Some studies on integrated design approach for product like stretcher under extreme ambient conditions

Abstract

Product design is a scientific process and it can be engineered as per the customer needs. To develop a successful and customer oriented product, product design model, tools and methodology play important roles as these help the designer to perform all the required design activities in a systematic manner and to eliminate even small design errors at various stages which collectively may cause failure of design. In this research work the IPD approach and few important design tools like computer aided design (CAD), benchmarking, quality function deployment (QFD) and TRIZ (the innovative problem solving method) were studied and a generic product design model and approaches were proposed to design an advance casualty evacuation stretcher for our Armed Forces. Modern day warfare is highly mechanized and technology oriented, with the result, the casualty figures are likely to increase with every war and conflict. Medical fraternity is geared up to minimize loss of life and limb by providing immediate first aid and speedy evacuation. The casualty evacuation (Casevac) stretcher is a medical device and used to carry casualties or an incapacitated person from the place of incident to medical point. As per Charles et al. (2004) in medical science, it is known fact that the survival rate of patient treated within the golden hour i.e. first hour after serious injury occurs is 80%. At 1.5hr after serious injury without definitive treatment being administered, the chance of survival decreases to 20%. The historic wound and casualty data suggests that more than 90 % of those severely wounded persons die within the first hour of injury unless treated. Therefore, casualty evacuation stretcher forms a very important link in carriage of casualties’ right from the forward defended locality (FDL) to rearwards and thus, it is one of the most important requirements of the Armed Forces. The Armed Forces have to be deployed in difficult terrains, high altitudes and snow bond areas where the load carrying capacity of a soldier reduces up to 70 %; therefore in such conditions casualty evacuation becomes more difficult. From the literature and conducted customer survey reports it is found that there is a strong need of a lightweight, portable, comfortable, safe, strong and cost effective casualty evacuation stretcher to meet the military and civil requirements, specifically suitable for difficult terrains and harsh environments i.e. extreme ambient conditions where the army has to be deployed. The research efforts have been focused on building up a broad theoretical foundation based on literature review which includes various product design models, tools/techniques like CAD, TRIZ and QFD to develop a systematic integrated product design approach and case studies. Since, in the present era of global marketing, innovation and creativity are becoming more and more important and necessary in product design to win the market as the countries having higher innovation capabilities are economically stronger and advance; therefore, based on the literature review and research work, two approaches were developed. The first approach is to evaluate the degree of novelty of a design concept at concept development stage to guide the designer to decide either rejection or modification of the concept. The second is the QFD integrated TRIZ” (QIT) approach for improving the design concept by trading off the design attributes in the innovative and structured way. The proposed approaches have been incorporated with the integrated design methodology to develop a generic product design model. To verify the proposed product design model and proposed approaches, “Light Weight Foldable Stretcher” (LWF-Stretcher) and “Multipurpose Army Field Cot cum Stretcher” (MPAFCS) were designed by applying them. The concept evaluation approach guided the design team to evaluate the novelty of the stretcher and MPAFCS concepts at the initial design stage which led to the innovative and successful product designs. The QIT approach, guided the design team to improve the designs of the stretcher and MPAFCS by trading off the design parameters in the structured manner and to achieve the set target values of the “higher priority-design attributes” required by the customer like lesser weight, higher safety and lower cost. By incorporating the approaches, approximately 19.375% weight of the stretcher could be reduced. Besides even after adding additional features like, backpack size, patient gripping straps, IV fluid rod, and auto locking joints .The overall weight of the stretcher was still lesser than that of the existing design. Another very useful product developed with the help of the proposed approaches is MPAFCS which can be used by the doctors and surgeons to examine as well to perform the field surgery of the soldiers to save his/her life or limbs. Besides being used during war or disaster situations MPAFCS can also be used for various civil applications like as transit camp beds, night shelter beds, sleeping beds in metro cities where houses are small, medical beds in primary health centres for carrying and treating patient etc. Acceptance of the patent and award of design registration by the Indian Patent Office proved the novelty of the products and purchasing of manufacturing licenses of stretcher and MPAFCS by three reputed firms showed the business potential and commercial success of the products. Therefore it can be said that the proposed integrated product design proposed approaches are very useful and can be applied to design and develop the customer oriented product successfully and to make the nation economically stronger.