Impedance of Biological Tissue
Development of Technology Based on Biological Tissue Impedance Nonlinear Fluctuations Analysis for Organism Functional State Evaluation
Tech Area / Field
- INS-MEA/Measuring Instruments/Instrumentation
- PHY-RAW/Radiofrequency Waves/Physics
- PHY-SSP/Solid State Physics/Physics
3 Approved without Funding
VNIIEF, Russia, N. Novgorod reg., Sarov
- Russian Academy of Sciences / Institute of Biomedical Problems, Russia, Moscow
- Strategieteam e.V., Germany, Neustrelitz\nMedizinische Hochschule Hannover / Klinische Pharmakologie, Germany, Hannover
Project summaryAt present more and more attention is being paid to the problem of assessment of a healthy person functional state in connection with the adverse effect of the environment. The ecological situation on the planet Earth is becoming worse each year. The disease incidence is becoming higher. Social and psychological tension is increasing. Technical progress results in drastic reduction of physical activity and domination of sedentary life style. All the reasons mentioned above cause deterioration of health and reduction of work efficiency. According to the definition given by the World Health Organization “health is not only absence of disease or physical flaws, but also entire physical, psychological and social wellbeing.” For that reason health studies and especially a scientific branch concerning the problems of assessment of body functional states on border-line between the norm and pathology, health and disease have been actively developing for the last decades (R.M. Baevsky, 1979, 2001). The best results have been shown in space medicine, due to the professional peculiarities of humane life and activity in space. Physical and psychological stresses, accelerations and being at the state of weightlessness for a long time, huge responsibility are among the factors that require from astronauts especially good health and ability to adapt to the changing conditions of the environment. The modern definition of health describing it as adaptive abilities of a body comes from space medicine (A.I. Grigoryev, R.M. Baevsky). The techniques and devices available today in everyday medical practice are not suitable for the purpose of adaptive body abilitiesassessment, as they measure the results of a body adaptation processes, but not the processes themselves. Such well-known characteristics as pulse rate, blood pressure, respiration rate, body temperature, and also data received through ultrasound examination of heart and other inner organs and through complex biochemical blood analyses only help to determine the homeostasis existing at the moment, a particular current state of a body and do not directly reflect the adaptation process. However, the transition from health to illness is connected with exertion of regulatory systems and in case when no preventive measures are taken can result in overexertion and emaciation of adaptive vehicles which leads to the dysfunction of the body abilities to adapt to the changing environment (disadaptation).
New fundamentally different biometrical approaches are needed for adaptation processes to be evaluated. It is known from the G. Selliet’s theory on the common adaptation syndrome that the adaptation mechanisms emaciation stage is caused by regulatory systems disbalance. As the regulation and control processes in a living organism represent oscillatory (quasi-periodic) processes, then in order to study adaptation processes biorhythmological techniques where the object of measurement is oscillations of different vital functions are more and more widely applied. Different approaches to the problem which take into consideration the organizational level of biological systems and characteristics of biological rhythms under study are being developed. And the analysis of nonlinear oscillation processes in physiological systems is one of them. In the course of the project we are going to develop this approach.
The principal objective of the project is to investigate, develop and demonstrate biorhythmical approaches for the assessment of the health level and of the functional state of a person on the basis of nonlinear oscillation processes in physiological systems registered through the wavelength characteristics of the biological tissue conductivity variation.
Scientific and practical importance of the work lies in the development of biometrical approaches to registration and analysis of nonlinear oscillation processes in physiological systems on the basis of characteristics of body conductivity variations and identification of the functional state and health level of a person. The specific feature of the approach developed under this project is the complex character of mathematical assessment and physiological interpretation of the varying features of nonlinear oscillation processes which allows determining the interconnection between the measured values dynamics and the course of adaptation processes. The approaches developed will be taken as the basis for creating new construction principles for technology (techniques and equipment) to be used in healthcare practice and to be widely applied in every-day life.
The latter point takes special significance as at present there are no devices for objective evaluation of the health level and functional state of a healthy person designed to be widely used in every-day life and in ordinary clinics and hospitals, similar to a so widely used thermometer and a blood pressure measuring device.
In the course of the project implementation we aim to achieve the following results:
- Biophysical basis for registration of nonlinear oscillation processes in physiological systems based on the variation characteristics of a biological tissue impedance will be investigated.
- The principles and methodology of evaluation and automatic identification of the humane organism functional state on the basis of wavelength characteristics of biological tissue impedance variations will be developed.
- The principles and techniques of investigation of adaptation processes in real-time conditions on the basis of the analysis of nonlinear oscillations of biological tissue impedance will be developed.
- Prototypes of hardware-software systems for registration and analysis of nonlinear oscillation processes in physiological systems on the basis of biological tissue impedance variation characteristics will be created.
- Technical proposals on application of hardware-software systems in medicine and every-day life will be worked out.
Technical approaches and methodology The essence of the new approach for investigation of the humane organism functional state and adaptation processes developed under this project is measuring of the characteristics of oscillation processes complex inside one or in different physiological systems, their frequency, phase and amplitude synchronization and correlation of these characteristics with adaptation process stages: anxiety stage (exertion stage, resources mobilization), transition stage, resistance stage, emaciation stage. It should be noted that lately attempts at developing an integrated approach at nonlinear oscillation processes analysis in physiological systems (nervous, vascular, endocrine systems, motor activity control, at the cell level) has been undertaken. Integrated character of the new approach is revealed through unified theoretical base and strategy of different physiological and pathological processes analysis, through unified mathematical and algorithmic analysis tools, through study of similar time series variability phenomena (spectral, nonlinear, etc.) in different systems, through development of similar algorithms of diagnostics and treatment on the basis of new nonlinear dynamics factors (A.N. Flayshman A.N. Slow oscillation processes in the humane body. Theoretical and applied aspects of nonlinear dynamics in physiology. Collection of articles of the 3rd Symposium, Novokuznetsk, 2001, pp. 11-23). The integral approach is based on the registration and analysis of nonlinear oscillation processes in certain physiological systems, and it also allows via nonlinear constituent receiving indirect data about systems’ interactions, about the state of other systems, especially those about which it is difficult to obtain direct information.
For the biometrical approach at evaluation of the health level and functional state of a person developed under this project it seems promising to develop direct techniques of registration and analysis of the totality of nonlinear oscillation processes in physiological systems. This will allow obtaining data about both the general state of the humane organism and particular physiological systems states. It is a well-known fact that the humane organism nonlinear oscillation processes dynamics objectively reflects the health level and the functional state of a person. Amplitude-frequency spectrum which is unique for each person is considered to be a formalized description of nonlinear oscillation processes dynamics. Registration of the whole totality of humane organism oscillations and their amplitude-frequency spectrum construction will allow applying biometrical approach (formalized description of the unique features of a person) for the purposes of solving the problem of automatized identification of the health level and functional state of a person.
Direct conversion of biological tissue impedance into frequency will be employed for the purpose of integrated registration of oscillation processes in humane body physiological systems. The increase of impedance-to-frequency conversion transconductance and, as the result, of the device receptiveness, is achieved by synchronous accumulation of probing signal lagging resulting from biological tissue features. That will allow improving signal-noise ratio registering the smallest tested organ conductivity variations caused by the humane body vital activity. Such technical approach to registration of oscillation processes in physiological systems will allow developing simple and space-saving devices based on both discrete elements and on microchips. Such devices will allow applying biometrical approach for evaluation of the health level and functional state of a person in his/her every-day life and in his/her working activity.
Modern techniques, such as electrocardiography, pneumotachography, blood pressure measurements, etc., will be used to test the developed devices and to establish correlation between amplitude-frequency spectra and the health level and functional state. For the purpose of comparative assessment physiological signals variability analysis techniques, especially heart rate variability analysis, will be of great importance.
FSUE RFNC-VNIIEF and RFSSC –IMBP RAS members possess great practical expertise in the area of theoretical and experimental research into different physiological processes registration techniques, evaluation and prediction of the humane body functional state. Some intermediary results on registration of oscillation processes in the humane organism physiological systems based on direct conversion of biological tissue impedance into frequency demonstrate the effectiveness of the approach chosen and the lucky combination of technical capabilities and scientific and practical expertise of the specialists, which gives hope of achieving success in solving the
Potential role of foreign collaborators. The project orientation on solving urgent problems can foster establishing business relations with foreign partners. Particularly, the results obtained in the course of the project implementation may be of interest to a number of firms involved in developing and production of medical and diagnostic equipment. Participation of foreign collaborators will benefit both perfection of the project ideas and its implementation. It is supposed that foreign collaborators will take part in seminars and joint publications, in material specimen exchanges, in technical testing of the activities on the project implementation and will be partners in the project results realization. All the joint activities can be specified in joint programs.
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