Development of Microwave Radiation Dosimeter for Human Safety Provision and Ecological Monitoring
Tech Area / Field
- ENV-EHS/Environmental Health and Safety/Environment
- ENV-MIN/Monitoring and Instrumentation/Environment
3 Approved without Funding
MIFI, Russia, Moscow
- Anokhin Institute of Normal Physiology, Russia, Moscow\nNIIIT (Pulse Techniques), Russia, Moscow
- Ecole Nationale d'Ingenieurs de Saint-Etienne, France, Saint-Etienne\nKemsing Engineers Ltd., UK, London\nSARAD GmbH, Germany, Dresden
Project summaryThe aim of the project is to develop a portable device for an on-line measurement of the dose of microwave radiation energy, absorbed by a bio-object in a wide frequency band, and control of the safety threshold of absorption.
The topicality of the project follows from the constantly growing level of environment “pollution” by electromagnetic fields. Biophysical and biomedical researches showed that the greatest influence on the psycho-physiologic state of a human being is exerted by the electromagnetic radiation of the microwave range. The “microwave dosimeter”, developed in the project, can be used as a device, measuring isotropically and with high sensitivity the level of microwave radiation and, moreover, its dose – the amount of microwave energy, absorbed by a human being during a specific time, and warning on the excess of electromagnetic safety thresholds. The majority of technical means, used nowadays for the electromagnetic monitoring of production areas, aircraft compartments, radar stations and so on allow, as a rule, to evaluate the intensity of microwave energy fluxes, but do not evaluate directly the dose of microwave energy, absorbed by a bio-object. Hence there is vigorously discussed the question of change-over to dose measurements at evaluating the microwave influence on the psycho-physiologic state of a human being. That requires the creation of new measurement techniques and devices.
The given project is namely aimed at the development and creation of a measurement technique and experimental sample of a portable microelectronic device, allowing to measure the exposition dose of microwave energy, absorbed by a human being isotropically (that is irrespective of the direction of electromagnetic wave incidence) and in a wide frequency band. It is expected, that the experimental sample of the device will consist of two dielectric spheres, inserted one inside the other. The volume between the spheres is filled by a physiologic solution, in which the absorption factors of microwave energy are close to those in bio-tissues. Six pairs of microelectronic microwave sensors, forming a three-dimensional coordinate basis, are placed on the surfaces of both spheres. The sensors should be designed so, as to register only the direct incident radiation wave and not respond on the lateral ones. The difference of read-outs of two sensors, placed on one axis, but on different spheres, is being the informative parameter. In order to avoid the interference of microwave radiations, being incident on the device from different directions, the internal sphere is filled with a material, strongly absorbing microwave energy. The choice of the sensitive microelectronic sensor is one of the major projects tasks. However, already the preliminary studies showed that the new solid-state detector, based on a solid-state diode array with hot carriers, has the characteristics best for application in the device. In order to avoid the influence of temperature on the sensitivity of sensors, the dosimeter volume is expected to be thermo-stabilized. Its temperature thereat will be close to the one of human body, what will minimize the misbalance of sensor differential circuits and provide the closeness of microwave absorption factors of bio-electrolyte to those of living tissue. A complicated task is presented by the requirement to make a design not inducing any substantial distortions in the microwave field measured. The problem will be solved by preliminary simulations and further bench tests of design versions. And, finally, a major direction of works under the project is being the experimental evaluation of microwave influence on the psycho-physiologic state of animals and, later, of the human operator. For this purpose it is planned to perform a series of biophysical experiments, using the laboratory sample of device and the techniques, elaborated in RINP (Research Institute of Normal Physiology) – one of the project’s executants. At the first stage of research the animals (rabbits) will be exposed to a weak microwave radiation at a simultaneous control by the designed dose-meter. At the same time multi-channel electro-physiologic information will be collected from the bio-object and processed in real time, which will allow evaluating the psycho-physiologic changes, emerging in the bio-object under microwave action. Thus, it is expected to evaluate the minimal threshold, at which the faults in psychophysiology begin. The accumulation of statistics will allow carrying out an averaged calibration of device. The project supposes to extrapolate the obtained results for a human being with account of the mass and dimension characteristics. Further some psycho-physiologic experiments with humans are planned.
Thus, the project is aimed at the development of a new technique and new device for the electromagnetic environment supervision and human safety control. The promotion of progress in the given field by the project will consist in enhancing the capability to measure the integral dose of microwave energy, absorbed by human tissues during a specified time interval, and evaluate the radiation safety threshold.
The project will be participated by highly proficient specialists in the fields of physics, electronics, instrumentation, biology and medicine from the three Russian institutes MEPhI, RIPT and RINP. Among the 25 project participants there are 3 doctors and 8 candidates of science.
The project’s objective fully corresponds to the important and humane tasks of ISTC, since it will allow using the experience, accumulated by the majority of project participants in the course of their work on weapon subjects, for solving the significant and urgent problems of ecological safety and the electromagnetic one of a human being.
In the project frames there will be solved the tasks, belonging to the following five directions:
- Creation of the technique of a continuous isotropic measurement of the microwave energy dose, absorbed by a bio-object.
- Development and manufacture of experimental samples of new microelectronic microwave sensor types and their experimental study.
- Development of the device’s electronic units and their tests.
- Creation of an experimental sample of microwave dosimeter.
- Experimental studies of the device in the conditions of electrophysiological experiments with animals and as part of the systems of production process safety and ecological monitoring.
The duration of project is 24 months at a labour consumption of 5589 person-days; of which 3541 person-day (above 63%) pertain to weapon specialists.
The final result of the project is to create an experimental sample of a microwave dosimeter with the following expected specifications:
- sensitivity – 10µGr;
- frequency band – (1…15)GHz;
- shape and dimensions – sphere with a diameter about 6cm;
- isotropy of measurements;
- type of microwave sensor – semiconductor diode array, measuring 1.5*1.5mm.sq.;
- digital display;
- light and sound signalization of exceeding the ultimate safe (tolerable) dose;
- accumulator supply, providing a continuous operation time not less than 10 hours.
On the basis of a complex study of the device’s experimental sample there can be developed in future its refined modification, the introduction of which will allow bringing into reality the commercial potential of the project and ensuring an independent science and engineering activity of the created team with a possible participation of foreign specialists.
The role of foreign partners will consist in exchanging information, reviewing the obtained results, conducting joint meetings and participating in international conferences. Besides that, the foreign collaborators expressed their readiness to carry out joint tests of the device, using their own measuring equipment. Joint activity with the collaborators has already begun (mutual visits with the purpose of discussing the work plans) and will, certainly, extend in the course of project task accomplishment.
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