Improved surgical procedures and implant developments for ligament or tendon repair require an in-depth understanding of tissue load-deformation and fatigue properties. Cyclic testing will provide crucial information on the behavior of these materials under reoccurring loads and on fatigue strength. Sparse data are available describing soft tissue behavior under cyclic loading. To examine fatigue strength, a new technology was trialed deploying 3D-printing to facilitate and standardize cyclic tests aiming to determine tendon fatigue behavior. Cadaveric flexor digitorum tendons were harvested and mounted for tensile testing with no tapering being made, using 3Dprinted clamps and holder arms, while ensuring a consistent testing length. Loads ranging between 200 to 510 N were applied at a frequency of 4 Hz, and cycles to failure ranged between 8 and >260,000. S–N curves (Woehler curves) were generated based on the peak stresses and cycles to failure. Power regression yielded a combined coefficient of determination of stress and cycles to failure of R 2 = 0.65, while the individual coefficients for tissues of single donors ranged between R 2 = 0.54 and R 2 = 0.88. The here-presented results demonstrate that S–N curves of human tendons can be obtained using a standardized setting deploying 3D-printing technology

Промышленное строительство, развитие аддитивных технологий, эффективность реализации 3D-печати, бизнес-модель реализации аддитивных технологий в промышленном строительстве. Предмет исследования – управленческие отношения возникающие в процессе интеграции технологий 3D-печати при реализации проектов промышленного строительства. Цель работы – разработка механизма интеграции технологий 3D-печати при их внедрении в строительство промышленных зданий и оценке их влияния на производственные процессы. Проведение исследования опирается на общенаучные методы и подходы, ведущим из которых является моделирование. Также, в работе используется системный анализ, методы факторного, логического и сравнительного анализа, графических изображений, обеспечивающие комплексный и объективный характер изучения проблемы. Рассмотрены теоретические и методические основы аддитивных технологий в промышленном строительстве, изложена сущность исследуемой проблемы. Произведен структурный анализ предпосылок применения, существующих методов и опыта использования, исследование методов и возможностей формирования модели ценообразования аддитивных технологий. Предложена бизнес-модель реализации технологий 3D-печати. На основе анализа финансовых показателей выявлено, что интеграция аддитивных технологий в промышленное строительство повышает эффективность производства и снижает экономические затраты на реализацию проектов. Сформулированы рекомендации для дальнейшего развития технологий 3D-печати в отрасли. / The subject of the study is management relations arising in the process of integrating 3D printing technologies in the implementation of industrial construction projects. The purpose of the work is to develop a mechanism for integrating 3D printing technologies when they are introduced into the construction of industrial buildings and assessing their impact on production processes. The research is based on general scientific methods and approaches, the leading of which is modeling. Also, the work uses system analysis, methods of factorial, logical and comparative analysis, graphic images, providing a comprehensive and objective nature of the study of the problem. The theoretical and methodological foundations of additive technologies in industrial construction are considered, the essence of the problem under study is outlined. A structural analysis of the prerequisites for the application, existing methods and experience of use, research of methods and possibilities of forming a pricing model of additive technologies is carried out. A business model for the implementation of 3D printing technologies is proposed. Based on the analysis of financial indicators, it was revealed that the integration of additive technologies into industrial construction increases production efficiency and reduces the economic costs of project implementation. Recommendations are formulated for the further development of 3D printing technologies in the industry.

Indiana University-Purdue University Indianapolis (IUPUI) / Instrument assisted soft tissue mobilization (IASTM) is a form of massage using rigid manufactured or cast devices. The delivered force, which is a critical parameter in massage during IASTM, has not been measured or standardized for most clinical practices. In addition to the force, the angle of treatment and frequency play an important role during IASTM. As a result, there is a strong need to characterize the delivered force to a patient, angle of treatment, and stroke frequency. This thesis proposes two novel mechatronic designs for a specific instrument from Graston Technique(Model GT3), which is a frequently used tool to clinically deliver localize pressure to the soft tissue. The first design is based on compression load cells, where 4-load cells are used to measure the force components in three-dimensional space. The second design uses a 3D load cell, which can measure all three force components force simultaneously. Both designs are implemented with IMUduino microcontroller chips which can also measure tool orientation angles and provide computed stroke frequency. Both designs, which were created using Creo CAD platform, were also analyzed thorough strength and integrity using the finite element analysis package ANSYS. Once the static analysis was completed, a dynamic model was created for the first design to simulate IASTM practice using the GT-3 tool. The deformation and stress on skin were measured after applying force with the GT-3 tool. Additionally, the relationship between skin stress and the load cell measurements has been investigated. The second design of the mechatronic IASTM tool was validated for force measurements using an electronic plate scale that provided the baseline force values to compare with the applied force values measured by the tool. The load cell measurements and the scale readings were found to be in agreement within the expected degree of accuracy. The stroke frequency was computed using the force data and determining the peaks during force application. The orientation angles were obtained from the built-in sensors in the microchip.

3D printing applications have achieved increased success as an additive manufacturing (AM) process. Micro-structure of mechanical/biological materials present design challenges owing to the resolution of 3D printers and material properties/composition. Biological materials are complex in structure and composition. Efforts have been made by 3D printer manufacturers to provide materials with varying physical, mechanical and chemical properties, to handle simple to complex applications. As 3D printing is finding more medical applications, we expect future uses in areas such as hip replacement - where smoothness of the femoral head is important to reduce friction that can cause a lot of pain to a patient. The issue of print resolution plays a vital role due to staircase effect. In some practical applications where 3D printing is intended to produce replacement parts with joints with movable parts, low resolution printing results in fused joints when the joint clearance is intended to be very small. Various 3D printers are capable of print resolutions of up to 600dpi (dots per inch) as quoted in their datasheets. Although the above quoted level of detail can satisfy the micro-structure needs of a large set of biological/mechanical models under investigation, it is important to include the ability of a 3D slicing application to check that the printer can properly produce the feature with the smallest detail in a model. A way to perform this check would be the physical measurement of printed parts and comparison to expected results. Our work includes a method for using ray casting to detect features in the 3D CAD models whose sizes are below the minimum allowed by the printer resolution. The resolution validation method is tested using a few simple and complex 3D models. Our proposed method serves two purposes: (a) to assist CAD model designers in developing models whose printability is assured. This is achieved by warning or preventing the designer when they are about to perform shape operations that will lead to regions/features with sizes lower than that of the printer resolution; (b) to validate slicing outputs before generation of G-Codes to identify regions/features with sizes lower than the printer resolution.