Gateway for:

Member Countries

Tomography of Cordial Muscle

#3518


Development of Tomographical Methods for a Research of an Electrical Activity of a Cordial Muscle

Tech Area / Field

  • MED-OTH/Other/Medicine
  • PHY-OPL/Optics and Lasers/Physics

Status
3 Approved without Funding

Registration date
06.05.2006

Leading Institute
Moscow State Institute of Electronics Technology (Technical University), Russia, Moscow reg., Zelenograd

Supporting institutes

  • VNIITF, Russia, Chelyabinsk reg., Snezhinsk

Collaborators

  • Kemsing Engineers Ltd., UK, London\nWashington University, USA, MO, Saint Louis

Project summary

The Project goal is the development of tomographic methods for an investigation of an electrical activity of the cardiac muscle, especially the imaging of spatial distribution of the cardiac muscle transmembrane potential (TMP), in the context of photoluminescent tomography of biological media, which will have allowed to receive the fundamentally new information about mechanisms of a cardiac electrical activity for the norm and the pathology.

The results of the Project execution will allowe to improve an understanding of electrical defibrillation mechanisms, to find new ways for the solution of the actual problem of optimization of pulse form during defibrillation, thus to improve defibrillation efficiency.

At present the mechanism of defibrillation is remaining indeterminate. However it's clear that the effective electroshock impact to the ventricle fibrillation demands the synchronous stimulation and de-excitement of myocytes by a transmission of an electric current with adequate magnitude during adequate time period. It is known, that bipolar pulses of a defibrillation are the much more effective than monopolar pulses. Nevertheless optimal bipolar pulse shape is remaining unknown. Usually the optimization of a bipolar pulse shape is realized by empirical trial methods. At the same time such optimization is possible on the base of the analysis of a correlation of applied electric field in extracellular space and changes of transmembranian potential. Recently optical methods based on potential-sensible dyes have provided an opportunity of quantitative estimation of this correlation. However ventricles of heart may have sizeable thickness, and therefore an interpretation of optical signals is rather difficult problem because of scattering and absorption of light in the muscular tissue. The Project proposes the optical mapping and the computer 3D-modelling of the light propagation through the cardiac muscle in order to improve an understanding of the defibrillation mechanism.

Proposed investigations consist of the following. A photoluminescent agent is injected in cardiac muscle. The radiation spectrum of this agent is uniquely associated with spatial distribution of TMP. Then cardiac muscle is being irradiated by outer laser radiation generating secondary photoluminescent radiation.

After registration of photoluminescent radiation spectrum, emanating from cardiac muscle, it is possible to reconstruct spatial distribution of TMP. During the realization of the Project it is planned to develop mathematical models and algorithms of reconstruction of spatial distribution of TMP in the context of photoluminescent tomography. A long with this initially an absorption and afterwards the scattering of probing and photoluminescent radiation in cardiac muscle substance will be considered. In the Project the results of earlier investigations will be exploited. These investigations have been realized by project participants in the area of transmission optical tomography of biological high scattering media, of luminescent tomography of semiconductor material as well as in the area of tomographic images contrasting by means of special dyes. Developed algorithms will be realized as computer programs for imaging of model and real objects. This will provide the investigation of influence of different factors and verification of adequacy of obtained results.

Scientific importance of the Project. As a result of offered investigations physical and mathematical basis for imaging of the spatial distribution of TMP in cardiac muscle will develope. In its own turn preconditions for experimental investigations of basic mechanisms of a cardiac electrical activity for a norm and a pathology will be created.

The scientific, technical and methodical potential of MIET is based on the specialization in the area of the development of optical and computer technologies, on the experience of the development of different technologies for basic and applied researches, on results of the development of new physical-mathematical methods and complicated opto-electronic systems. The extensive software, which has been developed by Project participants for scientific and technical problem solutions in the Project direction, has been created and used.

The Project realization is directed to a development of new technologies in peaceful purposes (especially in the medical area). It is contributing to the solution of national and international scientific and technical problems and it is supporting the transition to the market economy, which is corresponding to the civil needs.

Expected Results

In the process of project realization it is supposed to receive following results.

  • To develop the mathematical model of optical mapping with potentiometric dyes for the monitoring of an electrical activity of a thick cardiac tissue, which is based on integro-differential equations of the light transport in a thick cardiac tissue for given spatial distributions of potentiometric dyes and TMP.
  • To develop algorithms and programs for the reconstruction of optical images of 3D-distribution of TMP.

The results of investigation will allow creating the system of TMP-visualization in the thick cardiac tissue, which will be effective for biological and medical applications, especially for an optimization of the pulse shape during the electrical cardiac defibrillation.

Work Content:

Work duration – 2 years.

First year:

  • The development of the mathematical model and algorithms for the reconstruction of the spatial distribution of TMP taking into account the absorption of probing and photoluminescent radiation in a cardiac muscle substance.
  • The development of the computer program and the image reconstruction of a model object taking into account the absorption of probing and photoluminescent radiation in cardiac muscle substance.
  • The analysis of results received.

Second year:
  • The development of the mathematical model and the algorithm for a reconstruction of a spatial distribution of TMP taking into account both the absorption and the scattering of probing and photoluminescent radiation in a cardiac muscle substance.
  • The development of the computer program and the image reconstruction of a model object taking into account both the absorption and the scattering of probing and photoluminescent radiation in cardiac muscle substance.
  • Investigations of results of the reconstruction for the model spatial distribution of TMP.
  • The analysis of results received.

This Project will allow to specialists, who are working in the area of nuclear and missile weapon creation, to take a part in the execution of applied researches and in the development of peaceful technologies as well as it will contribute to the international science integration.


Back