Computer-based Creativity Enhanced Conceptual Design Model for Non-routine Design of Mechanical Systems

Computer-based conceptual design for routine design has made great strides, yet non-routine design has not been given due attention, and it is still poorly automated. Considering that the function-behavior-structure（FBS） model is widely used for modeling the conceptual design process, a computer-based creativity enhanced conceptual design model（CECD） for non-routine design of mechanical systems is presented. In the model, the leaf functions in the FBS model are decomposed into and represented with fine-grain basic operation actions（BOA）, and the corresponding BOA set in the function domain is then constructed. Choosing building blocks from the database, and expressing their multiple functions with BOAs, the BOA set in the structure domain is formed. Through rule-based dynamic partition of the BOA set in the function domain, many variants of regenerated functional schemes are generated. For enhancing the capability to introduce new design variables into the conceptual design process, and dig out more innovative physical structure schemes, the indirect function-structure matching strategy based on reconstructing the combined structure schemes is adopted. By adjusting the tightness of the partition rules and the granularity of the divided BOA subsets, and making full use of the main function and secondary functions of each basic structure in the process of reconstructing of the physical structures, new design variables and variants are introduced into the physical structure scheme reconstructing process, and a great number of simpler physical structure schemes to accomplish the overall function organically are figured out. The creativity enhanced conceptual design model presented has a dominant capability in introducing new deign variables in function domain and digging out simpler physical structures to accomplish the overall function, therefore it can be utilized to solve non-routine conceptual design problem.

Effect of Non-Routine Perioperative Laboratory Values on 30 Day Mortality after Non-Cardiac Surgery

Background: It is known that certain laboratory value abnormalities may increase mortality in patient populations with specific risk factors and specific procedures. The purpose of this paper was to investigate the effect of drawing a non-routine lab (regardless of its result) on 30 day mortality and to investigate the effect of an abnormal non-routine laboratory value on 30 day mortality. Methods: The electronic medical records of adult patients undergoing non-cardiac surgery from 2011-2014 at LAC + USC Medical Center were reviewed retrospectively as approved by our institutional review board. Demographic data, surgical risk assessment, and routine and non-routine laboratory values (TSH, Troponin, Creatine Kinase, Hb A1c) were recorded;patients were grouped according to the single non-routine lab they had drawn. Multivariate logistic regression analysis was used to determine significant risk factors associated with increased 30 day mortality. Results: 11,306 patients met our inclusion criteria. Drawing a non-routine lab was associated with a statistically significant increase in mortality in the Troponin group (OR = 3.05, P < 0.001) but not in the TSH, Creatine Kinase, or Hb A1c groups. An abnormal non-routine lab value was associated with a statistically significantly increase in mortality in the TSH group (OR = 11.07, P = 0.008) but not in the other three groups. Conclusions: Drawing a non-routine lab was associated with a statistically significant increase in mortality in the Troponin group but not in the TSH, Creatine Kinase, or Hb A1c groups. An abnormal TSH value was associated with a statistically significant increase in mortality but not an abnormal Troponin, Creatine Kinase, or Hb A1c. Routine and non-routine laboratory testing may guide perioperative patient care and result in improved post-surgical outcome.