Dynamic response of a neonatal catheter-manometer system in situ

Objective. The purpose of this study was to develop, validate, and apply a flush-pulse method to determine the dynamic response of a neonatal catheter-manometer system (CMS) in situ.Methods. In the flush-pulse method, the opened fast-flush valve of the CMS is closed; as a result, the fluid column in the CMS is impacted. This procedure can be done without affecting the net flow of infusion fluid. We validated the method in laboratory conditions by comparing 14 paired results obtained with this method to the results obtained using a generally accepted step-response method. The measurable values are the resonance frequency (fr) and the damping coefficient (d). The analysis of the flush-pulse method in situ is complicated by the patient's blood pressure wave. A remedy for this problem that is based on the first derivative of the pressure signal has been developed. The flush-pulse method is applied 14 times in situ.Results. In laboratory settings, the fr ranged from 12.5 to 64.0 Hz and d ranged from 0.14 to 0.32. The correlation coefficient was 0.99 for fr and 0.91 for d. We found four overdamped systems in situ (d>1). In other systems fr values between 8.5 and 41.0 Hz and d values between 0.16 and 0.72 were observed. The dynamic response in situ appeared to deteriorate with time due to routine intensive care procedures.Conclusions. The flush-pulse method proved to be a valid test for determining the dynamic response. The results obtained in situ emphasize the need for a regular evaluation of the dynamic response of the neonatal CMS in order to assess the shape of the pressure wave

Prevalence of stress and urge urinary incontinence in elite athletes and controls

Etude de l'interaction entre l'incontinence urinaire à l'effort , les troubles de l'alimentation et des régles chez des athlètes féminines de haut niveau

Otoacoustic emissions in preterm infants: Indications for cochlear development?

A longitudinal study of click-evoked otoacoustic emissions (CEOAEs) in 19 ears of 11 preterm infants-post-conceptional age (PCA): 30 to 39 weeks-resulted in a total of 90 CEOAE recordings. All but one of the 19 ears showed an increase of CEOAE amplitude at increasing PCA. The mean increase rate was 1.36 dB per week (dB/wk) for the left ears (n=11, SD=1.04 dB/wk), and 1.17 dB/wk for the right ears (n=8, SD=0.87 dB/wk). In six ears of three infants we were able to follow a total of 15 frequencies of spontaneous otoacoustic emissions (SOAEs), All of the monitored SOAE frequencies showed a positive shift in frequency with time, ranging from about 10 Hz/wk around 2000 Hz to about 50 Hz/wk around 5000 Hz, This increase of CEOAE amplitude and SOAE frequency indicates that OAE properties are not fully developed in preterm infants. Although the influence of middle ear properties cannot be excluded or proved, the observed SOAE frequency shift suggests development of the fine structures in the cochlea itself