Application of online instrumentation in industrial wastewater treatment plants - a survey in Flanders, Belgium.

A survey regarding online instrumentation and control was conducted among 90 companies managing their own biological wastewater treatment plant in Flanders, Belgium. In this study, all types of online instrumentation have been found suitable for automatic process control. However, its integration in general process control as well as in nitrogen removal and chemical dosing control appeared to be rather limited. Only dissolved oxygen and pH sensors were widely applied, being present in 96% and 69% of the plants, respectively. Widespread process integration is mainly obstructed by the fact that companies, especially small and medium-sized, still do not regard wastewater treatment as a full-fledged part of the production process. Operators often lack technical expertise in this domain and tend to be skeptical towards automated control mechanisms. In addition, the price of online instrumentation is still perceived as too high, in particular at smaller companies. Lastly, the design of the existing wastewater treatment plant does not always allow for real-time control. Certain measures such as operator training, monitoring of energy and chemical consumption and reduction of instrumentation costs are essential for widespread application of online process control in future years. Additionally, water reuse can create an important incentive.

The effect of alternating influent carbon source composition on activated sludge bioflocculation.

The impact of alternating influent carbon sources, i.e., glucose and starch, on activated sludge bioflocculation was investigated. To this end, four lab-scale reactors were operated during a long-term experiment. During this period the influent carbon source ratio (glucose/starch) was alternated every 7 or 35 days (i.e., a fast and slow switching frequency). Bioflocculation was monitored throughout the entire experiment using an extensive set of parameters, including macroscopic and microscopic activated sludge characteristics. Sludge hydrophobicity remained high (>80%) throughout the experiment indicating good bioflocculation. However, sludge settleability decreased for all four reactors after a 60 day adaptation period to the applied alternation in influent carbon source. During this adaptation period, floc size decreased due to the release of microcolonies. The subsequent period was characterized by a decrease in settleability, coinciding with a release of primary particles and an increase in floc size. The observed phenomena could be linked with the protein concentration near the floc surface. This fraction mainly consists of hydrolytic enzymes necessary for the degradation of starch and is responsible for a progressive deterioration of the EPS matrix. The results of this specific study indicate to be independent of the influent carbon source ratio or switching frequency.

Towards a low complexity carbon removal model for the optimal design of compact decentralised wastewater treatment systems.

On-site decentralised wastewater treatment systems can provide a financially attractive alternative to a sewer connection in locations far from existing sewer networks. Operational problems and shortcomings in the design of these systems still occur frequently. The aim of this paper is to provide a low complexity (i.e. easy to calibrate) but still accurate mathematical model that can be used to optimise the operational design of compact individual wastewater treatment systems. An integrated hydraulic and biological carbon removal model of a biofilm-based compact decentralised treatment system is developed. The procedure for drafting the model is generic and can be used for similar types of wastewater treatment systems since (i) the hydraulic model is based on an N-tanks-in-series model inferred from tracer test experiments and (ii) (biofilm) respirometry experiments are exploited to determine the biodegradation kinetics of the biomass. Based on the preliminary validation results of the integrated model, the carbon removal in the system can be predicted quite accurately. While some adjustments could further improve the modelling strategy, the here presented results can already assist the manufacturers of compact treatment systems in efficiently (re)designing their systems.

Picture archiving and communication system (PACS): medical perspectives.

PACS represents the natural evolution from the digital new modalities (US, CT, MRI,...) to a global digital environment, where the film based activities are progressively replaced by their digital counterpart. The advantages of the technique, as well as the drawbacks of the first implementations, are described. The "second generation" PACS concept is presented (modular architecture, progressive implementation, multivendor environment, integration with the Hospital Information System, standardization,...). As "case study", the example of the A.Z.-V.U.B. Hospital Implementation is described.

Guidelines for cost-effective implementation of Picture Archiving and Communication Systems. An approach building on practical experiences in three European hospitals.

This paper describes a comprehensive approach for the assessment of the impact of (partial) Picture Archiving and Communication Systems (PACS). The approach is developed, based on actual clinical experience in three European hospitals and tested in these environments. The approach departs from a thorough analysis of the working procedures and information flows before implementation, both descriptive and quantitative. On the basis of this analysis, quantitative (and hence testable) objectives of the implementation are defined. The implementation strategy is defined after comparison of various scenarios, taking costs and effects for both the final and the transition phases into account. The approach is supported by a comprehensive evaluation protocol and a software package (PACER). The approach is demonstrated in this paper by applying it on a hypothetical PACS implementation for CT, ultrasound and for the part of the radiology department serving ICU. The objectives of this PACS are: (1)--to shorten the turn around time between the radiology department and ICU from 4 h to 30 min, (2)--to save 2000 m2 of film per year and (3)--to save personnel time. In this case the PACS is introduced in three phases and completed after three years. The cost analysis shows that, if started in 1995, a financial break even point is reached after 6 years, when comparing costs for the film-based system with those of the PACS. Experiences in the three sites show that the approach helps to harvest potential benefits, allowing a cost-effective implementation of PACS.

Picture archiving and communication system (PACS): a progressive approach with small systems.

PACS represents the natural evolution from working with digital modalities (e.g. CT, US, MRI, CR) towards a global digital environment where the film based activities are progressively replaced by their digital counterpart. The advantages of the technique and the drawbacks of the first implementations are described, as well as the recent advances in terms of technology, architecture, medical integration and cost-effectiveness. The so called 'second generation' PACS concept is presented with its features: modular architecture, progressive implementation, multi-vendor environment, integration with the Hospital Information System, standardization. This approach is particularly suited for progressive implementation in an existing hospital, in contrast to the possible top-down construction of a filmless radiology department, as a project for a totally new hospital. The implementation into the university hospital AZ-VUB is described as case study.

Virological and immunological analysis of a triple combination pilot study with loviride, lamivudine and zidovudine in HIV-1-infected patients.

OBJECTIVE: To compare two antiretroviral regiments, loviride plus lamivudine (3TC) plus zidovudine (ZDV) (triple combination) and loviride plus ZDV (double combination) in terms of pharmacokinetic interactions, tolerability, safety, and immunological and virological efficacy. STUDY DESIGN: An open, case-controlled, pharmacokinetic and 24-week continuous treatment pilot study. PATIENTS: Twenty p24 antigen-positive patients, 10 per treatment group, were matched according to p24 antigenaemia less or more than 100 pg, CD4 count less or more than 150 x 10-(6)/l, and gender. Eight out of 10 cases and seven out of 10 controls had received previous antiretroviral therapy. RESULTS: No clinically relevant pharmacokinetic interactions were observed. Both treatment combinations were well tolerated. Median absolute and percentage CD4 count increases above baseline were more pronounced in the triple combination arm than in the double combination arm. Median p24-antigen and plasma viraemia level decreases below baseline were more pronounced in the triple combination arm. The M(184)I/V mutation was detected in all plasma samples of triple combination patients examined at week 12. Mutations conferring resistance to loviride and ZDV were found in a significant subset of patients in both treatment arms. CONCLUSIONS: Both combination regimens have an excellent safety/tolerability profile, but a higher level of in vivo efficacy is achieved by the triple combination, despite genotypic changes conferring resistance to one or all of these agents. The conclusions drawn are limited by small population size and the heterogenous pretreatment history. However, they support the validity of and strongly encourage a rationally designed multidrug combination approach to HIV therapy.

From archives to picture archiving and communications systems.

Keeping organised and consistent film archives is a well-known problem in the radiological world. With the introduction of digital modalities (CT, MR,...) the idea of archiving the image data in a non common way was born. The aim is to keep the information in digital form from acquisition to destination, e.g. archives, viewing station, teleradiology, a task that was not as easy as some people believed, due to bare technical possibilities and to the lack of standards concerning medical image data. These reasons made it not so common to integrate components of different origins into a digital Picture Archiving and Communication environment. How should we attempt to integrate the analogue examinations? It is ridiculous to exclude the conventional XR-examination that accounts for more than 70% of the total production. We believe that there will be a migration to light-stimulable phosphor plates, but these are not yet user friendly and certainly not cost effective. We have similar problems of immature technology as we had for the digital modalities. In a first attempt the bridge can be crossed, between the two worlds by means of converters (laser scanner, CCD camera). PACS will become a reality in the future as almost all examinations will be digitalized. We are now in a transition period with its inconveniences, but we will gain a lot soon. The migration from piles of films through a computer assisted radiological archiving system to a full digital environment is sketched in a historical survey.

Clinical efficacy of N-acetyl-aspartyl-glutamic acid nasal spray in children suffering from pollinosis: a double-blind multicentre study.

A double-blind, four-centre study was carried out in 66 children to compare the clinical efficacy and safety of N-acetyl-aspartyl-glutamic acid (NAAGA) and disodium cromoglycate (DSCG) nasal sprays. At similar dosage conditions (one puff per nostril, four times daily, for 3 weeks), no significant differences between the treatments were discernible in the primary efficacy parameters (scores, patients' and physicians' opinion). Both products induced statistically significant improvements in the nasal, ocular and total scores, but not in the respiratory (breathing) score. The hay-fever symptoms improved clinically in > 50% of the children after only two weeks with both treatments. The exact figures depended on the parameters considered. Thirteen out of 25 patients (52%) in the NAAGA group found the efficacy "good" or "excellent" at the end of the treatment period; the corresponding opinion in the DSCG group was expressed by 10 out of 24 patients (41.7%). Of the 28 patients that used the rescue medication, 12 (42.8%) were from the NAAGA group and 16 (57.1%) from the DSCG group. One patient on NAAGA treatment reported side effects, i.e. pruritus in the nose and sneezing.

PACER: a software tool for PACS decision makers.

This paper describes the development of the software package PACER as it evolved from a cost model to a software package for PACS decision making. PACER was developed as part of the TEASS topic from the EurIPACS project. EurIPACS is an EU subsidized project covering a wide area of PACS related research. The TEASS topic concerns the evaluation of prototype PACSystems in three European hospitals. PACER allows the user to evaluate costs of various PACS implementation scenarios and compare them to the costs of the current film based situation. Its cost calculation is based on a straight forward description of costs of a film based radiology department and of PACS. The PACER cost analysis can consider stepwise introduction of PACS and a corresponding stepwise disappearance of the film environment. This analysis includes effects of price developments. PACER calculates costs and expenses for a number of years in succession. The calculated results can be analysed using graphs, tables and sensitivity analysis tools. Preliminary tests in three hospitals indicate that PACER can indeed be a useful tool in the decision process concerning PACS.

HIPIN--a generic HIS/RIS-PACS interface based on clinical radiodiagnostic procedures.

Within the EurIPACS HIPIN topic a generic HIS/RIS-PACS interface will be designed, implemented and evaluated. It is generally agreed that integration with the HIS/RIS is essential for the acceptance of PACS in a clinical environment. An interface between HIS/RIS and PACS allows more efficient usage of both systems, better integration of data, better consistency checking on shared data and better security and error handling. Also the PACS performance is improved by using HIS/RIS information to steer the image migration within the PACS. In this paper the functional specifications of the interface are described. These specifications are based on descriptions of clinical radiodiagnostic procedures. The generic interface consists of a common part, and of site specific adapters. The common part is identical for all incarnations and performs message scheduling, processing and logging. The adapters are specific for each communication standard, e.g. ACR-NEMA or HL7, and for each hospital. The interface will be implemented at the radiology department of the Philipps University Hospital in Marburg (Germany) and at the orthopaedic and neuroradiology departments of the hospital of the Free University in Brussels (Belgium).

Overview of CAPACITY data.

This paper presents an overview of the data from 15 cases collected with the CAPACITY software for cost analysis of PACS. The data suggest that both hospital wide and partial PACS implementations do not pay back yet. Only Nuclear Medicine PACS systems may be introduced cost-neutral in the near future. Because of the assumed price drop of hardware components of 5-25% per year, hospital wide and partial PACS may allow cost savings within the next 10-20 years. There are major differences in viewpoints concerning the required PACS configurations and their costs. The experiences with the CAPACITY software suggest the need for the establishment of key rules, for designing a PACS configuration and for estimating PACS costs.

[Biomedical study on consultation for the young child]. / Biomedisch onderzoek op de raadpleging voor het jonge kind.

In 1983 an attempt was made for the first time in the consultations of Children Welfare in order to analyse some biomedical data. This analysis demonstrates the feasibility of this method and a methodology was elaborated to make a permanent information system.