Human Body Surface Research Articles

A Practical Algorithm to Improve Tracking Accuracy of Symmetric Body Surface Using Optical Surface Imaging System

The human body surface has a property of right-left symmetry. Some anatomical sites, such as breasts, legs, and arms, also possess rotational symmetry. This geometric symmetry constitutes a difficult technical barrier for 3D scanner-based optical surface imaging systems. Such systems only measure the distance between the interrogation light source and points of interest on the body surface. Because of this, these systems are unable to differentiate those points on the body surface that move along the symmetry direction or rotate about the symmetry axis simultaneously. This technical limitation hinders their applications on symmetric body surfaces. To overcome this technical barrier, we have developed an algorithm which can calculate a surface-specific region of interest (ROI) for accurate surface tracking. Our algorithm consists of 6 steps: 1) remove background noise; 2) create a seed ROI; 3) add a maximal margin to the seed ROI; 4) rectify ROI overexpansion; 5) eliminate flat topography; and 6) maximize asymmetry and height differences of ROI. Briefly, the algorithm starts by cutting off irrelevant surfaces, including floor, couch, head, lower body, and immobilization devices. A square seed ROI is computed and centered on isocenter, assigned an initial size of 80x80 mm in x and y-axis. The algorithm searches for the maximal and minimal height (z-axis) within it. Thereafter, a 200 mm growth margin is added to the seed ROI. The algorithm compares z-values of two neighboring points in the new ROI. If they are significantly different, then there is a change in topographic feature. ROI grows and repeats the same operation along this direction. The algorithm stops if z-values are too close. The algorithm may expand into body lateral side. To avoid it, a z-value thresholding technique is used so that points with a height lower than the set threshold are eliminated. Two additional thresholding techniques are employed to eliminate a surface with very flat topography. Finally, a symmetry break-up loop is used to maximize the asymmetry and height standard deviation of the ROI. To speed up algorithm performance and circumvent unexpected noise features (such as mask and sheet), the idea of contour line is used in the algorithm. With the ROIs generated by our algorithm, it was found that our optimized asymmetric ROIs were more effective and accurate in detecting shifts by symmetric body surfaces than using symmetric ROIs. It is particularly effective and sensitive in detecting rotational shifts by body surfaces with a rotational symmetry. For optical surface imaging systems, poorly defined large ROIs may produce stable, but often wrong tracking results. This problem is particularly pronounced for symmetric surfaces, such as the breast surface. Our novel concept of optimized asymmetric ROI with a limited size is extremely valuable for real-time patient local tracking applications.

A pyroelectric generator as a self-powered temperature sensor for sustainable thermal energy harvesting from waste heat and human body heat

Conversion of temperature fluctuations to useable electrical energy is rendered by the pyroelectric effect. Waste of heat in our day to day environment and in industrial sector constitutes an abundant source of energy. Herein, we report a pyroelectric generator (PyG) that produces pyroelectric output up to 1.5 V and 1.5 µA. Its power density is 0.034 µW/cm2 upon exposure to heat-cool condition for a temperature variation from 310 K to 340 K. Due to the fast response time (121 ms) of the PyG, it is expected to be use as a self-powered temperature sensor. The generated electricity could also be stored in a capacitor up to 0.8 V in three heating–cooling cycles. It has been also demonstrated that PyG is possible to drive by water vapour where energy-consuming alternating devices is not necessary. The temperature oscillation achieved by spontaneous water condensation and evaporation from the surface of the PyG that produces open-circuit voltage of 1.6 V for a temperature variation from 303 K to 333 K. Thus the PyG driven by water vapour supports an efficient retrieval of energy from hot water vapour, which is wasted mostly. The linear increment of voltage as a function of temperature indicates PyG is also suitable to use a temperature sensor that may also work in self-powered mode. In addition, the PyG can also harvest the waste body heat, i.e., heat dissipation from human body surface and from the process of respiration. That promises an effective self-powered temperature sensor that might be useful in healthcare monitoring, safety and security sectors.

Simulation and analysis of airbag parameter variation under different gas flows

In order to improve the accuracy of the airbag-based flexible robot in simulating the human body, and make its surface fit the human body surface better. For the balloon filled airbag in flexible robot, the process of airbag parameters under different gas flow is simulated and analyzed. First, for the traditional airbag inflatable simulation method ignoring the different gas volume flow on the impact of airbag deformation. The air bag inflation control model based on gas volume flow is constructed, the pressure of the airbag inflated is optimized by calculation of gas mass flow simulation inflation and leakage. Finally, the grid unit is used to divide the internal volume of the airbag, and its discrete optimization is carried out to simulate the expansion of the airbag. The simulation results show that the simulation method proposed in this paper can complete the process of spherical airbag. The maximum safety pressure of the airbag and the corresponding temperature are obtained from the simulation results, which can provide the theoretical basis for the surface fitting of the flexible garment fitting robot based on airbag.

Area-Averaged Transmitted Power Density at Skin Surface as Metric to Estimate Surface Temperature Elevation

In the international guidelines/standards for human protection, the specific absorption rate (SAR) is used as a metric to prevent excessive surface temperature elevation at frequencies up to 3 or 10 GHz. Above that transition frequency, including the frequency region assigned to 5th generation wireless communication systems, an area-averaged incident power density on human body surface is used as the physical quantity to specify the restrictions on human exposure to electromagnetic fields. However, the incident power density is an external physical quantity, resulting in frequency-dependent temperature elevation, which is attributable to frequency-dependent variations in the reflection coefficient at the skin surface and energy penetration depth into tissue. In this paper, we discuss analytically and computationally the effectiveness of the transmitted power density (TPD) at the skin as a new metric to estimate the steady-state skin temperature elevation above the transition frequency. We also consider simplified models for uniform and Gaussian beam patterns and the analytical solutions to the bioheat equation for an one-dimensional model, which are in good agreement with numerical solutions. These show that the TPD provides an excellent estimate of skin temperature elevation through the millimetre-wave band (30-300 GHz) and a reasonable and conservative estimate down to 10 GHz, whereas the SAR is a good metric below 3 GHz. Computational results for the dipole and patch antenna arrays demonstrated that the one-dimensional analysis is conservative metric as compared with the TPD averaged over the area of 4 cm2 (2-cm square). Considering extreme cases, averaging area smaller than 4 cm2 is needed above 30 GHz for beam exposure with small diameters. Finally, we consider the choice of averaging area as related to peak temperature increases for small beams. For extremely small exposure areas, limits on peak power density may be needed.

The method of suppressing spatial filter output noise-power gain for cardiac electrical activity imaging

For non-invasive imaging of cardiac electrical activity using magnetocardiogram (MCG) data measured on human body surface, a key problem that needs to be solved is to enhance the spatial resolution of reconstructing distributed current source dipole moment strength in MCG imaging. In this paper, a beamforming method of suppressing spatial filter output noise-power gain (SONG) is proposed based on the minimum variance beamforming (MVB). The purpose is to improve the resolution of the distributed source dipole moment strength reconstruction, i.e., the ability to resolve the source for distributed current source spatial spectrum estimation, in order to enhance the resolution of the cardiac electrical activity magnetic imaging. The method offers a new spatial filter weight matrix by using a low-trace positively-semidefinite matrix that will affect the spatial filter output power, on the premise that the influence of noise spatial spectrum of spatial filter on the estimation of current source spatial spectrum has been constrained by the noise spatial spectrum intensity normalization. The positively-semidefinite matrix is specially constructed to satisfy the condition that the eigenvalue is not greater than 1 and the trace of the matrix is lower than its order, so that it can be used to constrain the spatial filter output noise-power gain for improving the robustness to noise of the source spatial spectrum estimation. In addition, a classical model of the horizontally layered conductor is used as the heart-torso model to calculate the lead-field matrix that needs to be used in source spatial spectrum estimation. The results obtained in this study are as follows. For validating the proposed method, a theoretical analysis and simulation tests of the current source reconstruction are performed, where the SONG and MVB methods are compared and a parameter of the signal-to-noise ratio is considered according to the realistic MCG data. In this paper we also give the cardiac electrical activity imaging of 36-channel cardiac magnetic field data of single-cycle from two healthy people, where a heart profile from the magnetic resonance imaging is used as a reference and adjusted to the MCG measurement system. The results show that the SONG method has ability to better resolve the current source and can observe the significant electrophysiological characteristics such as the strong electrical activity in the ventricles of the healthy people at the time of Rpeak. In summary, our proposed method can improve the visual effect of the cardiac electrical activity imaging, when the signal-to-noise ratio of the single-cycle cardiac magnetic signal is not lower than 10 dB. Therefore, this method of measuring the non-invasively imaging cardiac electrical activity is a promising one and helpful for relevant medical research and applications.

MicroRNAs in mucosal inflammation.

Of the total human body's surface, the majority is internal surface, belonging to the lungs (100m2) and intestinal tract (400m2). In comparison, the external surface area, belonging to the skin, comprises less than 1% (2m2). Continuous exposure of the mucosal surface to external factors (e.g., pathogens, food particles) requires tight regulation to maintain homeostasis. MicroRNAs (miRNAs) have gained noticeable attention as playing important roles in maintaining the steady-state of tissues by modulating immune functions and inflammatory responses. Accordingly, associations have been found between miRNA expression levels and human health conditions and diseases. These findings have important implications in inflammatory diseases involving pulmonary and intestinal mucosa, such as acute lung injury or inflammatory bowel disease. In this review, we highlight the known biology of miRNAs and discuss the role of miRNAs in modulating mucosal defense and homeostasis. Additionally, we discuss miRNAs serving as potential therapeutic targets to treat immunological conditions, particularly mucosal inflammation.

Noise Reduction of 3D Human Body Surface Reconstruction Algorithm and Surface Continuous Optimization

Noise Reduction of 3D Human Body Surface Reconstruction Algorithm and Surface Continuous Optimization

A Framework for Analyzing the Whole Body Surface Area from a Single View

We present a virtual reality (VR) framework for the analysis of whole human body surface area. Usual methods for determining the whole body surface area (WBSA) are based on well known formulae, characterized by large errors when the subject is obese, or belongs to certain subgroups. For these situations, we believe that a computer vision approach can overcome these problems and provide a better estimate of this important body indicator. Unfortunately, using machine learning techniques to design a computer vision system able to provide a new body indicator that goes beyond the use of only body weight and height, entails a long and expensive data acquisition process. A more viable solution is to use a dataset composed of virtual subjects. Generating a virtual dataset allowed us to build a population with different characteristics (obese, underweight, age, gender). However, synthetic data might differ from a real scenario, typical of the physician’s clinic. For this reason we develop a new virtual environment to facilitate the analysis of human subjects in 3D. This framework can simulate the acquisition process of a real camera, making it easy to analyze and to create training data for machine learning algorithms. With this virtual environment, we can easily simulate the real setup of a clinic, where a subject is standing in front of a camera, or may assume a different pose with respect to the camera. We use this newly designated environment to analyze the whole body surface area (WBSA). In particular, we show that we can obtain accurate WBSA estimations with just one view, virtually enabling the possibility to use inexpensive depth sensors (e.g., the Kinect) for large scale quantification of the WBSA from a single view 3D map.

High Precision Infrared Temperature Measurement System Based on Distance Compensation

To meet the need of real-time remote monitoring of human body surface temperature for optical rehabilitation therapy, a non-contact high-precision real-time temperature measurement method based on distance compensation was proposed, and the system design was carried out. The microcontroller controls the infrared temperature measurement module and the laser range module to collect temperature and distance data. The compensation formula of temperature with distance wass fitted according to the least square method. Testing had been performed on different individuals to verify the accuracy of the system. The results indicate that the designed non-contact infrared temperature measurement system has a residual error of less than 0.2°C and the response time isless than 0.1s in the range of 0 to 60cm. This provides a reference for developing long-distance temperature measurement equipment in optical rehabilitation therapy.

Human action recognition with skeleton induced discriminative approximate rigid part model

Human action recognition has a long research history. Despite various approaches have been designed in the last decades, it still remains challenging in computer vision and pattern recognition. In this paper, we present a skeleton induced discriminative approximate rigid part model for human action recognition, which not only captures the geometrical structure of human body, but also takes rich human body surface cues into consideration. In conventional approaches, the joint feature and the surface feature are discussed separately. While, in our proposed approach, the structural information is embedded into the surface model. In addition, to separate different approximate rigid parts generated from different human activities, a novel sparsity induced feature selection scheme is introduced. This scheme produces a discriminative feature subspace that can best separate different action classes. The presented approach is validated on two widely adopted benchmark datasets, i.e. the MSR Daily Activity 3D Dataset and the MSR Action 3D dataset. Experimental results demonstrate the effectiveness of our approach.

Multi-layer low frequency tissue equivalent phantoms for noninvasive test of shallow implants and evaluating antenna-body interaction.

In this work, a tissue equivalent compound phantom with dielectric properties equivalent to an average human body surface has been developed for a low frequency operating range of 30 MHz to 200 MHz. The compound phantom consists of skin, fat, and muscle layers respectively. The phantom is simple to fabricate with low cost components. A custom coaxial test fixture has been developed to characteristic phantom dielectric properties, which eliminates use of a specialized expensive dielectric measurement probe. The proposed composite phantom can be used as a noninvasive technique to evaluate shallow biomedical implants, antenna-body interaction, and specific absorption rate of tissue media.

Electrophysiocardiogram: For the first time EPCG has been recorded on human body surface

Since ECG was invented in 1903, this is the first time in history that a full information multi-band and multi-linear electrophysiological cardiogram has been used to successfully scan and record on the human body surface. Since it is able to record various multi-band, multi-track linear electric signals of cardiac electrophysiological activities that correspond to different regions of the entire heart, it has thus been denominated as “electrophysiocardiogram” (EPCG). A traditional ECG is always represented by a characteristic wave form, which resembles a string. For a long period of time, ECG has had a lot of mysteries surrounding it, it maybe because ECG has a lot of mixed signals buried in such convolutionary forms, which limits the amount of the signals that are discernable and determinable. For the first time, the EPCG technology has allowed cardiac signals to be convoluted into the linear wave form, which is then processed through various new approaches featuring multiple frequency bands, multiple dimensions and multiple patterns, and consequentially recorded as the following types of signals within the ranges of P wave and T wave: multiple frequency band signals, signals of different regions and different locations, forward waves and negative waves. Therefore, EPCG may help to solve many puzzling scientific questions regarding heart, such as exactly how many electric signals are involved in heart excitation, pacing, conduction and action, as well as many other intriguing questions about heart, and thus would become a very helpful tool in clinical practice.

EDITORIAL

The editorial of Engenharia Térmica of this issue continues the discussion on scientific research needs in vital areas in which thermal engineering has important participation. The main goal is to motivate the readers, within their specialties, to identify possible subjects for their future research. With the development of modern high resolution infrared cameras, the utilization of thermal imaging exams has gained new appeal in medical practice, although the method has been applied for the first time more than 60 years ago. The technique is noninvasive, there is no ionizing radiation emission, low cost, fast in image capturing and of easy application. However, there are some aspects such as method imprecision due to the individual metabolism and surrounding ambient temperature that interfere in precise results, making the method subjective. In Engineering it is a well established field, mainly for the detection of heat leaks in boilers, hot fluid pipes, and other equipment, in which high temperatures are observed, thus with high temperature gradients with respect to the ambient, that are much above measurements uncertainties, what allows for well conclusive analyses. On the other hand, surface temperatures on human skin are close to the ambient temperature, therefore the observed temperature gradients are small, what makes the analyses less conclusive. In sum, there is need for the development of structured methodologies for adequate selection of human body surface temperatures that are related to diverse diseases. Expected normality ranges could be established based on infrared imaging temperature measurements of volunteers without complaints. It is expected that measurements in patients previously diagnosed with traditional techniques (e.g., biopsy) fall out of such ranges. The main objective would be to concretely demonstrate that infrared imaging has potential for utilization as a noninvasive screening exam for people with complaints, what would indicate whether or not the individual should be submitted to a more complex exam. The mission of Engenharia Térmica is to document the scientific progress in areas related to thermal engineering (e.g., energy, oil and renewable fuels). We are confident that we will continue to receive articles’ submissions that contribute to the progress of science.

A Literature Review of the Human Body as a Communication Medium using RedTacton

At present many technologies for networking are known and are in use. These technologies connect people, objects and other networks together so as to dispense data and thus make information ready for access. In the world of computers, networking is the practice of linking two or more computing devices together for the purpose of dispensing data. In this paper, we introduce novel networking technology called RedTacton was announced by NTT labs from Japan in 2005, which makes use of human body surface as communication medium when exchanging data among people, objects and networks. The RedTacton takes a different technical viewpoint. Instead of relying on electromagnetic waves or light waves to carry data, RedTacton uses feeble electric fields on the surface of the body as a transmission medium. Electricfield communication is dissimilar from orthodox wireless or infrared communication which simply does not rely on electromagnetic or light wave to transmit data because it uses the electric field procreate on the surface of the human body. This is mainly developed to conquer an interposing of unwanted signal in intensive places has become a major issue and the better solution to this can be, a human body functioning as non-stop transmitter and receiver. The RedTacton communication is possible using any body surfaces, such as the hands, fingers, arms, feet, face, legs or toes. Red Tacton can be used in any media including water, glass, wood, shoes and clothing as well etc. The electric field/Photonics method employed by Red Tacton is preferable to conventional methods in terms of communication distance, speed, and interactivity. In this paper, I will discuss about RedTacton, and it’s working states, body coupled communications, transceiver and applications of RedTacton in various fields.

Analysis of thermal comfort properties of jacquard knitted mattress ticking fabrics

Purpose – Sleep is a vital and a basic activity of human life and it is a physiological need for human body. Sleep quality is directly influenced by the comfort conditions of sleep environment. The purpose of this paper is to define the role of textile materials utilized as bed fabrics on air and mass transfer from the human body. Design/methodology/approach – Thermal conductivity, thermal resistance, thickness, water vapour permeability and air permeability properties of fabrics were analyzed and statistically evaluated. Thermal conductivity and resistance measurements were performed in Alambeta test instrument. Water vapour permeability tests were done according to the Rotating Platform method, and air permeability was measured in FX 3300 Textest air permeability tester. Relationships between comfort parameters were statistically evaluated with correlation analysis. Findings – Comfort is a major concept in the determination of overall life quality as well as sleep quality of a resting person. Therefore academic studies about thermal comfort prediction of sleep environment and bed surface fabrics are of great importance. This study investigates conventional mattress ticking fabrics in terms of comfort parameters and defines the important fabric properties on comfort parameters. Originality/value – Sleep comfort is a promising area in textile comfort studies with its dynamics different from body thermal comfort during daily life. However, in general comfort studies are about garment materials which are in direct contact with the skin. This study tries to define the comfort status of textile materials which have indirect contact with the human body surface during sleep duration.

Computing the stresses and deformations of the human eye components due to a high explosive detonation using fluid–structure interaction model

IntroductionIn spite the fact that a very small human body surface area is comprised by the eye, its wounds due to detonation have recently been dramatically amplified. Although many efforts have been devoted to measure injury of the globe, there is still a lack of knowledge on the injury mechanism due to Primary Blast Wave (PBW). The goal of this study was to determine the stresses and deformations of the human eye components, including the cornea, aqueous, iris, ciliary body, lens, vitreous, retina, sclera, optic nerve, and muscles, attributed to PBW induced by trinitrotoluene (TNT) explosion via a Lagrangian-Eulerian computational coupling model. Materials and methodsMagnetic Resonance Imaging (MRI) was employed to establish a Finite Element (FE) model of the human eye according to a normal human eye. The solid components of the eye were modelled as Lagrangian mesh, while an explosive TNT, air domain, and aqueous were modelled using Arbitrary Lagrangian-Eulerian (ALE) mesh. Nonlinear dynamic FE simulations were accomplished using the explicit FE code, namely LS-DYNA. In order to simulate the blast wave generation, propagation, and interaction with the eye, the ALE formulation with Jones-Wilkins-Lee (JWL) equation defining the explosive material were employed. ResultsThe results revealed a peak stress of 135.70kPa brought about by detonation upsurge on the cornea at the distance of 25cm. The highest von Mises stresses were observed on the sclera (267.3kPa), whereas the lowest one was seen on the vitreous body (0.002kPa). The results also showed a relatively high resultant displacement for the macula as well as a high variation for the radius of curvature for the cornea and lens, which can result in both macular holes, optic nerve damage and, consequently, vision loss. ConclusionThese results may have implications not only for understanding the value of stresses and strains in the human eye components but also giving an outlook about the process of PBW triggers damage to the eye.

An Intelligent Adaptive Filter for Elimination of Power Line Interference From High Resolution Electrocardiogram

Electrocardiogram (ECG) is a non-invasive method to monitor electric activities inside the heart. The signals observed on the surface of human body have very low amplitude, and thus, ECG is highly vulnerable to noise. One of the most devastating noise is power line interference (PLI) and its harmonics, which are interlaced with ECG signal even if the ECG equipment is operated on battery. The problem is further complicated when the frequency of PLI is not static, making the conventional notch filter completely ineffective. High-resolution electrocardiogram (HRECG) is a specialized technique in which higher frequency components present in the ECG signal are observed; here, we need to eliminate the harmonics of PLI as well. In this paper, we propose an intelligent adaptive noise rejection filter, which tracks and eliminates PLI as well as its harmonics. The proposed system can estimate the frequency of PLI and tune the adaptive filter for precise elimination of PLI as well as its harmonics without the requirement of an auxiliary reference input. The proposed system is based on recursive state space model, inherited with less computational complexity and performs well in a non-stationary environment. The proposed system responds well to the ongoing variations in amplitude and frequency of PLI present in the HRECG signal as well as intracardiac signal. The proposed system does not require any reference signal for tracking the PLI and its harmonics, and it is capable to self-adjust its tracking frequency for highly precise filtration of first, third, and fifth harmonics of PLI.

Wireless monitoring of the biological object state at microwave frequencies: A review

Radio-frequency identification systems used for the remote diagnostics of diseases and contactless monitoring and assessment of human health are reviewed. The propagation of electromagnetic waves inside a biological medium and along interfaces between different media, as well as the problem of telemetry data acquisition from implanted systems or system on the human body surface using wireless sensors, is considered. Emphasis is on radio-frequency identification systems that use far-field electromagnetic radiation, since they are necessary in emergency situations to find injured people in hard-to-reach places and assess the state of emergency response workers.

支持面の水平移動時における立位人体のモデリングと制御

This study focuses on the balance modeling of human body on frontal plane. For practical use, the model should be effective when its support surface moves to horizontal direction in low frequencies below 1 Hz. The frequency range allows us to regard the mechanism of the model as a single degree of freedom system. Then the balance model can be expressed as a transfer function whose input is acceleration of the support surface and output is moment acted from support surface to hold human body balance. To obtain the transfer function model being stable, three characteristic roots of the model were estimated from impulse response test. Finally, the third-order transfer function model was derived from frequency response test. The results of frequency response test indicated that they are reproduced and acceleration of the support surface and posture of human body become inverted in low frequency range (< 0.2 Hz). To verify the effectiveness of the identified models, state estimation based on full-order state observer and full-state feedback control to keep the subject 's balance easily were applied in experiment. Although it is possible to estimate and control the state variables of human body, the accuracy is insufficient to aid the balance control of human body standing on moving board. The result indicates that dimension of the model should be higher than third order in our future work.

Becoming the intelligible other: speaking intersex bodies against the grain

ABSTRACTAlthough genitalia only make up a tiny portion of the human body's surface area, their shape and appearance have great consequence for life trajectories and the ways in which bodies and people are understood. Intersex people, born with bodies that are not classifiable under a binary male/female construct, are increasingly embracing intersex identities, but intelligibility in society can be difficult to realize because cultural models and language serve to render their bodies unintelligible. This study explores a case study from New Zealand, deploying discourse analysis to examine two sources of data: recordings in a secondary school sexuality education classroom and published government documents. Cultural models of binary male–female hold sway in both data sources, but by looking past this apparent dissonance during the analysis it becomes clear that the classroom participants stop orienting to the binary. In this way, they speak intersex genitals and bodies into existence despite the lack of specific lexical items for the task.