Influence of heart motion on cardiac output estimation by means of electrical impedance tomography: a case study.

Electrical impedance tomography (EIT) is a non-invasive imaging technique that can measure cardiac-related intra-thoracic impedance changes. EIT-based cardiac output estimation relies on the assumption that the amplitude of the impedance change in the ventricular region is representative of stroke volume (SV). However, other factors such as heart motion can significantly affect this ventricular impedance change. In the present case study, a magnetic resonance imaging-based dynamic bio-impedance model fitting the morphology of a single male subject was built. Simulations were performed to evaluate the contribution of heart motion and its influence on EIT-based SV estimation. Myocardial deformation was found to be the main contributor to the ventricular impedance change (56%). However, motion-induced impedance changes showed a strong correlation (r = 0.978) with left ventricular volume. We explained this by the quasi-incompressibility of blood and myocardium. As a result, EIT achieved excellent accuracy in estimating a wide range of simulated SV values (error distribution of 0.57 ± 2.19 ml (1.02 ± 2.62%) and correlation of r = 0.996 after a two-point calibration was applied to convert impedance values to millilitres). As the model was based on one single subject, the strong correlation found between motion-induced changes and ventricular volume remains to be verified in larger datasets.

Aortic blood pressure measured via EIT: investigation of different measurement settings.

Electrical impedance tomography (EIT) allows the measurement of intra-thoracic impedance changes related to cardiovascular activity. As a safe and low-cost imaging modality, EIT is an appealing candidate for non-invasive and continuous haemodynamic monitoring. EIT has recently been shown to allow the assessment of aortic blood pressure via the estimation of the aortic pulse arrival time (PAT). However, finding the aortic signal within EIT image sequences is a challenging task: the signal has a small amplitude and is difficult to locate due to the small size of the aorta and the inherent low spatial resolution of EIT. In order to most reliably detect the aortic signal, our objective was to understand the effect of EIT measurement settings (electrode belt placement, reconstruction algorithm). This paper investigates the influence of three transversal belt placements and two commonly-used difference reconstruction algorithms (Gauss-Newton and GREIT) on the measurement of aortic signals in view of aortic blood pressure estimation via EIT. A magnetic resonance imaging based three-dimensional finite element model of the haemodynamic bio-impedance properties of the human thorax was created. Two simulation experiments were performed with the aim to (1) evaluate the timing error in aortic PAT estimation and (2) quantify the strength of the aortic signal in each pixel of the EIT image sequences. Both experiments reveal better performance for images reconstructed with Gauss-Newton (with a noise figure of 0.5 or above) and a belt placement at the height of the heart or higher. According to the noise-free scenarios simulated, the uncertainty in the analysis of the aortic EIT signal is expected to induce blood pressure errors of at least ± 1.4 mmHg.

Turvallista liikkumista tukevat sisäkengät ikäihmisille vanhuskeskusympäristöön

Tutkimuksen tarkoituksena oli selvittää, minkälaisia sisäkenkiä ikäihmiset käyttävät vanhustenkeskuksessa ja arvioida, millä tavalla he kävelevät. Tutkimus toteutettiin Helsingissä Kustaankartanon vanhustenkeskuksen F1-osastolla maalis-huhtikuussa 2007 osana IKU-pojektia. Tutkimukseen osallistui seitsemän 70 - 94-vuotiasta, itsenäisesti ja ilman apuvälineitä liikkuvaa naisasukasta. Viisi tutkittavista käytti Pirka-sisäkenkiä, yksi sandaaleja ja yksi tohveleita. Tutkimusstrategia oli kvantitatiivis-kvalitatiivinen ja tietoa kerättiin havainnointi- ja arviointilomakkeilla sekä videotallentein. Tulokset esitettiin frekvensseinä ja prosenttiosuuksina sekä kävelyn arviointi laadullisena kuvauksena. Lähes kaikilla asukkailla oli ehjä ja terve iho. Melkein kaikilla tutkituista todettiin vaivaisenluu ja levinnyt päkiä. Vasaravarpaita ja kynsimuutoksia havaittiin alle puolella. Ikäihmisten kengistä suurin osa oli pituudeltaan sopivia, eikä kantakapissa ollut muutoksia. Kahdella oli venymisjälkiä kengän kärkiosassa. Kävelyssä oli havaittavissa normaaleja ikääntymiseen liittyviä muutoksia, jotka olivat yksilöllisiä. Osalla asukkaista varvastyöntö oli heikentynyt ja nilkan liikelaajuus koukistussuuntaan oli pienentynyt sekä osalla kävely oli matalaa ja laahaavaa. Osalla ikäihmisistä kengät olivat huonosti kiinnitetty. Kantapään ja kengän kantaosan väliin jäi 1 - 2 cm:n rako, jolloin kengät ei tue jalkaterän toimintoja ja kaatumisriski lisääntyy. Tulosten mukaan ikäihmiset näyttäisivät tarvitsevan ohjausta oikeanlaisten sisäkenkien valinnassa. Kenkien valinnassa keskeistä on huomioida yksilölliset tarpeet, jotta jokainen ikäihminen saa kävellä omille jalkaterille sopivilla kengillä. Pirka-kenkiä olisi hyvä kehittää ikäihmisten tarpeiden mukaisesti. Jalkaterapeutit ja jalkojenhoitajat voivat hyödyntää tutkimustuloksia antaessa ohjeita sisäkenkien valinnassa. Koska osalla asukkaista on jalkaterän etuosan virheasentoja, jotka vaativat leveämmän lestin sekä kärjen muodon naisten malliin, Pirka-kengässä voisi olla naisten koossa kahta erimallista kärkiosaa sekä leveyttä.

Reducing Cardiovascular Mortality Through Prevention and Management of Raised Blood Pressure: A World Heart Federation Roadmap.

Prospective epidemiological data have shown that blood pressure has a graded, continuous adverse effect on the risk of various forms of CVD (including stroke, myocardial infarction, heart failure, peripheral arterial disease and end-stage renal disease). 'Raised blood pressure' is frequently considered to be any systolic blood pressure greater than 115 mmHg. It accounts for 45% of all heart disease deaths and 51% of all stroke-related deaths [1], which together are the biggest causes of morbidity and mortality worldwide [2,3,4]. Annually, there are >17 million deaths due to CVD worldwide, of which 9.4 million are attributable to complications of raised blood pressure. This highlights the importance of both high-risk and population-based strategies in blood pressure management and control.

Prévention dans les entreprises: plus facile à dire qu'à faire

Les problèmes de santé liés au travail sont en augmentation. Des stratégies d'entreprise intégrant la santé au travail doivent être mises en place. Les rapports entre activité professionnelle et santé restent cependant complexes.

How much protein and energy are needed to equilibrate nitrogen and energy balances in ventilated critically ill children?

BACKGROUND & AIMS: Protein and energy requirements in critically ill children are currently based on insufficient data. Moreover, longitudinal measurements of both total urinary nitrogen (TUN) and resting energy expenditure (REE) are lacking. The aim of this study was to investigate how much protein and energy are needed to equilibrate nitrogen and energy balances in ventilated critically ill children on the basis of daily measurements of TUN, REE and protein and energy intakes. Comparisons were made with the guidelines of the American Society for Parenteral and Enteral Nutrition and the Dietary Reference Intakes. METHODS: Children with an expected duration of mechanical ventilation ≥72 h were prospectively recruited. TUN was measured by chemiluminescence, and REE was measured by indirect calorimetry. Generalised linear models for longitudinal data were used to study the relation between protein intake and nitrogen balance and to calculate the minimum intake of protein needed to achieve nitrogen equilibrium. A similar approach was used for energy. Results were compared to the recommended values. RESULTS: Based on 402 measurements performed in 74 children (median age: 21 months), the mean TUN was high at 0.20 (95% CI: 0.20, 0.22) g/kg/d and the REE was 55 (95% CI: 54, 57) kcal/kg/d. Nitrogen and energy balances were achieved with 1.5 (95% CI: 1.4, 1.6) g/kg/d of protein and 58 (95% CI: 53, 63) kcal/kg/d for the entire group, but there were differences among children of different ages. Children required more protein and less energy than the Dietary Reference Intakes. CONCLUSIONS: In critically ill children, TUN was elevated and REE was reduced during the entire period of mechanical ventilation. Minimum intakes of 1.5 g/kg/d of protein and 58 kcal/kg/d can equilibrate nitrogen and energy balances in children up to 4 years old. Older children require more protein.

Estetiikan jäljillä, maiseman äärellä

Kirja-arvio

Humanistista ympäristön tarkastelua : : Folklore ja ympäristö : Kansantietouden Tutkijain Seuran III kevätkoulu 9.5.2008, Tieteiden talo, Helsinki

Ajankohtaista

Rajaseudun kirjoituskulttuurit ja traditiot

Ajankohtaista: projektiesittely.

Experiências e impactos do aprendizado em Homeopatia: relatos de médicos egressos do Curso de Especialização em Homeopatia da FMJ

Nas últimas décadas, a insatisfação com o cuidado médico contribuiu para a valorização de formações médicas mais abrangentes e humanizadas e para a busca das medicinas complementares e alternativas (CAM) como opções de tratamento. Desde 2003, o Curso de Pós-Graduação em Homeopatia da Faculdade de Medicina de Jundiaí (PGH-FMJ) oferece o ensino da Homeopatia para médicos, integrando-a à medicina convencional. Este estudo analisa as experiências de aprendizado em Homeopatia dos egressos das duas primeiras turmas do Curso de Especialização em Homeopatia da PGH-FMJ, totalizando 14 participantes. A metodologia compreendeu questionários de múltipla escolha, entrevistas não estruturadas e a técnica de História Oral. Os resultados revelaram que os egressos adquiriram competências para o exercício da especialidade, com ganhos nas dimensões afetivas, intelectivas e de atitude, maior satisfação profissional e pessoal, e melhora na relação médico-paciente.

Ammattinaiset ja -miehet metsässä

Kirja-arvio