RESUMO
BACKGROUND: Measurement of intra-abdominal pressure (IAP) is realized with the Kron's method. However, this technique has drawbacks like an infusion of water into the bladder of the patient. OBJECTIVE: The prove a new novel disposable sensor in the way to measure the IAP (DSIAP) this one addresses some limitations of the Kron method. MATERIALS AND METHODS: The DSIAP was tested in vitro and clinical settings. The proposed technique was compared with Kron's method through Pearson correlation and Bland-Altman analysis. For in vitro tests, 159 measurements were taken performed by simulating the IAP in the bladder. For the clinical test, 20 pairs of measurements were made in patients with routine IAP monitoring in the intensive care unit. RESULTS: In vitro measurements showed a strong correlation between the DSIAP and the reference (r = 0.99, p-value < 2.2 × 10-16). The bias and 95% confidence intervals were 0.135 and -0.821-1.091 cmH2O, respectively. Measurements in patients with DSIAP versus Kron's method shown a very good correlation (r = 0.973, p-value < 5.46 × 10-13), while the bias and confidence intervals were 0.018 and -3.461-3.496 mmHg, respectively. CONCLUSIONS: The results suggest that the proposed DSIAP showed a profile similar to pressure transducers already in clinical use while overcoming some limitations of the former.
ANTECEDENTES: La medición de la presión intraabdominal (PIA) generalmente se realiza con el método de Kron, a pesar de presentar inconvenientes como la infusión de agua en la vejiga del paciente. OBJETIVO: Introducir un nuevo sensor desechable para medir la PIA (SDPIA) que aborda algunas limitaciones del método de Kron. MÉTODO: Se probó el SDPIA en pruebas in vitro y clínicas. La técnica se contrastó con el método de Kron empleando la correlación de Pearson y el análisis de Bland-Altman. Para las pruebas in vitro se realizaron 159 mediciones simulando la PIA en la vejiga. Para las pruebas clínicas se realizaron 20 mediciones en pacientes con monitorización rutinaria de la PIA en la unidad de cuidados intensivos. RESULTADOS: En las mediciones in vitro se encontró una alta correlación (r = 0.99; p < 2.2 × 10−16). El sesgo para la diferencia entre los dos métodos de medición fue de 0.135 cmH2O, con un intervalo de confianza del 95% de −0.821 a 1.091 cmH2O. En las mediciones clínicas también se encontró una alta correlación (r = 0.973; p < 5.46 × 10−13) para la diferencia entre los dos métodos de medición de 0.18, con un intervalo de confianza del 95% de −3.302 a 3.650 mmHg. CONCLUSIONES: Los resultados sugieren que el SDPIA propuesto muestra un desempeño similar al de los transductores de presión actualmente en uso clínico, mientras sobrelleva algunas limitaciones de estos últimos.
Assuntos
Equipamentos Descartáveis , Hipertensão Intra-Abdominal/diagnóstico , Transdutores de Pressão , Abdome , Adulto , Intervalos de Confiança , Desenho de Equipamento , Humanos , Técnicas In Vitro/métodos , Manometria/instrumentação , México , Pessoa de Meia-Idade , Pressão , Padrões de Referência , Valores de Referência , Bexiga Urinária , Adulto JovemRESUMO
INTRODUCTION: Atrial fibrillation (AFib) ablation is alternative treatment to drugs. Literature suggests that use of contact force (CF) catheter with higher power for short periods is effective and safe. METHODS/RESULTS: Retrospectively analyzed 76 patients undergoing the first ablation. Third five patients-group A: 27 (77%) paroxysmal AFib (PAFib) and 8 (23%) persistent AFib (PersAFib) who underwent ablation at the power of 30 W-17 mL/minute flow with a CF of 10-30 g for 30 seconds. Fourty one patients-group B: 28 (68.3%) PAFib and 13 (31.70%) PersAFib underwent ablation using 45 W on posterior wall with CF of 8/15 g, as well as 50-W anterior wall with CF of 10/20 g-35 mL/minute flow for 6 seconds. Pulmonary vein isolation in both groups and ablated. For patients not in the sinus, we performed cardioversion before ablation. No complications. Group A: Left atrial time 110 ± 29 minutes, total 148 ± 33.6 minutes, radiofrequency time (RF) 4558 ± 1998 seconds, X-ray 8.5 ± 3.5 minutes, and elevation of esophageal temperature (ET) in 26 (74.3%). group B: Left atrial time 70.7 ± 18.5 minutes ( P < .00001), total 106 ± 23 minutes ( P < .00001), RF 1909 ± 675.8 seconds ( P < .00001), X-ray 8.8 ± 6.6 minutes ( P = .221) and elevation of ET in 21 (51.20% - P = .0578). In 6 and 12 months follow-up, we had 9 (25.71%) and 11 (31.42%) recurrences in group A and 5 (12.19%) and 7 (17.07%) in group B ( P = .231 at 6 and P = .14 at 12 months), respectively. CONCLUSIONS: HPSD was safe, useful, and efficient compared with CT, and reduced procedural time and total RF time. HPSD may reduce esophageal injury because of lower heating rate and it may reduce the recurrence of atrial tachyarrythmias.
Assuntos
Fibrilação Atrial/cirurgia , Cateterismo Cardíaco/instrumentação , Cateteres Cardíacos , Ablação por Cateter/instrumentação , Veias Pulmonares/cirurgia , Transdutores de Pressão , Potenciais de Ação , Idoso , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Cateterismo Cardíaco/efeitos adversos , Ablação por Cateter/efeitos adversos , Desenho de Equipamento , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Veias Pulmonares/fisiopatologia , Recidiva , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do TratamentoRESUMO
Introducción: La calibración de los transductores tiene gran importancia para la medición precisa de las presiones, durante la monitorización hemodinámica invasiva de los pacientes que requieren observación estrecha en las unidades de atención al grave y en el quirófano. Objetivo: Desarrollar y validar un método de calibración para transductores de presión, sencillo, eficaz y de bajo costo. Métodos: Se desarrolló un método manométrico alternativo, basado en la ley de Pascal, para la calibración de los transductores de presión durante la monitorización hemodinámica invasiva que se realiza en la Unidad de Cuidados Intensivos de Cirugía Cardiovascular del Hospital Clínico-Quirúrgico Hermanos Ameijeiras. Este método fue validado mediante la comparación con el estándar recomendado en un total de 215 pacientes que requirieron monitorización hemodinámica invasiva entre los meses de enero y junio del 2015. Resultados: Con el método manométrico alternativo creado se obtiene el mismo resultado que con el método hidráulico recomendado por la literatura. Conclusiones: El método alternativo creado es preciso, eficaz y costo-efectivo(AU)
Introduction: Transducer calibration is very important for the accurate measurement of pressures during invasive hemodynamic monitoring of patients requiring close observation in the primary care units and in the operating room. Objective: To develop and validate a method of calibration of pressure transducers, which is simple, efficient and low-cost. Methods: An alternative manometric method, based on Pascal's law, was developed for the calibration of pressure transducers during invasive hemodynamic monitoring performed at the intensive care unit of the cardiovascular surgery department at Hermanos Ameijeiras Clinical-Surgical Hospital. This method was validated by its comparison with the recommended standard in a total of 215 patients who required invasive hemodynamic monitoring between January and June 2015. Results: With the alternative manometric method created, the same result was obtained as with the hydraulic method recommended by the literature. Conclusions: The alternative method created is accurate, efficient and cost-effective(AU)
Assuntos
Humanos , Transdutores de Pressão/normas , Calibragem/normas , Invenções/normas , Monitorização Hemodinâmica/instrumentaçãoRESUMO
Franciscana dolphin (Pontoporia blainvillei) whistles were documented for the first time during 2003-2013 in Babitonga Bay estuary, South Brazil, together with burst pulses. Recordings were made from small boats under good sea conditions, and recording equipment that allowed analysis of sounds up to 96 kHz. The recordings were made in the presence of 2-31 franciscana dolphins. During 23 h and 53 min, 90 whistles and 51 burst pulse series were recorded. Although Guiana dolphins (Sotalia guianensis) inhabit nearby waters, none were observed in the area during the recordings. The authors recorded ten types of whistles. The initial frequency varied between 1.6 and 94.6 kHz, and the final frequency varied between 0.7 and 94.5 kHz; the authors were not able to determine if dolphin whistles exceeded the 96 kHz recording limit of the authors' equipment, although that is likely, especially because some whistles showed harmonics. Whistle duration varied between 0.008 and 0.361 s. Burst pulses had initial frequencies between 69 and 82.1 kHz (77 ± 3.81). These results showed that P. blainvillei produces whistles and burst pulses, although they seem to be produced infrequently.
Assuntos
Golfinhos/fisiologia , Comportamento Social , Vocalização Animal , Acústica/instrumentação , Animais , Brasil , Golfinhos/classificação , Golfinhos/psicologia , Desenho de Equipamento , Feminino , Masculino , Movimento (Física) , Reconhecimento Automatizado de Padrão , Densidade Demográfica , Processamento de Sinais Assistido por Computador , Razão Sinal-Ruído , Som , Espectrografia do Som , Fatores de Tempo , Transdutores de Pressão , ÁguaRESUMO
OBJECTIVE: The Pressure Biofeedback Unit (PBU) is used to assess the transversus abdominis muscle activity in order to determine the effectiveness of segmental stabilization, but not to verify its accuracy for measuring the pressure values of breathing from transversus abdominis activation. The objective of this study was to cross-validate the PBU pressure evaluated in transversus abdominis muscle activation with the respiratory pressure assessed through manovacuometry in order to verify the extent to which the PBU can be used to indirectly evaluate the strength of the respiratory muscle in both men and women and verify the reliability of the methods. PARTICIPANTS: A total of 39 healthy subjects. METHODS: Manovacuometry and Pressure Biofeedback Unit tests were performed in three days each with three replications: 1) Maximal Inspiratory Pressure; 2) Maximal Expiratory Pressure; and 3) Pressure Biofeedback Unit. RESULTS: Both tests showed good reliability and low correlation between the Pressure Biofeedback Unit and Maximal Inspiratory Pressure (r = 0.40; p = 0.01) and Maximal Expiratory Pressure (r = 0.33; p = 0.04). High differences were observed between pressures and wide limits of agreement in Bland-Altman analysis. CONCLUSION: It seems that the Pressure Biofeedback Unit is not able to effectively predict the respiratory muscles' strength as routinely evaluated through the use of the manovacuometry presenting a low cross-validation and good reliability.
Assuntos
Músculos Abdominais/inervação , Biorretroalimentação Psicológica/instrumentação , Contração Muscular , Respiração , Músculos Respiratórios/inervação , Transdutores de Pressão , Adulto , Estudos Transversais , Desenho de Equipamento , Feminino , Humanos , Masculino , Manometria , Valor Preditivo dos Testes , Pressão , Reprodutibilidade dos Testes , Adulto JovemRESUMO
BACKGROUND: The use of esophageal catheters with microtransducer promises advantages over traditional catheters with air-filled balloons. However, performance comparisons between these 2 types of catheters are scarce and incomplete. METHODS: A catheter with a 9.5-cm air-filled balloon at the distal tip and a catheter with a microtransducer mounted within a flexible silicone rubber were tested in vitro and in vivo. In vitro, the response times of both catheters were compared, and the drift of the baseline pressure of the microtransducer catheter was evaluated over a 6-h period. In vivo, 11 healthy volunteers had both catheters inserted, and the drift of the baseline esophageal pressure was measured over a 3-h period. Also, the correlation and agreement of the baseline and changes in the esophageal pressure of both catheters were evaluated. RESULTS: In vitro, the microtransducer catheter had a response time significantly higher (262 × 114 Hz, P < .01) and a good pressure stability, with a mean baseline pressure drift of 1.4 cm H2O. In vivo, both catheters presented a small and similar baseline esophageal pressure drift (P = 0.08). For measurements of baseline and changes in esophageal pressure, the correlation and agreement between the catheters were poor, with a large bias between them. CONCLUSIONS: The catheter with the microtransducer had a small baseline pressure drift, similar to the air-filled balloon catheter. The low agreement between the catheters does not allow the microtransducer catheter to be used as a surrogate for the traditional air-filled balloon catheter.
Assuntos
Catéteres , Esôfago/fisiologia , Manometria/instrumentação , Monitorização Ambulatorial/instrumentação , Transdutores de Pressão , Adulto , Desenho de Equipamento , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Pressão , Adulto JovemRESUMO
OBJECTIVE: To assess the inter-rater reliability of two raters for the mean and single maximal value of three vaginal maximum voluntary contractions (MVCs) using the Peritron™ perineometer for study participants in the first and second trimesters of pregnancy. PARTICIPANTS: Thirty-six low-risk pregnant women. METHODS: The assessments were done by two different examiners with an interval of 2 to 7 days. For statistical analysis, the concordance correlation coefficient (CCC) and Bland-Altman limits of agreement were used. RESULTS: For the overall sample, good reliability of 0.80 was found analyzing the mean of three MVCs and for the single maximal value (CCC = 0.79). Good reliability was found for the mean of three MVCs (0.81 and 0.78) for the first and second trimesters, respectively. Good reliability of 0.89 was found in the first trimester and a moderate reliability of 0.70 for the second trimester when analyzing the single maximal value of three MVCs. CONCLUSION: Good inter-rater reliability was found for the overall sample and first trimester of pregnancy for both mean values and single maximal values of the three MVCs. A good and moderate reliability was respectively found in the second trimester in analyzing the mean and single maximum values of three MVCs.
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Contração Muscular , Diafragma da Pelve/fisiologia , Transdutores de Pressão , Adolescente , Adulto , Desenho de Equipamento , Feminino , Humanos , Variações Dependentes do Observador , Valor Preditivo dos Testes , Gravidez , Primeiro Trimestre da Gravidez , Segundo Trimestre da Gravidez , Pressão , Reprodutibilidade dos Testes , Vagina , Volição , Adulto JovemRESUMO
PURPOSE: To evaluate intraocular pressure (IOP) changes during experimental vitrectomy and the efficacy of Constellation Vision System's IOP control (IOPc) feature in reestablishing baseline pressure. METHODS: Using a pressure transducer in freshly enucleated porcine eyes, a broad range of parameters (baseline pressures, aspiration levels, and cut rates) were tested with 23- and 25-gauge probes and IOPc turned ON versus OFF. RESULTS: IOPc turned ON was significantly more effective than IOPc turned OFF in controlling IOP drop and stabilizing pressure during vitrectomy using a wide range of baseline pressures (20-70 mmHg). The 23-gauge system consistently presented a reduced drop from baseline compared with the 25-gauge system. The overall average drop for the 23- and 25-gauge systems was 12.79 mmHg and 21.17 mmHg, respectively. Both gauge sizes reestablished baseline pressure approximately 1.6 seconds after the initial pressure drop generated at the beginning of aspiration. A peak of IOP (overshooting) was observed when the pressure was returning to baseline using both 23- and 25-gauge systems. CONCLUSION: Using IOPc feature turned ON, 23- and 25-gauge probes were effective in reestablishing and sustaining baseline infusion pressures, although 23-gauge probes showed less IOP fluctuation than did 25-gauge probes.
Assuntos
Pressão Intraocular/fisiologia , Vitrectomia , Animais , Esclerostomia , Suínos , Tonometria Ocular , Transdutores de PressãoRESUMO
BACKGROUND: The Forced Oscillation Technique (FOT) has the potential to increase our knowledge about the biomechanical changes that occur in Cystic Fibrosis (CF). Thus, the aims of this study were to investigate changes in the resistive and reactive properties of the respiratory systems of adults with CF. METHODS: The study was conducted in a group of 27 adults with CF over 18 years old and a control group of 23 healthy individuals, both of which were assessed by the FOT, plethysmography and spirometry. An equivalent electrical circuit model was also used to quantify biomechanical changes and to gain physiological insight. RESULTS AND DISCUSSION: The CF adults presented an increased total respiratory resistance (p < 0.0001), increased resistance curve slope (p<0.0006) and reduced dynamic compliance (p<0.0001). In close agreement with the physiology of CF, the model analysis showed increased peripheral resistance (p<0.0005) and reduced compliance (p < 0.0004) and inertance (p<0.005). Significant reasonable to good correlations were observed between the resistive parameters and spirometric and plethysmographic indexes. Similar associations were observed for the reactive parameters. Peripheral resistance, obtained by the model analysis, presented reasonable (R=0.35) to good (R=0.64) relationships with plethysmographic parameters. CONCLUSIONS: The FOT adequately assessed the biomechanical changes associated with CF. The model used provides sensitive indicators of lung function and has the capacity to differentiate between obstructed and non-obstructed airway conditions. The FOT shows great potential for the clinical assessment of respiratory mechanics in adults with CF.
Assuntos
Simulação por Computador , Fibrose Cística/fisiopatologia , Impedância Elétrica , Manometria/métodos , Modelos Biológicos , Testes de Função Respiratória/métodos , Mecânica Respiratória , Adulto , Infecções por Burkholderia/complicações , Infecções por Burkholderia/fisiopatologia , Burkholderia cenocepacia , Estudos Transversais , Fibrose Cística/complicações , Feminino , Humanos , Modelos Lineares , Masculino , Manometria/instrumentação , Pletismografia , Pneumonia Bacteriana/complicações , Pneumonia Bacteriana/fisiopatologia , Infecções por Pseudomonas/complicações , Infecções por Pseudomonas/fisiopatologia , Ventilação Pulmonar , Testes de Função Respiratória/instrumentação , Espirometria , Transdutores de Pressão , Adulto JovemRESUMO
This report describes a new crank arm-based force platform designed to evaluate the three-dimensional force applied to the pedals by cyclists in real conditions. The force platform was designed to be fitted on a conventional competition bicycle crankset while data is transmitted wirelessly through a Bluetooth™ module and also stored on a SD card. A 3D solid model is created in the SolidWorks (Dassault Systèmes SOLIDWORKS Corp.) to analyze the static and dynamic characteristics of the crank arm by using the finite elements technique. Each crankset arm is used as a load cell based on strain gauges configured as three Wheatstone bridges. The signals are conditioned on a printed circuit board attached directly to the structure. The load cell showed a maximum nonlinearity error between 0.36% and 0.61% and a maximum uncertainty of 2.3% referred to the sensitivity of each channel. A roller trainer equipped with an optical encoder was also developed, allowing the measurement of the wheel's instantaneous velocity.