Description:Field of the innovation
Innovation in wheelchairs and mobility aids has been rapidly advancing in recent years. One notable development in this field is the modification of wheelchairs into stretchers, which offer several advantages over traditional wheelchairs. Primary innovation and novelty of this wheelchair is that it can be easily modified into a stretcher. This modified wheelchair is designed to be fully stretched out into a stretcher cum bed, providing a comfortable sleeping surface for patients where there are issues of shortages of lying and sleeping spaces for patients, or hospital institutions with limited capacity of beds. The stretcher design also makes it easier to use, particularly for caregivers who need to move individuals from the wheelchair to the bed.
Background of the innovation/ Prior art and problem to be solved.
The corona virus crisis has brought India’s public health system to its knees. Scenes of hospitals running out of beds, and people searching desperately for life-saving oxygen or critical medical supplies for their loved ones have hogged international headlines. While the pandemic has underscored the structural weaknesses in India’s public health system, those problems have always existed. One of them is severe shortages of beds in Indian hospitals.
From the need for a mobility aid, that could provide a comfortable and convenient alternative to beds, as well as use less amount of storage space, the idea of modifying traditional wheelchairs into a stretcher came. The modified wheelchair would offer several benefits, such as reducing the need for transfers between a wheelchair and a bed, eliminating the discomfort and inconvenience of sitting in a wheelchair for extended periods, and allowing for availability of beds at times where there are shortages from the hospital side.
There are currently some models of modified wheelchair stretchers in the market that have gained popularity among people with disabilities, caregivers, and healthcare professionals, as it provides a cost-effective, practical, and innovative solution for mobility and comfort. It is especially useful for individuals who require long-term care, as it eliminates the need for multiple mobility aids and transfers.

Many researchers and innovators have attempted to work on wheel chairs with convertible facility. However, each of these works have their own pros and cons which gives the present model a scope to address the problem with a new simple mechanism which is easy to operate with minimum steps involved in conversion.
The existing works are briefly discussed below:
• Meng-Hui Hsu et.al [1] proposed and prepared Dual purpose wheel chair mechanism design which has basic principle of links and kinematic chains. Though the model has innovative approach but it has less support for the upper parts of the user and the bed form don’t convert to exactly flat position. The effort needed to convert the bed to chair and vice versa was obviously very high in this mechanism.
• Ninad M. et.al [2] has proposed a spring operated mechanism to retract the stretcher to wheel chair position. This mechanism has a huge drawback of not being able to be operated when patient is lying in stretcher position. The stability of the arrangement and safety has not been addressed properly in the system.
• P. C. Santhosh Kumar et.al [3] has used reverse motion linkage mechanism to control the movements of upper and feet portion of the chair. The radial spring forces are used with leavers to retract the chair from stretcher to chair position but it is in sufficient when patient is lying on stretcher. The model has stability issues causing threat to tooling as there is no support of head portion in lying condition which normally has the major weight share of human body. In addition to this the model is not having any convenient method to give reverse motion to the arrangement.
• Feng Li et.al [4] has proposed a model of wheel chair attachable to a separate bed arrangement to complete the later. The arrangement certainly has issues related to movement; part of the bed has to be kept static in a position where chair has to be fitted perfectly to complete the setup.
• Chen et.al [5] has patented mechanism design for stretcher to wheel chair and vice versa. The mechanism is gear operated and movement of the head portions and feet portions are connected by links which has stability and position locking issues. This arrangement has lesser comfort particularly in the head side if moved over a rough surface. Moreover head and feet movements have to be operated separately which increases longer conversion times. Smaller wheels may not be convenient to move in all kinds of surface.
Objectives of the innovation
• To make a wheelchair that can convert into bed at will, reducing the effort of transferring the patient.
• To make the product affordable and durable at the same time.
• To solve the issue of limited space and beds in various medical institutions.
• To consolidate the concept of wheelchair and stretcher.
• To make it easy to use, safe and ergonomic.
Summary/Detailed description of the innovation
Design consideration

● The dimensions of the innovation are mainly based on the ergonomic standards of a wheelchair and modified in places to suit the ones of a hospital stretcher.
● The common length of a person is considered as 1450 mm to 1600 mm, from ground to waist it is 450 to 800 mm and from waist to head it is 450 to 800 mm feet. So, keeping this in mind we have taken a total length of the bed equal to 1570 mm.
● Common width of a person is 380 to 500 mm so, to make the patient comfortable, we have chosen the width of 560 mm.
● Common length of the legs is 350-500 mm so the height of the bed from the ground is 480 mm approximately.
● The average weight of a person considered is 90kgs.
● However, the parametric length and width of the bed when converted from wheelchair can be enhanced when if needed as proportionate. This parametric data is not included in this study.

Material consideration

The major structural material will be used for the construction of the wheelchair is stainless steel (SS 304L) as it possesses good strength, rust free and antibacterial properties suited for medical usage. This has fitted with structural brackets for holding other medical equipment’s like oxygen cylinder, blood/saline feeding stands etc.

Description of the Innovation

The stretcher form and wheelchair form of the innovation have several features like. (shown in the Drawings page)
a) Folding and unfolding feature
b) Provisions of footrests and oxygen cylinder.
c) Detachable telescopic stand for IV Saline
d) Rubber coated handles for movement in both wheelchair form and stretcher form.
e) The caster wheels, behind the backrest, are mounted on spring suspensions for shock absorption.
, Claims:a) Quick conversion from chair to stretcher and vice versa with minimum effort. Simple mechanism used for conversion which is easy to manually operate.
b) Suspensions are used in the stretcher position of the system which is retractable when converted to chair. This suspension provides comfort and safety to patient moving in stretcher in lying position.
c) Built in storing capacity to keep essential things in the form of a drawer. There is also a provision to keep an oxygen cylinder.
d) Safety measures are followed to avoid toppling of the system and to ensure complete stability in chair and stretcher position.
e) A foldable footrest, which can be used as an optional bed extension to accommodate long persons in addition to its normal uses.