Bondgraph modelling and simulation of the dynamic behaviour of above-knee prostheses

A mathematical model was used to investigate the dynamic behaviour of an above-knee (AK) prosthesis in the swing phase and to analyse the influence of mass and mass distribution on the maximal stump load and the required energy. The model consists of a bondgraph model of the prosthesis and a “walking” model which predicts the walking velocity, step length and the femoral trajectory. Equipment was developed to measure the inertial properties of the components of the prosthesis. \ud \ud Through computer simulation, stickdiagrams of the swing phase and graphs of the variation with time of the hip and stump forces were obtained. It was found that for a normal AK prosthesis with a knee-lock mechanism the axial stump load is greatest at the beginning and at the end of the swing phase. At a walking velocity of 5 km/hr the maximum axial stump load amounts to 2.1 times the static weight of the prosthesis. \ud \ud The maximum axial stump force appeared to be almost directly proportional to the total mass of the prosthesis but independent of the mass distribution. The required energy also increased with the mass of the prosthesis but is' dependent on mass distribution. \ud \ud Because of their comparable weights the influence of the shoe is almost equal to the influence of the prosthetic foot. Thus lightweight shoes should be used with lightweight prosthetic feet in order to add to their advantages

HST Snapshot Survey of Post-AGB Objects

The results from a Hubble Space Telescope (HST) snapshot survey of post-AGB objects are shown. The aim of the survey is to complement existing HST images of PPN and to connect various types of nebulosities with physical and chemical properties of their central stars. Nebulosities are detected in 15 of 33 sources. Images and photometric and geometric measurements are presented. For sources with nebulosities we see a morphological bifurcation into two groups, DUPLEX and SOLE, as previous studies have found. We find further support to the previous results suggesting that this dichotomy is caused by a difference in optical thickness of the dust shell. The remaining 18 sources are classified as stellar post-AGB objects, because our observations indicate a lack of nebulosity. We show that some stellar sources may in fact be DUPLEX or SOLE based on their infrared colors. The cause of the differences among the groups are investigated. We discuss some evidence suggesting that high progenitor-mass AGB stars tend to become DUPLEX post-AGB objects. Intermediate progenitor-mass AGB stars tend to be SOLE post-AGB objects. Most of the stellar sources probably have low mass progenitors and do not seem to develop nebulosities during the post-AGB phase and therefore do not become planetary nebulae.Comment: 21 pages, 11 figure

Association between workarounds and medication administration errors in bar-code-assisted medication administration in hospitals

Objective: To study the association of workarounds with medication administration errors using barcode-assisted medication administration (BCMA), and to determine the frequency and types of workarounds and medication administration errors. Materials and Methods: A prospective observational study in Dutch hospitals using BCMA to administer medication. Direct observation was used to collect data. Primary outcome measure was the proportion of medication administrations with one or more medication administration errors. Secondary outcome was the frequency and types of workarounds and medication administration errors. Univariate and multivariate multilevel logistic regression analysis were used to assess the association between workarounds and medication administration errors. Descriptive statistics were used for the secondary outcomes. Results: We included 5793 medication administrations for 1230 inpatients. Workarounds were associated with medication administration errors (adjusted odds ratio 3.06 [95% CI: 2.49-3.78]). Most commonly, procedural workarounds were observed, such as not scanning at all (36%), not scanning patients because they did not wear a wristband (28%), incorrect medication scanning, multiple medication scanning, and ignoring alert signals (11%). Common types of medication administration errors were omissions (78%), administration of non-ordered drugs (8.0%), and wrong doses given (6.0%). Discussion: Workarounds are associated with medication administration errors in hospitals using BCMA. These data suggest that BCMA needs more post-implementation evaluation if it is to achieve the intended benefits for medication safety. Conclusion: In hospitals using barcode-assisted medication administration, workarounds occurred in 66% of medication administrations and were associated with large numbers of medication administration errors

Huisartsgeneeskundige zorg in het verzorgingshuis

Een deel van de Nederlandse huisartsenzorg bestaat uit zorg voor ouderen in verzorgingshuizen. We vergelijken de huisartsenzorg aan patiënten in deze verzorgingshuizen met die aan leeftijdsgenoten die zelfstandig, buiten het verzorgingshuis, wonen. Omdat mensen langer zelfstandig wonen en de indicatiestelling voor plaatsing in een verzorgingshuis op basis van slecht functioneren in ADL gebeurt, verwachtten we een groep ouderen te vinden in het verzorgingshuis die meer complexe zorg behoeft van de huisarts. Het onderzoek is een ‘matched case-control’-studie in 3 Nederlandse huisartspraktijken in de periode 1/1/1998 tot 1/7/2004. De belangrijkste resultaten zijn dat de prevalentie van cognitieve problemen twee keer zo hoog en de prevalentie van depressie drie keer zo hoog is in de groep verzorgingshuisbewoners vergeleken met hun zelfstandig wonende leeftijdsgenoten. Problemen van het bewegingsapparaat worden ook veel gezien in de verzorgingshuizen. Chronische longproblemen, hart- en vaatziekten (excl. CVA) en urineweginfecties komen meer voor, maar CVA, diabetes en kanker komen juist evenveel voor binnen en buiten het verzorgingshuis. Geïnstitutionaliseerde ouderen gebruiken gemiddeld meer medicamenten tegelijkertijd. De conclusie is dat de huisarts in het verzorgingshuis te maken heeft met een specifieke kwetsbare groep ouderen waarbij de zorg niet beperkt is tot de behandeling van chronische aandoeningen, maar meer gericht is op het complexe samenspel van ziekte, afnemende functionele en cognitieve status en het levensperspectief van kwetsbare ouderen in het verzorgingshuis