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

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Daisuke Yamada ◽  
Alperen Değirmenci ◽  
Robert D. Howe
Keyword(s):  
Ultrasound Imaging ◽  
Human Body ◽  
Human Subjects ◽  
Excitation Amplitude ◽  
Whole Body ◽  
Ultrasound Images ◽  
Body Dynamics ◽  
Excitation Pattern

Abstract 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.

scholarly journals Comprehensive assessment of post-prandial protein handling by the application of intrinsically labelled protein in vivo in human subjects

2021 ◽  
pp. 1-9
Author(s):  
Jorn Trommelen ◽  
Andrew M. Holwerda ◽  
Philippe J. M. Pinckaers ◽  
Luc J. C. van Loon
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Stable Isotope ◽  
Dietary Protein ◽  
Protein Metabolism ◽  
Muscle Protein ◽  
Human Subjects ◽  
Whole Body ◽  
Body Protein

All human tissues are in a constant state of remodelling, regulated by the balance between tissue protein synthesis and breakdown rates. It has been well-established that protein ingestion stimulates skeletal muscle and whole-body protein synthesis. Stable isotope-labelled amino acid methodologies are commonly applied to assess the various aspects of protein metabolism in vivo in human subjects. However, to achieve a more comprehensive assessment of post-prandial protein handling in vivo in human subjects, intravenous stable isotope-labelled amino acid infusions can be combined with the ingestion of intrinsically labelled protein and the collection of blood and muscle tissue samples. The combined application of ingesting intrinsically labelled protein with continuous intravenous stable isotope-labelled amino acid infusion allows the simultaneous assessment of protein digestion and amino acid absorption kinetics (e.g. release of dietary protein-derived amino acids into the circulation), whole-body protein metabolism (whole-body protein synthesis, breakdown and oxidation rates and net protein balance) and skeletal muscle metabolism (muscle protein fractional synthesis rates and dietary protein-derived amino acid incorporation into muscle protein). The purpose of this review is to provide an overview of the various aspects of post-prandial protein handling and metabolism with a focus on insights obtained from studies that have applied intrinsically labelled protein under a variety of conditions in different populations.

In Vivo Analysis of Intramuscular Gene Transfer in Human Subjects Studied by On-line Ultrasound Imaging

2001 ◽  
Vol 12 (12) ◽  
pp. 1543-1549 ◽  
Author(s):  
Guenter Rauh ◽  
Ann Pieczek ◽  
William Irwin ◽  
Robert Schainfeld ◽  
Jeffrey M. Isner
Keyword(s):  
Gene Transfer ◽  
Ultrasound Imaging ◽  
Human Subjects ◽  
On Line ◽  
In Vivo Analysis

scholarly journals Noninvasive Measurements of Human Brain Temperature Using Volume-Localized Proton Magnetic Resonance Spectroscopy

1997 ◽  
Vol 17 (4) ◽  
pp. 363-369 ◽  
Author(s):  
Ron Corbett ◽  
Abbot Laptook ◽  
Paul Weatherall
Keyword(s):  
Magnetic Resonance ◽  
Frontal Lobe ◽  
Mr Spectroscopy ◽  
Brain Temperature ◽  
Human Subjects ◽  
Normal Subjects ◽  
Whole Body ◽  
Resonance Spectroscopy ◽  
Noninvasive Measurements

Elucidation of the role of cerebral hyperthermia as a secondary factor that worsens outcome after brain injury, and the therapeutic application of modest brain hypothermia would benefit from noninvasive measurements of absolute brain temperature. The present study was performed to evaluate the feasibility of using 1H magnetic resonance (MR) spectroscopy to measure absolute brain temperature in human subjects on a clinical imaging spectroscopy system operating at a field strength of 1.5 T. In vivo calibration results were obtained from swine brain during whole-body heating and cooling, with concurrent measurements of brain temperature via implanted probes. Plots of the frequency differences between the in vivo MR peaks of water and N-acetyl-aspartate and related compounds (NAX), or water and choline and other trimethylamines versus brain temperature were linear over the temperature range studied (28–40°C). These relationships were used to estimate brain temperature from 1H MR spectra obtained from 10 adult human volunteers from 4 cm3-volumes selected from the frontal lobe and thalamus. Oral and forehead temperatures were monitored concurrently with MR data collection to verify normothermia in all the subjects studied. Temperatures determined using N-acetyl-aspartate or choline as the chemical shift reference did not differ significantly, and therefore results from these estimates were averaged. The brain temperature (mean ± SD) measured from the frontal lobe (37.2 = 0.6°C) and thalamus (37.7 ± 0.6°C) were significantly different from each other (paired t-test, p = 0.035). We conclude that 1H MR spectroscopy provides a viable noninvasive means of measuring regional brain temperatures in normal subjects and is a promising approach for measuring temperatures in brain-injured subjects.

Numerical model of detector for in vivo internal dosimetry in radiological incidents

2012 ◽  
Vol 18 (2) ◽  
pp. 29-39
Author(s):  
Jakub Ośko ◽  
Katarzyna Tymińska
Keyword(s):  
Numerical Model ◽  
Dose Rate ◽  
Human Body ◽  
Radioactive Isotopes ◽  
Whole Body ◽  
Internal Dosimetry ◽  
Internal Contamination ◽  
Contaminated Area ◽  
Selection Of

The aim of this work was to create a numerical model of scintillation detector and to check whether such detector can be used for the measurements of internal contamination in emergency conditions. The purpose of the measurements would be only detection of possible contamination, without identification of radioactive isotopes, and hence without estimation of effective dose. However, in emergency conditions, it is sufficient for the rapid selection of a group of contaminated persons, who should be subjected to careful inspection in the laboratory conditions. The calculations were performed for three detector positions relatively to the phantom. The distribution of dose rate was also calculated, in order to find the best geometry for dose rate measurements around human body. Another problem under consideration was the possible influence of radioactive contamination in the environment on the registration of the gamma spectrum emitted from the whole body phantom. Performed calculations showed that there is a possibility to measure internal contamination outside laboratory, even in contaminated area.

scholarly journals Establishment and Characterization of a Multi-Purpose Large Animal Exposure Chamber for Investigating Health Effects

2018 ◽  
Author(s):  
Xinze Peng ◽  
Mia R. Maltz ◽  
Jon K. Botthoff ◽  
Emma L. Aronson ◽  
Tara M. Nordgren ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Animal Studies ◽  
Exposure Chamber ◽  
Whole Body ◽  
Large Animal ◽  
Uniform Dispersion ◽  
Health Studies ◽  
Animal Exposure

Air pollution poses a significant threat to the environment and human health. Most in-vivo health studies conducted regarding air pollutants, including particulate matter (PM) and gas phase pollutants, have been either through traditional medical intranasal treatment or using a tiny chamber, which limit animal activities. In this study, we designed and tested a large, whole-body, multiple animal exposure chamber with uniform dispersion and exposure stability for animal studies. The chamber simultaneously controls particle size distribution and PM mass concentration. Two different methods were used to generate aerosol suspension through either soluble material (Alternaria extract), liquid particle suspension (Nanosilica solution) or dry powder (silica powder). We demonstrate that the chamber system provides well controlled and characterized whole animal exposures, where dosage is by inhalation of particulate matter.

Respiratory quotients of human kidney in vivo

1963 ◽  
Vol 18 (4) ◽  
pp. 815-817 ◽  
Author(s):  
Earl S. Barker ◽  
Archer P. Crosley ◽  
John K. Clark
Keyword(s):  
Human Subjects ◽  
Human Kidney ◽  
Mean Value ◽  
Whole Body ◽  
Mean Values ◽  
Anesthetized Dogs ◽  
The Mean ◽  
Urine Formation ◽  
Analytical Errors

Renal respiratory quotient (RQ) has been calculated from data collected in unanesthetized human subjects. In contrast to RQ recently reported on anesthetized dogs, these data do not indicate a mean value greater than 1. Under control conditions in 24 subjects, renal RQ calculated without special corrections averaged 0.88. Correcting for differences in blood flow between renal artery and vein due to urine formation the mean was 0.73, with 95% confidence limits 0.49–0.97. With alkaline urines an additional correction for urinary excretion of CO2 is advised. Excluding procedures known to alkalinize the urine, RQ values were similar in 46 observations after a variety of experimental procedures. Since both numerator and denominator of the ratio involve small differences between large values, small analytical errors can produce large changes indistinguishable from physiologic variation. Therefore mean values rather than individual observations are stressed. While such values in our data appear similar to RQ for other organs and the whole body, they do not preclude considerable anaerobic metabolism. Submitted on August 9, 1962

Chemical and elemental analysis of humans in vivo using improved body composition models

1991 ◽  
Vol 261 (2) ◽  
pp. E190-E198 ◽  
Author(s):  
S. B. Heymsfield ◽  
M. Waki ◽  
J. Kehayias ◽  
S. Lichtman ◽  
F. A. Dilmanian ◽  
...  
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Actual Body ◽  
Elemental Analysis ◽  
Human Subjects ◽  
National Laboratory ◽  
Brookhaven National Laboratory ◽  
Whole Body ◽  
Highly Correlated

Six chemical compartments [water, protein, mineral (osseus and cellular), glycogen, and fat] consisting of 11 elements (N, C, Ca, Na, Cl, K, H, P, O, S, and Mg) comprise greater than or equal to 99% of body weight in living humans. The combination of three neutron-activation systems, whole body 40K counting, and 3H2O dilution at Brookhaven National Laboratory now potentially makes it possible to quantify greater than or equal to 96% of the chemical and elemental determinants of body weight in vivo. The aims of the present study were 1) to develop 6- and 11-compartment chemical and elemental models, respectively, and 2) to evaluate these models in a group of 20 healthy adults. Results demonstrated that body weight estimated from either chemical or elemental components was highly correlated with (both r = 0.97, P less than 0.001) and on average differed by less than 4% from actual body weight. The compartmental results obtained using the chemical model were also evaluated by comparing calculated and actual body density (Db) estimated by underwater weighing. Calculated Db [1.041 +/- 0.017 (SD) g/ml] agreed closely and was highly correlated with actual Db (1.039 +/- 0.018 g/ml; r = 0.82; P less than 0.001). Hence a near-complete chemical and elemental analysis of living human subjects is now possible and, with potential future refinements, represents an important opportunity to quantify the effects of gender, aging, and ethnic status on body composition.

scholarly journals An Online Method to Detect and Locate an External Load on the Human Body with Applications in Ergonomics Assessment

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4471
Author(s):  
Marta Lorenzini ◽  
Wansoo Kim ◽  
Elena De Momi ◽  
Arash Ajoudani
Keyword(s):  
Human Body ◽  
External Load ◽  
Sagittal Plane ◽  
Human Subjects ◽  
Vertical Component ◽  
Industrial Applications ◽  
The Body ◽  
Whole Body ◽  
Contact Points ◽  
Reaction Forces

In this work, we propose an online method to detect and approximately locate an external load induced on the body of a person interacting with the environment. The method is based on a torque equilibrium condition on the human sagittal plane, which takes into account a reduced-complexity model of the whole-body centre of pressure (CoP) along with the measured one, and the vertical component of the ground reaction forces (vGRFs). The latter is combined with a statistical analysis approach to improve the localisation accuracy, (which is subject to uncertainties) to the extent of the industrial applications we target. The proposed technique eliminates the assumption of known contact position of an external load on the human limbs, allowing a more flexible online body-state tracking. The accuracy of the proposed method is first evaluated via a simulation study in which various contact points on different body postures are considered. Next, experiments on human subjects with three different contact locations applied to the human body are presented, revealing the validity of the proposed methodology. Lastly, its benefit in the estimation of human dynamic states is demonstrated. These results add another layer to the online human ergonomics assessment framework developed in our laboratory, extending it to more realistic and varying interaction conditions.

scholarly journals Biomedical photoacoustic imaging

2011 ◽  
Vol 1 (4) ◽  
pp. 602-631 ◽  
Author(s):  
Paul Beard
Keyword(s):  
Optical Imaging ◽  
Ultrasound Imaging ◽  
Spatial Resolution ◽  
Breast Imaging ◽  
Clinical Medicine ◽  
Blood Oxygenation ◽  
Whole Body ◽  
Practical Implementation ◽  
Wide Range

Photoacoustic (PA) imaging, also called optoacoustic imaging, is a new biomedical imaging modality based on the use of laser-generated ultrasound that has emerged over the last decade. It is a hybrid modality, combining the high-contrast and spectroscopic-based specificity of optical imaging with the high spatial resolution of ultrasound imaging. In essence, a PA image can be regarded as an ultrasound image in which the contrast depends not on the mechanical and elastic properties of the tissue, but its optical properties, specifically optical absorption. As a consequence, it offers greater specificity than conventional ultrasound imaging with the ability to detect haemoglobin, lipids, water and other light-absorbing chomophores, but with greater penetration depth than purely optical imaging modalities that rely on ballistic photons. As well as visualizing anatomical structures such as the microvasculature, it can also provide functional information in the form of blood oxygenation, blood flow and temperature. All of this can be achieved over a wide range of length scales from micrometres to centimetres with scalable spatial resolution. These attributes lend PA imaging to a wide variety of applications in clinical medicine, preclinical research and basic biology for studying cancer, cardiovascular disease, abnormalities of the microcirculation and other conditions. With the emergence of a variety of truly compelling in vivo images obtained by a number of groups around the world in the last 2–3 years, the technique has come of age and the promise of PA imaging is now beginning to be realized. Recent highlights include the demonstration of whole-body small-animal imaging, the first demonstrations of molecular imaging, the introduction of new microscopy modes and the first steps towards clinical breast imaging being taken as well as a myriad of in vivo preclinical imaging studies. In this article, the underlying physical principles of the technique, its practical implementation, and a range of clinical and preclinical applications are reviewed.

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