Density of trunk tissues of young and medium age people

Erdmann, Wlodzimierz S.; Gos, Tomasz

doi:10.1016/0021-9290(90)90360-f

Cited by 29 publications

(19 citation statements)

References 2 publications

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“…Tissue densities of 1.178 g/cm 3 for muscle, 1.705 g/cm 3 for bone, 1.158 g/cm 3 for liver, and 0.563 g/cm 3 for lung tissue (Erdmann and Gos, 1990; Martin et al, 1989) were used to calculated segment masses. Adipose tissue density was approximated as 0.947 g/cm 3 , which was an average of the densities of the colon, off-peritoneum, and subcutaneous adipose tissue (Erdmann and Gos, 1990). All other tissues were defined as lean tissue with a density of 1.138 g/cm 3 , which was an average of densities for blood, vasculature, tendon, stomach, intestines, and heart (Erdmann and Gos, 1990).…”

Section: Methodsmentioning

confidence: 99%

Changes in body segment inertial parameters of obese individuals with weight loss

Matrangola

Madigan

Nussbaum

et al. 2008

Journal of Biomechanics

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Forward dynamic simulation of human movement has the potential to investigate the biomechanical effects of weight loss in obese individuals. However, guidelines for altering body segment inertial parameters (BSIPs) of a biomechanical model to approximate changes that occur with weight loss are currently unavailable. Therefore, the goal of this study was to quantify three-dimensional changes in BSIPs with weight loss. Nineteen Caucasian men of age 43.6 ± 7.5 years (mean ± standard deviation) were evaluated. Body mass and body mass index prior to weight loss were 102.7 ± 3.6 kg and 32.6 ± 3.2 kg/m2, respectively. Both before and after weight loss, magnetic resonance imaging scans were acquired along the length of the body to discriminate muscle, bone, organ, and adipose tissues. Segment masses, center of mass (COM) positions, and radii of gyration were determined from these scans using published tissue densities and established methods. A number of significant changes in BSIPs occurred with the 13.8 ± 2.4 % average weight loss. Mass decreased in all segments. COM position moved distally for the thigh and upper arm, superiorly for the trunk, and inferiorly for the whole body. Radius of gyration, in general, decreased in all segments. The changes in BSIPs with weight loss reported here could be used in forward dynamic simulations investigating the biomechanical implications of weight loss.

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Section: Methodsmentioning

confidence: 99%

Changes in body segment inertial parameters of obese individuals with weight loss

Matrangola

Madigan

Nussbaum

et al. 2008

Journal of Biomechanics

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“…We created the FDTD model of subject 1 by modifying the model used in previous calculations [14]: the thickness of skin was decreased to be more realistic. The model of subject 2 was newly created by segmenting the images of the female cadaver from the National Libraries of Medicine's Visible Human Project and then assigning appropriate electric conductivity, electric permittivity, and mass density to each tissue at each frequency [14,[20][21][22][23][24], The values of these properties for all the tissue types (33 for the male and 36 for the female) are listed in Table 1. The resolution of the final FDTD meshes is 5 mm in all three dimensions, which has been shown to be adequate for SAR calculations in a head model at 64 MHz [25].…”

Section: Methodsmentioning

confidence: 99%

Calculations ofB 1 distribution, specific energy absorption rate, and intrinsic signal-to-noise ratio for a body-size birdcage coil loaded with different human subjects at 64 and 128 MHz

2005

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A numerical model of a female body is developed to study the effects of different body types with different coil drive methods on radio-frequency magnetic (B 1 ) field distribution, specific energy absorption rate (SAR), and intrinsic signal-to-noise ratio (ISNR) for a body-size birdcage coil at 64 and 128 MHz. The coil is loaded with either a larger, more muscular male body model (subject 1) or a newly developed female body model (subject 2), and driven with two-port (quadrature), four-port, or many (ideal) sources. Loading the coil with subject 1 results in significantly less homogeneous B 1 field, higher SAR, and lower ISNR than those for subject 2 at both frequencies. This dependence of MR performance and safety measures on body type indicates a need for a variety of numerical models representative of a diverse population for future calculations. The different drive methods result in similar B 1 field patterns, SAR, and ISNR in all cases.

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“…The main reason for this over-estimation is the change in thorax density between cadavers (Dempster Uniform Density Method) and living population (Personalized and Improved Uniform Density Method) due to the lung tissue. Reported lung densities on cadavers ranged from 0.563 g/cm 3 (Erdmann and Gos, 1990) to 1.050 g/cm 3 (Woodard and White, 1986) while in vivo measures were found to be 0.254 g/cm 3 during expiration (Kohda and Shigematsu, 1989) and the mean lung density used for the Personalized method was 0.28 g/cm 3 . Therefore, in vivo density of the thorax computed with the Personalized Method was in average lower than the density calculated by Dempster (Dempster, 1955) and used in the Dempster Uniform Density Method.…”

Section: Discussionmentioning

confidence: 98%

“…Densities for each thorax tissues and segment have been well documented in the literature (Dempster, 1955;Erdmann and Gos, 1990;Hayashi et al, 2011;Li et al, 2010). The aim of this study was to combine those existing data to propose a new estimation of the thorax density.…”

Section: Introductionmentioning

confidence: 98%

Determination of a new uniform thorax density representative of the living population from 3D external body shape modeling

Amabile

Choisne

Nérot

et al. 2016

Journal of Biomechanics

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Body segment parameters (BSP) for each body׳s segment are needed for biomechanical analysis. To provide population-specific BSP, precise estimation of body׳s segments volume and density are needed. Widely used uniform densities, provided by cadavers׳ studies, did not consider the air present in the lungs when determining the thorax density. The purpose of this study was to propose a new uniform thorax density representative of the living population from 3D external body shape modeling. Bi-planar X-ray radiographies were acquired on 58 participants allowing 3D reconstructions of the spine, rib cage and human body shape. Three methods of computing the thorax mass were compared for 48 subjects: (1) the Dempster Uniform Density Method, currently in use for BSPs calculation, using Dempster density data, (2) the Personalized Method using full-description of the thorax based on 3D reconstruction of the rib cage and spine and (3) the Improved Uniform Density Method using a uniform thorax density resulting from the Personalized Method. For 10 participants, comparison was made between the body mass obtained from a force-plate and the body mass computed with each of the three methods. The Dempster Uniform Density Method presented a mean error of 4.8% in the total body mass compared to the force-plate vs 0.2% for the Personalized Method and 0.4% for the Improved Uniform Density Method. The adjusted thorax density found from the 3D reconstruction was 0.74g/cm(3) for men and 0.73g/cm(3) for women instead of the one provided by Dempster (0.92g/cm(3)), leading to a better estimate of the thorax mass and body mass.

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Density of trunk tissues of young and medium age people

Cited by 29 publications

References 2 publications

Changes in body segment inertial parameters of obese individuals with weight loss

Changes in body segment inertial parameters of obese individuals with weight loss

Calculations ofB 1 distribution, specific energy absorption rate, and intrinsic signal-to-noise ratio for a body-size birdcage coil loaded with different human subjects at 64 and 128 MHz

Determination of a new uniform thorax density representative of the living population from 3D external body shape modeling

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