Blood pressure measurement by oscillometric and auscultatory methods in normotensive pregnant women.

OBJECTIVE: to compare blood pressure values obtained by auscultatory and oscillometric methods in different gestational periods, considering cuff width. METHOD: it is a cross-sectional and quasi-experimental study approved by the Research Ethics Committee. The sample consisted of 108 low-risk pregnant women. Blood pressure measurements were performed in gestational periods of 10-14, 19-22 and 27-30 weeks. RESULTS: The oscillometric device presented values similar to the auscultatory method in systolic blood pressure, but overestimated diastolic blood pressure. Underestimation of blood pressure occurred when using the standard width cuff rather than the correct width cuff in both measuring methods. CONCLUSION: Verification of brachial circumference and use of adequate cuffs in both methods are indispensable to obtain reliable blood pressure values in pregnant women. We recommend performance of additional studies to evaluate diastolic blood pressure overestimation by the Microlife 3BTO-A.

Blood pressure measurement by oscillometric and auscultatory methods in normotensive pregnant women / Evaluación de la presión arterial por los métodos oscilométrico e auscultatorio en embarazadas normotensas / Avaliação da pressão arterial pelos métodos oscilométrico e auscultatório em gestantes normotensas

ABSTRACT Objective: to compare blood pressure values obtained by auscultatory and oscillometric methods in different gestational periods, considering cuff width. Method: it is a cross-sectional and quasi-experimental study approved by the Research Ethics Committee. The sample consisted of 108 low-risk pregnant women. Blood pressure measurements were performed in gestational periods of 10-14, 19-22 and 27-30 weeks. Results: The oscillometric device presented values similar to the auscultatory method in systolic blood pressure, but overestimated diastolic blood pressure. Underestimation of blood pressure occurred when using the standard width cuff rather than the correct width cuff in both measuring methods. Conclusion: Verification of brachial circumference and use of adequate cuffs in both methods are indispensable to obtain reliable blood pressure values in pregnant women. We recommend performance of additional studies to evaluate diastolic blood pressure overestimation by the Microlife 3BTO-A.

RESUMEN Objetivo: Comparar los valores de presión arterial obtenidos por los métodos auscultatorio e oscilométrico en distintos períodos del embarazo, en función del ancho del manguito. Método: Se trata de un estudio transversal y cuasiexperimental aprobado por el Comité de Ética en Investigación. Se analizó una muestra compuesta por 108 embarazadas de bajo riesgo. Las medidas de presión arterial se obtuvieron en los períodos gestacionales de 10-14, 19-22 y 27-30 semanas. Resultados: El aparato oscilométrico presentó valores similares al método auscultatorio en la presión arterial sistólica, sin embargo sobreestimó la presión arterial diastólica. Hubo subestimación de la presión arterial al utilizar el manguito de anchura estándar en lugar del manguito de anchura adecuada, en los dos métodos de medida. Conclusión: La verificación de la circunferencia braquial y el uso de manguitos adecuados en los dos métodos son indispensables para obtener valores confiables de la presión arterial en embarazadas. Recomendamos que se realicen nuevos estudios para evaluar la sobreestimación de la presión arterial diastólica por el aparato Microlife 3BTO-A.

RESUMO Objetivo: Comparar os valores de pressão arterial, obtidos pelos métodos auscultatório e oscilométrico em diferentes períodos gestacionais, em função da largura do manguito. Método: Trata-se de um estudo transversal e quase-experimental aprovado pelo Comitê de Ética em Pesquisa. A amostra foi composta por 108 gestantes de baixo risco. As medidas de pressão arterial foram realizadas nos períodos gestacionais de 10-14, 19-22 e 27-30 semanas. Resultados: O aparelho oscilométrico apresentou valores similares ao método auscultatório na pressão arterial sistólica, porém superestimou a pressão arterial diastólica. Houve subestimação da pressão arterial ao utilizar o manguito de largura padrão ao invés do manguito de largura correta, nos dois métodos. Conclusão: A verificação da circunferência braquial e o uso de manguitos adequados nos dois métodos são indispensáveis para obter valores confiáveis da pressão arterial em gestantes. Recomendamos que novos estudos sejam realizados para avaliar a superestimação da pressão arterial diastólica pelo aparelho Microlife 3BTO-A.

The Influence of Different Mouthpieces on Impulse Oscillometry Results.

BACKGROUND: Impulse oscillometry is a method of airway assessment and diagnosis that provides data on lung mechanics. In the literature, studies have used different types of mouthpieces or did not describe the model used for the tests. We sought to compare the 3 most commonly described mouthpieces in terms of test results, comfort, and subject preference. METHODS: Thirty-nine healthy volunteers were evaluated with spirometry and impulse oscillometry, assessing the resistance at 5 Hz and 20 Hz (R5 and R20, respectively), reactance at 5 Hz (X5), reactance area, and resonant frequency. A filter heat exchanger with a circular mouthpiece (B1), a filter heat exchanger with an oval mouthpiece (B2), and a filter heat exchanger with a circular mouthpiece coupled with a free-flow piece (B3) were compared using an acceptability and tolerance scale, and subjects noted their preference. RESULTS: Statistical analysis showed differences between all the mouthpieces and the predicted values for R5, R20, and X5. The mouthpiece comparison showed differences in R5 between a filter heat exchanger with an oval mouthpiece (B2) and a circular mouthpiece coupled with a free-flow piece (B3) (P = .007); resonant frequency between a filter heat exchanger with a circular mouthpiece (B1) and a filter heat exchanger with an oval mouthpiece (B2) (P = .004) and between a filter heat exchanger with a circular mouthpiece (B1) and a circular mouthpiece coupled with a free-flow piece (B3) (P = .003); and reactance area between a filter heat exchanger with a circular mouthpiece (B1) and a circular mouthpiece coupled with a free-flow piece (B3) (P = .01). In the subjective evaluation, acceptability and tolerance differences were found in the ease of carrying out the evaluation, and no difference was found with regard to the degree of discomfort. Ten subjects preferred a filter heat exchanger with a circular mouthpiece (B1), 15 preferred a filter heat exchanger with an oval mouthpiece (B2), and 14 preferred a circular mouthpiece coupled with a free-flow piece (B3). CONCLUSIONS: A circular mouthpiece coupled with a free-flow piece (B3) appeared to be the most suitable mouthpiece for the impulse oscillometry tests. It assured smaller impedance values for the respiratory system, and subjects expressed the most confidence in using this mouthpiece.

Agreement analysis of oscillometric devices in the measure of resting heart rate in breast cancer survivors.

OBJECTIVE: The aim of this study was to verify the reproducibility of an oscillometric device in the measurement of resting heart rate (RHR) in breast cancer survivors. METHODS: This study included 85 breast cancer survivors with a mean age of 58.87±10.03 years. For the RHR evaluation, the equipment used was the Omron HEM 742, electronic and digital arm device, for measurement of blood pressure and heart rate (HR), with automatic cuff inflation and deflation. At the same time as the oscillometric measurement, HR was measured by the HR monitor Polar RS800 CX, which has been validated previously for HR uptake. The HR value obtained by the cardiofrequency meter was registered at the same time that the Omron device measured blood pressure and HR values. RESULTS: It was observed that the RHR values were very close in both devices and that the correlation values and intraclass correlation coefficient were high. These results were replicated when the female breast cancer survivors were stratified by age group. The agreement values presented by the Bland-Altman analysis showed good values; both for the entire sample and stratified by age, few cases were outside beyond 95% confidence interval range. CONCLUSION: The present study showed that the oscillometric device used presented good values of reproducibility in the detection of RHR values in breast cancer survivors compared with a cardiac monitor.

Comparison of two species-specific oscillometric blood pressure monitors with direct blood pressure measurement in anesthetized cats.

OBJECTIVE: To compare the performance of 2 species-specific oscillometric blood pressure (OBP) monitors (petMAPclassic and petMAPgraphic ) with direct blood pressure measurement in anesthetized cats. DESIGN: Prospective, experimental study. SETTING: Veterinary teaching hospital. ANIMALS: Eight adult cats (3.2-5.5 kg). INTERVENTIONS: During isoflurane anesthesia, OBP cuffs were placed on the thoracic limb and on the base of the tail while invasive blood pressure (IBP) was recorded from a dorsal pedal artery. End-tidal isoflurane concentrations, with or without intravenous dopamine (n = 8), norepinephrine (n = 1), or phenylephrine (n = 1) were adjusted to change invasive mean arterial pressure (MAP) between 40 to 100 mm Hg. Data were analyzed by the Bland-Altman method and 4-quadrant plots. MEASUREMENTS AND MAIN RESULTS: Mean biases and limits of agreement (LOA: ± 1.96 SD) (mm Hg) recorded between the petMAPclassic (thoracic limb) and IBP for systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and MAP were 4.2 ± 28.5, -6.1 ± 13.2, and -1.9 ± 14.6, respectively; mean biases and LOA (mm Hg) recorded with the tail cuff were 7.2 ± 31.3 (SAP), -6.1 ± 11.6 (DAP), and -1.1 ± 11.7 (MAP). Mean biases and LOA (mm Hg) between petMAPgraphic (thoracic limb) and IBP were 7.7 ± 27.0 (SAP), -4.3 ± 11.5 (DAP), 0.2 ± 13.0 (MAP); values recorded with the tail cuff were 10.9 ± 29.6 (SAP), -4.4 ± 11.7 (DAP), and -0.1 ± 12.1 (MAP). Concordance rates after excluding arterial pressure changes ≤ 5 mm Hg was ≥ 93% for both devices. CONCLUSIONS: Although both OBP monitors provide unacceptable SAP estimations, MAP values derived from both monitors and DAP measured by the petMAPgraphic result in acceptable agreement with the reference method according to the Association for the Advancement of Medical Instrumentation (mean bias ≤ 5 mm Hg with LOA ≤ ± 16 mm Hg). Both monitors provide acceptable trending ability for SAP, DAP, and MAP.

Office blood pressure measurements with oscillometric devices in adolescents: a comparison with home blood pressure.

PURPOSE: Compare multiple in office BP measurements in adolescents using an oscillometric device with out-of-office blood pressure measurements (home blood pressure monitoring - HBPM). MATERIALS AND METHODS: Office measurements were performed with validated semi-automatic devices twice (3 minutes interval) in two different moments (1 week apart), with a total of four readings. These BP readings were named R1, R2, R3 and R4 (following the sequence they were performed), FDM (mean of two readings on first day) and SDM (mean of two readings on second day) and SRM (R2-R4 means). The HBPM protocol included two day-time and two evening-time measurements over 6 days. RESULTS: A total of 1024 students between 12 and 17 years were included (mean age 14.68 years; 52.4% females). The mean systolic blood pressure (SBP) values of R2, SDM and SRM were similar to HBPM values. Regarding diastolic blood pressure (DBP) HBPM value was different than R4. High SBP and DBP correlation coefficients with HBPM values were found for R2, SDM and SRM values. CONCLUSION: The second office BP measurement performed with an oscilometric device in adolescents was comparable to HBPM values, suggesting that two office readings might be suitable to rule out hypertension in this age group.

A influência da postura corporal nos parâmetros do sistema de oscilometria de impulso em crianças / The influence of body posture on the impulse oscillometry system parameters in children

Oscilometria de impulso (IOS) é um método alternativo e complementar de avaliação da mecânica respiratória, mas cuja técnica de execução ainda necessita padronização. Objetivo: Analisar e comparar os resultados de parâmetros do IOS quando realizado em escolares nas posições ortostática e sentada. Método: estudo analítico observacional transversal. Escolares saudáveis de 6 a 12 anos foram submetidos à espirometria e dois exames de IOS randomizados quanto à postura (sentada e ortostática). Os dados foram analisados no SPSS 20.0. Utilizou-se o teste Shapiro-Wilk e, segundo a normalidade dos dados, aplicou-se o teste de Wilcoxon ou t de Student para comparação das posturas. Na correlação entre dados antropométricos e as variáveis oscilométricas empregouse o teste de Pearson ou Spearman, com p ≤ 0,05. Resultados: participaram 72 crianças, idade média de 8,42 ± 1,26. Não houve diferença entre as variáveis oscilométricas nas duas posturas. Na posição sentada, houve correlação negativa baixa entre altura de tronco (Altronco) e variáveis: resistência a 20Hz (R20) (p = 0,034) e a 5Hz (R5) (p = 0,041), resistência central (Rescent) (p = 0,018) e impedância (Z) (p = 0,030). Em ortostatismo verificou-se correlação negativa baixa entre idade e resistência periférica (Resper) (p = 0,011), R5 (p = 0,014) e Z (p = 0,009). Conclusão: Não houve diferença nos valores das variáveis oscilométricas entre a postura sentada e ortostática. Contudo, a resistência das vias aéreas foi influenciada pela Altronco, estatura e idade. O ortostatismo parece ser a melhor posição para análise da Resper

Impulse oscillometry (IOS) is an alternative and supplementary method for evaluating respiratory mechanics, but whose performance technique still requires standardization. Objective: This study sought to analyze and compare the results of IOS parameters when done with schoolchildren in standing (orthostatic) and sitting positions. Method: Analytical cross-sectional study. Healthy school children of 6 to 12 years were submitted to spirometry and two exams with IOS (randomized sitting and standing). Data were analyzed with SPSS 20.0. Using the Shapiro-Wilk test and, according to the normality of the data, applying the Wilcoxon or Student T-tests, the postures were compared. In correlating between the anthropometric data and the oscillometric variables, the Pearson or Spearman test was used, with p ≤ 0.05. Results: Participating were 72 children with a mean age of 8.42 ± 1.26. There was no difference between the oscillometric variables in the two postures. In the sitting position, there was low negative correlation between trunk height (Hetrunk) and the following variables: resistance to 20Hz (R20) (p = 0.034) and 5Hz (R5) (p = 0.041), central resistance (Rescent) (p = 0.018), and impedance (Z) (p = 0.030). In the standing position there was low negative correlation between age and peripheral resistance (Resper) (p = 0.011), R5 (p = 0.014), and Z (p = 0.009). Conclusion: There was no difference noted in comparing the oscillometric variables in the two postures. However, the airway resistance was influenced by Hetrunk, height, and age. The orthostatic position seems to be the best position to analyze Resper

Synchronization properties of self-sustained mechanical oscillators.

We study, both analytically and numerically, the dynamics of mechanical oscillators kept in motion by a feedback force, which is generated electronically from a signal produced by the oscillators themselves. This kind of self-sustained systems may become standard in the design of frequency-control devices at microscopic scales. Our analysis is thus focused on their synchronization properties under the action of external forces and on the joint dynamics of two to many coupled oscillators. Existence and stability of synchronized motion are assessed in terms of the mechanical properties of individual oscillators, namely, their natural frequencies and damping coefficients, and synchronization frequencies are determined. Similarities and differences with synchronization phenomena in other coupled oscillating systems are emphasized.

Reference ranges for Mexican preschool-aged children using the forced oscillation technique.

INTRODUCTION: Recently, multi-ethnic reference ranges for spirometry have been created for use worldwide. In comparison, forced oscillation technique (FOT) reference values are limited to specific equipment and study populations, with current FOT reference ranges created in a Caucasian population. We aimed to develop FOT reference ranges for preschool-aged Mexican children and to compare these with current FOT reference ranges. PATIENTS AND METHODS: Respiratory resistance (Rrs) and reactance (Xrs) was measured in healthy Mexican children three to five years of age using commercial FOT equipment. The relationship between height and Rrs and Xrs was determined using regression analyses, taking into account age, weight, sex, and exposure to tobacco smoke. Reference equations were calculated for the Mexican children and Z-scores determined for Rrs and Xrs at 6 and 8Hz. A paired t-test assessed the difference in Z-scores between the Australian reference values and those created for the Mexican cohort. RESULTS: FOT was successfully measured in 584 children. Height was a significant predictor of Rrs and Xrs at 6 and 8Hz (P<.05). Z-scores calculated using the Australian reference equations overestimated lung function in Mexican children for both Rrs and Xrs at 6 and 8Hz (P<.001). CONCLUSION: The development of FOT reference ranges specific to Mexican preschool-aged children will allow for the correct interpretation of FOT measurements. This study also showed that current FOT reference ranges overestimate lung function in Mexican children. Highlighting, the importance of using ethnic appropriate reference ranges for interpreting lung function.

Similarity between blood pressure values assessed by auscultatory method with mercury sphygmomanometer and automated oscillometric digital device.

INTRODUCTION: One of the biggest challenges in the management of hypertension is adequate blood pressure (BP) control. To achieve this goal, home blood pressure measurement (HBPM) with automated devices has been encouraged. However, part of the medical community still disputes its validity, believing that HBPM may lead to incorrect readings. OBJECTIVE: To evaluate the correspondence between the simultaneous measurements of BP with the auscultatory method and an oscillometric digital method, commonly used in HBPM. METHODS: BP was determined simultaneously in 423 individuals (normotensive and hypertensive) with a validated automated digital device (ONROM 705IT) and with the auscultatory method with a mercury sphygmomanometer. Both devices were connected through a Y-shaped connection to a cuff whose size was adjusted to the arm circumference. RESULTS: The values represent mean ± SD (minimum-maximum values): age 40.8 ± 16.3 years (18-92), arm circumference 28.2 ± 3.7 cm (19-42), systolic BP (SBP) auscultatory 127.6 ± 22.8 mmHg (69-223), SBP automated 129.5 ± 23.0 mmHg (56-226), diastolic BP (DBP) auscultatory 79.5 ± 12.6 mmHg (49-135) DBP automated 79.0 ± 12.6 mmHg (48-123). The mean difference in SBP between the two methods was 1.9 mmHg (-15 to +19) and 0.5 mmHg for DBP (-19 to +13). The Bland-Altman analysis showed clinically acceptable agreement between the methods. CONCLUSION: BP measured with the automated method closely mirrors that determined with the conventional auscultatory method and should be used to improve the diagnosis and control of hypertension.

Similaridade entre os valores da pressão arterial aferida pelo método auscultatório com aparelho de coluna de mercúrio e o método oscilométrico automático com aparelho digital / Similarity between blood pressure values assessed by auscultatory method with mercury sphygmomanometer and automated oscillometric digital device

INTRODUÇÃO: Um dos maiores desafios no manejo da hipertensão arterial é o adequado controle pressórico. Para se alcançar esse objetivo tem se difundido a medida residencial da pressão arterial (MRPA) com aparelhos automáticos. Entretanto, parte da comunidade médico-científica ainda discute sua validade, acreditando que as medidas pressóricas domiciliares podem ser incorretas. OBJETIVO: Avaliar a correspondência entre as medidas simultâneas da pressão arterial (PA) pelo método auscultatório convencional e método digital automático, habitualmente utilizado na MRPA. MÉTODOS: Através de uma conexão em "Y" acoplamos um manguito a um aparelho digital automático validado (ONROM 705IT) e a um esfigmomanômetro de coluna de mercúrio, permitindo aferir simultaneamente a PA pelos dois métodos. Determinamos a PA em 423 indivíduos (normotensos e hipertensos), adequando o tamanho do manguito à circunferência braquial. RESULTADOS: Os valores representam média ± desvio padrão (DP) (valores mínimo-máximo): Idade 40,8 ± 16,3 anos (18-92), circunferência braquial 28,2 ± 3,7 cm (19-42), PA sistólica (PAS) auscultatório 127,6 ± 22,8 mmHg (69-223), PAS automático 129,5 ± 23,0 mmHg (56-226), PA diastólica (PAD) auscultatório 79,5 ± 12,6 mmHg (49-135), PAD automático 79,0 ± 12,6 mmHg (48-123). A diferença média da PAS entre os dois métodos foi de 1,9 mmHg (-15 a +19) e a diferença da PAD de 0,5 mmHg (-19 a +13). Os índices de correlação de Pearson entre os métodos são para a PAS (r = 0,97), e PAD (r = 0,91). A análise de Bland-Altman mostrou concordância clinicamente aceitável entre os métodos. CONCLUSÃO: A PA aferida pelo método digital automático apresenta boa concordância com o método auscultatório convencional, devendo ser usada no auxílio do diagnóstico e controle da hipertensão arterial (HA).

INTRODUCTION: One of the biggest challenges in the management of hypertension is adequate blood pressure (BP) control. To achieve this goal, home blood pressure measurement (HBPM) with automated devices has been encouraged. However, part of the medical community still disputes its validity, believing that HBPM may lead to incorrect readings. OBJECTIVE: To evaluate the correspondence between the simultaneous measurements of BP with the auscultatory method and an oscillometric digital method, commonly used in HBPM. METHODS: BP was determined simultaneously in 423 individuals (normotensive and hypertensive) with a validated automated digital device (ONROM 705IT) and with the auscultatory method with a mercury sphygmomanometer. Both devices were connected through a Y-shaped connection to a cuff whose size was adjusted to the arm circumference. RESULTS: The values represent mean ± SD (minimum-maximum values): age 40.8 ± 16.3 years (18-92), arm circumference 28.2 ± 3.7 cm (19-42), systolic BP (SBP) auscultatory 127.6 ± 22.8 mmHg (69-223), SBP automated 129.5 ± 23.0 mmHg (56-226), diastolic BP (DBP) auscultatory 79.5 ± 12.6 mmHg (49-135) DBP automated 79.0 ± 12.6 mmHg (48-123). The mean difference in SBP between the two methods was 1.9 mmHg (-15 to +19) and 0.5 mmHg for DBP (-19 to +13). The Bland-Altman analysis showed clinically acceptable agreement between the methods. CONCLUSION: BP measured with the automated method closely mirrors that determined with the conventional auscultatory method and should be used to improve the diagnosis and control of hypertension.

Flutter valve improves respiratory mechanics and sputum production in patients with bronchiectasis.

BACKGROUND AND PURPOSE: Although the application of airway clearance techniques is considered an important component in the treatment of several obstructive pulmonary diseases, there is no scientific evidence supporting the use of Flutter Valve™ in the management of patients with bronchiectasis. Moreover, the consequences of respiratory physiotherapy techniques on respiratory mechanics have not been fully studied. Therefore, we investigated the acute, short-term effects of Flutter Valve™ on respiratory mechanics and sputum production in bronchiectatic patients. METHODS: EIGHT patients were evaluated in a randomized, blinded, cross-over trial. Impedance at 5 Hz (R5), resistance as a function of oscillation frequency (dR/dF), reactance at 5 Hz (X5), resonant frequency (f(0) ) and integral of reactance between 5 Hz and resonant frequency (AX) were recorded. RESULTS: Flutter Valve™ cleared 8.4 mL more secretions than the Sham Flutter intervention (95% confidence interval [95% CI], 3.4-13.4). There was a higher percentage decrease in R5 (-11.2%; 95% CI, -4.4 to -18.2), dR/dF (-20.8%; 95% CI, -32.4 to -9) and AX (-7.8%; 95% CI, -11.9 to -3.7) under Flutter Valve™. X5 and f(0) variation did not differ between interventions. CONCLUSIONS: Flutter Valve™ increases sputum removal during treatment and diminishes total and peripheral airway resistance in hypersecretive patients with bronchiectasis. Impulse oscillometry is a user-friendly tool to evaluate the effects of airway clearance techniques on respiratory mechanics.

Reliability of resting blood pressure measurement and classification using an oscillometric device in children with chronic kidney disease.

OBJECTIVE: To compare the reliability of blood pressure (BP) readings obtained with an oscillometric device with those obtained by auscultation and assess for differences in BP status classification based on the 2 techniques. STUDY DESIGN: Resting BP was measured by auscultation and with an oscillometric device at the same encounter in 235 subjects enrolled in the Chronic Kidney Disease in Children study. Resting auscultatory BP values were averaged and compared with averaged oscillometric readings. BP agreement by the 2 methods was assessed using Bland-Altman plots, and BP status classification agreement was assessed by calculation of kappa statistics. RESULTS: Oscillometric BP readings were higher than auscultatory readings, with a median paired difference of 9 mm Hg for systolic BP (SBP) and 6 mm Hg for diastolic BP (DBP). Correlation for mean SBP was 0.624 and for mean DBP was 0.491. The bias for oscillometric BP measurement was 8.7 mm Hg for SBP (P < .01) and 5.7 mm Hg for DBP (P < .01). BP status classification agreement was 61% for SBP and 63% for DBP, with Kappa values of .31 for SBP and .20 for DBP. CONCLUSIONS: Compared with auscultation, the oscillometric device significantly overestimated both SBP and DBP, leading to frequent misclassification of BP status.

Efficient predictive estimator for holdover in GPS-based clock synchronization.

This paper addresses an unbiased p-step predictive finite impulse response (FIR) filter of the local clock K-degree time interval error (TIE) polynomial model with applications to the global positioning system (GPS)-based clock synchronization. Generic coefficients are derived for a 2-parameter family of the polynomial filter gains. A generalization is provided for the p-step linear (ramp) gain allowing for close to optimal predictive filtering of the TIE. Basic holdover algorithms are discussed along with their most critical properties. Efficiency of the proposed filter in holdover is demonstrated by simulation and in real applications to GPS-based (sawtooth and sawtoothless) measurements of the TIE of a crystal clock.

Performance of oscillometric blood pressure devices in children in resource-poor settings.

OBJECTIVE: To compare oscillometric blood pressure devices with mercury sphygmomanometry in children. PATIENTS AND METHODS: Blood pressure measurements were obtained with a mercury sphygmomanometer and one of two oscillometric devices. Correlations within each device and agreement between the two devices were evaluated. RESULTS: In children, blood pressure measured by the oscillometric device was poorly correlated and had wide limits of agreements with the sphygmomanometer. Furthermore, the oscillometric devices overestimated systolic blood pressure in children with higher readings. CONCLUSION: The applicability of automated blood pressure measuring devices in children has limitations and cannot be recommended.

Assessing Ankle-Brachial Index (ABI) by using automated oscillometric devices.

BACKGROUND: Assessing Ankle-Brachial Index is an essential procedure in clinical settings, but since its measurement by the gold standard Doppler Ultrasonic (DU) technique is impaired by technical difficulties, it is underperformed. OBJECTIVE: The aim of this study was to assess the efficacy of an automated oscillometric device (AOD) by performing Ankle-Brachial Index (ABI) assessments and to suggest delta brachial-brachial (delta-BB) and delta-ABI as markers of cardiovascular risk. METHODS: In this observational and descriptive study, 247 patients (56.2% females, mean age 62.0 years) had their arterial blood pressure (ABP) measured for ABI calculation. Two AOD (OMRON-HEM705CP) devices were used for simultaneous measurements of the ABP, first of the two arms and then of the arm with higher systolic ABP and a leg, first the left and then the right one. When leg ABP measurements were not possible, ABI determination was performed by using the standard Doppler Ultrasonic (DU) technique. Patients were designated to Group N (normal ABI: 0.91 to 1.30) or Group A (abnormal ABI: < or =0.90 or >1.30). Other indexes were also calculated: delta-BB (absolute difference in mmHg of systolic ABP between arms) and delta-ABI (absolute difference of ABI between legs) and the results were compared. RESULTS: In most patients (90.7%), it was possible to determine the ABI. Group N data allowed calculation of the 95th percentile reference values (RV) of delta-BB (0 to 8 mmHg) and delta-ABI (0 to 0.13). When compared to Group N, Group A had a significantly higher prevalence of high values greater than the RVs of delta-ABI (30 of 52 and 10 of 195, respectively; Odds Ratio = 25.23; p<0.0001) and delta-BB (13 of 52 and 7 of 195, respectively; Odds Ratio = 8.95; p<0.0001). CONCLUSION: In most patients, the ABI could be measured by AOD. Both indexes, delta-BB and delta-ABI greater than the RVs, were significantly more prevalent in patients with abnormal ABI values, and their usefulness as new markers of cardiovascular disease should be further appraised in epidemiological studies.

Índice Tornozelo-Braquial (ITB) determinado por esfigmomanômetros oscilométricos automáticos / Assessing Ankle-Brachial Index (ABI) by using automated oscillometric devices

FUNDAMENTO: Índice Tornozelo-Braquial (ITB) é essencial na prática clínica, mas dificuldades técnicas na sua execução pelo padrão de referência Doppler vascular (DV) tornam-no ainda pouco utilizado. OBJETIVO: Avaliar aplicabilidade da determinação do ITB com uso de esfigmomanômetros oscilométricos automáticos (EOA) e sugerir a utilização dos índices delta-Bráquio-Braquial (delta-BB) e delta-ITB como marcadores de risco cardiovascular. MÉTODOS: Estudo descritivo e observacional de 247 pacientes ambulatoriais (56,2 por cento feminino, média 62,0 anos) submetidos à determinação do ITB com aferição simultânea da pressão arterial (PA) em membros superiores (MMSS) e inferiores (MMII) utilizando-se dois EOA (OMRON-HEM705CP). Nos casos em que não foi possível aferir PA em pelo menos um dos MMII utilizou-se DV. Os pacientes divididos em Grupo N (ITB normal: 0,91 a 1,30) e Grupo A (ITB alterado: <0,90 ou >1,30) tiveram comparados entre si os valores de delta-ITB (diferença absoluta ITB/MMII) e delta-BB (diferença absoluta PAS/MMSS). RESULTADOS: Utilizando-se EOA foi possível determinar ITB em 90,7 por cento. Com dados do Grupo N determinaram-se valores de referência (VR) no percentil 95 de delta-ITB (0-0,13) e delta-BB (0-8 mmHg). Quando comparado com o Grupo N, o Grupo A apresentou prevalência mais elevada tanto de delta-ITB (30/52 contra 10/195; Razão de Chances: 25,23; p<0,0001) como de delta-BB (13/52 contra 7/195; Razão de Chances: 8,95; p<0,0001) acima dos VR. CONCLUSÃO: O ITB pode ser determinado na maioria das vezes com EOA. Delta-ITB e delta-BB acima dos VR estiveram significativamente mais prevalentes nos portadores de ITB alterado e podem ser sugeridos como marcadores de risco cardiovascular em futuros estudos epidemiológicos.

BACKGROUND: Assessing Ankle-Brachial Index is an essential procedure in clinical settings, but since its measurement by the gold standard Doppler Ultrasonic (DU) technique is impaired by technical difficulties, it is underperformed. OBJECTIVE: The aim of this study was to assess the efficacy of an automated oscillometric device (AOD) by performing Ankle-Brachial Index (ABI) assessments and to suggest delta brachial-brachial (delta-BB) and delta-ABI as markers of cardiovascular risk. METHODS: In this observational and descriptive study, 247 patients (56.2 percent females, mean age 62.0 years) had their arterial blood pressure (ABP) measured for ABI calculation. Two AOD (OMRON-HEM705CP) devices were used for simultaneous measurements of the ABP, first of the two arms and then of the arm with higher systolic ABP and a leg, first the left and then the right one. When leg ABP measurements were not possible, ABI determination was performed by using the standard Doppler Ultrasonic (DU) technique. Patients were designated to Group N (normal ABI: 0.91 to 1.30) or Group A (abnormal ABI: <0.90 or >1.30). Other indexes were also calculated: delta-BB (absolute difference in mmHg of systolic ABP between arms) and delta-ABI (absolute difference of ABI between legs) and the results were compared. RESULTS: In most patients (90.7 percent), it was possible to determine the ABI. Group N data allowed calculation of the 95th percentile reference values (RV) of delta-BB (0 to 8 mmHg) and delta-ABI (0 to 0.13). When compared to Group N, Group A had a significantly higher prevalence of high values greater than the RVs of delta-ABI (30 of 52 and 10 of 195, respectively; Odds Ratio = 25.23; p<0.0001) and delta-BB (13 of 52 and 7 of 195, respectively; Odds Ratio = 8.95; p<0.0001). CONCLUSION: In most patients, the ABI could be measured by AOD. Both indexes, delta-BB and delta-ABI greater than the RVs, were significantly more prevalent in patients with abnormal ABI ...

Self-measurement of blood pressure: validation of the Braun BP VitalScan Plus 1650 monitor according to the European Society of Hypertension International Protocol.

BACKGROUND: Self-measurement of blood pressure (BP) has been increasingly encouraged as a supplement to measurements in the clinic. OBJECTIVE: The main objective of this study is to clinically evaluate a new device for self-measurement of BP according to the International Protocol of the European Society of Hypertension (2002). METHODS: Measurements of systolic and diastolic BP in 33 volunteers (15 for phase 1 and a further 18 for phase 2 providing 99 measurements) were obtained using the mercury sphygmomanometer (HgS; Baumanometer) and the Braun BP VitalScan Plus 1650 device. Nine sequential same-arm measurements between the test device and the standard HgS were carried out according to the International Protocol of the European Society of Hypertension in two phases (phase 1, phase 2.1 and phase 2.2). RESULTS: The device passed phase 1 as 30 systolic and 33 diastolic readings fell within 5 mmHg exceeding the 25 required. In addition, the equipment also passed phase 2.1 as 74 systolic and 77 diastolic readings fell within 5 mmHg exceeding the 65 required for being approved. Finally, it also passed the phase 2.2 as 25 volunteers for systolic and 28 for diastolic had at least 2/3 of their comparisons falling within 5 mmHg (exceeding the 22 required) and only two of the 33 volunteers had their three comparisons over 5 mmHg apart (at the most three are required). The difference-against-mean plots showed that the disagreement between the HgS and the device was -2.57+/-4.36 mmHg for systolic BP and +0.83+/-4.97 mmHg for diastolic BP, respectively. CONCLUSION: The equipment passed the different phases satisfactorily and the study suggests that it can be used for self-BP monitoring. The device, however, needs to be used with care by the patients following the instructions, because even when it may be accurate in a laboratory setting, there is potential for them to be used inaccurately in the home setting.

A novel system using the Forced Oscillations Technique for the biomechanical analysis of swallowing.

Physiological studies of swallowing and the diagnosis and treatment of dysphagia are crucially dependent of detailed information of respiratory and feeding events. However, this information has been obtained by indirect and/or expensive methods, as well as by methods demanding exposure to radiation. In this context, the purpose of this study was twofold: (1) describe a new low-cost system for the analysis of the respiratory events during swallowing using the Forced Oscillation Technique and (2) evaluate the performance of this device in the description of physiological events during water swallowing. The device consists of a personal computer adapted to measurement modules able to characterize the soft palate movement, the elevation of the larynx, the duration of deglutition apnoea, and the direction of airflow at the end of the swallow apnoea. These parameters were studied in eight healthy subjects under conditions of saliva swallowing and three doses of water (5,10 and 20 mL). The system allowed a real time description of the respiratory and feeding events, which were in close agreement with physiological principles. Mean results showed an increase of the apnoea time that was not statistically significant. In contrast, a highly significant increase of respiratory impedance during swallowing was observed (p < 0.0001). The described instrument does not use radiation. It shows itself particularly well suited for studies of deglutition physiology, including mechanisms involved in airway protection during swallowing. It can also be potentially useful contributing to easy clinical bedside evaluations and biofeedback procedures for the rehabilitation of paediatric and elderly patients.