TEST OF PHYSIOLOGICAL PERFORMANCE: RATIONALE AND FEASIBILITY

Rigorous clinical evaluation of the physiological performance is currently performed with complex and long procedures which need expensive technology and skilled operators. In a wide range of situations (frail patients, daily clinical practice, etc.), these approaches are difficult to be applied and simpler tests, with a lack of scientific background, are mandatory. To avoid these problems, we propose a test (test of physiological performance (TOPP)) to evaluate the physiological behavior of a subject, in a really easy and safe clinical setting, measuring only the heart rate. The subject is submitted to an active standing-up test and then two submaximal exercises (with a low power load) on a cycle-ergometer. The heart rate modifications due to each submaximal step are analyzed by exponential interpolation to calculate the ascending and descending time constants and evaluate the way each subject adapts his heart rate to work. The standard deviation of the RR for each stationary phase (warm-up, load, recovery) was calculated as an index of short-term variability. Then a standard Fourier analysis of the stationary periods of the standing-up procedures allows to quickly and easily evaluate the autonomic nervous activation. We tested the protocol on five healthy subjects to verify the feasibility and the acceptance of the procedure. The five subjects demonstrated a good tolerance of the entire procedure. The standing-up showed a behavior of the autonomic system consistent with the physiology (with an increase in sympathetic activation in the passage to standing position). The analysis of the two submaximal steps highlights how younger and trained subjects present lower heart rates (both in the ascending phase and in the recovery) with a quicker adaptation ability (smaller time constants) consistent with what is expected. The short-term variability of heart rate is greater in young and trained subjects, thus confirming how the sympatho-vagal balance, in these subjects, is more dynamic. The proposed test is well tolerated by the subjects and the results, albeit in a small cohort of healthy volunteers, are consistent with what is expected from physiology and is already present in the literature. Our work aims to be a proposal with a feasibility check of a method for evaluating performance. The work to be done for the clinical validation of the TOPP is still long, but we are aware that it can give important results and that the TOPP can become an effective tool for the assessment of the physiological performance even of fragile subjects

BIOMECHANICAL OPTIMIZATION OF CO2ANGIOGRAPHY

Carbon dioxide (CO2) angiography represents an important technique to overcome most clinical problems related to the use of iodine contrast medium. The recent technologic advancements in the fields of gas injection and image reconstructions made CO2 angiography a very efficient method for clinical evaluation of peripheral cardiovascular system. Despite that, some challenges are still open and a better knowledge of the biomechanical behavior of CO2 and its interactions with blood flowing into the vessels is necessary to optimize this technology and to expand its field of application. This paper presents a quick overview about biomechanical behavior of carbon dioxide during injection, suggesting possible optimization tricks to make CO2 angiography procedures more effective to improve imaging and reduce the patients' radiological dose. Particular attention has been also paid to 3D imaging techniques, which can certainly be opened to the use of carbon dioxide

Management of patients with atrial fibrillation: different therapeutic options and role of electrophysiology-guided approaches.

At present the approach to atrial fibrillation treatment is based on the electrophysiological patterns of atrial fibrillation (on the basis of multiple intra-atrial recordings or sophisticated new mapping techniques) only in a restricted minority of patients, those who are candidate to ablation of the substrate and/or of the triggers. Atrial fibrillation has a broad spectrum of clinical presentations and a heterogeneous electrophysiological pattern. The treatment of this arrhythmia, both with drugs and non pharmacological treatments, has been based, classically, on empirical basis and on a clinically-guided staged-approach. The limitations of pharmacological treatment led in recent years to the development of a wide spectrum of non pharmacological treatments. This implies a change in the approach to atrial fibrillation and the need to identify potentially ideal candidates to complex and expensive treatments. In this view it is currently under investigation the possibility to identify potential responders to a definitive treatment or a combination of treatments (both pharmacological and non-pharmacological) on the basis of the electrophysiological pattern

Diagnosing Clostridioides difficile infections with molecular diagnostics: multicenter evaluation of revogene C. difficile assay

Clostridioides difficile infections are a significant threat to our healthcare system, and rapid and accurate diagnostics are crucial to implement the necessary infection prevention and control measurements. Nucleic acid amplification tests are such reliable diagnostic tools for the detection of toxigenic Clostridioides difficile strains directly from stool specimens. In this multicenter evaluation, we determined the performance of the revogene C. difficile assay. The analysis was conducted on prospective stool specimens collected from six different sites in Europe. The performance of the revogene C. difficile assay was compared to the different routine diagnostic methods and, for a subset of the specimens, against toxigenic culture. In total, 2621 valid stool specimens were tested, and the revogene C. difficile assay displayed a sensitivity/specificity of 97.1% [93.3-99.0] and 98.9% [98.5-99.3] for identification of Clostridioides difficile infection. Discrepancy analysis using additional methods improved this performance to 98.8% [95.8-99.9] and 99.6% [99.2-99.8], respectively. In comparison to toxigenic culture, the revogene C. difficile assay displayed a sensitivity/specificity of 93.0% [86.1-97.1] and 99.5% [98.7-99.9], respectively. These results indicate that the revogene C. difficile assay is a robust and reliable aid in the diagnosis of Clostridioides difficile infections.This article is freely available via Open Access. Click on the Publisher URL to access it via the publisher's site.This study was supported by grants from GenePOC, now part of Meridian Biosciences.published version, accepted versio

Mechanical aspects of CO2 angiography

Abstract The aim of this paper is to clarify some physicalemechanical aspects involved in the carbon dioxide angiography procedure (CO2 angiography), with a particular attention to a possible damage of the vascular wall. CO2 angiography is widely used on patients with iodine intolerance. The injection of a gaseous element, in most cases manually performed, requires a long training period. Automatic systems allow better control of the injection and the study of the mechanical behaviour of the gas. CO2 injections have been studied by using manual and automatic systems. Pressures, flows and jet shapes have been monitored by using a cardiovascular mock. Photographic images of liquid and gaseous jet have been recorded in different conditions, and the vascular pressure rises during injection have been monitored. The shape of the liquid jet during the catheter washing phase is straight in the catheter direction and there is no jet during gas injection. Gas bubbles are suddenly formed at the catheter\u2019s hole and move upwards: buoyancy is the only governing phenomenon and no bubbles fragmentation is detected. The pressure rise in the vessel depends on the injection pressure and volume and in some cases of manual injection it may double the basal vascular pressure values. CO2 angiography is a powerful and safe procedure which diffusion will certainly increase, although some aspects related to gas injection and chamber filling are not jet well known. The use of an automatic system permits better results, shorter training period and limitation of vascular wall damage risk

Monitoring of performance's improvment during legs training and functional analysis of the movement

Gjennomføring av risikovurderinger er en viktig del av sikkerhetsstyringen i en virksomhet. Som en del av sikkerhetsstyringen til Bane NOR har de etablert håndbøker for sikkerhet og RAMS som skal etterleves ved utførelse av prosjekter som involverer endring i jernbaneinfrastrukturen. Sikkerhetshåndboken består blant annet av krav og en retningslinje for gjennomførelse av risikovurderinger, hvor det blant annet er beskrevet at risikovurderinger kan ha kvalitativ eller kvantitativ tilnærming. Derimot er det ikke angitt i hvilke forhold og omstendigheter som tilsier at en risikovurdering bør ha en kvantitativ tilnærming. Formålet med masteroppgaven er å gi innspill til etablering av en retningslinje som avklarer behovet for kvantifisering av risiko ved gjennomførelse av risikovurderingen innen trafikksikkerhet og utbyggingsprosjekter i Bane NOR. Etablering av retningslinjen vil være i samsvar med Bane NORs sikkerhetshåndbok. I den forbindelse ble det først gjennomført en begrepsavklaring med støtte fra relevant litteratur etter sentrale begrep og definisjoner om risiko og risikovurderinger. Dette for å oppnå en klar forståelse og bruk av relevante definisjoner i Bane NOR. En litteraturgjennomgang ble gjennomført for å presentere teori om gjennomførelse av risikovurderinger med kvalitativ og kvantitativ tilnærming, beregning av risiko og utvikling av retningslinjer. En oversikt over Bane NORs prosess for risikovurderinger med beskrivelse av krav som ligger til grunn fra forskrifter og standarder er også presentert. En gjennomgang av tidligere utførte risikovurderinger i Bane NOR danner et sammenligningsgrunnlag for gjennomførelse av risikovurderinger i Bane NOR. Basert på litteraturstudien og Bane NORs risikovurderingsprosess er forhold og faktorer som påvirker og tilsier en kvantitativ tilnærming bør benyttes identifisert og diskutert. Her ble forhold som datagrunnlag, ulykkessituasjon, type prosjekt og analyse presentert. Med dette som utgangspunkt er det utviklet en retningslinje for kvantifisering av risiko ved gjennomførelse av risikovurderinger spesifikt for jernbanesektoren. Retningslinjen identifiserer forhold som har betydning for valg av tilnærming og lister opp forhold hvor en kvantitativ tilnærming skal benyttes og hvor kvalitativ tilnærming er tilstrekkelig. En første versjon av retningslinjen ble uttestet i samarbeid med representanter fra Bane NOR. Retningslinjen fungerte optimalt på de to casestudiene som ble benyttet ved uttestingen, men det ble behov for noen endringer og videreutvikling. Spesielt ble det påpekt behov for et flytskjema og utarbeide eksempler som henviser til hvordan forholdene vil fungere i praksis. De viktigste forholdene som krever en kvantitativ tilnærming ble konkludert til å være: 1. Prosjektering av nye strekninger. 2. Prosjektering av tekniske systemer som er nye og/eller komplekse. 3. Valg av løsninger som har ulikt sikkerhetsnivå og/eller kostnadsbilde. 4. Den totale risikoen anses som høy. 5. Uønskede hendelser og/eller situasjoner med nytt eller økt storulykke-potensiale