Internal Human Body Research Articles

Current-direction-controllable Ag-embedded stretchable layers to enhance and extend the applicability of stretchable sensors

We suggest a multi-layered stretchable sensor with a carbon nanotube (CNT) layer enclosed by an embedded layer of silver (Ag-Ecoflex), and show how it can be used in biomedical applications. The current direction can be controlled along the vertical or lateral axis on the Ag-Ecoflex layer by adjusting the composite Ag ratio; the CNT layer can determine electrical conductivity from the bypassed current path. The multi-layered stretchable sensor can ensure electrical conductivity up to a maximum strain of 245% with a high resistance change of 3782% when Ag-Ecoflex concentration was increased to 60 wt%, showing an electrical resistance of 71.64 Ω/mm along its vertical axis. The sensor functioned normally on a heated state and for up to three weeks on an immersed state possessing a linear characteristic; it can be used for sensor calibration. We confirmed its reliability by 1000 cycles of the strain-release test, detected body motions and tissue swelling, applied it to intravesical cystometric test, and verified compatibility with analog-to-digital conversion in real-time. Resulting, this sensor can secure both high sensitivity and modulus of elasticity, proposing the stability of sensor by simulating the external environment and internal human body. This proposed multi-layered stretchy sensor is anticipated to have a wide range of wearable monitoring device applications.

Versatile magnetic hydrogel soft capsule microrobots for targeted delivery

Maintaining the completeness of cargo and achieving on-demand cargo release during long navigations in complex environments of the internal human body is crucial. Herein, we report a novel design of magnetic hydrogel soft capsule microrobots, which can be physically disintegrated to release microrobot swarms and diverse cargoes with almost no loss. CaCl2 solution and magnetic powders are utilized to produce suspension droplets, which are put into sodium alginate solution to generate magnetic hydrogel membranes for enclosing microrobot swarms and cargos. Low-density rotating magnetic fields drive the microrobots. Strong gradient magnetic fields break the mechanical structure of the hydrogel shell to implement on-demand release. Under the guidance of ultrasound imaging, the microrobot is remotely controlled in acidic or alkaline environments, similar to those in the human digestion system. The proposed capsule microrobots provide a promising solution for targeted cargo delivery in the internal human body.

A Study on Automatic Extraction of Retinal Blood Vessels in Fundus Images

Medical imaging is the practice of visualizing internal human body parts in order to make diagnoses. The discipline of medicine now relies heavily on medical imaging as a tool. Digital image processing and pattern recognition techniques in medical imaging aid in the detection of eye disorders. Changes in retinal Blood Vessels (BVs) are used in retinal image analysis to help diagnose retinal vascular illnesses such Diabetic Retinopathy (DR), Macular Edema, and Glaucoma. The retinal blood vessels are given a brief introduction in this review paper, along with a detailed description of the methods/techniques utilised to segment the retinal blood vessels. This paper also discusses the difficulties in segmenting BVs.

Denaturation of the SARS-CoV-2 spike protein under non-thermal microwave radiation

SARS-CoV-2, the virus that causes COVID-19, is still a widespread threat to society. The spike protein of this virus facilitates viral entry into the host cell. Here, the denaturation of the S1 subunit of this spike protein by 2.45 GHz electromagnetic radiation was studied quantitatively. The study only pertains to the pure electromagnetic effects by eliminating the bulk heating effect of the microwave radiation in an innovative setup that is capable of controlling the temperature of the sample at any desired intensity of the electromagnetic field. This study was performed at the internal human body temperature, 37 °C, for a relatively short amount of time under a high-power electromagnetic field. The results showed that irradiating the protein with a 700 W, 2.45 GHz electromagnetic field for 2 min can denature the protein to around 95%. In comparison, this is comparable to thermal denaturation at 75 °C for 40 min. Electromagnetic denaturation of the proteins of the virus may open doors to potential therapeutic or sanitation applications.

Are TREK Channels Temperature Sensors?

Internal human body normal temperature fluctuates between 36.5 and 37.5°C and it is generally measured in the oral cavity. Interestingly, most electrophysiological studies on the functioning of ion channels and their role in neuronal behavior are carried out at room temperature, which usually oscillates between 22 and 24°C, even when thermosensitive channels are studied. We very often forget that if the core of the body reached that temperature, the probability of death from cardiorespiratory arrest would be extremely high. Does this mean that we are studying ion channels in dying neurons? Thousands of electrophysiological experiments carried out at these low temperatures suggest that most neurons tolerate this aggression quite well, at least for the duration of the experiments. This also seems to happen with ion channels, although studies at different temperatures indicate large changes in both, neuron and channel behavior. It is known that many chemical, physical and therefore physiological processes, depend to a great extent on body temperature. Temperature clearly affects the kinetics of numerous events such as chemical reactions or conformational changes in proteins but, what if these proteins constitute ion channels and these channels are specifically designed to detect changes in temperature? In this review, we discuss the importance of the potassium channels of the TREK subfamily, belonging to the recently discovered family of two-pore domain channels, in the transduction of thermal sensitivity in different cell types.

Ultrasound Imaging Characterization of Soft Tissue Dynamics of the Seated Human Body.

To characterize the dynamics of internal soft organs and external anatomical structures, this paper presents a system that combines medical ultrasound imaging with an optical tracker and a vertical exciter that imparts whole-body vibrations on seated subjects. The spatial and temporal accuracy of the system was validated using a phantom with calibrated internal structures, resulting in 0.224 mm maximum root-mean-square (r.m.s.) position error and 13 ms maximum synchronization error between sensors. In addition to the dynamics of the head and sternum, stomach dynamics were characterized by extracting the centroid of the stomach from the ultrasound images. The system was used to characterize the subject-specific body dynamics as well as the intrasubject variabilities caused by excitation pattern (frequency up-sweep, down-sweep, and white noise, 1-10 Hz), excitation amplitude (1 and 2 m/s2 r.m.s.), seat compliance (rigid and soft), and stomach filling (empty and 500 mL water). Human subjects experiments (n = 3) yielded preliminary results for the frequency response of the head, sternum, and stomach. The method presented here provides the first detailed in vivo characterization of internal and external human body dynamics. Tissue dynamics characterized by the system can inform design of vehicle structures and adaptive control of seat and suspension systems, as well as validate finite element models for predicting passenger comfort in the early stages of vehicle design.

Virtual Anatomical and Endoscopic Exploration Method of Internal Human Body for Training Simulator.

BackgroundVirtual environments have brought the use of realistic training closer to many different fields of education. In medical education, several visualization methods for studying inside the human body have been introduced as a way to verify the structure of internal organs. However, these methods are insufficient for realistic training simulators because they do not provide photorealistic scenes or offer an intuitive perception to the user. In addition, they are used in limited environments within a classroom setting.MethodsWe have developed a virtual dissection exploration system that provides realistic three-dimensional images and a virtual endoscopic experience. This system enables the user to manipulate a virtual camera through a human organ, using gesture-sensing technology. We can make a virtual dissection image of the human body using a virtual dissection simulator and then navigate inside an organ using a virtual endoscope. To improve the navigation performance during virtual endoscopy, our system warns the user about any potential collisions that may occur against the organ's wall by taking the virtual control sphere at the virtual camera position into consideration.ResultsExperimental results show that our system efficiently provides high-quality anatomical visualization. We can simulate anatomic training using virtual dissection and endoscopic images.ConclusionOur training simulator would be helpful in training medical students because it provides an immersive environment.

A Survey on Brain Tumor Detection and Segmentation from Magnetic Resonance Image

Even with tremendous advancement in medical technology tumor segmentation remain most tedious and complex work for doctors. Magnetic Resonance Imaging (MRI) is the most commonly used technique by the radiologist for inspection of internal human body parts without any dissection, but manual inspection consumes time and precious work hours. A possible solution for early detection of diseases such as a tumor, cancer can be computer-aided image analysis. Precise computerized classification of brain tumor form the MRI image is very important as it will lead to early detection, reduction in work hour and mistakes, propagation of automation in tumor removal and will also help to decide the course of treatment. Considering the difficulties, this work is aimed to highlight the techniques proposed in contemporary literature by summarizing the novel facts of research.

Effect of sitting posture and seat on biodynamic responses of internal human body simulated by finite element modeling of body-seat system

This study aimed at developing a detailed three-dimensional (3D) finite element (FE) model of the body-seat system to investigate the effect of sitting posture and seat on the biodynamic responses of internal human body under vertical white noise excitation. Three postures of human models (vertical seated body (VSB), reclined seated body (RSB), and seated body in driving posture (DSB)) and three different stiffness seats were modeled. The initial boundary condition between human body and seat for biodynamic response analysis was obtained by static analysis of the body-seat system under the action of gravity. Random response analysis was performed under white noise excitation at 0–20 Hz in the vertical direction by a modal superposition method. Principal responses of lumbar intervertebral discs (LIDs) in VSB were in the range of human body natural frequencies. The damping ratio greatly decreased the peak response values of LID. When compared with the supports of the elastic seat in VSB, those of the elastic seat in RSB increased the peak response frequencies of LID in the anterior-posterior direction and decreased them in the vertical direction, thus making them equal in both directions. Compared to RSB, DSB not only increased the peak response frequencies but also changed the peak response values. The principal response frequencies of LID in both directions increased with the increase in seat stiffness. The proposed FE model of biodynamic random response analysis is a new fundamental method for gaining insights on the responses of internal human body to vibrations and can be used to investigate the responses of the human body-seat system instead of conducting experiments to evaluate the dynamic characteristics of newly designed seats and guide the design of seats for reducing the injury risk of the lumbar spine.

Study on Temperature Measurement Using MRI during Acupuncture and Moxibustion

SUMMARYIn the field of traditional oriental medicine, two types of treatment style, which are acupuncture treatment and moxibustion treatment, have been performed. These treatments are used and effected by doctors or acupuncturists in their clinic or hospital and widely spread. Although such a general treatment, mechanism of heat transfer modality and temperature distribution in the treatment of moxibustion is not deeply discussed. Also, temperature distribution of deep human tissue during acupuncture treatment is not discussed. It is derived from the difficulty of noninvasive measurement of internal human body with small change of electromagnetic wave signals noninvasively. In this study, a temperature distribution for acupuncture and moxibustion treatment is measured and analyzed using thermography and MRI by measuring the phase of longitudinal relaxation time of protons. The experimental results of measured temperature distribution under the human legs have been demonstrated. The result of temperature analysis in the human body is also reported.

Calculation of Human Body Resistance at Power Frequency Using Anatomic Numerical Human Model

Contact current flows through the human body when a high voltage line worker touches a distribution line that results in a high potential difference. In most cases it is difficult to measure how much contact current flows in the body. But, it is possible to determine the contact current easily if the body impedance between the two points of contact is known. Recently, development of an anatomic numerical human model with high resolution, and advancement of computer technology, have made calculations using such human models possible. We intend in this study to establish the electrical properties of a numerical model. The internal human body resistance between left wrist and left ankle, which was the typical current pathway at 60Hz, was calculated using the model. From this result, partial resistance and current density on the cross-sectional plane of the body model can be visually viewed. The calculated value of the internal human body resistance was 1181Ω and had a value of about 2-fold compared to the 500-700Ω value given in measurement results. Further work is necessary to fully understand the cause of this discrepancy, however some possible reasons are discussed.

Using oscillation voltage to drive dynamic-domino circuits for designing low-power bio-implanted electronics

Power supply is a key constraint for designing bio-implanted electronic devices. Most conventional internal bio-electronic systems are expected to produce power through wirelessly transmitted technology. However, due to the low efficiency of wireless transmission, the technology cannot be validated. Current generic static CMOS circuits require a constant-level voltage (DCVdd) supply – otherwise, the circuits will malfunction. This work demonstrates that the oscillation voltage (OscVdd) can be directly applied to low-speed dynamic-domino circuits. We successfully designed a test chip that uses OscVdd (validated by TSMC 0.18μm technology). Compared to DCVdd, OscVdd chips allow for a 68% reduction of dynamic power consumption. With the latch functionality enabled, the OscVdd chip results in a further 42% reduction of power consumption. Therefore, wireless inductive power can be broadly used for future bio-electronics internal human body medical care applications, which are designed by using dynamic-domino circuits.

MRIによる鍼灸施術時の温度分布測定

SUMMARY In the field of traditional oriental medicine, two types of treatment style, which are acupuncture treatment and moxibustion treatment, have been performed. These treatments are used and effected by doctors or acupuncturists in their clinic or hospital and widely spread. Although such a general treatment, mechanism of heat transfer modality and temperature distribution in the treatment of moxibustion is not deeply discussed. Also, temperature distribution of deep human tissue during acupuncture treatment is not discussed. It is derived from the difficulty of noninvasive measurement of internal human body with small change of electromagnetic wave signals noninvasively. In this study, a temperature distribution for acupuncture and moxibustion treatment is measured and analyzed using thermography and MRI by measuring the phase of longitudinal relaxation time of protons. The experimental results of measured temperature distribution under the human legs have been demonstrated. The result of temperature analysis in the human body is also reported.

Toward wearable wireless thermometers for internal body temperature measurements

This article overviews the motivations and challenges for non-invasive wireless measurements of internal human body temperature. Microwave radiometry is an attractive method for internal thermometry, with the possibility of a wearable device that can continuously monitor temperature inside body tissues in different parts of the body, store the data, and transmit it to a digital medical record. Currently, there are a limited number of available device solutions, and they are usually not wearable or wireless. Here we discuss a possible path to implementing such a thermometer, with some initial results demonstrating about 0.2 K measurement sensitivity, and a difference between the maximal and minimal error w.r.t. a thermocouple measurement of 0.5 K. Several probes for multi-band radiometers are also presented at frequencies of 410 MHz, and 1.4, 2.7, and 4.9 GHz. The main challenges of RF interference, sensitivity, calibration, spatial resolution, miniaturization, and probe design are discussed.

3D Surface Reconstruction of Coronary Artery Trees for Vessel Locations’ Detection

Surface reconstruction is rarely been investigated to reconstruct 3D surfaces from data obtained from the internal human body organs. The 3D cloud of points can view objects in R3 space, however, it will not clearly demonstrate the curvatures of the outside of objects. Our 3D clouds of points are obtained from coronary artery trees. Each single-view angiogram can produce a 3D coronary artery tree. An approach to reconstruct 3D-oriented surfaces of 3D coronary artery trees is proposed. The approach leverages the Poisson problem for 3D surfaces from oriented data. The approach does not require the establishment of topological relations between adjacent points and involves no implicit parameter fitting. The approach consists of three stages: first, calculation of Euclidean distances between the clouds of points. Second, 3D-oriented data structuring. Finally, Poisson surface reconstruction of the 3D-oriented data (oriented cloud of points). An additional stage is added to measure the curvatures inside the 3D surfaces. Experimental evaluation has been done to raw of clinical data sets and results revealed that the proposed approach is efficient to reconstruct 3D surfaces of coronary artery trees. Results show that our proposed approach has high robustness for a variety of 3D cloud of points. The output surface can clearly display all the details and curvatures of the cloud of points. Our proposed algorithm of surface reconstruction plus the curvatures estimation is able to automatically indicate the locations of arteries and warn specialists of any abnormal medical cases of artery’s penetration inside the heart.

‘It's a personal thing': visitors' responses to Body Worlds

von Hagens' Body Worlds is a traveling exhibition that allows the public to experience the internal human body through the use of plastinated cadavers. Visitor responses to Body Worlds have been mixed – ranging from awe and fascination to disgust. Some feel that the exhibition is undignified and disrespectful to the human body. Others marvel at the beauty and complexity of the human body and the ability to see such detail. This study investigates visitor responses and meaning-making to a controversial exhibition, Body Worlds. Using a naturalistic, qualitative case study approach, three highly personal visitor responses emerged: (1) personal narratives; (2) validations; and (3) transpositions. Our study suggests that the personal context of learning in informal settings is central to visitor meaning-making for visitors to exhibitions of this type. In particular, personal histories and strong emotional responses were pervasive. We infer that by encouraging personal connections to exhibits, science centers may enhance visitor meaning-making.

MARVEL IN VIVO WIRELESS VIDEO SYSTEM

This article describes the design, optimization, and prototype testing of a Miniature Anchored Robotic Videoscope for networked Expedited Laparoscopy (MARVEL), which is a camera module (CM) that features wireless communications and control and is designed to decrease the surgical-tool bottleneck experienced by surgeons in state-of-the art Laparoscopic Endoscopic Single-Site (LESS) minimally invasive abdominal surgery. Software simulation is utilized to characterize the internal human body (in vivo) wireless channel to optimize the antenna, transceiver architecture, and communication protocols between multiple CMs. A CM research platform has been realized that includes: a near-zero latency video wireless communications link; a pan/tilt camera platform, actuated by two motors, which provides surgeons a full hemisphere field of view inside the abdominal cavity; a small wireless camera; an illumination control system; wireless controlled focus; digital zoom; and a wireless human– machine interface (HMI) to control the CM. An in vivo experiment on a porcine subject has been carried out to test the performance of the system and features, with the exception of recently added autofocus and digital zoom. MARVEL is a research platform for a broad range of experiments for faculty and students in the Colleges of Engineering and Medicine at USF and at Tampa General Hospital.

Three-dimensional human body model reconstruction and manufacturing from CT medical image data using a heterogeneous implicit solid based approach

This paper presents a simple and effective method for reconstructing 3D bio-CAD models from a sequence of computer tomography (CT) medical image data. In this work, a heterogeneous implicit solid representation method is proposed to describe a heterogeneous model of the human body. The use of implicit solid as a basis for 3D bio-CAD models facilitates the robustness and simplification of the process for converting CT images to a 3D bio-CAD model. An almost perfect 3D bio-CAD model is achieved from implicit solid interpolation combined with domain decomposition. The implicit solid is defined by a radial basis function which is a continuous scalar-value function over the domain R3. The generated solid consists of the set of all points at which this scalar function value is the Houndsfield unit (HU) value obtained from the CT image. CT images of human bone were used as the case studies for the reconstruction of the 3D solid model from CT scan data. Experimental results show that the proposed method has the potential to represent internal human body details accurately and efficiently suitable for rapid prototyping, finite element analysis, and tissue engineering.

Numerical Calculation of Internal Human Body Resistances at Power Frequency, and Comparison of them with Experimental Ones

A numerical method, which is newly developed here, is used in order to calculate internal body resistances in a voxelized biological model. By using this method, the internal resistances of an anatomical human model were calculated for the two current paths: 1400 Ω for a hand to foot, and 1500 Ω for a hand to hand. They are compared with experimental ones (500 ∼ 600 Ω for the hand to foot and 500 ∼ 700 Ω for the hand to hand), resulting in the conclusion that the numerical values of the internal resistance are twice or three times higher than the experimental ones. While there is the discrepancy between the calculated and measured results in the absolute values, the profiles of their relative values along the current paths showed good agreement. This implies that the factors such as the anisotropy of muscle conductivity and the difference between in vivo and in vitro conductivities need to be considered. In fact, in consideration of those factors, the calculated results approached the experimental ones.

Effects of Electrode Systems on Numerical Estimation of Internal Human Body Impedance at Power Frequency

AbstractInternal body impedances Ri of an anatomically realistic human model were numerically calculated at 60 Hz under various current scenarios and electrode sizes. On the basis of the numerical results, the effects of electrode systems on Ri were investigated. It is found that Ri obtained for a two‐electrode model are larger than those for a four‐electrode model by a factor of up to about 1.3. This means that the body impedances measured by using the four‐wire method are smaller than the calculated ones by up to about 23%. At the end, it is concluded that, although the difference in the electrode systems is a cause of the disagreements between the calculated and measured body impedances, its effect is insufficient to fully reconcile the actual disagreements. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.