Digital healthcare technologies: Modern tools to transform prosthetic care.

INTRODUCTION: Digital healthcare technologies are transforming the face of prosthetic care. Millions of people with limb loss around the world do not have access to any form of rehabilitative healthcare. However, digital technologies provide a promising solution to augment the range and efficiency of prosthetists. AREAS COVERED: The goal of this review is to introduce the digital technologies that have the potential to change clinical methods in prosthetic healthcare. Our target audience are researchers who are unfamiliar with the field of prostheses in general, especially with the newest technological developments. This review addresses technologies for: scanning of amputated limbs, limb-to-socket rectification, additive manufacturing of prosthetic sockets, and quantifying patient response to wearing sockets. This review does not address biomechatronic prostheses or biomechanical design practices. EXPERT OPINION: Digital technologies will enable affordable prostheses to be built on a scale larger than with today's clinical practices. Large technological gaps need to be overcome to enable the mass production and distribution of prostheses digitally. However, recent advances in computational methods and CAD/CAM technologies are bridging this gap faster than ever before. We foresee that these technologies will return mobility and economic opportunity to amputees on a global scale in the near future.

Cholla cactus frames as lightweight and torsionally tough biological materials.

Biological materials tested in compression, tension, and impact inspire designs for strong and tough materials, but torsion is a relatively neglected loading mode. The wood skeletons of cholla cacti, subject to spartan desert conditions and hurricane force winds, provide a new template for torsionally resilient biological materials. Novel mesostructural characterization methods of laser-scanning and photogrammetry are used alongside traditional optical microscopy, scanning electron microscopy, and micro-computed tomography to identify mechanisms responsible for torsional resistance. These methods, in combination with finite element analysis reveal how cholla meso and macro-porosity and fibril orientation contribute to highly density-efficient mechanical behavior. Selective lignification and macroscopic tubercle pore geometry contribute to density-efficient shear stiffness, while mesoscopic wood fiber straightening, delamination, pore collapse, and fiber pullout provide extrinsic toughening mechanisms. These energy absorbing mechanisms are enabled by the hydrated material level properties. Together, these hierarchical behaviors allow the cholla to far exceed bamboo and trabecular bone in its ability to combine specific torsional stiffness, strength, and toughness. STATEMENT OF SIGNIFICANCE: The Cholla cactus experiences, due to the high velocity desert winds, high torsional loads. Our study has revealed the amazingly ingenious strategy by which the tubular structure containing arrays of voids intermeshed with wood fibers resists these high loads. Deformation is governed by compressive and tensile stresses which are greatest at 45 degrees to the cross section. It proceeds by stretching, sliding, and bending of the wood fibers which are coupled with the pore collapse, resulting in delayed failure and a high torsional toughness.

Mechanical Optimization of Diatomite Monoliths from Freeze Casting for High-Throughput Applications.

The silica cell walls of diatoms, the abundant microalga 1-100 µm in size, show a highly ordered hierarchical porosity and are widely available through their fossilized form known as diatomite. The goal of this research was to use this cost-effective source of porous silica in a unidirectional freezing process called ice-templating, or freeze casting, to create a ceramic membrane with unidirectional lamellar walls of ∼15 µm channels, which allows for an efficient mass transport of fluids (i.e., low pressure drop), while maintaining the optimal mechanical properties. Control over the monoliths was explored by varying the mass ratio of diatomite and sodium carbonate and the solid ratio in the initial slurry before freeze casting. The resultant monolith properties were assessed using scanning electron microscopy, mercury intrusion porosimetry, and mechanical testing. The membranes then underwent an in-line vacuum filtration of methylene blue dye and monodisperse latex beads to quantify the membrane filtration performance through chemical adsorption and depth filtration capabilities, respectively. Control over the material properties of the biosourced ceramic monoliths allows for a cost-efficient and hierarchically porous ceramic template with efficient mass transfer capabilities that can be potentially functionalized with a variety of sophisticated nanomaterials for various adsorbent, filter, catalysis, and sensor applications.