WHEELCHAIR CUM STRETCHER

PRASANT PARAMATMUNI

NETTUR TECHNICAL TRAINING FOUNDATION, BANGALORE, INDIA

E-mail: paramatmuni_prasanth@yahoo.com

SURAJ S PARIKH

NETTUR TECHNICAL TRAINING FOUNDATION, BANGALORE, INDIA

E-mail: surajs_parikh@yahoo.com

SHRIKANT RAVAJI BHURE

NETTUR TECHNICAL TRAINING FOUNDATION, BANGALORE, INDIA

E-mail: shri_bhure1986@yahoo.com

CHRISTU RAJ

NETTUR TECHNICAL TRAINING FOUNDATION, BANGALORE, INDIA

E-mail: blackhawk619@gmail.com

DENNY V JOHNY

ENVENTURE TECHNOLOGY SERVICES PVT Ltd.

E-mail: dennyvj@gmail.com

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 Disability: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

MOBILITY AID:

A mobility aid is a device designed to assist walking or otherwise improve the

mobility of people with mobility impairment.

There are various walking aids which can help with impaired ability to walk and

wheelchairs or mobility scooters for more severe disability or longer journeys which

would otherwise be undertaken on foot. For people who are blind or visually impaired

the white cane and guide dog have a long history of use. Other aids can help with

mobility or transfer within a building or where there are changes of level.

Traditionally the phrase "mobility aid" has applied mainly to low technology

mechanical devices. The term also appears in government documents, for example

dealing with tax concessions of various kinds. It refers to those devices whose use

enables a freedom of movement similar to that of unassisted walking or standing up

from a chair.

Technical advances can be expected to increase the scope of these devices

considerably, for example by use of sensors and audio or tactile feedback.

Types of Mobility Aid1. Walking aids

a. Cane

b. Crutches

c. Canes, crutches, and forearm crutch combinations

d. Walkers

e. Walker Cane Hybrid

f. Gait Trainers

2. Wheelchairs and Scooters

3. Stairlifts and similar devices

4. Others

a. Sling lifts

b. Lift chairs

c. Knee scooters

PROBLEM DEFINITION

The percentage of patients in India is increasing day by day. In hospitals patients

need to be shifted from wheelchair to stretcher, stretcher to beds, bed to wheelchair,

or vice versa; which creates unsafe conditions for patients. Transferring patients in

hospitals is a common problem for the caretakers

PROJECT SCOPE

Propose a design which will reduce the effort of the caretaker and provide a safer

transfer for the patients in hospitals.

LITRATURE STUDY

ABOUT THE PROBLEM

The problem of transfer patients exists from ancient times. People who got seriously

injured or ill, were carried by others by means of wooden stretcher with cloth or

leather tied to it. Later they were carried on wheels which reduced the effort of the

people carrying them. Today the problem still exists. Though we have evolved in the

field of healthcare and technology we are not yet able to address the problem

efficiently.

WHEELCHAIR

Wheelchairs have been around for hundreds of years, but early wheelchairs were

intended only to help a disabled individual move from point A to point B. As society

progressed and disabled individuals became more integrated, the role of the

wheelchair began to change as well. Wheelchairs are now considered not only a

means of transportation but also as a way to allow users to express their

individuality.

The earliest records of wheeled furniture was an inscription found on a stone

slate in China and a child’s bed depicted in a frieze on a Greek vase, both dating

back to the 6th century B.C.E. The first records of wheeled seats being used for

transporting the disabled date to three centuries later in China; the Chinese used

their invented wheelbarrow to move people as well as heavy objects. A distinction

between the two functions was not made for another several hundred years until

when images of wheeled chairs made specifically to carry people begin to occur in

Chinese art. There were many attempts to connect furniture to wheels dating back to

the time of Christ. But perhaps the first wheelchair was invented for King Phillip II of

Spain. A drawing of the King dated 1595 shows him in a chair with wheels, armrests

and footrests. However, he needed assistance to propel it. In 1665 one of the first

self-propelled vehicles was invented by Stephan Farfler. Harry Jennings and his

disabled friend Herbert Everest, both mechanical engineers, invented the first

lightweight, steel, collapsible wheelchair in 1933. Mr. Everest had broken his back in

a mining accident. The two saw the business potential of the invention and went on

to become the first mass-manufacturers of wheelchairs: Everest and Jennings. Their

"x-brace" design is still in common use, albeit with updated materials and other

improvements. In the 1950’s the first powered wheelchair was developed. It used a

motor to power the wheelchair. It was around the same time that wheelchair sports

were first started. In the year 1964 the first Paralympics games were held in Tokyo,

Japan.

Modern day wheel chairs contain light materials, microprocessor controlled

and many more sophisticated systems. There is a revolution of wheelchairs available

today driven by needs and desire or man today. The future expects a better range of

wheelchairs that could suit the imagination of the human mind and serve the needy.

The basic structure of the wheelchair contains various parts. In simple words

its nothing but a set of wheels attached to a chair. There are some important things a

wheelchair must contain. A seat must be comfortable, so that the person does not

get tired sitting on it for a long time. It must contain a backrest that provides a good

lumbar support. It must have an arm rest at an optimum height and a also a foot rest.

The most important think is it must have brakes for the wheels.

Since the birth of the wheelchair there have been many modifications in its design.

Today there exists a huge variety of wheelchairs- manually, electric, or self

propelled, foldable or rigid. Apart from these they are classified based on their

usage, standing wheelchair, sports wheelchair, mobility scooters, bathroom

wheelchair, steps climbing wheelchair etc. The range of wheelchairs reflects the

demand to meet individual needs.

TYPES OF WHEELCHAIRS

Some of the types of wheelchairs are discussed below :

Manual wheelchairsManual wheelchairs are those moved by the user or an attendant. By controlling the

push rims, users can travel forward and backward at speeds dictated by the amount

of force they are able to apply, they can also turn left or right and negotiate small

dips and rises that lie ahead.

.

Manual Transit wheelchairsManual transit chairs generally have small rear wheels without push rims. These

wheelchairs are most likely to be seen in buildings such as airports and hospitals

where porters act as attendants. These are also called manual transfer chairs.

Electric wheelchairsPower (Electric) Wheelchairs are also called “motorized wheelchairs” and sometimes

abbreviated EPW (electric powered wheelchairs); are powered by an electric motor.

These chairs are navigated by controls systems. Individuals too weak to maneuver a

manually powered or standard wheelchair benefit from power chairs, as do

individuals with heart and/or breathing conditions.

WheelbaseA wheelbase chair, otherwise known as a scooter, has four small wheels extending

from a low platform. The type of chair mounted on this platform varies according to

the disability and needs of the user; some are even molded from a cast taken of the

user’s most appropriate sitting position. The controls of the wheelbase chair are

mounted on a frame that curves upward from the front of the platform to a height and

position convenient for the user. A horizontal steering bar is attached across the top

of the frame.

Sports chairsSince the 1970s, disabled athletes have had an increasing array of specialized

wheelchairs to help them achieve the most from their chosen sport. These chairs can

look very different from each other, but what they usually have in common is

lightweight frames made from composite material; solidity (which means that they do

not fold); and enhanced stability for sudden turns (this is achieved by using angled

wheels).Sports wheelchairs or recreation wheelchairs are specially designed for

athletes with disabilities who are competing in sports that require agility and speed

such as basketball, tennis, rugby or racing.

Stand-upStand-up wheelchairs are fitted with a hydraulic pump that lifts and tilts the seat,

thereby enabling the user to "stand up" and yet be fully supported. This is an

invaluable feature if the user needs to reach an item on a shelf either at home or

while out shopping

Stair-climbing wheelchairsClimbing stairs is the ultimate test for a wheelchair, and there are a number of

solutions available. Battery-operated supports at the back that act as stabilisers as

the chair climbs.

A series of flexible wheels turning within rubber tracks that grip the steps.

.

STRETCHER

A stretcher is a medical device to carry patients for a short duration of time. A

stretcher contains a surface which support for carrying patients, and has handles on

either side along its length to help carry it.

Stretchers have been used since antiquity, on battlefields and in emergency

situations, where wheeled vehicles are hindered by rough terrain. In their simplest

form, they generally consisted of a canvas sling with long edges sewn to themselves

to form pockets through with wooden poles could be slid. Today there are a wide

variety of stretchers available, involving light weight materials, attachments so that it

can be fitted to other contraptions.

TYPES OF STRETCHERSSome of the types of stretchers are explained below :

Basket stretcher A basket stretcher is used in situation when an injured person needs transportation

by foot to medical attention. The stretcher disassembles in two halves, and if needed

for rescue assembles in seconds.

Ambulance stretcherAn ambulance stretcher, also known as a little or gurney, consists of a solid frame

and a heavy-duty cloth that stretches across it. The ambulance often gives a rough

ride. This type of stretcher absorbs part of the impact to prevent further injury.

Ambulance stretchers often adjust in position, aiding the paramedic in tending to the

injured person’s needs.

Folding stretchersA folding stretcher is used to transport the injured from the inside of a building to an

ambulance stretcher. It is portable and folds in half for convent storage. This

stretcher is also light weight when carried, and made of high strength materials. They

are available in several sizes to fit people of various sizes.

Pole StretcherThe military often used pole stretchers to transport the wounded to a medical facility.

The stretcher have heavy-duty poles that extend on each side so two men can carry

it. Pole stretchers also are lightweight, and have no-slip handgrips for firm control

while handling.

THEME BOARD

CONCEPTS

CONCEPT SELECTION

Various concepts were generated and selection was based on a matrix comparison

involving all the concepts and some parameters.

CONCEPT REFINEMENT

Based on the selection some refinements were made.

Above Fig depicts the folding mechanism of product. “Link 1” is the back rest, “link 2”

is seating area, “link 3” is leg support. “Link a” is perpendicular to “link 1” and “link e”

is perpendicular to “link 3”. “Link c” is a ball screw which moves linearly to and fro on

the lead screw which is shown in dotted line. “Link e” and “link a” is connected to

“link c” by other links d and b respectively. Red arrow shows the ball screw moving to

the right of the reader upon which the product will become stretcher or bed and this

conversion is done when the desired entire platform is raised to desired position.

When the ball screw is moved to left of reader product becomes a wheelchair and

this conversion is done when the desired entire platform is raised to desired position.

Height adjustment is done with the help of pneumatic cylinder mechanism. There will

be totally 4 pneumatic cylinders which are at the 4 corners of the seating area which

are actuated to change the height.

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 DATA

Human dimensions are considered for both male and female and 95 percentile for

stature, maximum body breadth relaxed,

DETAIL DESIGN

Uniqueness of this design is when the product is in stretcher or bed mode height will

match the conventional stretcher or bed. Height is adjustable to bed or stretcher or

wheelchair or to any height desired. Conversion from wheelchair to bed or stretcher

or vice versa can be done by both the patient and handler. Below are the three

different platforms of product

g. Backrest

h. Seating Portion

i. Leg support

Hip95th percentile

406 mm (combined)

Maximum body breadth relaxed

95th percentile619 mm (combined)

Stature95th percentile

1771 mm (combined)

Ratchets are provided at the joint where these meet so that it will lock at each step of

conversion assuring the safety while converting. Ratchets are also provided to the

Upper legs so that those will be in locked position when the product is in wheelchair

mode. Detailed images are as below

LEVER WHEEL WHICH HELPS IN

CONVERSIONPOSITIONS OF RATCHETS

FINAL PRODUCT

CONCLUSION:

The main objective of this product is to make the helper life easy and to make sure

the patient is not hurt during the process of treatment. This product eliminates the

step of shifting patient from bed or stretcher to wheelchair and vice versa as handling

of old age people is very difficult.

REFERENCES:

An Integrated Decision Making Model for Evaluation of Concept

Design:http://ctn.cvut.cz/ap/, ActaPolytechnica Vol. 44 No. 3/2004, Czech

Technical University Publishing House

Bariatric Bed: http://www.camtecproducts.com/3954b.html, Camtec

Dr. S. Ray, “Disabled Persons in India",

Spinal Cord Injury; Available from: www.apparelyzed.com, August 2007

“Guidelines & Space Standards for Barrier Free Built Environment for

Disabled & Elderly People” By Central Public Works Department of India

Indian anthropometric dimensions for ergonomic design practice, by NID