Reliability and Safety Embedded Design Thinking and Frugal Engineering-based Approach in Assistive Product System Engineering
Authors: Tiwari Tushar , Kumar Sharma Vikas , Kumar Dan Pranab 
Published: June 2024

Product system engineering, the mainstay in providing utility, is an integral part of system engineering, where reliability and safety remain indispensable considerations, which is more pronounced in the present case of an assistive product system of the wheelchair extended with the sit-to-stand feature, closely bound with the users. Product system engineering involves designing and developing sit-to-stand wheelchairs that meet user-specific requirements and goals [25]. It defines the requirement and objective of the assistive product that consists of conceptual design, feasibility assessment, detailed design, and safety and reliability compliance with quality assurance [13]. System reliability and safety are critical aspects of assistive mobility products engineering, including sit-to-stand wheelchairs, these products are essential to protect the well-being and independence of the users from being addressed by risk assessment analysis, safety standards regulation, and durability of the material with testing and validation. Due to affordability issues, the wheelchair could not be made available to a large proportion of the wanting population in emerging economies, that is, in developing countries, and a type of assistive mobility device (wheelchair) is the quintessence and archetype in this article, and with a proposed cost-efficient design and therefore affordable. This research evaluates design feasibility, reliability, and safety for an assistive mobility device in keeping with affordability engineering, that is ‘frugal innovation and engineering’ precepts in tandem with the ‘design thinking’ paradigm. The development of a ‘sit-to-stand’ wheelchair, an assistive mobility variant is selected for objectification, as there is a need to engineer this category, as gathered from various reports [2,3], since this permits to access the ‘height’, such as racks, independently by disabled people and this also circumvents the postural confinement of constant sitting that creates a physiological condition causing restricted blood flow in the body resulting in cardiovascular diseases, sores and ulcer due to unrelieved pressure exerted by body weight, [25,26] etc. So, ‘Sit-to-Stand’ is an indispensable feature in a wheelchair, and researchers attempt solutions scantily [13-15] as elaborated in literature, which, however, do not address affordability. The shortcomings of the extant designs are analysed, and this article conceives a new mechanism and design that reduces the effort required as well as cost, for including this functionality in a wheelchair. The required effort force and system reliability are intersected in the design and operation of systems, mainly when human operators are involved. Reducing excessive effort forces, considering ergonomic factors, and ensuring that effort-related tasks do not compromise system reliability [21] are essential considerations in assistive product design and maintenance. These factors collectively contribute to the overall effectiveness and dependability of a product system engineering [7]. This feature also empowers people and aids in performing jobs in workplaces, in an unassisted manner that helps to support the livelihood of a wheelchair-bound person and thence restores self-esteem as well as relieves a disabled from social stigma. Furthermore, a substantial cost reduction for the feature in the proposed solution is highly beneficial for users from emerging economies, which has high potential in terms of improvement in healthcare.