Quantifying contact force artefact in near infrared spectroscopy

Transcutaneous near infrared spectroscopy (NIRS) of muscle requires coupling between the device and the skin. An unfortunate by-product of this coupling is contact force artefact, where the amount of contact force between the device and the skin affects measurements. Contact force artefact is well known, but largely ignored in most NIRS research. We performed preliminary investigations of contact force artefact to quantify tissue behaviour to inform future NIRS designs. Specifically, we conducted three studies on contact force artefact: (i) an experimental investigation of static load at varied levels of contact force and muscle activation, (ii) an experimental investigation of oscillating load at varied levels of contact force and frequency, and (iii) a Monte Carlo simulation of photon propagation through skin, adipose tissue, and muscle. Our results confirmed that contact force artefact is a confounding factor in NIRS muscle measurements because contact force affects measured hemoglobin concentrations in a manner consistent with muscle contractions. Further, the effects of contact force are not altered by muscle contraction and a likely candidate for the mechanism responsible for contact force artefact is the viscoelastic compression of superficial tissues (skin and adipose) during loading. Simulation data suggests that adipose tissue plays a key role in diffuse reflectance of photons, so any compression of the superficial tissues will affect the reflected signal. Further research is required to fully understand the mechanisms behind contact force artefact, which will, in turn, inform future NIRS device designs.

Techniques for In Vivo Measurement of Ligament and Tendon Strain: A Review

The critical clinical and scientific insights achieved through knowledge of in vivo musculoskeletal soft tissue strains has motivated the development of relevant measurement techniques. This review provides a comprehensive summary of the key findings, limitations, and clinical impacts of these techniques to quantify musculoskeletal soft tissue strains during dynamic movements. Current technologies generally leverage three techniques to quantify in vivo strain patterns, including implantable strain sensors, virtual fibre elongation, and ultrasound. (1) Implantable strain sensors enable direct measurements of tissue strains with high accuracy and minimal artefact, but are highly invasive and current designs are not clinically viable. (2) The virtual fibre elongation method tracks the relative displacement of tissue attachments to measure strains in both deep and superficial tissues. However, the associated imaging techniques often require exposure to radiation, limit the activities that can be performed, and only quantify bone-to-bone tissue strains. (3) Ultrasound methods enable safe and non-invasive imaging of soft tissue deformation. However, ultrasound can only image superficial tissues, and measurements are confounded by out-of-plane tissue motion. Finally, all in vivo strain measurement methods are limited in their ability to establish the slack length of musculoskeletal soft tissue structures. Despite the many challenges and limitations of these measurement techniques, knowledge of in vivo soft tissue strain has led to improved clinical treatments for many musculoskeletal pathologies including anterior cruciate ligament reconstruction, Achilles tendon repair, and total knee replacement. This review provides a comprehensive understanding of these measurement techniques and identifies the key features of in vivo strain measurement that can facilitate innovative personalized sports medicine treatment.

Preoperative preparation of infected wounds of superficial tissues, using the method of hyperbaric oxygenation with the ozone-containing mixture

Preoperative preparation of infected wounds of superficial tissues, using the method of hyperbaric oxygenation with the ozone-containing mixture

The Dynamic Microanatomy of skin and fascia. From the deep fascia to the skin surface.

The study of the structure of the skin and fascia in recent years has made important advances with respect to the "dynamic anatomy" that they present, that is, the anatomical relationships and tissue interconnections that you share through different tissues. In the same way fascias have been recognized as important sources of origin of different pathologies in the last years, so the greater knowledge of their function and structure is indispensable. The aim of this article is to review the last advances in the anatomic terminology of the soft superficial tissues as advances and recent anatomical discoveries.

Diversity of coelomycetous fungi in human infections: a 10-year experience of two European reference centres

ABSTRACTThe coelomycetous fungi are difficult to properly identify from their phenotypic characterization and their role as etiologic agents of human infections is not clear. We studied the species distribution of these fungi among clinical isolates that had been collected and stored over a ten-year period in two European reference laboratories (France and Spain). We identified phenotypically and molecularly 97 isolates by sequencing the D1-D2 fragment of the 28S nrRNA (LSU) gene. Species of the ordersPleosporalesandGlomerellaleswere present in both collections, andBotryosphaerialesandDiaporthalesonly in the French one. The most prevalent species wereMedicopsis romeroi,Neocucurbitaria keratinophila,Neocucurbitaria unguis-hominisandParaconiothyrium cyclothyrioides, which had been recovered primarily from superficial tissues. TheDidymellaceaewas the most common family represented, with 27 isolates distributed into five genera.