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In this paper, a multiband noncontact temperature-measuring microwave radiometer system is developed. The system can passively receive the microwave signal of the core temperature field of the human body without removing the clothes of the measured person. In order to accurately measure the actual temperature of multilayer tissue in human core temp...
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... angular cone horn antenna is formed by the gradual expansion of the feed waveguide at a certain angle. Antenna schematic diagram of E-plane and H-plane are shown in Figure 4. The gradual expansion of the waveguide interface improves the match between the waveguide and the free space, making the reflection coefficient smaller [26]. ...
Citations
... Between 2019 and 2024, various research groups employed custom-built microwave radiation detectors to ascertain the non-contact temperatures of human tissue substitutes. While these efforts somewhat enhanced measurement precision, a clinically applicable medical device has yet to be realized [59][60][61][62][63][64]. ...
... Current domestic and international research primarily focuses on the contact temperature measurement of human epidermis and subcutaneous tissue [30,[61][62][63]. However, in clinical settings, there is a need to implement non-contact temperature measurements for patients' epidermis and subcutaneous tissues, along with the capability to continuously monitor within the tissue area. ...
... Since 1974, scholars worldwide have explored the structure of microwave radiometers, identifying performance limitations in both full-power and Dicke-type devices [26,69]. Recently, our team and other researchers have delved into the architecture of radiometers [60][61][62]. While the architecture's sensitivity is negligible in equilibrium, the correlation radiometer is prone to gain fluctuations during operation, adversely affecting sensitivity. ...
Microwave radiometry (MWR) is instrumental in detecting thermal variations in skin tissue before anatomical changes occur, proving particularly beneficial in the early diagnosis of cancer and inflammation. This study concisely traces the evolution of microwave radiometers within the medical sector. By analyzing a plethora of pertinent studies and contrasting their strengths, weaknesses, and performance metrics, this research identifies the primary factors limiting temperature measurement accuracy. The review establishes the critical technologies necessary to overcome these limitations, examines the current state and prospective advancements of each technology, and proposes comprehensive implementation strategies. The discussion elucidates that the precise measurement of human surface and subcutaneous tissue temperatures using an MWR system is a complex challenge, necessitating an integration of antenna directionality for temperature measurement, radiometer error correction, hardware configuration, and the calibration and precision of a multilayer tissue forward and inversion method. This study delves into the pivotal technologies for non-invasive human tissue temperature monitoring in the microwave frequency range, offering an effective approach for the precise assessment of human epidermal and subcutaneous temperatures, and develops a non-contact microwave protocol for gauging subcutaneous tissue temperature distribution. It is anticipated that mass-produced measurement systems will deliver substantial economic and societal benefits.
... Relevant research indicates that the temperature measurement performance of full-power and Dick-type radiometers has encountered bottlenecks [14,15]. In recent years, our team and other scholars have begun to research related radiometer architecture [16][17][18][19]. The architecture's sensitivity can be disregarded when in equilibrium. ...
Microwave radiation diagnosis technology can detect thermal changes in skin tissue earlier than anatomical changes, but its detection accuracy is limited by non-target radiation interference in the measurement environment, additional measurement errors of system units, and energy scattering and transmission between skin tissues. This paper aims to address the scientific challenges of analyzing the forward and inversion modelling detection mechanism of layered accurate temperature measurement of human skin tissue based on multi-band. The study focuses on the construction of a pencil beam antenna optimization system, the optimization strategy of high-sensitivity correlated radiometer architecture, and the high-precision multi-band forward and inversion modelling detection algorithm. The key technologies include: (1) A new method of integrated modeling and multi-index optimization of antenna with high directivity and small aperture is proposed, and a priori knowledge-guided neural network of pencil beam distribution is constructed to realize the inversion model of antenna structural parameters; (2) The influence mechanism of high sensitivity correlated radiometer architecture error is analyzed, and a periodic phase shift error correction algorithm based on uniform polar circle is designed; (3) Combining deep learning theory and hyperparameter optimization framework, an iterative model is established, and the objective function modified by the penalty factor is defined to realize a new detection method combining forward and inversion. This paper presents a theoretical foundation for the industrialization of microwave radiation diagnostic technology.
... Relevant research indicates that the temperature measurement performance of full-power and Dick-type radiometers has encountered bottlenecks [14,15]. In recent years, our team and other scholars have begun to research related radiometer architecture [16][17][18][19]. The architecture's sensitivity can be disregarded when in equilibrium. ...
Microwave radiation diagnosis technology can detect thermal changes in skin tissue earlier than anatomical changes, but its detection accuracy is limited by non-target radiation interference in the measurement environment, additional measurement errors of system units, and energy scattering and transmission between skin tissues. This paper aims to address the scientific challenges of analyzing the forward and inversion modelling detection mechanism of layered accurate temperature measurement of human skin tissue based on multi-band. The study focuses on the construction of a pencil beam antenna optimization system, the optimization strategy of high-sensitivity correlated radiometer architecture, and the high-precision multi-band forward and inversion modelling detection algorithm. The key technologies include: (1) A new method of integrated modeling and multi-index optimization of antenna with high directivity and small aperture is proposed, and a priori knowledge-guided neural network of pencil beam distribution is constructed to realize the inversion model of antenna structural parameters; (2) The influence mechanism of high sensitivity correlated radiometer architecture error is analyzed, and a periodic phase shift error correction algorithm based on uniform polar circle is designed; (3) Combining deep learning theory and hyper-parameter optimization framework, an iterative model is established, and the objective function modified by the penalty factor is defined to realize a new detection method combining forward and inversion. This paper presents a theoretical foundation for the industrialization of microwave radiation diagnostic technology.
... Therefore, to diagnose injuries directly at the workplace, in cases of natural or man-made disasters, as well as in military operations, non-contact passive microwave radiometry is preferable. It was noted in [18] that microwave radiometers can provide non-contact temperature monitoring of patients in intensive care units in real time at an appropriate distance, reducing the number of contacts between medical workers and patients. In [19], the possibility of using this diagnostic method simultaneously with a therapy session is shown. ...
... However, practically all methods of implementing the second main approach [17][18][19] have a serious drawback. This disadvantage, as shown in [7], is the lack of an adequate mathematical apparatus that allows describing the state of the diagnosed biosystem with sufficient accuracy. ...
The object of study is a three-layer model of a damaged human body. In the course of the study, it was found that the generally accepted three-layer model of a damaged human body is built, in particular, on the assumption that the characteristics of dressings remain unchanged over time. Therefore, the vast majority of modern research in the field of passive radiometry requires the removal of such materials from the human body during the measurement or considers their characteristics to be unchanged and insignificant. Questions of a possible change in the results of measuring the radiation of the human body due to the use of plaster casts of varying degrees of humidity remain almost unexplored. As a result of the study, the mathematical three-layer model of the damaged human body was refined. An element was introduced into the model that describes the dependence of the attenuation of radio wave energy on the relative humidity of the plaster cast. The refined model makes it possible to increase the accuracy of measuring the temperature of the human body, taking into account the time of applying a plaster cast to it. Unlike the existing ones, the proposed model is based on an experimental study that simulates the measurement of the radiation of a human body with a plaster cast of different degrees of humidity. To refine the model, the obtained experimental data were processed by regression analysis methods. The results of processing the experimental data made it possible to establish the specific type and value of the coefficients of the desired dependence. The use of the obtained results of the study proves the possibility of remote non-invasive express diagnostics of the state of the human body in the presence of plaster-gauze bandages. Providing such an opportunity allows disaster medicine workers to increase the ability to fulfill the so-called “golden hour rule”, as well as to clarify the requirements for a medical radiothermal mapping system
... Microwave radiometer has been widely used in astronomical observation [1], atmospheric remote sensing [2], security sensing [3,4], temperature measurement [5], and other scenarios. Since body temperature is one of the vital signs of the human body and an important indicator to measure the condition of the body, the accurate detection of human body temperature can assist doctors to diagnose and treat patients faster. ...
Human body temperature is a fundamental physiological sign that reflects the state of physical health. It is important to achieve high-accuracy detection for non-contact human body temperature measurement. In this article, a Ka band (32 to 36 GHz) analog complex correlator using the integrated six-port chip is proposed, and a millimeter-wave thermometer system based on the designed correlator is completed for human body temperature measurement. The designed correlator utilizes the six-port technique to achieve large bandwidth and high sensitivity, and miniaturization of the correlator is achieved through an integrated six-port chip. By performing the single-frequency test and the broadband noise measurement on the correlator, we can determine that the dynamic range of input power of the correlator is −70 dBm to −35 dBm, and the correlation efficiency and equivalent bandwidth are 92.5% and 3.42 GHz, respectively. Moreover, the output of the correlator varies linearly with the input noise power, which reveals that the designed correlator is suitable for the field of human body temperature measurement. Then, a handheld thermometer system, with a size of 140 mm × 47 mm × 20 mm, is proposed using the designed correlator, and the measurement results show that the temperature sensitivity of the thermometer is less than 0.2 K.
... New radiometer approaches have attempted to reduce the impact of the receiver in the measured temperature in terms of gain instabilities, system temperature and reflection variations in the interface between the antenna and the human body [27][28][29][30]. The work presented in this paper is aimed at the development of a multifrequency response microwave system for biomedical applications, which retrieves an unknown temperature of the biological tissue or object under investigation. ...
... The set of output voltages enables the recalibration of the receiver, correcting its drifts to perform temperature retrieval. The system noise temperature of a receiver is degraded by the input switch in Dicke topologies [27][28][29][30]. Consequently, the proposed topology includes low-noise amplifiers located just after the antenna to minimize the impact of the receiver. ...
The analysis of near-field radiometry is described for characterizing the internal temperature of biological tissues, for which a system based on multifrequency pseudo-correlation-type radiometers is proposed. The approach consists of a new topology with multiple output devices that enables real-time calibration and performance assessment, recalibrating the receiver through simultaneous measurable outputs. Experimental characterization of the prototypes includes a well-defined calibration procedure, which is described and demonstrated, as well as DC conversion from the microwave input power. Regarding performance, high sensitivity is provided in all the bands with noise temperatures around 100 K, reducing the impact of the receiver on the measurements and improving its sensitivity. Calibrated temperature retrievals exhibit outstanding results for several noise sources, for which temperature deviations are lower than 0.1% with regard to the expected temperature. Furthermore, a temperature recovery test for biological tissues, such as a human forearm, provides temperature values on the order of 310 K. In summary, the radiometers design, calibration method and temperature retrieval demonstrated significant results in all bands, validating their use for biomedical applications.
Останнім часом українські військовослужбовці та члени їхніх сімей дедалі стають центральною темою у засобах масової інформації, привертаючи громадську увагу. Це пов’язано з війною, що йде на території України. У сучасних умовах сім’ї військовослужбовців стикаються з труднощами, що пов’язані зі змінами їхнього соціального статусу. Зараз, проблеми клієнтів цієї категорії посідають важливе місце у соціальній роботі. «Настрій сім’ї» військовослужбовця може бути досить мінливим через різні соціальні кризи, що обумовлені негативними подіями у світі та державі (пандемія та війна). Так, наприклад, у ході соціального супроводу можна бачити поведінкові зміни, що відбуваються в сім’ї військовослужбовця (сварки, насильство, розлучення, внутрішня та зовнішня міграції дружин і дітей, пияцтво тощо). Але, водночас, саме сім’я, у більшості випадках, є тим стримуючим і надихаючим чинником, що має великий позитивний вплив на морально-бойовий дух і, загалом, на всю службову діяльність військовослужбовця.
