

Suspension system of the wheelchair: The seat of the wheelchair consists

of two parts namely

Seat lower base

Seat back rest

Front wheel: The front wheel of the wheelchair is basically the wheel

assembly of the kids cycle

Electrical circuit: The electrical circuit consists of the motor, the controller

and the switch to change the motor phase between forward and reverse.

CONCEPT 4c

PROTO TYPE:

CONCEPT 4d

CONCLUSION:

A novel approach has been made by designing and fabricating an electric wheelchair that also can be used in conjunction with a kinetic Honda. This design helps paraplegics who have motor disabilities to move easily and function as an integral part of the society.

Regular wheelchairs and three wheelers are separate units and can never be used in conjunction. The three wheelers available in the market currently come at high cost and they are restricted to outdoor use.

The cost of the wheelchair is also significantly lower than any electric wheelchairs currently available in the market. The low cost helps paraplegics who are a part of the lower class of society to function better as it does not only help in moving indoors but also on the road.

REFERENCES:

Spinal Cord Injury; Available from: www.apparelyzed.com, August 2007 Details about Hub Motors; Available from: www.goldenmotor.com, August 2007 K Mahadevan and K Balaveera Reddy, , “Design data hand books” Dr. S. Ray, “Disabled Persons in India",