The effect of visual and kinesthetic feedback on the performance of a static balance task in rhythmic gymnastics

The purpose of this study was to examine the role of kinesthetic or visual plus kinesthetic feedback in the performance of a complex static balance in rhythmic gymnastics. Thirty-six female P.E. students between the ages of 19-21 years old (M = 20.7), performed a dynamic balance task requiring standing on the right leg while the left leg was extended in the lateral plane forming a 90degrees angle to the body ("balance a la second with passe developpe"). Participants were divided in two practice groups. The first group practiced the skill facing a white wall while the second group practiced the skill facing a mirror. Performance was evaluated by two independent observers under the same sensory conditions: a) just after the practice phase (post-test) and b) one week later (retention test) according to fifteen technical points defined by the Code of Points of the International Federation of Gymnastics. The duration of tip-tow stance, the total and partial technical performance scores were analyzed using a 2(group) x 2 (test) multivariate ANOVA model. When the performance was evaluated just after the practice session (post-test), it was noted than the group practicing the skill in front of the mirror had significantly higher partial and total technical performance scores and stayed longer in the tip-toe stance than the group who practiced the skill using only kinesthetic feedback. However, this superiority of performance by the group using kinesthetic plus visual feedback was not permanent, as this was confirmed by the absence of significant differences between the groups in the retention test one week later. It is concluded that kinesthetic feedback plays the same crucial role as visual plus kinesthetic feedback in complex and difficult sport skills that require high level of total body coordination

Design and Prototype Fabrication of a Cost-Effective Microneedle Drug Delivery Apparatus Using Fused Filament Fabrication, Liquid Crystal Display and Semi-Solid Extrusion 3D Printing Technologies

The current study describes the design of a cost-effective drug delivery apparatus that can be manufactured, assembled, and utilized as easily and quickly as possible, minimizing the time and expense of the supply chain. This apparatus could become a realistic alternative method of providing a vaccine or drug in harsh circumstances, including humanitarian disasters or a lack of medical and nursing staff, conditions that are frequently observed in developing countries. Simultaneously, with the use of microneedles (MNs), the apparatus can benefit from the numerous advantages offered by them during administration. The hollow microneedles in particular are internally perforated and are capable of delivering the active substance to the skin. The apparatus was designed with appropriate details in computer aided design software, and various 3D printing technologies were utilized in order to fabricate the prototype. The parts that required minimum accuracy, such as the main body of the apparatus, were fabricated with fused filament fabrication. The internal parts and the hollow microneedles were fabricated with liquid crystal display, and the substance for the drug loading carrier, which was an alginate gel cylinder, was fabricated with semi-solid extrusion 3D printing

3D printed hollow microneedles for transdermal insulin delivery

Microneedles (MN) are miniature devices of a maximum length of 1000 μm, capable of perforating painlessly stratum corneum and releasing their active content in the skin layers beneath. The significance of MNs lies on the fact that they have the potential to substitute the fear inducing injections, while avoiding first pass effect or other possibly unwished metabolic changes of the oral administration1. In the current study 3D printed microneedles were fabricated by means of liquid crystal display (LCD) vat polymerization 3D printing technology for the transdermal delivery of human insulin in vitro.In the current study the structural features of two different 3D printed 6x6 HMN geometries were assessed. Non-destructive 3D (volumetric) imaging by means of μCT demonstrated that the 3D printing method used in this study allows for high consistency and reproducibility with respect to needles’ geometric characteristics. Diffusion studies demonstrated that syringe-like HMNs were more effective upon insulin administration compared with curved pyramid ones. Although syringe-like geometry penetrates skin at higher insertion force, it is probably more suitable for macromolecular drug delivery which might be attributed to the geometrical characteristics of the microneedles

Computer aided design and 3D printing for STEAM education: A technical reference guide for teachers

The paper will present the MAKEITREAL Technical Reference Guide, an open educational resource (OER) which provides technical information on Computer Aided Design (CAD) and 3D printing for STEAM education (Science, Technology, Engineering, Arts, Math). The reference guide presents in an easy to grasp way all the technical issues and the practicalities that should be considered by the teachers regarding the digital fabrication tools, 3D modelling, 3D printing technologies in the classroom. The guide elaborates on key technical decisions at a high level helping teachers overcome any obstacles or problems regarding technical aspects. The MAKEITREAL Technical Reference Guide offers an insight into CAD technologies, and current software developments and offers a comprehensive workflow from design to production. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only

A 3D printed bilayer oral solid dosage form combining metformin for prolonged and glimepiride for immediate drug delivery

Fused Deposition Modelling (a.k.a. FDM-3D printing) has been previously employed in the development of personalized medicines with unique properties and release behavior. In the present work, a bilayer dosage form containing two anti-diabetic drugs with different daily dosage regimens; i.e. metformin and glimepiride, was manufactured via FDM 3D printing, studied using a variety of techniques and characterized in vitro. Metformin and glimepiride were embedded in Eudragit® RL sustained release layer and polyvinyl alcohol (PVA) layer respectively. Incorporation of more than one API's into the formulation is desirable, as it increases patient compliance and reduces cost of treatment, especially when distinct dosages of API's can be adjusted individually in situ, in order to meet each patient's specific needs, a capability provided by 3D printing. A number of different preparation methods, which involved different plasticizers and extruders, were tested on manufacturing Eudragit® RL drug-loaded filaments for printing the sustained release layer. The properties of the produced filaments were assessed by means of mechanical and physicochemical characterization techniques and the filaments with the optimum properties were used for printing. Microfocus computed tomography (μCT) imaging-based actual/nominal comparison analysis showed a printing accuracy ranging between −100, +200 μm, while X-ray (XRD) diffractograms revealed the incorporation of the (initially crystalline) API's as amorphous dispersions into polymer matrices. Dissolution tests showed sufficient drug release for both drugs in desired time frames (75 min for glimepiride and 480 min for metformin). The results from the current study emphasize the potentiality of 3D printing technology for tailor-made solid dosage forms for combined pharmacotherapy, even at the cases when API's with different desirable release profiles are employed.</p

Fabrication of an osmotic 3D printed solid dosage form for controlled release of active pharmaceutical ingredients

In pharmaceutical formulations, pharmacokinetic behavior of the Active Pharmaceutical Ingredients (API's) is significantly affected by their dissolution profiles. In this project, we attempted to create personalized dosage forms with osmotic properties that exhibit different API release patterns via Fused Deposition Modelling (FDM) 3D printing. Specifically, cellulose acetate was employed to create an external shell of an osmotically active core containing Diltiazem (DIL) as model drug. By removing parts of the shell (upper surface, linear lateral segments) were created dosage forms that modify their shape at specific time frames under the effect of the gradually induced osmotic pressure. Hot-Melt Extrusion (HME) was employed to fabricate two different 3DP feeding filaments, for the creation of either the shell or the osmotic core (dual-extrusion printing). Printed formulations and filaments were characterized by means of (TGA, XRD, DSC) and inspected using microscopy (optical and electron). The mechanical properties of the filaments were assessed by means of micro- and macro mechanical testing, whereas micro-Computed Tomography (μCT) was employed to investigate the volumetric changes occurring during the hydration process. XRD indicated the amorphization of DIL inside HME filaments and printed dosage forms, whereas the incorporated NaCl (osmogen) retained its crystallinity. Mechanical properties' testing confirmed the printability of produced filaments. Dissolution tests revealed that all formulations exhibited sustained release differing at the initiation time of the API dissolution (0, 120 and 360 min for the three different formulations). Finally, μCT uncovered the key structural changes assonated with distinct phases of the release profile. The above results demonstrate the successful utilization of an FDM 3D printer in order to create osmotic 3D printed formulations exhibiting sustained and/or delayed release, that can be easily personalized containing API doses corresponding to each patient's specific needs.</p