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Multi-infusion with integrated multiple pressure sensing allows earlier detection of line occlusions

BackgroundOcclusions of intravenous (IV) tubing can prevent vital and time-critical medication or solutions from being delivered into the bloodstream of patients receiving IV therapy. At low flow rates (≤ 1 ml/h) the alarm delay (time to an alert to the user) can be up to 2 h using conventional pressure threshold algorithms. In order to reduce alarm delays we developed and evaluated the performance of two new real-time occlusion detection algorithms and one co-occlusion detector that determines the correlation in trends in pressure changes for multiple pumps.MethodsBench-tested experimental runs were recorded in triplicate at rates of 1, 2, 4, 8, 16, and 32 ml/h. Each run consisted of 10 min of non-occluded infusion followed by a period of occluded infusion of 10 min or until a conventional occlusion alarm at 400 mmHg occurred. The first algorithm based on binary logistic regression attempts to detect occlusions based on the pump’s administration rate Q(t) and pressure sensor readings P(t). The second algorithm continuously monitored whether the actual variation in the pressure exceeded a threshold of 2 standard deviations (SD) above the baseline pressure. When a pump detected an occlusion using the SD algorithm, a third algorithm correlated the pressures of multiple pumps to detect the presence of a shared occlusion. The algorithms were evaluated using 6 bench-tested baseline single-pump occlusion scenarios, 9 single-pump validation scenarios and 7 multi-pump co-occlusion scenarios (i.e. with flow rates of 1 + 1, 1 + 2, 1 + 4, 1 + 8, 1 + 16, and 1 + 32 ml/h respectively). Alarm delay was the primary performance measure.ResultsIn the baseline single-pump occlusion scenarios, the overall mean ± SD alarm delay of the regression and SD algorithms were 1.8 ± 0.8 min and 0.4 ± 0.2 min, respectively. Compared to the delay of the conventional alarm this corresponds to a mean time reduction of 76% (P = 0.003) and 95% (P = 0.001), respectively. In the validation scenarios the overall mean ± SD alarm delay of the regression and SD algorithms were respectively 1.8 ± 1.6 min and 0.3 ± 0.2 min, corresponding to a mean time reduction of 77% and 95%. In the multi-pump scenarios a correlation > 0.8 between multiple pump pressures after initial occlusion detection by the SD algorithm had a mean ± SD alarm delay of 0.4 ± 0.2 min. In 2 out of the 9 validation scenarios an occlusion was not detected by the regression algorithm before a conventional occlusion alarm occurred. Otherwise no occlusions were missed.ConclusionsIn single pumps, both the regression and SD algorithm considerably reduced alarm delay compared to conventional pressure limit-based detection. The SD algorithm appeared to be more robust than the regression algorithm. For multiple pumps the correlation algorithm reliably detected co-occlusions. The latter may be used to localize the segment of tubing in which the occlusion occurs.

The perceived usage scenario's of continuous monitoring, continuous auditing and continuous assurance

Continuous monitoring, continuous auditing and continuous assurance are three methods that utilize a high degree of business intelligence and analytics. The increased interest in the three methods has led to multiple studies that analyze each method or a combination of methods from a micro-level. However, limited studies have focused on the perceived usage scenarios of the three methods from a macro level through the eyes of the end-user. In this study, we bridge the gap by identifying the different usage scenarios for each of the methods according to the end-users, the accountants. Data has been collected through a survey, which is analyzed by applying a nominal analysis and a process mining algorithm. Results show that respondents indicated 13 unique usage scenarios, while not one of the three methods is included in all of the 13 scenarios, which illustrates the diversity of opinions in accountancy practice in the Netherlands.

Rotatable Smart TinyLab, a platform for testing integrated façades and indoor climate

Towards Destination Stewardship

This paper presents four Destination Stewardship scenarios based on different levels of engagement from the public and private sector. The scenarios serve to support destination stakeholders in assessing their current context and the pathway towards greater stewardship. A Destination Stewardship Governance Diagnostic framework is built on the scenarios to support its stakeholders in considering how to move along that pathway, identifying the key aspects of governance that are either facilitating or frustrating a destination stewardship approach, and the required actions and resources to achieve an improved scenario. Moreover, the scenarios and diagnostic framework support stakeholders to come together to debate and scrutinise how tourism is managed in a way that meets the needs of the destination, casting new light on the barriers and opportunities for greater destination stewardship.

Imagining energy potential

Significant factors in the success or failure of energy transition arise from the spatial potential of places and their communities. Scenario planning appears to be an appropriate design instrument to enable architects to unveil, conceptualise, imagine, test and communicate this potential to stakeholders. This paper critically refelcts on the scenario as an architectural design instrument. Inscribed with political intentions, scenario planning may be a far from neutral design instrument. Instead of triggering communities to explore local energy potential, a scenario may have a normative effect on a community's imagination. The paper aims to define guidelines for the deployment of scenarios in an open, participatory planning process. To mediate in a local participatory planning process, we argue, scenarios should be situational, dynamic and open-ended, allowing or even triggering communities to (re)define the issues relevant to a place during the ongoing process of energy-transition. How, when and where should scenarios be deployed in order to enable communities to understand and develop their local energy potential?

Integrated Product Development BEDRIJFSPROJECTEN INTEGREREN HET ONDERWIJS!

Binnen het projectonderwijs wordt nog vaak drooggezwommen. Enerzijds door de verstrekte projectopdrachten anderzijds door de suboptimalisatie van oplossingen. Deze zijn namelijk sterk afhankelijk van de verbonden modules en docenten. In de praktijk zijn de oplossingen echter altijd een afweging van tijd, geld en kwaliteit. Onze Human Engineers leren om daar op een goede manier mee om te gaan. Dit door de integratiemodule Integrated Product Development (IPD). IPD is een multidisciplinair project waarbij studenten van verschillende Fontys Instituten werken aan de commercikle en technische uitwerking van een bedrijfsopdracht. Marktonderzoek, doelgroep bepaling en productspecificatie zijn een vast onderdeel van een IPD project evenals het ontwerpen en bouwen van een prototype en het financieel onderbouwen van een Go/NO go advies aan de ondernemer. Het project vindt plaats in het laatste onderwijssemester, net vssr het afstuderen en is dus te zien als een open project met een bedrijf als opdrachtgever. De Human Engineering studenten zijn in deze projecten de verbindende schakel. De specialisten in de projectgroepen, de technische studenten, willen nogal eens zoeken naar mooie oplossingen vooral in technische zin. Daarbij gaan ze vaak volledig voorbij aan het belang van de ondernemer (winst maken) en het belang van de klant (kwaliteit en bedieningsgemak). Ook het projectwerk heeft een enorme sprong vooruit gemaakt door het team uit te breiden met Human Engineers. De Human Engineering studenten focussen vooral ook op het halen van targets (kosten) en deadlines (tijd), het maken en nakomen van afspraken en de communicatie binnen de groep en naar buiten toe (ondernemer en klant). Huidige studenten en alumni geven aan dat het project zeer realistisch is en dat het vergelijkbaar is met problemen die ze in hun werk tegen komen. Zeker blijven doen is hun advies. Organisatorisch vergt het wel een en ander omdat er bijvoorbeeld afstemming dient te komen tussen de verschillende instituten met betrekking tot: beoordeling van de studenten, afstemmen van lesroosters en vergoeding voor docenten. Ook het onderhouden van bedrijfsrelaties om bijvoorbeeld aan de opdrachten te komen blijft een moeilijke, tijdrovende zaak.