Is a simplified Finite Element model of the gluteus region able to capture the mechanical response of the internal soft tissues under compression?

Abstract

Background: Internal soft tissue strains have been shown to be one of the main factors responsible for the onset of Pressure Ulcers and to be representative of its risk of development. However, the estimation of this parameter using Finite Element (FE) analysis in clinical setups is currently hindered by costly acquisition, reconstruction and computation times. Ultrasound (US) imaging is a promising candidate for the clinical assessment of both morphological and material parameters. Method: The aim of this study was to investigate the ability of a local FE model of the region beneath the ischium with a limited number of parameters to capture the internal response of the gluteus region predicted by a complete 3D FE model. 26 local FE models were developed, and their predictions were compared to those of the patient-specific reference FE models in sitting position. Findings: A high correlation was observed (R= 0.90, p-value < 0.01). A sensitivity analysis showed that the most influent parameters were the mechanical behaviour of the muscle tissues, the ischium morphology and the external mechanical loading. Interpretation: Given the progress of US for capturing both morphological and material parameters, these results are promising because they open up the possibility to use personalised simplified FE models for risk estimation in daily clinical routine.

Data Science Trends Relevant to Nursing Practice: A Rapid Review of the 2020 Literature

“…Of these 13 studies, 7 studies used a retrospective cohort design, 230 231 232 233 234 235 236 3 used a prospective cohort design, 237 238 239 1 used a clinical trial, 240 1 used a cross-sectional design, 241 and 1 used secondary data analysis. 242 A variety of data sources were used for the studies, including EHR data, 233 234 238 239 data warehouses, 230 231 235 236 a publicly available dataset, 232 sensor data, 240 242 and surveys as the primary collection tool. 237 The samples across studies were adult patients admitted in hospitals, 230 231 232 234 236 238 239 adults in residential hospices, 237 elderly patients in nursing homes (NHs), 241 Medicare beneficiaries, 235 and adults (unspecified).…”

“…237 The samples across studies were adult patients admitted in hospitals, 230 231 232 234 236 238 239 adults in residential hospices, 237 elderly patients in nursing homes (NHs), 241 Medicare beneficiaries, 235 and adults (unspecified). 240 242 Six studies were based in the United States, 230 231 232 234 235 236 with other study locations including Brazil, 239 Canada, 240 France, 242 Indonesia, 241 Italy, 237 South Korea, 238 and Taiwan. 233 Sample sizes ranged from 12 to 2,091,058 observations.…”

“…Most studies used the incidence rate of PIs as the outcome, except for one study 234 that projected PI closure and two studies 240 242 that explored PI images. Various data science methods were used to detect or predict PIs including logistic regression, 230 231 232 234 239 generalized estimating equations, 237 multiple regression, 235 path analysis, 241 supervised ML, 233 236 238 and imaging processing.…”

“…Various data science methods were used to detect or predict PIs including logistic regression, 230 231 232 234 239 generalized estimating equations, 237 multiple regression, 235 path analysis, 241 supervised ML, 233 236 238 and imaging processing. 240 242 The predominant predictor variables used across studies included demographics and diagnoses, 231 232 233 234 235 236 237 239 followed by clinical assessment data, 231 233 235 236 237 238 239 241 Braden's scale, 231 232 236 237 239 laboratory tests, 233 234 236 238 239 and medications. 232 236 239 Two studies used organizational factors such as nursing unit characteristics, nurse job satisfaction, facility types, or rural/urban hospital location.…”

MR-based quantitative measurement of human soft tissue internal strains for pressure ulcer prevention

“…Because direct validation of internal mechanical strains is a challenging problem, many research works proposed to evaluate FE models of the foot in terms of their capacity to predict interface plantar pressure by comparing the contact pressure predicted by the FE model with the measurements from pressure mattresses [11]. Yet, as observed in Macron et al [12] on data from 13 healthy volunteers, interface pressure distributions do not correlate with internal strains and one cannot be used to predict the other. This issue was partially addressed by Linder-Granz et al [13] for a buttock FE model in a study where the authors compared contours of the computational domain in the deformed configuration predicted by the simulations to the ground truth segmented contours obtained from MR images.…”