Mechanical Characterization of the Human Abdominal Wall Using Uniaxial Tensile Testing.

It is generally accepted that the human abdominal wall comprises skin, subcutaneous tissues, muscles and their aponeuroses, and the parietal peritoneum. Understanding these layers and their mechanical properties provides valuable information to those designing procedural skills trainers, supporting surgical procedures (hernia repair), and engineering-based work (in silico simulation). However, there is little literature available on the mechanical properties of the abdominal wall in layers or as a composite in the context of designing a procedural skills trainer. This work characterizes the tensile properties of the human abdominal wall by layer and as a partial composite. Tissues were collected from fresh-never-frozen and fresh-frozen cadavers and tested in uniaxial tension at a rate of 5 mm/min until failure. Stress-strain curves were created for each sample, and the values for elastic moduli, ultimate tensile strength, and strain at failure were obtained. The experimental outcomes from this study demonstrated variations in tensile properties within and between tissues. The data also suggest that the tensile properties of composite abdominal walls are not additive. Ultimately, this body of work contributes to a deeper comprehension of these mechanical properties and will serve to enhance patient care, refine surgical interventions, and assist with more sophisticated engineering solutions.

Applied use of biomechanical measurements from human tissues for the development of medical skills trainers: a scoping review.

OBJECTIVE: The objective of this review was to identify quantitative biomechanical measurements of human tissues, the methods for obtaining these measurements, and the primary motivations for conducting biomechanical research. INTRODUCTION: Medical skills trainers are a safe and useful tool for clinicians to use when learning or practicing medical procedures. The haptic fidelity of these devices is often poor, which may be because the synthetic materials chosen for these devices do not have the same mechanical properties as human tissues. This review investigates a heterogeneous body of literature to identify which biomechanical properties are available for human tissues, the methods for obtaining these values, and the primary motivations behind conducting biomechanical tests. INCLUSION CRITERIA: Studies containing quantitative measurements of the biomechanical properties of human tissues were included. Studies that primarily focused on dynamic and fluid mechanical properties were excluded. Additionally, studies only containing animal, in silico , or synthetic materials were excluded from this review. METHODS: This scoping review followed the JBI methodology for scoping reviews and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Sources of evidence were extracted from CINAHL (EBSCO), IEEE Xplore, MEDLINE (PubMed), Scopus, and engineering conference proceedings. The search was limited to the English language. Two independent reviewers screened titles and abstracts as well as full-text reviews. Any conflicts that arose during screening and full-text review were mediated by a third reviewer. Data extraction was conducted by 2 independent reviewers and discrepancies were mediated through discussion. The results are presented in tabular, figure, and narrative formats. RESULTS: Data were extracted from a total of 186 full-text publications. All of the studies, except for 1, were experimental. Included studies came from 33 countries, with the majority coming from the United States. Ex vivo methods were the predominant approach for extracting human tissue samples, and the most commonly studied tissue type was musculoskeletal. In this study, nearly 200 unique biomechanical values were reported, and the most commonly reported value was Young's (elastic) modulus. The most common type of mechanical test performed was tensile testing, and the most common reason for testing human tissues was to characterize biomechanical properties. Although the number of published studies on biomechanical properties of human tissues has increased over the past 20 years, there are many gaps in the literature. Of the 186 included studies, only 7 used human tissues for the design or validation of medical skills training devices. Furthermore, in studies where biomechanical values for human tissues have been obtained, a lack of standardization in engineering assumptions, methodologies, and tissue preparation may implicate the usefulness of these values. CONCLUSIONS: This review is the first of its kind to give a broad overview of the biomechanics of human tissues in the published literature. With respect to high-fidelity haptics, there is a large gap in the published literature. Even in instances where biomechanical values are available, comparing or using these values is difficult. This is likely due to the lack of standardization in engineering assumptions, testing methodology, and reporting of the results. It is recommended that journals and experts in engineering fields conduct further research to investigate the feasibility of implementing reporting standards. REVIEW REGISTRATION: Open Science Framework https://osf.io/fgb34.

Tools measuring high haptic fidelity of procedural skills trainers in physician training and education: a scoping review protocol.

OBJECTIVE: The objective of this scoping review is to identify instruments that measure the physical haptic fidelity of procedural skills trainers. INTRODUCTION: Procedural skills trainers have demonstrated beneficial outcomes for clinicians when used to practice and rehearse procedures. Despite this, several design flaws currently limit the widespread implementation of such trainers. One notable deficit in current trainer designs is haptic fidelity. Identifying measurements of haptic fidelity may maximize the benefit of using certain training devices as well as guiding future design. INCLUSION CRITERIA: This review will consider studies that assess the high fidelity haptics of procedural skills training devices in adult physicians above the level of an intern physician. Studies that do not include physicians will be excluded. METHODS: The review will follow the JBI methodology for scoping reviews and will be reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Both published and unpublished studies will be searched for in MEDLINE (PubMed), Scopus, Web of Science Core Collection, Cochrane Central Register of Controlled Trials (CENTRAL), Embase (Ovid), CINAHL (EBSCOhost), ProQuest Dissertations and Theses (ProQuest), and Google Scholar. There will be no date, setting, or geographical limits, but only studies in English will be included. REVIEW REGISTRATION: Open Science Framework osf.io/pvazu/.

Applied use of biomechanical measurements from human tissues for the development of medical skills trainers: a scoping review protocol.

OBJECTIVE: The objective of this scoping review is to identify the availability of quantitative biomechanical measurements from human tissues. This review will also consider the primary motivations for collecting biomechanical measurements of human tissues. The overall purpose of our research is to develop medical skills trainers that provide better haptic fidelity than those that are currently available. INTRODUCTION: Medical skills trainers are commonly used in clinician training, but trainers do not always have the same haptic properties as patients. This could be due to the limited availability or application of documented biomechanical properties of human tissues when developing trainers. INCLUSION CRITERIA: This scoping review will examine studies that have quantitatively measured the mechanical properties of human tissues. Only macroscopic specimens will be included, and articles primarily considering optical, acoustic, and thermal properties will be excluded. Included sources of evidence are from primary research, systematic reviews, meta-analyses, and conference proceedings. METHODS: This review will follow the JBI methodology for scoping reviews. Sources of evidence will be extracted from CINAHL, IEEE Xplore, MEDLINE, Scopus, and biomedical engineering conference proceedings. The search is limited to articles in English. Full articles will be retrieved if their title or abstract meet the inclusion criteria. Tabular, visual, and narrative summaries will be used to present the results. SCOPING REVIEW PROTOCOL REGISTRATION: Open Science Framework https://osf.io/fgb34.