תלמידת התואר השלישי במחלקה להנדסה ביו רפואית

אוניברסיטת תל אביב

The multi-domain fibroblast/myocyte coupling in the cardiac tissue – A theoretical study

Cardiac fibroblast proliferation and concomitant collagenous matrix accumulation (fibrosis) develop during multiple cardiac pathologies. Recent studies have demonstrated direct electrical coupling between myocytes and fibroblasts in-vitro, and assessed the electrophysiological implications of such coupling. However, in the living tissues, such coupling has not been demonstrated, and only indirect coupling via the extracellular space is likely to exist. In this study we employed a multi-domain model to assess the modulation of the cardiac electrophysiological properties by neighboring fibroblasts assuming only indirect coupling. Numerical simulations in 1D and 2D human atrial models showed that extracellular coupling sustains a significant impact on conduction velocity (CV) and a less significant effect on the action potential duration (APD). Both CV and the slope of the CV restitution increased with increasing fibroblast density. This effect was more substantial for lower extracellular conductance. In 2D, spiral waves exhibited reduced frequency with increasing fibroblast density, and the propensity of wavebreaks and complex dynamics at high pacing rates significantly increased.

העבודה נעשתה בהנחיית ד"ר שרון זלוצי'בר מהמחלקה להנדסה ביו-רפואית,

 אוניברסיטת תל-אביב

ההרצאה תתקיים ביום ראשון 08.01.17, בשעה 14:30

בחדר 315, הבניין הרב תחומי, אוניברסיטת תל אביב

Prof. Jacob (Koby) Scheuer

School of Electrical Engineering

Department of Physical Electronics, Tel-Aviv University

Wednesday, January 18th  , 2017

13:00-14:00

Abstract:

The transition from the contemporary low scale integration of optical devices to future highly-integrated photonic processors necessitates the development of new high-quality materials on one hand and inexpensive mass-production fabrication methods on the other. Polymeric materials have interesting optical and mechanical properties, making them an attractive choice for future photonic systems. In addition to low optical losses and material dispersion, polymers are simple to manipulate and to cast using a wide variety of fabrication methods such as soft-lithography and Nano-Imprinting Lithography (NIL) techniques. Furthermore, the ability to dope polymeric materials with molecules that exhibit a large electro-optic coefficient, nonlinear response or optical gain, paves the way to all-polymer integrated optical circuits that include on-chip sources, processors and detectors. In this talk I will show the recent progress the Nano-Photonics Lab at TAU made in developing polymeric and sol-gel based integrated optical devices and lasers by combining unique materials with NIL technology.

Light refreshments and drinks will be served starting 12:30

Auditorium 011, Engineering Class Room Building,

Faculty of Engineering, Tel-Aviv University

תלמיד המחלקה להנדסה ביו רפואית לתואר שני ירצה בנושא:

Parametric Electrical Impedance Tomography for Monitoring Pleural Effusion Using a 3D Human Model

The evaluation of the amount of fluid accumulated in the pleural cavity, an abnormality known as pleural effusion (PE), has an important diagnostic value. Monitoring of such congestions is a significant clinical challenge due to the lack of direct access to the pleural cavity. In this study, a novel parametric Electrical Impedance Tomography (pEIT) technique for monitoring PE is suggested. Like most EIT based systems this technique solves both the forward and the inverse problems however, unlike the conventional EIT approach it requires only a reduced number of electrodes for the reconstruction and therefore is more practical for clinical use.

The scheme is based on an optimization process which aims to reconstruct the optimal congested pleural cavity (CPC) volume using only several body surface potential measurements. A numeric model was used for estimating the potentials developed on the body surface as a response to predetermined series of current injections. An innovative technique for simulating varying volumes of CPC was used for the feasibility assessment and a preliminary test was performed in four consecutive non-congested subjects.

 The study results show that both the model's CPC volumes and the optimized CPC volumes are highly consistent. A high linear correlation between the optimized and the reconstructed CPC volumes was found. The preliminary test results show a strong linear correlation ( ) for all four patients.

Hence, the suggested technique can estimate a CPC volume in a 3D computerized model. Furthermore, these promising results imply that this method has the potential to monitor CPC volumes in PE patients and therefore improve the efficiency of care and prognosis.

העבודה נעשתה בהנחיית פרופ' שמעון עבוד המחלקה להנדסה ביו-רפואית, אוניברסיטת תל-אביב

ההרצאה תתקיים ביום ראשון 13.11.16, בשעה 14:30

בחדר 315, הבניין הרב תחומי, אוניברסיטת תל אביב