Properties Of Human Body Tissues Research Articles

Simulation of Magnetotargeting of Medicines Based on the Calculation of Permeability of Human Tissues by the Electromagnetic Field

Analysis of studies in the field of targeted delivery of drugs, genes and stem cells showed a low level of accuracy of both applied and practical research in this area. Sufficiently encouraging results were obtained with extracorporeal electromagnetic action on a pharmacological complex with a ferromagnetic nanoparticle. With this approach, it is rather difficult to implement the algorithm for introducing the drug into the topographic region (target organ), since in practice, approaches to the clinical application of drug transport technology, taking into account the physicochemical properties of human body tissues, have not been studied in detail. The available models represent various physical and mathematical approaches that do not take into account the bioelectrical and electrostatic properties of the tissues of the organisms of experimental animals and humans. The creation of algorithms and software simulation of this technology will allow calculating variable frequency variables for magnetotargeting in a human digital phantom, which will reduce time spent at the stage of pilot and clinical trials and in the future will form the applied part of the innovative technology. The article presents the methodology and results of multiphysics and mathematical modeling in the Sim4Life for Science, V7.0 package on the example of calculating the control parameters of the electromagnetic field of the region in the area of normal administration of drugs – the vessels of the forearm.

Model of the Impact of Focused Ultrasound on Biological Tissues

To study tissue permeability under extracorporeal exposure to various types of radiation, it is necessary to use multiphysical and mathematical modeling of all stages of the technology being developed, taking into account the dielectric and acoustic properties of human body tissues. The technologies used in medicine with focused ultrasound often have a high level of artifacts in the visualization of diagnostic studies and complications during therapy. When modeling exposure to focused ultrasound, the applied solvers must take into account pressure wave propagation, density changes and jumps, non-linearity and diffusion losses that occur in human tissues, and offer simulation of acoustic propagation in inhomogeneous installations in near real time. The article presents the results of multiphysics and mathematical modeling in the Sim4Life for Science V7.0 package using a full-wave acoustic solver (P-ACOUSTICS) of modern computational acoustics.

Thermal and Acoustic Properties of Agar Phantom Fabricated from Agar Powder

We present in this paper, step by step procedure in obtaining Agar Phantom from Agar Powder and degassed water using specified bioinstruments, therewith subsequently demonstrate by the Step - Wise Transient Method (STM), how the manufactured (TMM) was utilized in identifying the thermal, and acoustic properties of the fabricated material. TMMs are materials which mimic human body tissues, and as human body tissues are not readily easy to come by, Agar Agar has been used for fabrication of this suitable alternative to simulate the properties of human body tissues in certain medium. Keywords: Phantom, Transducer, Agar, Ultrasound, Step - wise Transient Plane Source (STPS) Method. DOI: 10.7176/ISDE/12-1-05 Publication date: March 31 st 2021

PERFORMANCE OF AN IMPLANTED ELECTRICALLY COUPLED LOOP ANTENNA INSIDE HUMAN BODY

Implanted antennas are widely used in hyperthermia and biomedical applications. The antenna needs to be extremely small while maintaining a permissible Speciflc Absorption Rate (SAR) and being able to cope with the detuning efiects due to the dielectric properties of human body tissues. Most of the proposed antennas for implanted applications are electric fleld antennas such as Planner Inverted-F Antennas (PIFA) and micro-strip patch antennas. By minimizing the size of an electric fleld antenna, the near zone electric fleld will increase, resulting in higher SAR. This work is devoted to design a miniaturized magnetic fleld antenna to overcome the above limitations. The proposed electrically coupled loop antenna (ECLA) has high magnetic fleld and low electric fleld in the near zone and therefore, has a small SAR and is less sensitive to detuning efiects. ECLA is designed at the Medical Implanted Communication Service (MICS) band with dimensions of (5£5£3mm 3 ). ECLA has been simulated inside one-layer human body model, three-layer spherical human head model, human head and human body. From the simulation results, ECLA inside the human body has a 5MHz{3dB bandwidth, i14dB gain, and radiation e-ciency of 0.525%. The 1g average SAR inside the human body for 10mW input power is about 1W/kg which is 7times lower than the SAR for a patch antenna of the same size with the same accepted power.

Developing a bio-mechanotronic probing system for estimating soft tissue Young’s modulus in vivo

In many medical applications such as rehabilitation, clinical palpation, and manipulation of organs, it is important to characterize soft-tissue properties accurately. This paper presents a bio-mechatronic probing system that could be used for estimating soft tissue Young’s modulus in vivo. The system employs an electromagnetic spatial displacement sensor. The accuracy and reliability of the system were investigated. In addition, the effect of indentation rate on the variation of the values of the measured effective Young’s modulus was also studied. A series of elastomers with different Young’s modulus (ranged from 13.08 to 36.19 kPa) were assessed with both the probing system and a Hounsfield material testing machine. Intra-individual and inter-individual variations of the system were tested by five independent operators. The probing system was applied to assess the effective Young’s modulus of human body parts in vivo. Fifteen healthy female subjects with age of 22.5 ± 4.3 years old were included for the in vivo test. The system was shown to be highly accurate (R2 = 0.995) in comparison with the results obtained by the mechanical testing machine and had good reliability (intra-individual variation = 5.43%, inter-individual variation = 5.99%). The average effective Young’s modules of the region of umbilicus were 13.33 and 10.71 kPa for two different sites, respectively. Based on the results obtained, it is believed that this probing system was an accurate and reliable tool for rapidly assessing the mechanical properties of human body tissues in vivo.

A Hand-Held Indentation System for the Assessment of Mechanical Properties of Soft Tissues In Vivo

Quantitative assessment of the mechanical properties of soft tissues <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">vivo</i> is required in both clinical and research fields. This paper introduces a hand-held indentation system that employed an electromagnetic spatial sensor as a displacement transducer. The system was pen-sized, portable, and easy to control. The accuracy and reliability of the system were investigated. The effect of indentation rate on the variation of the values of the measured effective Young's modulus was also studied. A series of elastomers with different Young's modulus (which ranged from 13.08 to 36.19 kPa) were assessed with both the hand-held indentation system and a Hounsfield material testing machine. Intraindividual and interindividual variations of the system were tested by five independent operators. The hand-held indentation system was applied to quantitatively assess the effective Young's modulus of human body parts <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">vivo</i> . Twenty healthy female subjects aged 21.1 plusmn 1.8 years old were included for the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">vivo</i> test. The system was shown to be highly accurate ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> = 0.99) compared with the results obtained by the mechanical testing machine and had good reliability (intraindividual variation = 5.43%, and interindividual variation = 5.99%). The average effective Young's moduli of the region of umbilicus were 11.31 and 12.65 kPa for two different sites, respectively. It is believed that this hand-held indentations system was an accurate reliable tool for rapidly assessing the mechanical properties of human body tissues <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">vivo</i> .

Effects of Dielectric Parameters of Human Body on Radiation Characteristics of Ingestible Wireless Device at Operating Frequency of 430 MHz

In order to assess the sensitivities of the radiation characteristics and the compliance of ingestible wireless device (IWD) in human body due to the uncertainty and intersubject variability of dielectric properties of human body tissues, the specific absorption rate (SAR) and radiation characteristics of the IWD in two realistic human body models with changed and unchanged dielectric values are quantitatively compared using the finite-difference time-domain method. Simulations are carried out in 13 scenarios where the IWD is placed in the center positions of abdomens in the two body models at the operating frequency of 430 MHz with three orientations. Results show that the variation of radiation intensity near the surface of abdomen is around 2.5 dB within 20% variation of dielectric values. The maximum SAR values increase with the increase in conductivities of human body tissues and decrease with the increase in relative permittivities of human body tissues. A variation of up to 20% in conductivities and relative permittivities, alone or simultaneously, always causes a variation of SAR to be less than 10%. As far as the compliance of safety is concerned, the maxima of 1-g-averaged and 10-g-averaged SARs can reach 3.16 and 0.89 W/kg at the input power of 25 mW.