Non-invasive monitoring method for lower-leg compartment syndrome using a wireless sensor system and finite element analysis

2020 ◽  
pp. 095441192098124
Author(s):  
Fuh-Yu Chang ◽  
Ping-Tun Teng ◽  
Liang-Chun Chen
Keyword(s):  
Finite Element ◽  
Compartment Syndrome ◽  
Lower Leg ◽  
Sensor System ◽  
Compartment Pressure ◽  
Posterior Compartment ◽  
Element Analysis ◽  
Non Invasive ◽  
Detecting Method

In this study, a non-invasive pressure monitoring system that is portable and convenient was designed for detecting compartment syndrome. The system combines a wireless module and smartphone, which aids in the achievement of mHealth objectives, specifically, the continuous monitoring of the compartment pressure in patients. A compartment syndrome detecting method using a wireless sensor system and finite element analysis is developed and verified with an in vitro lower-leg model by rapid prototyping. The sensor system is designed to measure a five point pressure variation from the outside of the lower leg and transmit the data to a smartphone via Bluetooth. The analysis model based on the finite element method is employed to calculate the change of pressure and volume inside the four compartments of the lower leg. The in vitro experimental results show that the non-invasive detecting method can monitor the compartment pressure and provide a warning for the occurrence of compartment syndrome if the compartment pressure is higher than 30 mmHg. Furthermore, the theoretical simulation of the real lower leg shows similar trends to those of the in vitro experiments and can promptly detect the occurrence of compartment syndrome. Measured pressure values exceeding 6.3, 2.7, and 2.8 kPa for the three sensors contacting the outside centers of the superficial posterior, anterior, and lateral compartments, respectively, can indicate that each compartment contains a pressure higher than 30 mmHg. These results can provide a warning for the risk of compartment syndrome of each compartment. In addition, the measured values from the three sensors contacting the superficial posterior compartment at the outside center, close to the tibia, and close to the lateral compartment exceeding 1.8, 0.7, and 0.7 kPa, respectively, can indicate the risk of deep posterior compartment syndrome.

scholarly journals Biomechanical assessment of different fixation methods in mandibular high sagittal oblique osteotomy using a three-dimensional finite element analysis model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charles Savoldelli ◽  
Elodie Ehrmann ◽  
Yannick Tillier
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Analysis Model ◽  
Element Analysis ◽  
Fixation Methods ◽  
Oblique Osteotomy ◽  
Von Mises

AbstractWith modern-day technical advances, high sagittal oblique osteotomy (HSOO) of the mandible was recently described as an alternative to bilateral sagittal split osteotomy for the correction of mandibular skeletal deformities. However, neither in vitro nor numerical biomechanical assessments have evaluated the performance of fixation methods in HSOO. The aim of this study was to compare the biomechanical characteristics and stress distribution in bone and osteosynthesis fixations when using different designs and placing configurations, in order to determine a favourable plating method. We established two finite element models of HSOO with advancement (T1) and set-back (T2) movements of the mandible. Six different configurations of fixation of the ramus, progressively loaded by a constant force, were assessed for each model. The von Mises stress distribution in fixations and in bone, and bony segment displacement, were analysed. The lowest mechanical stresses and minimal gradient of displacement between the proximal and distal bony segments were detected in the combined one-third anterior- and posterior-positioned double mini-plate T1 and T2 models. This suggests that the appropriate method to correct mandibular deformities in HSOO surgery is with use of double mini-plates positioned in the anterior one-third and posterior one-third between the bony segments of the ramus.

scholarly journals Modeling the pelvic region for non-invasive pelvic intraoperative neuromonitoring

2016 ◽  
Vol 2 (1) ◽  
pp. 185-188 ◽  
Author(s):  
Tomasz Moszkowski ◽  
Thilo Krüger ◽  
Werner Kneist ◽  
Klaus-Peter Hoffmann
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Intraoperative Neuromonitoring ◽  
Tetrahedral Mesh ◽  
Mesorectal Excision ◽  
Element Analysis ◽  
Pelvic Region ◽  
Non Invasive ◽  
Muscle Tissues ◽  
Mesh Models

AbstractFinite element analysis (FEA) of electric current distribution in the pelvis minor may help to assess the usability of non-invasive surface stimulation for continuous pelvic intraoperative neuromonitoring. FEA requires generation of quality volumetric tetrahedral mesh geometry. This study proposes the generation of a suitable mesh based on MRI data. The resulting volumetric mesh models the autonomous nerve structures at risk during total mesorectal excision. The model also contains the bone, cartilage, fat, skin, muscle tissues of the pelvic region, and a set of electrodes for surface stimulation. The model is ready for finite element analysis of the discrete Maxwell’s equations.

Influence of block-out on retentive force of thermoplastic resin clasps: an in vitro experimental and finite element analysis

2019 ◽  
Vol 63 (3) ◽  
pp. 303-308 ◽  
Author(s):  
Toshiki Yamazaki ◽  
Natsuko Murakami ◽  
Shizuka Suzuki ◽  
Kazuyuki Handa ◽  
Masaru Yatabe ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Thermoplastic Resin ◽  
Element Analysis ◽  
Retentive Force

Biomechanics of a posture-controlling cervical artificial disc: mechanical, in vitro, and finite-element analysis

2010 ◽  
Vol 28 (6) ◽  
pp. E11 ◽  
Author(s):  
Neil R. Crawford ◽  
Jeffery D. Arnett ◽  
Joshua A. Butters ◽  
Lisa A. Ferrara ◽  
Nikhil Kulkarni ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cervical Spine ◽  
Postural Control ◽  
Range Of Motion ◽  
Computer Modeling ◽  
Mechanical Testing ◽  
Artificial Disc ◽  
Element Analysis

Different methods have been described by numerous investigators for experimentally assessing the kinematics of cervical artificial discs. However, in addition to understanding how artificial discs affect range of motion, it is also clinically relevant to understand how artificial discs affect segmental posture. The purpose of this paper is to describe novel considerations and methods for experimentally assessing cervical spine postural control in the laboratory. These methods, which include mechanical testing, cadaveric testing, and computer modeling studies, are applied in comparing postural biomechanics of a novel postural control arthroplasty (PCA) device versus standard ball-and-socket (BS) and ball-in-trough (BT) arthroplasty devices. The overall body of evidence from this group of tests supports the conclusion that the PCA device does control posture to a particular lordotic position, whereas BS and BT devices move freely through their ranges of motion.

A Handheld Noninvasive Sensing Method for the Measurement of Compartment Pressures

2013 ◽  
Author(s):  
C. Flegel ◽  
K. Singal ◽  
R. Rajamani
Keyword(s):  
Compartment Syndrome ◽  
Fluid Pressure ◽  
Magnetic Field Measurement ◽  
In Vitro Test ◽  
Non Invasive ◽  
Fluid Compartment ◽  
Combat Casualty ◽  
The Individual ◽  
Compartment Pressures

Compartment syndrome is a major concern in cases of extremity trauma, which occur in over 70% of military combat casualty. Without treatment, compartment syndrome can lead to paralysis, loss of limb, or death. This paper focuses on the development of a handheld sensor that can be used for the non-invasive diagnosis of compartment syndrome. Analytical development of the sensing principle is first presented in which a relation is obtained between the pressure in a fluid compartment and the stiffness experienced by a handheld probe pushing on the compartment. Then a handheld sensor that can measure stiffness of an object without requiring the use of any inertial reference is presented. The handheld sensor consists of an array of three miniature force-sensing spring loaded pistons placed together on a probe. The center spring is chosen to be significantly stiffer than the side springs. The ratio of forces between the stiff and soft springs is proportional to the stiffness of the soft object against which the probe is pushed. Small mm-sized magnets on the pistons and magnetic field measurement chips are used to measure the forces in the individual pistons. Experimental results are presented using an in-vitro test rig that replicates a fluid pressure compartment. The sensor is shown to measure pressure accurately with a resolution of 0.1 psi over the range 0.75 psi to 2.5 psi.

A Finite Element Analysis of the C2-C7 Sheep Spine

2010 ◽  
Author(s):  
Nicole A. DeVries ◽  
Nicole A. Kallemeyn ◽  
Kiran H. Shivanna ◽  
Nicole M. Grosland
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Surgical Techniques ◽  
In Vitro Studies ◽  
Element Analysis ◽  
Spinal Disorders ◽  
Biomechanical Responses ◽  
Experimental Biomechanics ◽  
Similarities And Differences

Due to the limited availability of human cadaveric specimens, sheep are often utilized for in vitro studies of various spinal disorders and surgical techniques. Understanding the similarities and differences between the human and sheep spine is crucial for constructing a valuable study and interpreting the results. Several studies have identified the anatomical similarities between the sheep and human spine; however these studies have been limited to quantifying the anatomic dimensions as opposed to the biomechanical responses [1–2]. Although anatomical similarities are important, biomechanical correspondence is imperative for studying the effects of disorders, surgical techniques, and implant designs. Studies by Wilke and colleagues [3] and Clarke et al. [4] have focused on experimental biomechanics of the sheep cervical functional spinal units (FSUs).

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