Possible Applications of Focussed Impedance Method (FIM) in Biomedical and Other Areas of Study

Journal of Electrical Bioimpedance

2013

Focused impedance measurement (FIM) is a technique where impedance can be measured with the optimum level of localization without much increase in complexity of measuring instrument. The electrodes are applied on the skin surface while the organs inside also contribute to the measurement, as the body is a volume conductor. In a healthy and disease free lung region, the air enters at breathe-in, increases the impedance of the lung, and impedance reduces during breathe-out. In contrast, for a diseased lung, where part of the lungs is filled with water or some fluid, air will not enter into this zone reducing impedance change between inspiration and expiration. With this idea, the current work had been executed to have general view of localized impedance change throughout thorax using 6-electrode FIM. This generated a matrix mapping from both the front and from the back of the thorax, which showed how impedance change due to ventilation varies from frontal plane to back plane of human bodies.

Section: Introductionmentioning

confidence: 97%

Thorax mapping for localized lung impedance change using focused impedance measurement (FIM): A pilot study

Ferdous

Baig

Journal of Electrical Bioimpedance

2013

“…Scientists all over the world are trying to innovate simple, inexpensive, and non-invasive techniques for the physiological study and diagnosis of the human body. Electrical impedance techniques play a very significant role in this regard (Morucci andRigaud, 1996, Rabbani andKadir, 2011). Individual body tissues have various electrical properties which can change due to physiological changes or due to sickness (Gabriel et al,1996).…”

Section: Introductionmentioning

confidence: 99%

Improving Deep Sensitivity of Four-Electrode Focused Impedance Method In Lungs by Varying Electrode Geometries

Mobarak

2022

Bangla J Med Phys

Bio-Electrical impedance is of special interest in the detection and diagnosis of lung problems, particularly in the low and medium income countries. An age old simple technique employing four electrodes is known as ‘Tetra Polar Impedance Measurement (TPIM)’ but it cannot localize a particular zone of interest region. A new technique named as ‘Focused Impedance Method (FIM)’ was innovated by a Dhaka University group which gives high sensitivity in a localized zone of interest. Previously FIM was used from one side of the thorax which gave a rather limited information from the lungs, from shallow depths only. In order to get information from deeper regions of the lungs a new configuration of electrodes for FIM was proposed by the same group at Dhaka University which placed two electrodes at the front and two electrodes at the back of the thorax in a horizontal plane. It is expected that the degree of depth sensitivity would depend on electrode separation on both the sides. The electrode width may also have an effect. In order to study these quantitatively, COMSOL Multiphysics software was used to simulate the measurements in a rounded rectangular volume to represent a typical thorax, which was filled with isotonic saline. Electrode separations of 5cm, 10cm, 15cm and 20cm were studied while electrode widths studied were 0.15cm, 1cm and 3cm. The work supported the proposed new configuration of electrodes for FIM in that this method gives enhanced sensitivity throughout the depths of a lung and that for a thorax with a cross section of 33cm26cm, an electrode separation between 10cm and 15cm would give optimum results. For electrode width, the ones studied did not give any significant difference, however, the smallest (0.15cm) one appeared to give slightly better results. Bangladesh Journal of Medical Physics Vol.15 No.1 2022 P 43-54

“…Utilising the 3D sensitivity of FIM it is possible to detect objects at shallow depths using skin surface electrodes, typically of the order of the separation of the electrodes [Iquebal and Rabbani 2010]. FIM has potential applications in many physiological studies and in the detection and diagnosis of diseases and disorders of the human body [Rabbani and Kadir 2011]. Particularly it may be useful in studying stomach emptying, stomach acid secretion, localized lung ventilation [Kadir 2010], bladder emptying, etc., where temporal changes occur that may be discerned through a difference measurement.…”

Section: Introductionmentioning

confidence: 99%

Sensitivity study for a 4-electrode Focused Impedance Method (FIM) using Finite Element Method analysis

Abir

2015

Bangla J Med Phys

Focused Impedance Method (FIM) is a recent technique, innovated by one of the authors at Dhaka, and shows a promise in providing practical results with a minimum of instrumentation complexity. Out of three version using 8, 6 and 4 electrodes, this paper concentrates on the 4-electrode FIM. Earlier work mainly used phantom experiments to verify the concept and analytical methods for a semi-infinite medium. The present work uses Finite Element Method (FEM), implemented by a software package named COMSOL to obtain various sensitivity graphs for 4-FIM. Firstly, it has verified the focusing effect for a homogenous medium using point sensitivity calculations. Secondly, it obtained simulated impedances for finite sized objects embedded in a medium of uniform conductivity considering five important variables namely, electrode spacing, object size, object resistivity, background resistivity and depth. In this paper the effect of each of these variables has been studied by keeping the other four constant. The obtained graphs give an insight which is expected to lead to quantitative assessment of target objects, needed in physiological study and diagnosis.Bangladesh Journal of Medical Physics Vol.7 No.1 2014 1-7