Development of a flush ultrasonic probe for the measurement of the velocity and the angle of attack of an aircraft.

In this work, a flush ultrasonic probe has been developed for the measurement of the velocity and the angle of attack (AOA) of an aircraft. The probe is made of one emitting transducer located at the center of a rotating stage and several receiving transducers located downstream, all transducers radiating in a normal direction perpendicular to the airflow. The determination of speed and AOA are deduced from the time of flight measurement of an ultrasonic wave between the emitter and the receivers propagating in the boundary layer. Particular attention was paid to the instrumentation as well as to the signal processing to enhance the ultrasound transmission and reception and to increase the signal-to-noise ratio. Results are reported for airflow velocities up to 127 m/s (460 km/h) both as a function of the emitter-receiver distance and as a function of the wind incidence angle. These experimental results are compared to simulations that estimate the time of flight between a source and a receiver. It is shown that ultrasonic waves propagate in the boundary layer and that the simulation code can predict the time of flight as a function of the distance and the angle.

[Health technology assessment of innovative medical devices: Timing and decision at national and local level]. / Accès au marché des dispositifs médicaux innovants : articulation entre évaluations nationales et hospitalières.

INTRODUCTION: The Medical Device Committee (CODIMS) evaluates all innovative medical devices (MD) before their introduction in the hospitals of the Assistance publique-hôpitaux de Paris (AP-HP). At the national level, the Medical Device and Health Technology Evaluation Committee (CNEDiMTS) provides recommendation for MD with respects to reimbursement by the National Health Insurance Fund. The aim of this study is to compare the recommendations of both committees and to analyze their timing on a six-year period. MATERIAL AND METHOD: We selected all innovative MD assessed by the CODIMS between 2013 and 2018. We retrieved all the recommendations for these MD from the CNEDiMTS. We performed quantitative and qualitative analysis of data collected. RESULTS: On 30 innovative MD assessed by both the CODIMS and the CNEDiMTS, 11 (37%) evaluations were performed by the CODIMS before the CNEDiMTS evaluation. They occurred approximately a year before the CNEDiMTS recommendation (an average of 378 days). Among the 25 MD with a recommendation of both committees, the two opinions were consistent in 88 per cent of all cases. DISCUSSION/CONCLUSION: This study highlights that there is a good consistency between the recommendations of both committees. This suggests that the MD evaluations conducted at the hospital level are relevant and timely. Finally, a better coordination between the national and local levels should be promoted for the MD assessment.

[3D printed medical devices and anatomical models: What kind of distribution and which uses in French hospitals?] / Dispositifs médicaux et modèles anatomiques produits par impression 3D : quelle diffusion et quelles utilisations dans les établissements de santé français ?

3D printing plays an increasingly important role in the medical sector and particularly in surgery. Nowadays, numerous manufacturers benefit from this technology to produce their medical devices and some hospitals have also purchased 3D printers. In this context, the aim of the present study was to study the distribution and the use of 3D printing in French hospitals in order to its main features in surgery. By conducting a national survey, we targeted hospitals equipped with 3D printers and those using external providers to benefit from this technology. Forty-seven hospitals were identified as using 3D printing including eight equipped with in-house 3D printers. This work gives us a first picture of 3D printing for hospital use in France and it raises questions about hospital pharmacists' involvement in 3D printed medical device production.

[Introduction of Health technology assessment at hospital]. / Mise en place de l'évaluation des technologies de santé en milieu hospitalier.

INTRODUCTION: The Medical Devices Committee (CODIMS) of the Assistance publique-Hôpitaux de Paris (AP-HP) is responsible for deciding whether innovative and costly sterile medical devices (SMD) should be adopted for the AP-HP network and for issuing recommendations on their proper use. The aim of this study was to qualify retrospectively the level of evidence of clinical studies used for the device evaluations by the CODIMS in 2012 and 2013 and to analyze the relationship between levels of evidence and decisions. MATERIAL AND METHOD: Executive summaries written in 2012 and 2013 about studied SMD was analyzed and the level of evidence of clinical studies used was qualified in high/low levels of evidence according to the scale of Sackett et al. Then, levels of evidence were correlated to decisions published by the CODIMS. RESULTS: Sixty-one files of SMD (72.1% of implantable MD) have been evaluated (225 clinical studies). Among them, only 28% of clinical studies had a high level of evidence (and 28.6% of MD at-risk) and 18% did not have any clinical studies. The CODIMS delivered an unfavourable opinion for 16 SMD: only 28 clinicals studies were available for evaluation. Among these, only 6 studies had a high level of evidence. DISCUSSION ET CONCLUSION: The amount and level of evidence of clinical studies is naturally correlated to admittance of SMD. These findings suggest that the clinical evidence used to demonstrate safety and efficacy for high-risk medical devices is based on clinical studies with poor quality data, making more difficult the evaluation of SMD in hospital. The development of a multi-criteria tool to help decision-making would improve the process of SMD evaluation by the CODIMS.

[Hospital-based health technology assessment in France: how to proceed to evaluate innovative medical devices?]. / Évaluation des technologies de santé en milieu hospitalier : quelle organisation pour évaluer et acquérir des dispositifs médicaux innovants ?

Innovative medical devices offer solutions to medical problems and greatly improve patients' outcomes. Like National Health Technology Assessment (HTA) agencies, hospitals face numerous requests for innovative and costly medical devices. To help local decision-makers, different approaches of hospital-based HTA (HB-HTA) have been adopted worldwide. The objective of the present paper is to explore HB-HTA models for adopting innovative medical devices in France and elsewhere. Four different models have been conceptualized: "ambassador" model, "mini-HTA" model, "HTA unit" model and "internal committee". Apparently, "HTA unit" and "internal committee" (or a mixture of both models) are the prevailing HB-HTA models in France. Nevertheless, some weaknesses of these models have been pointed out in previous works. Only few examples involving hospital pharmacists have been found abroad, except in France and in Italy. Finally, the harmonization of the assessment of innovative medical devices in France needs a better understanding of HB-HTA practices.

[Computerized prescription for medical devices: examples, interest and limits]. / Vers la prescription informatisée des dispositifs médicaux : exemples d'application, intérêts et limites.

INTRODUCTION: Related to the good practice contract implemented in hospitals, the prescription dedicated to medical devices, such as pharmaceuticals, could promote safety and good practice. MATERIAL AND METHOD: We attempted to implement a computerized prescription for medical devices. In order to illustrate the method, two examples were selected: the Negative Pressure Wound Therapy (NPWT) and the Drug Eluting Stents (DES). RESULTS: In partnership with the medical teams was elaborated a computerized protocol which included all the needed items for the good use of NPWT. For DES, a pre-existing questionnaire was used. We updated it in order to integrate new items such as the prescriber's name, the patient's name, the characteristics of the wound, the DES references and the indications. DISCUSSION AND CONCLUSION: Computerized prescriptions for high-risk and expensive medical devices seem to be an interesting approach to guarantee the patient care safety and to reduce the budget impacts. In order to monitor the indications funded as fee-for-service medical devices, a prescription will emerge as a gold standard in the future in France. Eventually, this study highlights a new activity of clinical pharmacy for hospital pharmacists dealing with medical devices.

Which medical technology and/or local treatment is most conducive, as of 2012, to pressure sore debridement ? Developing French guidelines for clinical practice.

INTRODUCTION: Implementation of a curative strategy at the debridement stage associates systemic therapy with local therapy. OBJECTIVES: To determine which medical devices and technology other than support surfaces and what kinds of drugs to use in order to cleanse a pressure ulcer in 2012. METHOD: A systematic review of the literature querying the databases PASCAL Biomed, Cochrane Library and PubMed from 2000 to 2010 along with a compendium of prevailing professional practices. RESULTS: Pressure sore debridement is based on local care and on the use of alginates, hydrogels and hydrocolloids. DISCUSSION: The analyzed articles do not take into account any specific stage of pressure ulcer debridement. Data that might favor some kinds of dressings show a low level of evidence. Were it possible to decide on the dressing to be used for a given indication, professionals would be better able to orient and narrow down their choices. CONCLUSION: Use of alginates and hydrogels in pressure ulcer debridement is of real interest. According to expert opinion, other dressings (irrigo-absorbents, for instance) seem promising, but have yet to receive adequate scientific validation.

[Estimation of small and large fetal weight at delivery from ultrasound data]. / Estimation du poids de naissance de fœtus de petit poids (≤2500g) et de gros poids (≥4000g) à partir des données échographiques.

OBJECTIVE: Birth weight (BW) prediction is crucial to assess the risk of fetal and neonatal morbidity and mortality related to growth restriction or macrosomia. Our objective here was to devise an accurate BW prediction method for small fetuses (BW ≤ 2500 g) and large fetuses (BW ≥ 4000 g), based on ultrasound data collected starting at 20 weeks' gestational age. These new models were tested on a new sample of validation consisted of 397 small fetuses and 135 large fetuses. METHODS: We included 3486 fetuses whose age and weight at birth were known and for whom standard data were available from ultrasound scans. Extrapolation to full-term of the estimated fetal weight computed using Hadlock's equation identified 212 small and 291 large fetuses. We built a new regression model for predicting the BWs of small fetuses and large fetuses. The results obtained using these models were compared to those provided by Hadlock's equation. RESULTS: Predicted BWs of small and large fetuses obtained using the regression models showed significantly less systematic bias (1.0 versus 4.9) and (-3.4 versus -7.0, respectively) and random error (10.1 versus 11.6 and 7.5 versus 8.9, respectively) than Hadlock's estimate. These results are confirmed on the sample of validation. CONCLUSIONS: Our results support the accuracy and reliability of our BW prediction models for small and large fetuses. In addition, our models provide BW estimates as early as 5 ± 1 weeks before birth.

Small and large foetuses: Identification and estimation of foetal weight at delivery from third-trimester ultrasound data.

BACKGROUND: The estimation of foetal weight (EFW) at delivery is crucial to assess the risk of foetal and neonatal morbidity and mortality, most notably when the foetus is small or large. AIM: To accurately predict the EFW at delivery of small foetuses (birth weight [BW]≤2500g) and large foetuses (BW≥4000g) identified with third-trimester ultrasound data. METHODS: We included 1309 foetuses whose age and weight at birth were known and for whom standard data were available from third-trimester ultrasound scans. Small and large foetuses were identified by extrapolation to full term of the estimated foetal weight obtained using Hadlock's equation. We built two regression models for predicting the birth weights of small and large foetuses, respectively. The results obtained with these models were compared to those obtained with Hadlock's equation. RESULTS: Third-trimester sonograms were obtained at 33.6±1.3 weeks gestational age [WGA] and birth occurred at 38.7±1.2WGA. EFW of small foetuses predicted using the regression model showed significantly less systematic bias than the Hadlock estimate (2.3% vs. 7.2%, respectively), whereas random errors were similar. EFW of large foetuses predicted using the regression model showed significantly less random error than the Hadlock estimate (6.2% vs. 10.1%, respectively), whereas systematic bias was similar. Data from an independent validation sample indicate that our regression models are accurate. CONCLUSIONS: To apply distinct models for accurately predicting the EFWs at delivery of small and large foetuses should prevent adverse events related to newborn size.

[Evaluation of flow rate regulators for intravenous infusion]. / Evaluation des régulateurs de débit passifs utilisés pour la perfusion intraveineuse.

OBJECTIVE: The aim of our study is to evaluate seven flow rate regulators (FRR) to assess the reliability of these devices compared to standard perfuser with roller clamp. STUDY DESIGN: Each FRR was tested with 5% dextrose and 0.9% sodium chloride combined with three different theoretical flow rates (30, 80 and 250 ml/h). Accuracy was compared with the theoretical value. Repeatability of flow rate was assessed thanks to variance break-up. RESULTS: Each FFR exhibits at least one combination "flow rate-solution" significantly different of the theoretical flow rate. Exadrop was the least successful of the FFR according to the accuracy. This FFR had for each combination a flow rate different of the theoretical (mean error: -24.0 ml/h). Tutodrop was the most successful of the FFR according to the accuracy with five combinations comparable to the theoretical value (mean error: -1.2 ml/h). The standard perfuser with roller clamp, used without FRR, reported two combinations comparable to the theoretical value and showed lowest rates for repeatability. CONCLUSION: Our study exhibits the poor performances of the FRR studied: according to expected flow regulation, the reported results demonstrate the lack of accuracy. Their only one value added compare to the roller clamp is to improve the repeatability of the flow rate.

Estimation of fetal weight: accuracy of regression models versus accuracy of ultrasound data.

OBJECTIVES: To determine the respective importance of equation accuracy and variability in interexaminer measurements in estimation of fetal weight (EFW). METHODS: The study included 3 samples from three different French maternity hospitals. Sample 1 (6,508 fetuses) was used to compute a new linear regression model estimating fetal weight (FW) from ultrasound measurements. Sample 2, with 705 fetuses, was used to compare the accuracy of the new equation with Hadlock's equation. Sample 3 (1,461 fetuses) was used to assess - from our equation and from Hadlock's - the estimation errors due to the variability of ultrasound measurements recorded by 11 distinct examiners. Accuracy was determined by the signed percent difference (%Diff). Statistical analysis included the F test for correlated variances and comparisons of correlated variances. RESULTS: The random error of our model is 6.8%, significantly lower (p < 0.01) than Hadlock's which is around 7.4% (8.9% for low FW and 7.4% for high FW). The variability of ultrasound measurements among the different examiners in sample 3 generated a significant variation (p < 0.01) in the random error, ranging from 6.7 to 12.5%. This significant variation was also observed using Hadlock's equation for the same sample (from 7.2 to 12%). CONCLUSION: The accuracy of EFW depends much more on the quality of ultrasound measurements than on the choice of equation. Nevertheless, optimizing the accuracy of EFW (about 6.7-6.8%) imperatively requires standardized data collecting.

PCA-based magnetic field modeling: application for on-line MR temperature monitoring.

Magnetic Resonance (MR) temperature mapping can be used to monitor temperature changes during minimally invasive thermal therapies. However, MR-thermometry contains artefacts caused by phase errors induced by organ motion in inhomogeneous magnetic fields. This paper proposes a novel correction strategy based on a Principal Component Analysis (PCA) to estimate magnetic field perturbation assuming a linear magnetic field variation with organ displacement. The correction method described in this paper consists of two steps: a magnetic field perturbation model is computed in a learning step; subsequently, during the intervention, this model is used to reconstruct the magnetic field perturbation corresponding to the actual organ position which in turns allow computation of motion corrected thermal maps.

Representativeness of an automobile shredder residue sample for a verification analysis.

To apply a decision-making scheme using a statistical classification while conforming to the meaning of representativeness as defined by the US EPA, we propose an equation defining the representativeness of a sample. To utilize this equation, the batch must be homogenized. This requires analyzing the constitution and distribution heterogeneities. The equation relates the sample weight m(s) to its representativeness R either by a statistical approach or by a physical approach using the following equation: m(s) = {4/(1 - R)(2)}.[K + k(e)(1 - 2t(e))/t(e)]. In the equation, K and k(e) are the heterogeneity factors determined from a descriptive analysis. This equation is applicable to solid waste with majority constituents such as automobile shredder residue (ASR) and domestic waste. This analysis was applied to a sample of ASR in the framework of a verification for France. The results of the analysis showed that the sample weight must be at least 140 kg to have a representativeness of 90%.

MEP (Mars Environment Package): toward a package for studying environmental conditions at the surface of Mars from future lander/rover missions.

In view to prepare Mars human exploration, it is necessary to promote and lead, at the international level, a highly interdisciplinary program, involving specialists of geochemistry, geophysics, atmospheric science, space weather, and biology. The goal of this program will be to elaborate concepts of individual instruments, then of integrated instrumental packages, able to collect exhaustive data sets of environmental parameters from future landers and rovers of Mars, and to favour the conditions of their implementation. Such a program is one of the most urgent need for preparing human exploration, in order to develop mitigation strategies aimed at ensuring the safety of human explorers, and minimizing risk for surface operations. A few main areas of investigation may be listed: particle and radiation environment, chemical composition of atmosphere, meteorology, chemical composition of dust, surface and subsurface material, water in the subsurface, physical properties of the soil, search for an hypothesized microbial activity, characterization of radio-electric properties of the Martian ionosphere. Scientists at the origin of the present paper, already involved at a high degree of responsibility in several Mars missions, and actively preparing in situ instrumentation for future landed platforms (Netlander--now cancelled, MSL-09), express their readiness to participate in both ESA/AURORA and NASA programs of Mars human exploration. They think that the formation of a Mars Environment working group at ESA, in the course of the AURORA definition phase, could act positively in favour of the program, by increasing its scientific cross-section and making it still more focused on human exploration.

A new method specifically designed to expose cells isolated in vitro to radon and its decay products.

A system was set up to provide direct exposure of cells cultured in vitro to radon and its decay products. Radon gas emanating from a uranium source was introduced at a measured concentration in a closed 10-m(3) exposure chamber. Cells were cultured on the microporous membrane of an insert that was floating over the culture medium in a six-well cluster plate. Plates with cells were placed in an open thermoregulated bath within the chamber. Under these conditions, cells were irradiated by direct deposition of radon and radon decay products. During exposure, all parameters, including radon gas concentrations, decay product activities, and potential alpha-particle energy concentrations, were determined by periodic air-grab samplings inside the chamber. The energy spectrum of deposited decay products was characterized. An estimation of alpha-particle flux density on the area containing cells was performed using CR-39 detector films that were exposed in cell-free wells during the cell exposure. The number of alpha-particle traversals per cell was deduced both from the mean number of CR-39 tracks per surface unit and from measurements of entire cells or nuclear surfaces. This paper describes the design of experiment, the dosimetry of radon and radon decay product, and the procedures for aerosol measurements. Our preliminary data show the usefulness of the in vitro cell culture approach to the study of the early cellular effects of radon and its decay products.

[Use of the CD-ROM "Tox-Didact" for teaching of toxicology and pharmacology]. / Application du CD-ROM 'Tox-Didact' à l'enseignement de la toxicologie et de la pharmacologie.

Tox-Didact is a multimedia teaching software package for initial training, continuing training and self-learning of toxicology and pharmacology. This software covers a large part of toxicology in its acute and chronic pathology using several approaches: drugs (salicylics, paracetamol, lithium ...); toxins (lead, methanol, carbon monoxide ...); drug addiction and doping (cocaine, heroin, LSD, amphetamines ...); systemic targets (kidneys, skin, liver ...). Tox-Didact is currently composed of 39 modules in validation, each tackling the diagnosis, biological surveillance, treatment, prevention and documentation of a real clinical case. Each module is organized around four types of questions, requiring a choice either (drug, symptom, formula ...) or an open response. Each validated answer is analysed by software which then comments on or corrects it. The essential points which characterize this software are: its multidisciplinarity (toxicology, pharmacology, semiology ...), its reliability (validated by experts), its simplicity of use. It is modular and offers an interactive teaching approach. The objective is to create a portable multimedia tool operational with all computer systems (IBM PC, Macintosh). This program is sustained by the Région des Pays de la Loire and by the Multimedia Resource Office of the French Ministry of National Education.

Application of the Seveso Directive in France.

First, the paper presents a brief summary of the French actual regulation on installations registered for the protection of the environment and covered by the Seveso I Directive. Then the paper discusses research and development needs for a sound implementation of the Directive, and for the new requirements on safety reports established by the Seveso II Directive. Further, it discusses issues connected with coverage of hazardous activities, learning from accidents, technical and organisational measures (safety management systems and emergency response) and human factors. The conclusions stress the need for networking and dissemination of accident investigations, development of safety management systems, and research on cognitive ergonomics and psychology related to the decision making and interventions of the operator.

[Functional relationship between fat mass, skinfolds, under or overweight and the "ideal theoretical weight"]. / Relation fonctionnelle entre la masse grasse, les plis cutanés, le déficit ou l'excédent pondéral et le "poids théorique idéal".

Underscoring a functional relation between fat mass, skinfolds, under or overweight and the 'ideal theoretical weight', constitutes a fundamental datum in anthropology. Indeed, this relation, which differs according to age, sex, ethnic group and physical activity, provides information on the distribution of fat contained in the skinfolds, the under or overweight and the 'ideal theoretical weight'. The value of this relation lies not only in limiting the use of the corpulence index (W/H2) as an indicator of fat mass, but above all in the importance of physical activity and in the existence of a significant change in the distribution of fat according to the factors mentioned above.

[Determination of the corpulence index in newborn infants]. / Détermination d'un indice de corpulence chez le nouveau-né.

A biometric study of the somatic characteristics weight and stature carried out in 1994 on 5,751 newborn children of both sexes showed the existence of an index of corpulence of the P/T2.75 type which presents the particularity of being correlated to weight and without any link with stature, unlike Quetelet's index (P/T2) and P/T3 Roehrer's index. At fixed stature, the coefficients of the average weight variation are lower than in adults. Moreover, there is no significant difference between the average weight in boys and in girls, their fluctuations being comparable. The expression P/T2.75 allows us to compare the corpulence of newborns of both sexes having distinct weight and stature.