Clinical use of objective measures of physical activity

With measurement of physical activity becoming more common in clinical practice, it is imperative that healthcare professionals become more knowledgeable about the different methods available to objectively measure physical activity behaviour. Objective measures do not rely on information provided by the patient, but instead measure and record the biomechanical or physiological consequences of performing physical activity, often in real time. As such, objective measures are not subject to the reporting bias or recall problems associated with self-report methods. The purpose of this article was to provide an overview of the different methods used to objectively measure physical activity in clinical practice. The review was delimited to heart rate monitoring, accelerometers and pedometers since their small size, low participant burden and relatively low cost make these objective measures appropriate for use in clinical practice settings. For each measure, strengths and weakness were discussed; and whenever possible, literature-based examples of implementation were provided.

Clinical use of diodes and micro-chambers to obtain accurate small field output factor measurements

There have been substantial advances in small field dosimetry techniques and technologies, over the last decade, which have dramatically improved the achievable accuracy of small field dose measurements. This educational note aims to help radiation oncology medical physicists to apply some of these advances in clinical practice. The evaluation of a set of small field output factors (total scatter factors) is used to exemplify a detailed measurement and simulation procedure and as a basis for discussing the possible effects of simplifying that procedure. Field output factors were measured with an unshielded diode and a micro-ionisation chamber, at the centre of a set of square fields defined by a micro-multileaf collimator. Nominal field sizes investigated ranged from 6×6 to 98×98 mm2. Diode measurements in fields smaller than 30 mm across were corrected using response factors calculated using Monte Carlo simulations of the full diode geometry and daisy-chained to match micro-chamber measurements at intermediate field sizes. Diode measurements in fields smaller than 15 mm across were repeated twelve times over three separate measurement sessions, to evaluate the to evaluate the reproducibility of the radiation field size and its correspondence with the nominal field size. The five readings that contributed to each measurement on each day varied by up to 0.26%, for the “very small” fields smaller than 15 mm, and 0.18% for the fields larger than 15 mm. The diode response factors calculated for the unshielded diode agreed with previously published results, within 1.6%. The measured dimensions of the very small fields differed by up to 0.3 mm, across the different measurement sessions, contributing an uncertainty of up to 1.2% to the very small field output factors. The overall uncertainties in the field output factors were 1.8% for the very small fields and 1.1% for the fields larger than 15 mm across. Recommended steps for acquiring small field output factor measurements for use in radiotherapy treatment planning system beam configuration data are provided.

Clinical Use of the Volume-Time Curve for Endotracheal Tube Cuff Management

BACKGROUND: Previous investigation showed that the volume-time curve technique could be an alternative for endotracheal tube (ETT) cuff management. However, the clinical impact of the volume-time curve application has not been documented. the purpose of this study was to compare the occurrence and intensity of a sore throat, cough, thoracic pain, and pulmonary function between these 2 techniques for ETT cuff management: volume-time curve technique versus minimal occlusive volume (MOV) technique after coronary artery bypass grafting. METHODS: A total of 450 subjects were randomized into 2 groups for cuff management after intubation: MOV group (n = 222) and volume-time curve group (n = 228). We measured cuff pressure before extubation. We performed spirometry 24 h before and after surgery. We graded sore throat and cough according to a 4-point scale at 1, 24, 72, and 120 h after extubation and assessed thoracic pain at 24 h after extubation and quantified the level of pain by a 10-point scale. RESULTS: the volume-time curve group presented significantly lower cuff pressure (30.9 +/- 2.8 vs 37.7 +/- 3.4 cm H2O), less incidence and intensity of sore throat (1 h, 23.7 vs 51.4%; and 24 h, 18.9 vs 40.5%, P < .001), cough (1 h, 19.3 vs 48.6%; and 24 h, 18.4 vs 42.3%, P < .001), thoracic pain (5.2 +/- 1.8 vs 7.1 +/- 1.7), better preservation of FVC (49.5 +/- 9.9 vs 41.8 +/- 12.9%, P = .005), and FEV1, (46.6 +/- 1.8 vs 38.6 +/- 1.4%, P = .005) compared with the MOV group. CONCLUSIONS: the subjects who received the volume-time curve technique for ETT cuff management presented a significantly lower incidence and severity of sore throat and cough, less thoracic pain, and minimally impaired pulmonary function than those subjects who received the MOV technique during the first 24 h after coronary artery bypass grafting.

Validação e aplicação clínica de uma escala de cognição social na esquizofrenia = Validation and clinical use of a measure of social cognition in schizophrenia

RESUMO: A cognição social encontra-se frequentemente alterada na esquizofrenia. Esta alteração relaciona-se com a diminuição do funcionamento social,caracterizando-se quer por défices quer por vieses cognitivos sociais. No entanto, existem poucos instrumentos fiáveis e válidos para avaliar a cognição social na esquizofrenia, nomeadamente capazes de medir os vieses cognitivos sociais e a cognição social auto-relevante. Adicionalmente, as bases biológicas da disfunção social não estão totalmente esclarecidas. Evidências recentes sugerem que o peptídeo oxitocina (OXT) influencia o funcionamento social, e que esta relação poderá ser mediada pela cognição social. Este Trabalho de Projecto descreve a contribuição do autor para o desenvolvimento e avaliação psicométrica inicial de um novo instrumento de avaliação da cognição social, e a utilidade desta escala na investigação das associações entre a OXT e a capacidade e vieses cognitivos sociais. A Waiting Room Task (WRT), uma escala constituída por 26 vídeos sequenciais que simulam a experiência de observar outra pessoa numa sala de espera, foi administrada num estudo transversal com 61 doentes com esquizofrenia e 20 controlos saudáveis. Observou-se uma menor capacidade cognitiva social e um aumento dos vieses cognitivos sociais nos doentes com esquizofrenia, comparativamente aos controlos. Nos controlos e doentes com delírios, o desempenho na WRT correlacionou-se significativamente com os níveis de OXT. Esta correlação não se observou nos doentes sem delírios, sugerindo que o papel da OXT na cognição social poderá encontrar-se atenuado neste grupo. Estes achados fornecem suporte inicial para a adequação da WRT como instrumento de avaliação da cognição social na esquizofrenia, podendo ainda ser útil na investigação da sua base biológica. ------------ ABSTRACT: Social cognition is often impaired in schizophrenia. This impairment is related to poor social functioning and is characterized by both social cognitive deficits and biases. However, there are few reliable and valid measures of social cognition in schizophrenia, particularly measures of social cognitive bias and of self-relevant social cognition. Also, the biological bases of social dysfunction are not well understood. Emerging evidence suggests that the peptide oxytocin (OXT) influences social functioning, and that this relationship may be mediated by social cognition. This Research Project describes the author’s contribution to the development and initial psychometric testing of a new measure of social cognition, and the utility of this instrument to examine associations between OXT and social cognitive capacity and bias. The Waiting Room Task WRT), a video-based test comprising 26 sequential videos simulating the experience of facing another person in a waiting room, was administered in a cross-sectional study involving 61 patients with schizophrenia and 20 healthy controls. Social cognitive capacity was lower and social cognitive bias was increased in patients with schizophrenia compared with controls. Among controls and patients with delusions, performance on the WRT was significantly correlated with OXT level. This correlation was not found in patients without delusions suggesting that OXT’s role in social cognition may be blunted in this group. These findings provide initial support for the adequacy of the WRT as a measure for assessing social cognition in schizophrenia that may also be useful in understanding its biological underpinnings.

A hearing aid orientation pamphlet for clinical use with first-time hearing aid users

This paper discusses the use of a pamphlet to help first-time hearing aid users adjust to their hearing aids.

Wear of Ball Attachments After 1 to 8 Years of Clinical Use: A Qualitative Analysis

The purpose of this study was to analyze and compare scanning electron microscopy (SEM) observations of ball attachments that had been worn by patients during three periods of clinical use. One hundred forty-four specimens of ball anchor attachments (gold alloy matrix and titanium patrix) were studied by SEM after periods of approximately 1, 3.5, and 8 years of clinical use. Twenty new attachment components were examined as controls. SEM images revealed signs of mechanical wear for the ball attachments studied. The surfaces of the titanium patrix were associated primarily with roughening after short-term use, whereas surfaces of the gold alloy matrix showed wear, roughening, and loss of microscopic material in the form of flakes. Severe mechanical wear on both surfaces was noted after longer periods of use. The mechanical changes were not correlated with patient-mediated observations regarding the time-dependent retentive efficacy of the attachments. One year of clinical wear appeared to have limited effect on the ball attachment tested. Conversely, longer periods of use led to marked modifications in shape of the matrix and patrix components. Int J Prosthodont 2011;24:270-272.

Debris, Roughness and Friction of Stainless Steel Archwires Following Clinical Use

Objective: To investigate the degree of debris, roughness, and friction of stainless steel orthodontic archwires before and after clinical use.Materials and Methods: For eight individuals, two sets of three brackets (n = 16) each were bonded from the first molar to the first premolar. A passive segment of 0.019- x 0.025-inch stainless steel archwire was inserted into the brackets and tied by elastomeric ligature. Debris level (via scanning electron microscopy), roughness, and frictional force were evaluated as-received and after 8 weeks of intraoral exposure. Mann-Whitney, Wilcoxon signed-rank, and Spearman correlation tests were used for statistical analysis at the .05 level of significance.Results: There were significant increases in the level of debris (P = .0004), roughness of orthodontic wires (P = .002), and friction (P = .0001) after intraoral exposure. Significant positive correlations (P < .05) were observed between these three variables.Conclusion: Stainless steel rectangular wires, when exposed to the intraoral environment for 8 weeks, showed a significant increase in the degree of debris and surface roughness, causing an increase in friction between the wire and bracket during the mechanics of sliding. (Angle Orthod. 2010;80:521-527.)

Development, characterization and clinical use of a biodegradable composite scaffold for bone engineering in oro-maxillo-facial surgery

We have developed a biodegradable composite scaffold for bone tissue engineering applications with a pore size and interconnecting macroporosity similar to those of human trabecular bone. The scaffold is fabricated by a process of particle leaching and phase inversion from poly(lactide-co-glycolide) (PLGA) and two calcium phosphate (CaP) phases both of which are resorbable by osteoclasts; the first a particulate within the polymer structure and the second a thin ubiquitous coating. The 3-5 mu m thick osteoconductive surface CaP abrogates the putative foreign body giant cell response to the underlying polymer, while the internal CaP phase provides dimensional stability in an otherwise highly compliant structure. The scaffold may be used as a biomaterial alone, as a carrier for cells or a three-phase drug delivery device. Due to the highly interconnected macroporosity ranging from 81% to 91%, with macropores of 0.8 similar to 1.8 mm, and an ability to wick up blood, the scaffold acts as both a clot-retention device and an osteoconductive support for host bone growth. As a cell delivery vehicle, the scaffold can be first seeded with human mesenchymal cells which can then contribute to bone formation in orthotopic implantation sites, as we show in immune-compromised animal hosts. We have also employed this scaffold in both lithomorph and particulate forms in human patients to maintain alveolar bone height following tooth extraction, and augment alveolar bone height through standard sinus lift approaches. We provide a clinical case report of both of these applications; and we show that the scaffold served to regenerate sufficient bone tissue in the wound site to provide a sound foundation for dental implant placement. At the time of writing, such implants have been in occlusal function for periods of up to 3 years in sites regenerated through the use of the scaffold.

Adhesive systems: important aspects related to their composition and clinical use

This literature review article addresses the types and the main components of different etch-and-rinse and self-etch adhesive systems available in the market, and relates them to their function, possible chemical interactions and influence of handling characteristics. Scanning electron microscopy (SEM) images are presented to characterize the interface between adhesives and dentin. Adhesive systems have been recently classifed according to their adhesion approaches in etch-and-rinse, self-etch and glass ionomer. The etch-and-rinse systems require a specifc acid-etch procedure and may be performed in two or three steps. Self-etch systems employ acidic monomers that demineralize and impregnate dental substrates almost at the same time. These systems are separated in one or two steps. Some advantages and defciencies were noted for etch-and-rinse and self-etch approaches, mainly for the simplifed ones due to some chemical associations and interactions. The SEM micrographs illustrate different relationships between adhesive systems and dental structures, particularly dentin. The knowledge of composition, characteristics and mechanisms of adhesion of each adhesive system is of fundamental importance to permit the adoption of ideal bonding strategies under clinical conditions.

Cyclic fatigue resistance of rotary niti instruments after simulated clinical use in curved root canals

O objetivo deste estudo foi avaliar a resistência à fadiga cíclica de instrumentos rotatórios de níquel-titânio após simulação de uso clinico em canais curvos (curvatura de 40° e raio de 5 mm). Trinta e seis instrumentos, calibre n° 25 conicidade 0,04, foram divididos em três grupos: o Grupo A com um ciclo de uso; Grupo B, três ciclos de uso e grupo C, cinco ciclos de uso. Um cronômetro digital aferiu em segundos o tempo até a fratura do instrumento que, posteriormente, foi convertido em número de ciclos para fratura. Os dados foram analisados por ANOVA e teste de Tukey (p<0,05). O grupo que utilizou o instrumento por cinco ciclos (grupo C) atingiu significativamente menores números de ciclos antes da fratura (média = 197,5 ciclos) quando comparado com os instrumentos utilizados em um ciclo (média = 309,2) e três ciclos (média = 287,5). Os resultados mostraram que o número de uso de instrumentos RaCe para modelar canais curvos afeta negativamente a resistência à fadiga cíclica dos instrumentos após cinco usos.

Effect of clinical use of nickel-titanium springs

Introduction: Our objectives were to determine whether there are changes on the load deflection rate (L/DP) and the average force (FP) of the superelastic pseudoplateau, and whether permanent deformation is changed in nickel-titanium closed-coil springs (CCSs) after 6 months of clinical use. Methods: Twenty-two nickel-titanium CCSs (Sentalloy 100 g; Dentsply GAC, York, Pa) were subjected to tensile mechanical testing at 37 degrees C on activations varying from 3.2 to 16.0 mm before and after 6 months of clinical use. A regression line was fitted over the most horizontal area of the unloading part of the stress-strain graph of every CCS, and its slope was used as L/DP. The FP was determined by the midpoint of the longest segment of the curve that could be fit within the regression line with a R-2 of at least 0.999, and permanent deformation was determined graphically by obtaining the strain value when the measured stress reached zero. The data were analyzed by 3 analyses of variance at 2 levels, with 5% of significance. Results: Time and activation significantly influenced the variables tested (P < 0.001). Time increased the L/DP and permanent deformation but decreased the FP. Activation decreased L/DP, FP, and permanent deformation. Significant interactions between time and activation were detected for FP (P = 0.013) and deformation (P < 0.001). Conclusions: After 6 months of active clinical use, the analyzed springs had a significant but small increase in their L/DP; FP dropped up to 88%, and the CCSs deformed up to 1.26 mm.