New trend line of research about comfort evaluation: proposal of a framework for weighing and evaluating contributes coming from cognitive, postural and physiologic comfort perceptions

In HMI design, several parameters have to be correctly evaluated in order to guarantee a good level of safety and well-being of users (humans) and to avoid health problems like muscular-skeletal diseases. ISO Standards give us a good reference on Ergonomics and Comfort: ISO 11228 regulation deals with several parameters for evaluating Postural Ergonomics in manual loads’ push/pull, in manual loads’ lifting and carrying and in repetitive actions. Those parameters can be synthesized in a “Postural Load Index” that represents the Ergonomics level of examined posture. Nothing has be done, by ISO, in order to give a method/criterion for evaluating comfort performances of products and workplaces. More than 100.000 scientific papers dealing with comfort and discomfort can be easily found in main scientific databases and most of these speak about relationship between environmental factors (like temperature, humidity, applied forces etc.) and perceived comfort/discomfort. Several papers follow the assumption that there is a relationship between self-reported discomfort and musculoskeletal injuries and that those injuries affect the perceived comfort; however, the theories relating comfort to products/processes and products/processes’ design characteristics are rather underdeveloped. One of the most recent and interesting paper about comfort perception and its evaluation is the Vink-Hallbeck (2012) one in which the Moes’ comfort perception model (2005) has been developed and improved. In our paper, a simplified model of comfort perception, that seems to work well with the Vink-Hallbeck one, has been proposed and takes into account four aspects that strongly affect the global comfort perception: (B) – User Biomechanics/Posture, (P) - Physiologic factor, (E) – Environment contribute, (C) – Cognitive factor. Each of these aspects can be split in sub-aspects that have to be taken into account in order to be evaluated and correlated to subjective comfort perception. This paper want to explain all those sub-aspects, analyze the state of the art about their evaluation and propose an easy-to-use framework for weighing and evaluating contributes coming from cognitive, postural and physiologic comfort perceptions (no environment’s factors have been studied) to the global comfort perception.