A FEASIBILITY STUDY TO INVESTIGATE IF THERE IS A CORRELATION BETWEEN SOFT TISSUE DEFORMATION AND ACOUSTIC EMISSION

BACKGROUND: Background: Acoustic emission from structures subject to external loads can be monitored to detect internal damage before destruction occurs. It is hypothesised that deformation of soft tissue will emit acoustic signals which may aid early detection of deep tissue injury, particularly in the lower limb amputee population. No previous studies have applied this method to biological soft tissue. OBJECTIVE: To determine if skeletal muscle tissue produced measurable acoustic emission during dynamic tensile loading with the aim to establish a reliable biomarker for lower limb prosthetic socket fit quantification and prosthetic health. STUDY DESIGN: Experimental study design. METHODOLOGY: In this research article, Sus scrofa domesticus (pork) muscle and Gallus gallus domesticus (chicken) muscle specimens (10mm width x 45mm height x 4mm depth) were submerged into saline baths while an Instron testing machine applied displacement controlled tensile loads. Time stamped, load, displacement and acoustic signal (hydrophone) data was collected. FINDINGS: The pork muscle was tested to failure being subject to tensile load. Prior to failure, no peaks were found in the amplitude or frequency of the acoustic signal to indicate that either tissue deformation or failure was occurring. Data gathered during chicken muscle testing was inconclusive. CONCLUSIONS: Results displayed that tensile testing of pork intercostal muscle produced tissue deformation and failure with no detectable change in the amplitude or frequency of the background sound during tensile loading. The other specimens failed before reaching the same levels of tensile load. Further studies are required in order to address the numerous limitations of this study. LAYMAN’S ABSTRACT Humans are made of biological material, some are hard such as the skeleton and some are soft as in muscles. When the soft tissue are under a too high stress condition, such as in diabetic patients, we talk about deep tissue injury. It has been proven that deep tissue injury negatively impacts the affected persons’ quality of life, through a reduction in mobility and ability levels. Deep tissue injury is additionally very costly to health care systems worldwide. Unfortunately, those with lower limb dysvascularity (in particular, amputees with limb loss secondary to dysvascularity and/or neuropathy) are at heightened risk of further damage from deep tissue injury. Therefore, this study ultimately aims to be used as a basis in order to determine if, at some stage, it would be possible to detect tissue that was ‘at risk’ of developing deep tissue injury. ARTICLE PDF LINK: https://jps.library.utoronto.ca/index.php/cpoj/article/view/30354/23004 How to cite: Buis A, Guarato F, Law J, Ralston Z, Courtney A. A feasibility study to investigate if there is a correlation between soft tissue deformation and acoustic emission. Canadian Prosthetics & Orthotics Journal, Volume 1, Issue 1, No 5, 2018. DOI: https://doi.org/10.33137/cpoj.v1i1.30354

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Discomfort/Pain and Tissue Oxygenation at the Lower Limb During Circumferential Compression: Application to Soft Exoskeleton Design

Human Factors The Journal of the Human Factors and Ergonomics Society ◽

10.1177/0018720819892098 ◽

2020 ◽

Vol 62 (3) ◽

pp. 475-488 ◽

Cited By ~ 2

Author(s):

Tjasa Kermavnar ◽

Kevin J. O’Sullivan ◽

Adam de Eyto ◽

Leonard W. O’Sullivan

Keyword(s):

Soft Tissue ◽

Lower Limb ◽

Near Infrared ◽

Tissue Oxygenation ◽

Tissue Injury ◽

Soft Tissue Injury ◽

The Body ◽

Subjective Perception ◽

Deep Tissue ◽

Exoskeleton Design

Objective To establish the relationship between circumferential compression on the lower limb during simulated ramp and staircase profile loading, and the resultant relationship with discomfort/pain and tissue oxygenation. Background Excessive mechanical loading by exoskeletons on the body can lead to pressure-related soft tissue injury. Potential tissue damage is associated with objective oxygen deprivation and accompanied by subjective perception of pain and discomfort. Method Three widths of pneumatic cuffs were inflated at the dominant thigh and calf of healthy participants using two inflation patterns (ramp and staircase), using a computer-controlled pneumatic rig. Participants rated discomfort on an electronic visual analog scale and deep tissue oxygenation was monitored using near infrared spectroscopy. Results Circumferential compression with pneumatic cuffs triggered discomfort and pain at lower pressures at the thigh, with wider cuffs, and with a ramp inflation pattern. Staircase profile compression caused an increase in deep tissue oxygenation, whereas the ramp profile compression decreased it. Conclusion Discomfort and pain during circumferential compression at the lower limb is related to the width of pneumatic cuffs, the inflation pattern, and the volume of soft tissue at the assessment site. The occurrence of pain is also possibly related to the decrease in deep tissue oxygenation during compression. Application Our findings can be used to inform safe and comfortable design of soft exoskeletons to avoid discomfort and possible soft tissue injury.

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Exploring the role of transtibial prosthetic use in Deep Tissue Injury development: A scoping review

10.21203/rs.2.20127/v1 ◽

2020 ◽

Author(s):

Marisa Graser(Former Corresponding Author) ◽

Sarah Day ◽

Arjan Buis(New Corresponding Author)

Keyword(s):

Risk Factors ◽

Soft Tissue ◽

Scoping Review ◽

English Language ◽

Tissue Injury ◽

Weight Bearing ◽

Small Sample ◽

Deep Tissue ◽

Deep Tissue Injury ◽

Tissue Reactions

Abstract Background: The soft tissue of the residual limb in transtibial prosthetic users encounters unique biomechanical challenges. Although not intended to tolerate high loads and deformation, it becomes a weight-bearing structure within the residuum-prosthesis-complex. Consequently, deep soft tissue layers may be damaged, resulting in Deep Tissue Injury (DTI). Whilst considerable effort has gone into DTI research on immobilised individuals, only little is known about the aetiology and population-specific risk factors in amputees. This scoping review maps out and critically appraises existing research on DTI in lower-limb prosthetic users according to (1) the population-specific aetiology, (2) risk factors, and (3) methodologies to investigate both. Results: A systematic search within the databases Pubmed, Ovid Excerpta Medica, and Scopus identified 16 English-language studies. The results indicate that prosthetic users may be at risk for DTI during various loading scenarios. This is influenced by individual surgical, morphological, and physiological determinants, as well as the choice of prosthetic componentry. However, methodological limitations, high inter-patient variability, and small sample sizes complicate the interpretation of outcome measures. Additionally, fundamental research on cell and tissue reactions to dynamic loading and on prosthesis-induced alterations of the vascular and lymphatic supply is missing. Conclusion: We therefore recommend increased interdisciplinary research endeavours with a focus on prosthesis-related experimental design to widen our understanding of DTI. The results have the potential to initiate much-needed clinical advances in surgical and prosthetic practice and inform future pressure ulcer classifications and guidelines.

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Fast Soft Tissue Deformation and Stump-Socket Interaction Toward a Computer-Aided Design System for Lower Limb Prostheses

IRBM ◽

10.1016/j.irbm.2020.02.003 ◽

2020 ◽

Vol 41 (5) ◽

pp. 276-285 ◽

Cited By ~ 1

Author(s):

A. Ballit ◽

I. Mougharbel ◽

H. Ghaziri ◽

T.-T. Dao

Keyword(s):

Soft Tissue ◽

Lower Limb ◽

Computer Aided Design ◽

Design System ◽

Tissue Deformation ◽

Soft Tissue Deformation ◽

Computer Aided ◽

Aided Design ◽

Lower Limb Prostheses

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Validation of a Numerical Model of Skeletal Muscle Compression With MR Tagging: A Contribution to Pressure Ulcer Research

Journal of Biomechanical Engineering ◽

10.1115/1.2987877 ◽

2008 ◽

Vol 130 (6) ◽

Cited By ~ 28

Author(s):

K. K. Ceelen ◽

A. Stekelenburg ◽

J. L. J. Mulders ◽

G. J. Strijkers ◽

F. P. T. Baaijens ◽

...

Keyword(s):

Skeletal Muscle ◽

Animal Studies ◽

Tissue Injury ◽

Element Model ◽

Tissue Deformation ◽

Deep Tissue ◽

Deep Tissue Injury ◽

Muscle Tissues

Sustained tissue compression can lead to pressure ulcers, which can either start superficially or within deeper tissue layers. The latter type includes deep tissue injury, starting in skeletal muscle underneath an intact skin. Since the underlying damage mechanisms are poorly understood, prevention and early detection are difficult. Recent in vitro studies and in vivo animal studies have suggested that tissue deformation per se can lead to damage. In order to conclusively couple damage to deformation, experiments are required in which internal tissue deformation and damage are both known. Magnetic resonance (MR) tagging and T2-weighted MR imaging can be used to measure tissue deformation and damage, respectively, but they cannot be combined in a protocol for measuring damage after prolonged loading. Therefore, a dedicated finite element model was developed to calculate strains in damage experiments. In the present study, this model, which describes the compression of rat skeletal muscles, was validated with MR tagging. Displacements from both the tagging experiments and the model were interpolated on a grid and subsequently processed to obtain maximum shear strains. A correlation analysis revealed a linear correlation between experimental and numerical strains. It was further found that the accuracy of the numerical prediction decreased for increasing strains, but the positive predictive value remained reasonable. It was concluded that the model was suitable for calculating strains in skeletal muscle tissues in which damage is measured due to compression.

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Healing effects of curcumin nanoparticles in deep tissue injury mouse model.

Current Drug Delivery ◽

10.2174/1567201818666201214125237 ◽

2020 ◽

Vol 18 ◽

Author(s):

Zirui Zhang ◽

Shangcong Han ◽

Panpan Liu ◽

Xu Yang ◽

Jing Han ◽

...

Keyword(s):

Wound Healing ◽

Mrna Expression ◽

Tissue Injury ◽

Inflammatory Cells ◽

Pcr Analysis ◽

Protective Effects ◽

Deep Tissue ◽

Deep Tissue Injury

Background: Chronic inflammation and lack of angiogenesis are the important pathological mechanisms in deep tissue injury (DTI). Curcumin is a well-known anti-inflammatory and antioxidant agent. However, curcumin is unstable under acidic and alkaline conditions, and can be rapidly metabolized and excreted in the bile, which shortens its bioactivity and efficacy. Objective: This study aimed to prepare curcumin-loaded poly (lactic-co-glycolic acid) nanoparticles (CPNPs) and to elucidate the protective effects and underlying mechanisms of wound healing in DTI models. Methods: CPNPs were evaluated for particle size, biocompatibility, in vitro drug release and their effect on in vivo wound healing. Results : The results of in vivo wound closure analysis revealed that CPNP treatments significantly improved wound contraction rates (p<0.01) at a faster rate than other three treatment groups. H&E staining revealed that CPNP treatments resulted in complete epithelialization and thick granulation tissue formation, whereas control groups resulted in a lack of compact epithelialization and persistence of inflammatory cells within the wound sites. Quantitative real-time PCR analysis showed that treatment with CPNPs suppressed IL-6 and TNF-α mRNA expression, and up-regulated TGF-β, VEGF-A and IL-10 mRNA expression. Western blot analysis showed up-regulated protein expression of TGF-β, VEGF-A and phosphorylatedSTAT3. Conclusion: Our results showed that CPNPs enhanced wound healing in DTI models, through modulation of the JAK2/STAT3 signalling pathway and subsequent upregulation of pro-healing factors.

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