RESUMO
PURPOSE: Prompt detection of congestion is an essential target in order to prevent heart failure (HF) related hospitalization, being ambulatory monitoring a promising strategy to do so. A successful non-invasive ambulatory monitoring system requires automatic devices for physiological data recording; these data must give information about HF deterioration early enough to predict HF-related adverse events. This work aims to evaluate seven vascular parameters for the ambulatory monitoring of congestive heart failure patients. METHODS: Seven vascular parameters are proposed as indicators of HF deterioration. These parameters are obtained using venous occlusion plethysmography; a technique that uses hardware able of being miniaturized and easily integrated into wearables for ambulatory monitoring. The ability of the proposed vascular parameters to detect congestion is evaluated in eight healthy volunteers and ten congestive heart failure patients with different congestion levels-mild, moderate and severe. RESULTS: Most parameters distinguish between healthy volunteers and heart failure patients, and some of them present significant differences between volunteers and low levels of congestion-mild or moderate. CONCLUSION: Home monitoring of some of the proposed parameters could detect HF deterioration on its onset and alert to health personnel.
Assuntos
Insuficiência Cardíaca/diagnóstico , Hemodinâmica , Monitorização Ambulatorial/métodos , Pletismografia , Telemetria , Adulto , Idoso , Estudos de Casos e Controles , Desenho de Equipamento , Feminino , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Miniaturização , Modelos Cardiovasculares , Monitorização Ambulatorial/instrumentação , Pletismografia/instrumentação , Valor Preditivo dos Testes , Prognóstico , Estudo de Prova de Conceito , Índice de Gravidade de Doença , Telemetria/instrumentação , Função Ventricular Esquerda , Dispositivos Eletrônicos Vestíveis , Adulto JovemRESUMO
The ambulatory monitoring of biosignals involves the use of sensors, electrodes, actuators, processing tools and wireless communication modules. When a garment includes these elements with the purpose of recording vital signs and responding to specific situations it is call a 'Smart Wearable System'. Over the last years several authors have suggested that conductive textile material (e-textiles) could perform as electrode for these systems. This work aims at implementing an electrical characterization of e-textiles and an evaluation of their ability to act as textile electrodes for lower extremity venous occlusion plethysmography (LEVOP). The e-textile electrical characterization is carried out using two experimental set-ups (in vitro evaluation). Besides, LEVOP records are obtained from healthy volunteers (in vivo evaluation). Standard Ag/AgCl electrodes are used for comparison in all tests. Results shown that the proposed e-textiles are suitable for LEVOP recording and a good agreement between evaluations (in vivo and in vitro) is found.