Intelligent piezoelectric materials are helpful for monitoring the structural health. The principle of the piezoelectric impedance-based structural health monitoring (SHM) technique is to measure the electrical impedance of a piezoelectric patch attached to a structure in a certain frequency range. Electrical impedance variations indicate physical changes in the structure indirectly due to coup...

Abstract: A level set based shape and topology optimization approach to electrical impedance tomography (EIT) problems with piecewise constant conductivities is introduced. The proposed solution algorithm is initialized by using topological sensitivity analysis. Then it relies on the notion of shape derivatives to update the shape of the domains where conductivity takes different values.

Electrical impedance tomography (EIT) is a non-invasive, radiation-free tool to monitor regional changes in ventilation. This report describes, for the first time, that unilateral atelectasis in an extremely low birth weight infant results in a loss of regional ventilation measured by EIT in the affected lung. Conclusion: EIT is currently the most promising technique to monitor regional lung ae...

OBJECTIVES Aiming to improve the anatomical resolution of electrical impedance tomography images, we developed a fuzzy model based on electrical impedance tomography's high temporal resolution and on the functional pulmonary signals of perfusion and ventilation. INTRODUCTION Electrical impedance tomography images carry information about both ventilation and perfusion. However, these images ar...

Plasma membrane disruption is a characteristic feature of cell death induced by hypoxia or ischemia. Here, we investigated whether analysis of tissue electrical impedance allows detection of ongoing cell membrane rupture and necrotic cell death in hypoxic or ischemic myocardium. Twenty-eight isolated rat hearts were submitted to 5 h of ischemia (n = 8) or hypoxia (n = 20). Myocardial electrical...

BACKGROUND The effects of intermittent positive-pressure breathing (IPPB) and abdominal belt on regional lung ventilation in neuromuscular patients are unknown. We conducted a prospective physiologic short-term study in stable neuromuscular patients to determine the effects of IPBB, with and without abdominal belt, on regional lung ventilation. METHODS IPPB was performed as 30 consecutive dee...

The conventional impedance cardiogram is a record of pulsatile changes in the electrical impedance of the chest with each heartbeat. The signal seems intuitively related to cardiac stroke volume. However doubts persist about the validity of stroke volume measurements based on electrical impedance. This paper presents a new electrical axis for impedance cardiography that is perpendicular to the ...

OBJECTIVES The aim of this paper was evaluating the ratios of electrical impedance measurements reported in previous studies through a correlation analysis in order to explicit it as the contributing factor to the accuracy of electronic apex locator (EAL). MATERIALS AND METHODS The literature regarding electrical property measurements of EALs was screened using Medline and Embase. All data ac...

This paper presents a novel electrical needle integrated with microelectrodes, which can measure the electrical impedance of biotissues in real-time. The microelectrodes on the surface of a fine-needle (400 μm in diameter) were fabricated by using a flexible film photomask. This photomask allows a conformal contact with the curved surface, so the designed patterns on the photomask can be transf...