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http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=7&IType=2 Journal Impact Factor (2016): 9.2286 (Calculated by GISI) www.jifactor.com ISSN Print: 0976-6340 and ISSN Online: 0976-6359
© IAEME Publication
MECHANICALLY OPERATED
WHEELCHAIR CONVERTIBLE
STRETCHER
Ninad M. BorkarDepartment of Mechanical Engineering,
Dr. Babasaheb Ambedkar College of Engineering and Research, Nagpur, Maharashtra. India
Saurabh A. Apte
Department of Mechanical Engineering,
Dr. Babasaheb Ambedkar College of Engineering and Research, Nagpur, Maharashtra. India
Tejas N. Deshmukh
Department of Mechanical Engineering,
Dr.Babasaheb Ambedkar College of Engineering and Research, Nagpur, Maharashtra. India
Sampada M. Apte
Lecturer at Department of Computer Engineering, Dharampeth Polytechnic, Nagpur, Maharashtra. India ABSTRACT
The problem of transferring the patients exists from ancient times. People who get seriously injured or ill were carried by others by means of wooden stretcher with cloth or leather tied to it. Afterwards they were carried on wheels which reduced the effort of the people carrying the patients. Alhough we have evolved in the field of healthcare and technology we are not yet able to address this problem efficiently.
Mobility aids are used for transportation of patients. Wheelchairs and stretchers are the most commonly used mobility aids for the movement of patients. Transferring the patients from wheelchair to stretcher or to the medical bed or vice versa is always an issue for the attendant or nurse. There is a revolution of wheelchairs available today driven by needs and desire of man.
Hence we propose a design of wheelchair convertible stretcher which is a boon to the medical field. It is so made that it could be maintained and
operated easily either by the patient or by the attendant according to the comfort of the patient.
Cite this Article Ninad M. Borkar, Saurabh A. Apte, Tejas N. Deshmukh and Sampada M. Apte, Mechanically Operated Wheelchair Convertible Stretcher. International Journal of Mechanical Engineering and Technology, 7(2), 2016, pp. 261–265.
http://www.iaeme.com/currentissue.asp?JType=IJMET&VType=7&IType=2
1. INTRODUCTION
In simple words a wheelchair can be described as a structure having a set of wheels attached to a chair. Wheelchair is a device which can empower and enable a person with a disability to live a normal and independent life. Over the years wheelchairs have evolved rapidly from the manual wheelchairs to the powered wheelchairs. But still these wheelchairs have not been able to satisfy the needs of the disabled people. It is therefore critical that the problems of disabled be understood and accordingly wheelchairs are developed fulfilling their needs. So we have designed a multipurpose wheelchair that can work as wheelchair as well as a Stretcher. Its construction is so easy and can be operated and maintained easily. We have used simple mechanical linkages along with seat back recliner mechanism to achieve the required motion. This paper is the result of a design and development of a multi functional Wheelchair that would perform all the required functions.
Objectives of the study
Decrease the cost by using new mechanism.
Works reliably under different operating conditions.
To save space and precluding exertion of the patient.
2. LITERATURE REVIEW
The author in [1] gives us various concepts regarding wheelchair convertible stretcher. Concept 1 enlightens us about a sliding tubular frame which is attached to the back rest of the wheelchair. A handle is provided in the back rest so that the user can pull it easily and can convert it into stretcher. Concept 3 gives us an insight to the hydraulic scissor lifter mechanism, so that the height can be adjusted according to the user’s convenience. A hydraulic scissor lifter mechanism lifts the entire wheelchair into stretcher. Concept 5 is based on the gear mechanism. According to the rotation of the middle wheel, the front and back seats are rotated in opposite direction and stretcher arrangement is achieved. The author in [4] uses pneumatic power for the operation of the wheelchair convertible stretcher although the air supply is some distance away from the product.
3. CONSTRUCTION
The wheelchair convertible stretcher consists of following components:-
1. Backrest: Backrest of wheelchair convertible stretcher is made up of square cross-section (1” X 1”) and flat mild steel plates are welded in it. It is attached to the base with hinges and seat back recliner mechanism.
2. Seat: The seat is made up of mild steel of square cross-section (1” X 1”) and flat mild steel plates are welded in the frame. It is directly connected to the base of the wheelchair convertible stretcher.
3. Leg rest: Leg rest of wheelchair convertible stretcher is also made up of mild steel square cross-section (1” X 1”) and flat mild steel plates are welded in the frame. It is attached to the seat (base) by means of hinges.
4. Foot rest: The footrest is made of the mild steel square cross-section by bending its edges and is welded at the bottom of the leg rest.
5. Seat back recliner mechanism: The seat back recliner mechanism is rigidly attached to the seat and backrest by means of nuts and bolts. This mechanism helps in locking of backrest and leg rest at some specific angles. Fig. A and Fig. B shows the initial and final position of seat back recliner mechanism respectively.
6. Mechanical linkages: There are three linkages out of which two are welded at the backrest and leg rest respectively. The third link is used to connect the two links. The welded links at the backrest and leg rest are at an angle of 30° and 62.5° respectively. 7. Hinges: These are the most important part of wheelchair convertible stretcher. It is
connected in between backrest and seat (base) and in between seat (base) and leg rest. It is connected in order to convert wheelchair into stretcher and vice versa.
8. Fasteners: These are used to connect the linkages and to fix the seat back recliner mechanism rigidly which helps in the process of conversion of wheelchair into stretcher and vice versa.
9. Caster wheels: The caster wheels are used are used for smooth travelling of wheelchair convertible stretcher and are attached at the bottom of the base of wheelchair convertible stretcher. The height of caster wheels is 4”.
4. WORKING
The working of wheelchair convertible stretcher is so simple that the patient feels comfortable during the transformation from wheelchair into stretcher and vice versa.
In operation when the wheelchair is to be converted into stretcher the operation starts with pulling the lever. The lever is connected to the backrest with radial spring.
After pulling the lever, the gear in the seat back recliner mechanism un-meshes and due to the weight on the backrest it will gradually lower down. This will convert the wheelchair into the stretcher.
Now if we have to convert the stretcher into wheelchair, again pull the lever of the seat back recliner mechanism. By applying light load on the leg rest, the backrest will also rise up till its original position.
Fig. B
Fig. A
The advantage of using this mechanism is that during conversion of wheelchair into stretcher the backrest can be locked at any angle according to the need and comfort of patient.
5. DESIGN CALCULATIONS
Dimensions of wheelchair convertible stretcher are as follows:-
PART NAME LENGTH WIDTH THICKNESS
BACKREST 28” 22” 1”
SEAT 19” 22” 1”
LEGREST 23” 22” 1”
FOOTREST 6” 22” 1”
For the above mentioned dimensions of the wheelchair convertible into stretcher the length of links used are -
Link a = 21” Link b = 15.2” Link c = 16.9”
Fig. C shows the links at two extreme positions.
6. CONCLUSION
Our study was intended to develop a concept of wheelchair convertible stretcher with the motivation of saving space and prevent exertion of patient as well as by making sure that the patient does not get hurt.
The mechanism and safety of patient were our main priorities while designing the conceptual model of wheelchair convertible stretcher.
Our study shows that it is possible to save 50% space by using wheelchair convertible stretcher rather than using wheelchair and stretcher separately.
This design eliminates the steps of shifting patients from wheelchair to stretcher and vice versa as nurturing of disabled people becomes difficult. Our design will thus be an efficient mobility aid for the medical field.
REFERENCES
[1] Sreerag C S, Gopinath C, Manas Ranjan Mishra, “Design and Development of Conceptual Wheelchair Cum Stretcher”, SASTECH Volume 10, Issue 2, Sep 2011.
[2] Mr. Amos Winter, “Mechanical principle of wheelchair design”, Graduate Student, Department of Mechanical Engineering, Massachusetts Institute of Technology, US, retrieved on 24th Sept. 2010.
[3] Jingtao.Chen, Bing.Teng, Yali.Yang, “Design of the Wheelchair Bed”, Rev. Téc. Ing. Univ. Zulia. Vol. 37, Nº2, 66 - 68, 2014.
[4] Rashid Ahmed K., Safar Abdul Razack , Shamil Salam , Vishnu Prasad K.V.,Vishnu C. R., “Design and Fabrication of Pneumatically Powered Wheel Chair-Stretcher Device”, International Journal of Innovative Research in Science, Engineering and Technology, Vol. 4, Issue 10, October 2015.
[5] Prof. Abhinav v. Deshpande, A Low-Cost Electric Power Wheelchair With Manual And Vision-Based Control System. International Journal of Information Technology, 2(2), 2015, pp. 01–09.
[6] Deepthi J and Col Dr T S Surendra Various Types of Wheel Chair Control Methods: A Review. International Journal of Electronics and communication Engineering & Technology, 4(1), 2013, pp. 250–255.
[7] Sumedh J. Suryawanshi, Dr. K. Janardhan Reddy, “Conceptual Product Development of Wheelchair for People Disabled in Legs”, International Journal of Research in Mechanical Engineering Volume1, Issue 2, October-December, 2013, pp. 01-10.
