scholarly journals A Parametric Analysis of Embedded Tissue Marker Properties and Their Effect on the Accuracy of Displacement Measurements

2021 ◽  
Author(s):  
Scott Dutrisac ◽  
MacKenzie Brannen ◽  
T. Blaine Hoshizaki ◽  
Hanspeter Frei ◽  
Oren Petel
Keyword(s):  
Soft Tissues ◽  
Density Ratio ◽  
Vertical Displacement ◽  
Design Guidelines ◽  
Surrounding Tissue ◽  
Tissue Deformation ◽  
Design Choice ◽  
Drop Tests ◽  
Tissue Marker ◽  
Technological Improvements

Abstract Datasets obtained from cadaveric experimentation are broadly used in validating finite element models of head injury. Due to the complexity of such measurements in soft tissues, experimentalists have relied on tissue-embedded radiographic or sonomicrometry tracking markers to resolve tissue motion caused by impulsive loads. Dynamic coupling of markers with the surrounding tissue has been a previous concern, yet a thorough sensitivity investigation of marker influences on tissue deformation has not been broadly discussed. Technological improvements to measurement precision have bolstered confidence in acquired data, however precision is often conflated with accuracy; the inclusion of markers in the tissue may alter its natural response, resulting in a loss of accuracy associated with an altered displacement field. To gain an understanding of how marker properties may influence the measured response to impact, we prepared a set of nine marker designs using a Taguchi L9 array to investigate marker design choice sensitivity. Each of these designs was cast into a block of tissue simulant and subjected to repeated drop tests. Vertical displacement was measured and compared to the response of the neat material, which contained massless tracking markers. Medium density and medium stiffness markers yielded the least deviation from the neat material response. The results provide some design guidelines indicating the importance of maintaining marker matrix density ratio below 1.75 and marker stiffness below 1.0 MPa. These properties may minimize marker interference in tissue deformation. Overall, embedded marker properties must be considered when measuring the dynamic response of tissue.

scholarly journals A parametric analysis of embedded tissue marker properties and their effect on the accuracy of displacement measurements

2021 ◽  
Author(s):  
Scott Dutrisac ◽  
MacKenzie Brannen ◽  
Blaine Hoshizaki ◽  
Hanspeter Frei ◽  
Oren E. Petel
Keyword(s):  
Soft Tissues ◽  
Density Ratio ◽  
Vertical Displacement ◽  
Design Guidelines ◽  
Surrounding Tissue ◽  
Tissue Deformation ◽  
Design Choice ◽  
Drop Tests ◽  
Tissue Marker ◽  
Technological Improvements

Datasets obtained from cadaveric experimentation are broadly used in the validation of finite element models of head injury. Due to the complexity of such measurements in soft tissues, experimentalists have relied on tissue-embedded radiographic or sonomicrometry tracking markers to resolve the motion of the tissue due to impulsive loads. Dynamic coupling of markers with the surrounding tissue has been a previous concern, yet a thorough sensitivity investigation of marker influences on tissue deformation has not been broadly discussed. Technological improvements to measurement precision have bolstered confidence in acquired data, however precision is often conflated with accuracy; the inclusion of markers in the tissue may alter its natural response, resulting in a loss of accuracy associated with an altered displacement field. To gain an understanding of how marker properties may influence the measured response to impact, we prepared a set of nine marker designs using a Taguchi L9 array to investigate marker design choice sensitivity. Each of these designs was cast into a block of tissue simulant an subjected to repeated drop tests. Vertical displacement was measured and compared to the response of the neat material, which contained massless tracking markers. The best performing markers had both a medium density and medium stiffness. The results provide some design guidelines that indicate the importance of maintaining marker:matrix density ratio below 1.75 and marker stiffness below 1.0~MPa to minimize marker interference in tissue deformation. Overall, embedded marker properties must be considered when measuring the dynamic response of tissue.

scholarly journals Healing Pattern Analysis for Dental Implants Using the Mechano-Regulatory Tissue Differentiation Model

2020 ◽  
Vol 21 (23) ◽  
pp. 9205
Author(s):  
Ming-Jun Li ◽  
Pei-Ching Kung ◽  
Yuan-Wei Chang ◽  
Nien-Ti Tsou
Keyword(s):  
Dental Implants ◽  
Soft Tissues ◽  
Bone Ingrowth ◽  
Element Model ◽  
Design Guidelines ◽  
Tissue Differentiation ◽  
Bone Implant ◽  
Crestal Bone Loss ◽  
History Of ◽  
Good Agreement

(1) Background: Our aim is to reveal the influence of the geometry designs on biophysical stimuli and healing patterns. The design guidelines for dental implants can then be provided. (2) Methods: A two-dimensional axisymmetric finite element model was developed based on mechano-regulatory algorithm. The history of tissue differentiation around eight selected implants can be predicted. The performance of the implants was evaluated by bone area (BA), bone-implant contact (BIC); (3) Results: The predicted healing patterns have very good agreement with the experimental observation. Many features observed in literature, such as soft tissues covering on the bone-implant interface; crestal bone loss; the location of bone resorption bumps, were reproduced by the model and explained by analyzing the solid and fluid biophysical stimuli and (4) Conclusions: The results suggested the suitable depth, the steeper slope of the upper flanks, and flat roots of healing chambers can improve the bone ingrowth and osseointegration. The mechanism related to solid and fluid biophysical stimuli were revealed. In addition, the model developed here is efficient, accurate and ready to extend to any geometry of dental implants. It has potential to be used as a clinical application for instant prediction/evaluation of the performance of dental implants.

Effect of Continuous and Intermittent Mechanical Loading on the Development of Skeletal Muscle Damage - A Combined Experimental/Numerical Approach

2009 ◽  
Author(s):  
Sandra Loerakker ◽  
Anke Stekelenburg ◽  
Gustav J. Strijkers ◽  
Klaas Nicolay ◽  
Dan L. Bader ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Damage ◽  
Mechanical Loading ◽  
Soft Tissues ◽  
Tissue Injury ◽  
Ischemia Reperfusion ◽  
Clear Correlation ◽  
Tissue Deformation ◽  
Deep Tissue ◽  
Skeletal Muscle Damage

Prolonged mechanical loading of soft tissues, as present when individuals are bedridden or wheelchair-bound, can lead to degeneration of skeletal muscle tissue. This can result in a condition termed pressure-related deep tissue injury (DTI), a severe kind of pressure ulcer that initiates in deep tissue layers, e.g. skeletal muscle, near bony prominences and progresses towards the skin. Complications associated with DTI include sepsis, renal failure, and myocardial infarction. Damage pathways leading to DTI involve ischemia, ischemia-reperfusion injury, impaired lymphatic drainage, and sustained tissue deformation. Recently, the role of tissue deformation in the onset of skeletal muscle damage was established by combining animal experiments with finite element (FE) modeling [1]. After 2 hours of continuous loading, a clear correlation between maximum shear strain and damage was found.

In Vivo Evaluation of Wrist Cartilage Integrity Using T2 Relaxation Time After Scapholunate Ligament Injury and Surgical Repair

2012 ◽  
Author(s):  
Isaac D. Chappell ◽  
Phil Lee ◽  
Terence E. McIff ◽  
E. Bruce Toby ◽  
Kenneth J. Fischer
Keyword(s):  
Relaxation Time ◽  
Water Content ◽  
Soft Tissues ◽  
Free Water ◽  
Surrounding Tissue ◽  
Ligament Injury ◽  
T2 Relaxation Time ◽  
T2 Relaxation ◽  
In Vivo Evaluation

Osteoarthritis (OA) is a serious and frequently occuring outcome of untreated scapholunate dissocation, the most common form of carpal instability in the wrist [1]. As cartilage degenerates, the water content of surrounding tissue becomes less bound. Magnetic resonance imaging (MRI) T2 relaxation time is longer when water content is less bound [2]. MRI offers the advantageous combination of detailed images of soft tissues such as cartilage with the ability to evaluate free water content. Contrasting the various T2 relaxation times found in the cartilage of healthy wrist surfaces with those of injured wrists is thereby proposed as a method of evaluating cartilage degeneration. We hypothesized that T2 values obtained would be longer for the cartilage of the injured wrists. Though surgical treatment may relieve pain and restore some function to the wrist, it is hypothesized that T2 relaxation time will remain increased after surgery as cartilage regeneration is a very slow process, if it happens at all. The goal of this research is to provide a method to evaluate the biochemical and infer the biomechanical integrity of cartilage for various cartilage surfaces in a wrist after injury.

S53P4 Bioactive Glass - an Alternative Treatment of Bone Defects

2017 ◽  
Vol 68 (2) ◽  
pp. 387-389
Author(s):  
Cristian Trambitas ◽  
Tudor Sorin Pop ◽  
Alina Dia Trambitas Miron ◽  
Dorin Constantin Dorobantu ◽  
Klara Brinzaniuc
Keyword(s):  
Bioactive Glass ◽  
Soft Tissues ◽  
Bone Cells ◽  
Antibacterial Properties ◽  
Bone Defects ◽  
Surrounding Tissue ◽  
Congenital Disease ◽  
Bioactive Glasses ◽  
Rapid Healing ◽  
Specific Reactions

A challenging problem in orthopedic practice is represented by bone defects may they occur from trauma, malignancy, infection or congenital disease. Bioactive Glasses have a widely recognized ability to foster the growth of bone cells, and to bond strongly with both hard and soft tissues. Upon implantation, Bioactive Glasses undergoes specific reactions, leading to the formation of an amorphous calcium phosphate or crystalline hydroxyapatite phase on the surface of the glass, which is responsible for its strong bonding with the surrounding tissue. This phenomenon sustains a more rapid healing of bone defects and presents great antibacterial properties. In this paper we report on a clinical study that uses S53P4 Bioactive Glass to successfully treat bone defects and testify of the good compatibility of this material with human tissues.

Computed Tomography of Lipomatous and Myxoid Tumors

1985 ◽  
Vol 26 (6) ◽  
pp. 709-713 ◽  
Author(s):  
S. Lindahl ◽  
G. Markhede ◽  
Ö. Berlin
Keyword(s):  
Computed Tomography ◽  
Contrast Enhancement ◽  
Soft Tissues ◽  
Preoperative Evaluation ◽  
Surrounding Tissue ◽  
Round Cell ◽  
Cell Type ◽  
Radiographic Appearance ◽  
Histologic Types ◽  
Attenuation Values

Thirty-two lipomatous and myxoid tumors were examined by computed tomography (CT). An attempt was made to correlate the radiographic appearance of the tumor to different histologic types of these tumors. It was found that a well delineated lipomatous lesion with uniform radiographic density, an attenuation value below −73 Hounsfield units (HU) and absence of contrast enhancement can be considered strongly suggestive of a benign lipoma. Atypical lipomas, myxoma and well differentiated liposarcomas have good delineation against the surrounding tissue with no peripheral hypervascularity in the majority of cases. The attenuation values varied between −83 and +38 HU. Liposarcomas of myxoid type, mixed myxoid and round-cell type, round-cell type, and pleomorphic type were all poorly delineated with attenuation values between +12 and +38 HU and with varying contrast enhancement. Thus CT can be considered to play an important role in the preoperative evaluation of lipomatous and myxoid tumors of the soft tissues. Besides valuable topographic information CT helps, to some extent, to differentiate between various types of lipomatous tumors.

scholarly journals Ultrasound Shear Wave Simulation of Breast Tumor Using Nonlinear Tissue Elasticity

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Dae Woo Park
Keyword(s):  
Shear Modulus ◽  
Shear Wave ◽  
Breast Tumor ◽  
Breast Tissue ◽  
Soft Tissues ◽  
Surrounding Tissue ◽  
Tissue Elasticity ◽  
Subtle Change ◽  
Tissue Model ◽  
Shear Wave Elasticity Imaging

Shear wave elasticity imaging (SWEI) can assess the elasticity of tissues, but the shear modulus estimated in SWEI is often less sensitive to a subtle change of the stiffness that produces only small mechanical contrast to the background tissues. Because most soft tissues exhibit mechanical nonlinearity that differs in tissue types, mechanical contrast can be enhanced if the tissues are compressed. In this study, a finite element- (FE-) based simulation was performed for a breast tissue model, which consists of a circular (D: 10 mm, hard) tumor and surrounding tissue (soft). The SWEI was performed with 0% to 30% compression of the breast tissue model. The shear modulus of the tumor exhibited noticeably high nonlinearity compared to soft background tissue above 10% overall applied compression. As a result, the elastic modulus contrast of the tumor to the surrounding tissue was increased from 0.46 at 0% compression to 1.45 at 30% compression.

Effects of osmotic pressure in the extracellular matrix on tissue deformation

2006 ◽  
Vol 364 (1843) ◽  
pp. 1407-1422 ◽  
Author(s):  
Y Lu ◽  
K.H Parker ◽  
W Wang
Keyword(s):  
Extracellular Matrix ◽  
Osmotic Pressure ◽  
Soft Tissues ◽  
Moving Boundary ◽  
Analytic Solutions ◽  
Tissue Deformation ◽  
Large Molecules ◽  
Tissue Integrity ◽  
External Pressures ◽  
Dynamic Loading Conditions

In soft tissues, large molecules such as proteoglycans trapped in the extracellular matrix (ECM) generate high levels of osmotic pressure to counter-balance external pressures. The semi-permeable matrix and fixed negative charges on these molecules serve to promote the swelling of tissues when there is an imbalance of molecular concentrations. Structural molecules, such as collagen fibres, form a network of stretch-resistant matrix, which prevents tissue from over-swelling and keeps tissue integrity. However, collagen makes little contribution to load bearing; the osmotic pressure in the ECM is the main contributor balancing external pressures. Although there have been a number of studies on tissue deformation, there is no rigorous analysis focusing on the contribution of the osmotic pressure in the ECM on the viscoelastic behaviour of soft tissues. Furthermore, most previous works were carried out based on the assumption of infinitesimal deformation, whereas tissue deformation is finite under physiological conditions. In the current study, a simplified mathematical model is proposed. Analytic solutions for solute distribution in the ECM and the free-moving boundary were derived by solving integro-differential equations under constant and dynamic loading conditions. Osmotic pressure in the ECM is found to contribute significantly to the viscoelastic characteristics of soft tissues during their deformation.

scholarly journals P040 INFLAMMATORY REACTION TO ALD COATED POLYPROPYLENE MESHES USED FOR HERNIA REPIAR. AN EXPERIMENTAL STUDY IN ANIMALS

2021 ◽  
Vol 108 (Supplement_8) ◽  
Author(s):  
Magomed Khamidov ◽  
Ragimov Razin ◽  
Abay Maksumova ◽  
Naida Abdullaeva ◽  
Zeinab Gasanbekova ◽  
...  
Keyword(s):  
Inflammatory Reaction ◽  
High Performance ◽  
Soft Tissues ◽  
Atomic Layer ◽  
Scar Tissue ◽  
Tissue Reaction ◽  
Surrounding Tissue ◽  
Post Surgery ◽  
Bacteria Adhesion ◽  
Surface Modified

Abstract Aim The main goal of the present work is to study and ability of Atomic Layer Depostion (ALD) ultra-thin (<100nm) ceramic films on polypropylene (PP) hernia meshes to prevent the mesh-associated infections (post-surgery complications). Material and Methods Three types of ALD nanofilms were examined: Al2O3, TiO2, or TixVyOz. 10 rats and 5 rabbits were used to evaluate the tissue reaction of surface modified PP meshes and for biomechanical (antibacterial, inflammation effect), biocompatibility, and barrier testing of the healed tissue. The ALD coated PP meshes were implanted into rabbits and rats together with uncoated ones. After 10, 20, 30 and 60 days, the hernia meshes with the surrounding soft tissues were removed and fixed for histological and cytological studies. Results The TixVyOz (28nm) film showed enhanced antibacterial activity compare to Al2O3 and TiO2 films. The histology was performed on coated and uncoated PP mesh samples. Conclusions The ALD TixVyOz film helped to avoids formation of rough scar tissue (microscale roughness, which prevents ability biofilm formation) and, reduction of eosinophilic-cell and lymphocytic-cell reactions of the tissues surrounding the mesh, illustrate good integration into the surrounding tissue with minimal inflammatory reaction and minimal adhesions to intra-abdominal structures. The ALD film was highly effective in inhibiting S. aureus and E. coli bacteria adhesion and exhibited excellent biological activity in promoting osteoblastic adhesion. Speculatively, presence of vanadyl (≡V=O:) chemical groups, either on the surface or in the bulk, believe to play a key role in high performance of the TixVyOz compare to TiO2.

scholarly journals The Mechanism of Metallosis After Total Hip Arthroplasty

2021 ◽  
Author(s):  
Chinedu C. Ude ◽  
Caldon J. Esdaille ◽  
Kenneth S. Ogueri ◽  
Ho-Man Kan ◽  
Samuel J. Laurencin ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Soft Tissues ◽  
Chelation Therapy ◽  
Defense Mechanism ◽  
Fluid Pressure ◽  
Surrounding Tissue ◽  
Total Hip ◽  
Metal On Metal ◽  
Organ Systems

Abstract Metallosis is defined as the accumulation and deposition of metallic particles secondary to abnormal wear from prosthetic implants that may be visualized as abnormal macroscopic staining of periprosthetic soft tissues. This phenomenon occurs secondary to the release of metal ions and particles from metal-on-metal hip implants in patients with end-stage osteoarthritis. Ions and particles shed from implants can lead to local inflammation of surrounding tissue and less commonly, very rare systemic manifestations may occur in various organ systems. With the incidence of total hip arthroplasty increasing as well as rates of revisions due to prosthesis failure from previous metal-on-metal implants, metallosis has become an important area of research. Bodily fluids are electrochemically active and react with biomedical implants. Particles, especially cobalt and chromium, are released from implants as they abrade against one another into the surrounding tissues. The body’s normal defense mechanism becomes activated, which can elicit a cascade of events, leading to inflammation of the immediate surrounding tissues and eventually implant failure. In this review, various mechanisms of metallosis are explored. Focus was placed on the atomic and molecular makeup of medical implants, the component/surgical associated factors, cellular responses, wear, tribocorrosion, joint loading, and fluid pressure associated with implantation. Current treatment guidelines for failed implants include revision surgery. An alternative treatment could be chelation therapy, which may drive future studies. Lay Summary Arthroplasty is an invasive procedure which disrupts surrounding joint tissues, and can greatly perturb the joint’s immune homeostasis. In some instances, this may pose a difficult challenge to implant integration. Particles released from implants into the surrounding joint tissues activate the body’s defense mechanism, eliciting a cascade of events, which leads to biotribocorrosion and electrochemical attacks on the implant. This process may lead to the release of even more particles. Besides, implant makeup and designs, frictions between bearing surfaces, corrosion of non-moving parts with modular junctions, surgical mistakes, patient factor, comorbidities, and loosened components can alter the expected function of implants. High accumulations of these ions and particulates result in metallosis, with accompanying adverse complications. Current recommended treatment for failed prosthesis is revision surgeries. However, chelation therapy as a prophylactic intervention may be useful in future efforts but more investigation is required.

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