New Dependability Approach for Implanted Medical Devices

International audienceFunctional Electrical Stimulation (FES) is an attractive solution to restore some lost or failing physiological functions. Obviously, the FES system may be hazardous for patient and the reliability and dependability of the system must be maximal. Unfortunately, the present context, where the associated systems are more and more complex and their development needs very cross-disciplinary experts, is not favorable to safety. Moreover, the direct adaptation of the existing dependability techniques from domains such as space or automotive is not suitable. Firstly, this paper proposes a strategy for risk management at system level for FES medical implant. The idea is to give a uniform framework where all possible hazards are highlighted and associated consequences are minimized. Then, the paper focuses on one of the most critical part of the FES system: analog micro-circuit which generates the electrical signal to electrode. As this micro-circuit is the closest to the human tissue, any failure might involve very critical consequences for the patient. We propose a concurrent top-down and bottom-up approach where the critical element

Audit about Medical Decision: Data Transmission Concerning Patients with Dementia Entering French Nursing Homes Does Not Confirm the Diagnosis

Background. Dementia was affecting 855.000 patients in France in 2007. Lanmeur's rural hospital population was representative of the French nursing home's population. The followup was assumed by local GPs, which is also usual care in France for nursing homes. The study looked at clinical and paraclinical data transmitted at the institutionalization time of patients suffering from dementia. Aim. showing that admission letters did allow establishing a diagnosis of dementia for the GPs. Method. we included all patients with dementia at the time of institutionalization between July 2000 and July 2007. We searched in the admission letters for 25 criteria extracted from the French guidelines for dementia and Alzheimer disease diagnosis (multiple cross-sectional analysis per year). Results. 293 patients were included. The median number of diagnostic criteria present in the letters of admission is 1 (first quartile: zero, third quartile: 4, and maximum: 12). Conclusions. the data in admission letters did not allow the diagnosis of dementia according to the French guidelines. We know that dementia is underchecked and undertreated in France according to the same guidelines. What consequences did this lack of basic data give on motivation for treatment and recurrent diagnosis process for GPs? This has to be evaluated

The French version of the HSCL-25 has now been validated for use in primary care

Background The Hopkins Symptom Checklist in 25 items (HSCL-25) helps to assess anxiety and depression in Primary Care. Anxiety and depression show considerable overlap in primary care. This self-administrated questionnaire is valid, reliable and ergonomic in the original US version. We have translated it into French. The aim of this study was to estimate the test characteristics of the HSCL-25, in its French version (F-HSCL-25), by comparing it to the Present State Examination-9 French version (F-PSE-9) and by determining its internal validity and dimensions. Method Outpatients from three French General Practice settings (rural, semi-rural and urban) were recruited: approximately 20,000 outpatients among 17 GPs. Two groups were formed: F-HSCL-25 ≥1.75 and F-HSCL-25 1.75 was considered to indicate a clinically relevant level of symptoms of depression and anxiety. In order to obtain two balanced groups, a different method of randomization was chosen for each group. The F-PSE-9 was randomly administered to 1 in 2 patients in the F-HSCL-25 ≥1.75 group, and to 1 in 16 in the (much larger) F-HSCL-25 <1.75 group. The diagnostic performance was assessed and the test results obtained from both groups were compared with their F-PSE-9 results. Results Of the 1126 patients who completed the F-HCL-25, 886 joined the F-HSCL-25 <1.75 group and 240 the F-HSCL-25 ≥1.75 group. The overall prevalence of depression, using the F-HSCL-25, was 21% in these medical practices. The diagnostic performance of the F-HSCL-25 versus the F-PSE-9, the external criteria were as follows: Positive Predictive Value (PPV) 69.8%, Negative Predictive Value (NPV) 87%; Sensitivity 59.1%, and Specificity 91.4%. The Principal Component Analysis showed that F-HSCL-25 is a one-dimensional tool (anxiety and depression dimensions combined) with a Cronbach Alpha of 0.93. Conclusion The F-HSCL-25 is an appropriate diagnostic tool for anxiety and depression in primary care in France due to its high specificity and high NPV. The HSCL-25 scale has a high eigenvalue. This pilot study will be extended throughout Europe; however, preliminary evidence suggests that the HSCL-25 is a reliable and suitable diagnostic tool for primary care

Pyrobitumen occurrence and formation in a Cambro–Ordovician sandstone reservoir, Fahud Salt Basin, North Oman

The Cambro–Ordovician Barik Sandstone reservoirs in the Fahud Salt Basin in Oman contain bitumen which may fill up to 40% of the porosity. In well Jaleel-1, this bitumen was isolated (according to kerogen procedure) and typed by NMR, elemental analysis and density measurements. The isolated bitumen is characterized by: (1) a highly aromatic character (NMR 75% CAro, H/C atomic ratio: 0.65), (2) a very high sulphur content (4.2%) and (3) a relatively high density (1.3–1.4 g/cm3). The insolubility and the reflectivity of the bitumen (1.2% Vr) qualify it as a low mature pyrobitumen. The combination of Rock-Eval and density data was used to calculate the actual volume of the pyrobitumen in the rock, as a percentage of porosity. It was found that the pyrobitumen volume shows a negative correlation with total porosity, indicating that small pores are more invaded by bitumen than larger ones. Finally, closed system pyrolysis experiments, performed on oils with different NSO contents, indicate that an in situ oil with a very high content of NSO compounds is required to generate such large amounts of pyrobitumen in the pore system. These observations suggest that the precursor oil of the current pyrobitumen was a very heavy oil tentatively assumed to be the result of a severe biodegradation. Basin modeling shows that the reservoir was charged already in Devonian times. A major uplift brought the oil accumulation near the surface during the Carboniferous and a rather regular burial to the present day position (4500 m, 140°C) (Loosveld et al., 1996). This scenario, involving a residence time at shallow depth, strengthens the biodegradation hypothesis. The numerical modeling, which involves the IFP kinetic model for secondary oil cracking, suggests that pyrobitumen formation is a very recent event. Inclusion of pyrobitumen particles within quartz overgrowth, containing fluid inclusions, provides an upper temperature limit for the beginning of pyrobitumen formation which comforts the result of kinetic modelling

Evidence for a mitochondrial localization of the retinoblastoma protein

<p>Abstract</p> <p>Background</p> <p>The retinoblastoma protein (Rb) plays a central role in the regulation of cell cycle, differentiation and apoptosis. In cancer cells, ablation of Rb function or its pathway is a consequence of genetic inactivation, viral oncoprotein binding or deregulated hyperphosphorylation. Some recent data suggest that Rb relocation could also account for the regulation of its tumor suppressor activity, as is the case for other tumor suppressor proteins, such as p53.</p> <p>Results</p> <p>In this reported study, we present evidence that a fraction of the total amount of Rb protein can localize to the mitochondria in proliferative cells taken from both rodent and human cells. This result is also supported by the use of Rb siRNAs, which substantially reduced the amount of mitochondrial Rb, and by acellular assays, in which [³⁵S]-Methionine-labeled Rb proteins bind strongly to mitochondria isolated from rat liver. Moreover, endogenous Rb is found in an internal compartment of the mitochondria, within the inner-membrane. This is consistent with the protection of Rb from alkaline treatment, which destroys any interaction of proteins that are weakly bound to mitochondria.</p> <p>Conclusion</p> <p>Although a few data regarding an unspecific cytosolic localization of Rb protein have been reported for some tumor cells, our results are the first evidence of a mitochondrial localization of Rb. The mitochondrial localization of Rb is observed in parallel with its classic nuclear location and paves the way for the study of potential as-yet-unknown roles of Rb at this site.</p

High e-vector acuity in the polarisation vision system of the fiddler crab Uca vomeris

Polarisation vision is used by a variety of species in many important tasks, including navigation and orientation (e.g. desert ant), communication and signalling (e.g. stomatopod crustaceans), and as a possible substitute for colour vision (e.g. cephalopod molluscs). Fiddler crabs are thought to possess the anatomical structures necessary to detect polarised light, and occupy environments rich in polarisation cues. Yet little is known about the capabilities of their polarisation sense. A modified polarisation-only liquid crystal display and a spherical rotating treadmill were combined to test the responses of fiddler crabs to moving polarisation stimuli. The species Uca vomeris was found to be highly sensitive to polarised light and detected stimuli differing in e-vector angle by as little as 3.2 deg. This represents the most acute behavioural sensitivity to polarised light yet measured for a crustacean. The occurrence of null points in their discrimination curve indicates that this species employs an orthogonal (horizontal/vertical) receptor array for the detection of polarised light

Nine forward–backward translations of the Hopkins symptom checklist-25 with cultural checks

Introduction: The Hopkins Symptom Checklist-25 (HSCL-25) is an effective, reliable, and ergonomic tool that can be used for depression diagnosis and monitoring in daily practice. To allow its broad use by family practice physicians (FPs), it was translated from English into nine European languages (Greek, Polish, Bulgarian, Croatian, Catalan, Galician, Spanish, Italian, and French) and the translation homogeneity was confirmed. This study describes this process. Methods: First, two translators (an academic translator and an FP researcher) were recruited for the forward translation (FT). A panel of English-speaking FPs that included at least 15 experts (researchers, teachers, and practitioners) was organized in each country to finalize the FT using a Delphi procedure. Results: One or two Delphi procedure rounds were sufficient for each translation. Then, a different translator, who did not know the original version of the HSCL-25, performed a backward translation in English. An expert panel of linguists compared the two English versions. Differences were listed and a multicultural consensus group determined whether they were due to linguistic problems or to cultural differences. All versions underwent cultural check. Conclusion: All nine translations were finalized without altering the original meaning

Simple scoring system to predict in-hospital mortality after surgery for infective endocarditis

BACKGROUND: Aspecific scoring systems are used to predict the risk of death postsurgery in patients with infective endocarditis (IE). The purpose of the present study was both to analyze the risk factors for in-hospital death, which complicates surgery for IE, and to create a mortality risk score based on the results of this analysis. METHODS AND RESULTS: Outcomes of 361 consecutive patients (mean age, 59.1\ub115.4 years) who had undergone surgery for IE in 8 European centers of cardiac surgery were recorded prospectively, and a risk factor analysis (multivariable logistic regression) for in-hospital death was performed. The discriminatory power of a new predictive scoring system was assessed with the receiver operating characteristic curve analysis. Score validation procedures were carried out. Fifty-six (15.5%) patients died postsurgery. BMI >27 kg/m2 (odds ratio [OR], 1.79; P=0.049), estimated glomerular filtration rate 55 mm Hg (OR, 1.78; P=0.032), and critical state (OR, 2.37; P=0.017) were independent predictors of in-hospital death. A scoring system was devised to predict in-hospital death postsurgery for IE (area under the receiver operating characteristic curve, 0.780; 95% CI, 0.734-0.822). The score performed better than 5 of 6 scoring systems for in-hospital death after cardiac surgery that were considered. CONCLUSIONS: A simple scoring system based on risk factors for in-hospital death was specifically created to predict mortality risk postsurgery in patients with IE

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)