论文部分内容阅读
Using a 2-factor 6×3 factorial experimental design and the MultistageEvaluation Scale(MES)to estimate the respiratory sensation,we systematicallystudied in 17 healthy young men the physiological and psychological effects of sixlevels of suprathreshold added resistive loads,appliedeparately to eitherinspiration or expiration,or throughout the breathing cycle.We observed that(1)no matter what phase of the breathing cycle was impeded,mask cavity pressureswingas well as total external respiratory workrate(r)was a curvilinearfunction of the total resistive load added(R_T),which exhibited an upwardconvexity;(2)the perceived magnitude(PM)of the respiratory sensation estimatedby using MES(S_(MES))was directly related to intensity of the physiologicalstimulus and indirectly related to the intensity of the resistance added;and(3)under different loading conditions,S_(MES)was a curvilinear function of theintensity of the physiological stimulus,which exhibited an upward concavity.These results suggest that when we derive the standards of allowable resistancefor respiratory protective equipment,in addition to the total load intensity,theimportance of the ratio between inspiratory and expiratory resistance should alsobe considered.
Using a 2-factor 6 × 3 factorial experimental design and the Multistage Evaluation Scale (MES) to estimate the respiratory sensation, we systematically stutied in 17 healthy young men the physiological and psychological effects of sixlevels of suprathreshold added resistive loads, appliedeparately to either inspiration or expiration, or throughout the breathing cycle. We observed that (1) no matter what phase of the breathing cycle was impeded, mask cavity sizes well as total external respiratory workrate (r) was a curvilinear function of the total resistive load added (R_T), which exhibited an upwardconvexity; (2) the perceived magnitude (PM) of the respiratory sensation estimated by using MES (S_ (MES)) was directly related to intensity of the physiologicalstimulus and indirectly related to the intensity of the resistance added; and (3) under different loading conditions, S_ (MES) was a curvilinear function of the intensity of the physiological stimulus, which showed an upward concavity.These results suggestion gest that when we derive the standards of allowable resistance for respiratory protective equipment, in addition to the total load intensity, theimportance of the ratio between inspiratory and expiratory resistance should also be considered.