# Challenging COVID-19 with Creativity: Supporting Design Space Exploration for Emergency Vertilators
## 4 Discussion
### Limitations and Future Developments  
Many limitations can be ascribed to this work. First of all, the performances of the proposed framework in terms of creativity enhancement have not been measured, but only examples have been provided. Although this could be seen as a non-negligible limitation, hindering any comprehensive and scientific validation of the proposed approach and tools, it is worth highlighting that the main purpose of the work was to provide a practical approach to support designers in challenging the COVID-19 pandemic by generating new ideas for ventilators. Accordingly, the proposal actually provides an original way to exploit morphological matrices and the PSN.  
Nevertheless, also from a design science point of view, it can be considered an interesting result, but the actual performance of the proposal needs to be investigated with scientifically sound procedures. For that purpose, well-acknowledged metrics and approaches can be exploited for designing specific experiments and assessing the design outcomes in terms of creativity (e.g., [21; 22; 68; 73; 74]). Additionally, in order to better understand how the framework actually stimulates designers, experimental procedures based on the analysis of design protocols [75; 76] should be followed in future studies.  
Concerning the considered ventilators, the paper is focused only on the AMBU-based concepts reviewed in [17], without checking for the presence of other ideas. However, it is worth noting that the paper aims at providing the fundamentals and the instructions needed to apply the proposal. The PSN and the chart compiled in this paper can be updated and upgraded with new ideas, according to the procedure described in Section 2 and illustrated in Section 3. This constitutes possible guidance for future research activities where the proposed framework can be used to comprehensively collect and review all the available ventilator concepts. To this end, it is important to highlight that as declared at the beginning of this paper, only the main mechanism of the compression unit was considered in this work. However, the PSN and the chart allow users to model the whole ventilator system. The reason that led the authors to avoid a comprehensive modeling of the system was the need to provide an easy and ready-to-use tool. This implies that the possible combinations of solutions from different rows of the chart are quite limited. However, if needed, designers can use the PSN to model additional functional problems of the system, and then to obtain more rows on the chart. Therefore, a possible direction for future work can be the comprehensive modeling of the collected ventilator projects, in order to support design space explorations of the whole system.  
Finally, it is important to highlight that the design of a ventilator is quite a complex activity involving different disciplines. This paper only focuses on the mechanical design of the main mechanisms, but for obtaining good results, it is important to perform comprehensive discussions and co-design activities with medical staff and electronic and software engineers. The ideas whose generation is supported by the proposal presented here are intended to promote the mentioned discussions in the early design phases, limiting the negative effect of the sunk cost effect.  
Secondary design problems such as the filtration of exhalation, controls, and safety measures (although extremely important) were not considered here. This choice was made in order to ease the understanding of the proposal, but at the same time to allow designers to exploit it for the most impactful part of the system. It is implicitly assumed that for a correct design procedure, designers follow robust design procedures (e.g., [40; 52; 53]), where a thorough definition of the design task also plays a key role, and in which all the required functions and related requirements are carefully identified [40; 77; 78; 79; 80]. Accordingly, the proposed framework is intended to be used for early conceptual design phases.