VAD in failing Fontan: simulation of ventricular, cavo-pulmonary and biventricular assistance in systolic/diastolic ventricular dysfunction and in pulmonary vascular resistance increase.

Aim: Due to the lack of donors, VADs could be an alternative to heart transplantation for Failing Fontan patients (PTs). Considering the complex physiopathology and the type of VAD connection, a numerical model (NM) could be useful to support clinical decisions. The aim of this work is to test a NM simulating the VADs effects on failing Fontan for systolic dysfunction (SD), diastolic dysfunction (DD) and pulmonary vascular resistance increase (PRI). Methods: Data of 10 Fontan PTs were used to simulate the PTs baseline using a dedicated NM. Then, for each PTs a SD, a DD and a PRI were simulated. Finally, for each PT and for each pathology, the VADs implantation was simulated. Results: NM can well reproduce PTs baseline. In the case of SD, LVAD increases the cardiac output (CO) (35%) and the arterial systemic pressure (ASP) (25%). With cavo-pulmonary assistance (RVAD) a decrease of inferior vena cava pressure (IVCP) (39%) was observed with 34% increase of CO. With the BIVAD an increase of ASP (29%) and CO (37%) was observed. In the case of DD, the LVAD increases CO (42%), the RVAD decreases the IVCP. In the case of PRI, the highest CO (50%) and ASP (28%) increase is obtained with an RVAD together with the highest decrease of IVCP (53%). Conclusions: The use of NM could be helpful in this innovative field to evaluate the VADs implantation effects on specific PT to support PT and VAD selection

1st EFORT European Consensus: Medical & Scientific Research Requirements for the Clinical Introduction of Artificial Joint Arthroplasty Devices

Innovations in Orthopaedics and Traumatology have contributed to the achievement of a high-quality level of care in musculoskeletal disorders and injuries over the past decades. The applications of new implants as well as diagnostic and therapeutic techniques in addition to implementation of clinical research, have significantly improved patient outcomes, reduced complication rates and length of hospital stay in many areas. However, the regulatory framework is extensive, and there is a lack of understanding and clarity in daily practice what the meaning of clinical & pre‐clinical evidence as required by the MDR is. Thus, understanding and clarity are of utmost importance for introduction of new implants and implant-related instrumentation in combination with surgical technique to ensure a safe use of implants and treatment of patients. Therefore EFORT launched IPSI, The Implant and Patient Safety Initiative, which starting from an inaugural workshop in 2021 issued a set of recommendations, notably through a subsequent Delphi Process involving the National Member Societies of EFORT, European Specialty Societies as well as International Experts. These recommendations provide surgeons, researchers, implant manufacturers as well as patients and health authorities with a consensus of the development, implementation, and dissemination of innovation in the field of arthroplasty. The intended key outcomes of this 1st EFORT European Consensus on “Medical & Scientific Research Requirements for the Clinical Introduction of Artificial Joint Arthroplasty Devices”are consented, practical pathways to maintain innovation and optimisation of orthopaedic products and workflows within the boundaries of MDR 2017/745. Open Access practical guidelines based on adequate, state of the art pre-clinical and clinical evaluation methodologies for the introduction of joint replacements and implant-related instrumentation shall provide hands-on orientation for orthopaedic surgeons, research institutes and laboratories, orthopaedic device manufacturers, Notified Bodies but also for National Institutes and authorities, patient representatives and further stakeholders. We would like to acknowledge and thank the Scientific Committee members, all International Expert Delegates, the Delegates from European National & Specialty Societies and the Editorial Team for their outstanding contributions and support during this EFORT European Consensus

Design and Fabrication of Biomorphic Scaffolds for Tissue Regrowth by 3D Printing

Tissue engineering has shown a need for three-dimensional (3D) tissue scaffolds for cell growth as an improvement over slab scaffolds. We present a novel scaffold design and manufacturing process, utilizing biomorphic scaffold shapes based on computational models and defined by optimal surface area to volume ratios. Using these models and a low-cost 3D printer, we developed fractal-based biocompatible 3D tissue scaffolds that supported cell proliferation

Next-generation tissue-engineered heart valves with repair, remodelling and regeneration capacity

Valvular heart disease is a major cause of morbidity and mortality worldwide. Surgical valve repair or replacement has been the standard of care for patients with valvular heart disease for many decades, but transcatheter heart valve therapy has revolutionized the field in the past 15 years. However, despite the tremendous technical evolution of transcatheter heart valves, to date, the clinically available heart valve prostheses for surgical and transcatheter replacement have considerable limitations. The design of next-generation tissue-engineered heart valves (TEHVs) with repair, remodelling and regenerative capacity can address these limitations, and TEHVs could become a promising therapeutic alternative for patients with valvular disease. In this Review, we present a comprehensive overview of current clinically adopted heart valve replacement options, with a focus on transcatheter prostheses. We discuss the various concepts of heart valve tissue engineering underlying the design of next-generation TEHVs, focusing on off-the-shelf technologies. We also summarize the latest preclinical and clinical evidence for the use of these TEHVs and describe the current scientific, regulatory and clinical challenges associated with the safe and broad clinical translation of this technology.</p

Process–Structure–Properties in Polymer Additive Manufacturing II

Additive manufacturing (AM) methods have grown and evolved rapidly in recent years. AM for polymers is particularly exciting and has great potential in transformative and translational research in many fields, such as biomedicine, aerospace, and even electronics. The current methods for polymer AM include material extrusion, material jetting, vat polymerization, and powder bed fusion. In this Special Issue, state-of-the-art reviews and current research results, which focus on the process–structure–properties relationships in polymer additive manufacturing, are reported. These include, but are not limited to, assessing the effect of process parameters, post-processing, and characterization techniques

Biomimetic Electrospun Fibers for Peripheral Nervous System Repair.

Endogenous peripheral nerve regeneration is a slow and error-prone process, and injury to the peripheral nervous system is a significant cause of permanent disability. One promising approach to improving these outcomes is the use of artificial nerve conduits. The primary goal of this dissertation was to develop an artificial nerve conduit that outperformed the current gold standard, the autograft. The design approach was to mimic the internal microenvironment of native nerve physically and chemically, using aligned electrospun fibers modified with polypeptides to accelerate growth of regenerating neurites. In order to evaluate this candidate material however, it was necessary to develop a sufficiently rigorous in vitro system to partially predict how nanofibers could influence regenerating neurons in vivo. Three steps to this system process include electrospinning nanofibers, culturing neurons nanofibers, and assessing neuronal behavior, the first and third of which remained inefficient and irreproducible. Critical variables of electrospinning poly-L-lactide (PLLA) nanofibers were systematically investigated. A protocol to electrospin highly aligned nanofibers reproducibly was developed. We found that the distance between the spinneret tip and collector, decreasing solvent volatility, and concentrating the electric field with an aluminum sheet on the spinneret greatly improved density and alignment of electrospun nanofibers. To quantify the developmental response of neurons to nanofiber topography, a process was developed to analyze microscopic images of neurons using MetaMorph software and a custom-designed algorithm developed in MATLAB. The system was verified against analysis by hand and increased the speed of morphological analysis of neurons from 2 weeks to less than a day, roughly 90%. The peptide fragment IKVAV, when bound to nanofibers, was found to increase the speed of neurite growth in vitro compared to unbound nanofibers. As a result, IKVAV-bound nanofibers were incorporated into conduits and implanted into a gap in the sciatic nerve of Lewis rats. IKVAV-modified fibers supported regeneration, producing detectable nerve conduction after only six weeks of implantation, but underperformed autografts. Together, these results show that electrospun fibers can be reproducibly aligned, covalently bound, and used to promote peripheral nerve regeneration in vivo.PHDBiomedical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/97987/1/mkleach_1.pd

Book of Abstracts 15th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering and 3rd Conference on Imaging and Visualization

In this edition, the two events will run together as a single conference, highlighting the strong connection with the Taylor & Francis journals: Computer Methods in Biomechanics and Biomedical Engineering (John Middleton and Christopher Jacobs, Eds.) and Computer Methods in Biomechanics and Biomedical Engineering: Imaging and Visualization (JoãoManuel R.S. Tavares, Ed.). The conference has become a major international meeting on computational biomechanics, imaging andvisualization. In this edition, the main program includes 212 presentations. In addition, sixteen renowned researchers will give plenary keynotes, addressing current challenges in computational biomechanics and biomedical imaging. In Lisbon, for the first time, a session dedicated to award the winner of the Best Paper in CMBBE Journal will take place. We believe that CMBBE2018 will have a strong impact on the development of computational biomechanics and biomedical imaging and visualization, identifying emerging areas of research and promoting the collaboration and networking between participants. This impact is evidenced through the well-known research groups, commercial companies and scientific organizations, who continue to support and sponsor the CMBBE meeting series. In fact, the conference is enriched with five workshops on specific scientific topics and commercial software.info:eu-repo/semantics/draf

Optical and visual characterization of multifocal contact lenses and multifocal intraocular lenses

Vision is presented and universally accepted as the most precious of the human senses.lt is structured in three main parts: the optical system {eye), the photo-sensor {eye's retina), and the data processor (brain). If one of them is affected by any disease or dysfunction, vision will be terrible or even nonexistent One of the most common dysfunction is presbyopia.lt i s an age-related disorder that is undergone by all the population s ince their mid-late-40s and it is consists in the loss of the ability to focus near objects (accommodation). A huge number of possible corrections of it can be easily found. On one hand, there are temporary corrections ,as progressive spectacle tenses or multifocal contact tenses. On the other hand, permanent corrections as multifocal i ntraocular lenses, multifocal cornea! ablation, accommodating intraocular tenses, monovision systems, or scleral modifications are also applied to correct presbyopia. Another age-related dysfunction is cataract. Cataract is the opacification of the crystalline fens and decreases the quality of the visual function. Consequently, it is one of the leading visual impairments in adults over 60 years old, affecting the half of the adults aged between 75-85 years old. The only possible solution far cataract is the extraction of the opacified fibers of the crystalline lens and the replacement of them with an intraocular lens by surgery. Due to the fact that all the patients affected by an age-related cataract are also affected by presbyopia it is totally understandable that a number of patients choose mulltifocal introcular lens to substitute their crystalline tenses .This way, only one surgery is needed to salve both age-related dysfunctions. Usually, young presbyopes choose a temporary correction as a first option to correct presbyopia. Some presbyopia corrections are based on the simultaneous vision principie, as, far example, multifocal contact or intraocular lenses. The optical design of these kind of lenses is very complex. Consequently, It is characterization is also difficult When these lenses were launched into the market, it was only possible to characterize optical quality before the implantation or the adaptation of them (characterization in vitro) and the visual quality after the surgery or the clinical adaptation was performed (characterization) .M. present and thanks to the technological advances, different new commercial instruments that are to perform characterization in vivo of the visual quality before the implantation or the adaptation of simultaneous vis ion tenses. They are based on the simulation of the vision that these tenses give to the implanted eye. Some experimental prototypes and commercial aberrometers or double­ pass systems have used to perform an optical quality characterization in vivo, but some issues have been reported. Taking into account all this information, the main goal of this thesis is the design and the assembly of a new open-field double-pass system with asymmetric focus that is suitable to characterize invivo optical quality in patients implanted or adapted with multifocal intraocular or contact lenses. In order to achieve this aim, different studies and processes were carried out Review of presbyopia corrections and the characterization of them (Clinical study about objective over-refraction wearing multifocal contact lenses); Verification of the suitability of one commerciat simulator (Clinical study with the commercial simulator VirtlOL (10lens S.l.)); Design and assembly of the double-pass system with asymmetric focus (Opto-mechanical design/ Validation of all the elements included in the system/ Optical validation of the system); Programming of the softwares to manage the system; Validation of the new prototype (Two clinical studies characterizing eyes implanted with multifocal introcular tenses by using the new system were done).La visió és entesa i, universalment acceptada, com el sentit humà més valorat .Aquesta esta estructurada en tres parts principals: el sistema òptic (l'ull), el fot-sensor (la retina ocular) iel processador (el cervell). Si una d'aquestes parts es veu afectada per una disfunció o malaltia, la visió pot arribar a ser de molt baixa qualitat i, fins hi tot, inexistent Una de les disfuncions més comunes és la presbícia. La presbícia és una disfunció lligada a l'edat que pateix tota lla població a partir dels 40 anys, aproximadament. Consisteix en la pèrdua de la capacitat d'enfocar objectes propers (acomodació). Actualment, es troba un ampli nombre de possibles correccions. Per una banda, tenim les correccions temporals, com ulleres o lents de contacte progressives, i, per l'altre, correccions permanents, com lents intraoculars multifocals , ablacions corneals multifocals, lents intraoculars acomodatives, sistemes de monovisió, o modificacions esclerals, entre altres. Una altre disfunció associada a l'edat és la cataracta, la qual crea la opacificació del cristal·lí impedint una visió nítida. Conseqüentment, la cataracta és una de la deficiències visuals més estesa a partir dels 60 anys, afectant a la meitat de la població entre els 75 i els 85 anys . La única solució per eliminar les cataractes és eliminant les fibres opacificades i substituir-les per una lent intraocular quirúrgicament. Donat que tots els pacients amb cataractes són, a la vegada, prèsbites, està justificat que un nombre de pacients decideixi implantar-se lents intraoculars multifocals per substituir el seu cristal·lí. D'aquesta manera es solucionen dues degeneracions associades a l'edat en una sola cirurgia. Els joves prèsbites acostumen a optar per correccions prèsbites temporals, mentre que molts dels prèsbites amb cataractes opten per solucions permanents. Algunes de les correccions de la presbícia, com les lents de contacte o intraoculars multifocals , estan basades en el principi de visió simultània. Els dissenys òptics d'aquest tipus de lents són molt complexos, cosa que fa que la seva caracterització sigui molt complicada. Quan aquestes lents van aparèixer al mercat, només era possible caracteritzar-les òpticament abans de la seva implantació o adaptació de manera in vitro, i de caracteritzar-les visualment després de la seva adaptació o implantació de manera in vivo. Actualment, i gracies a tots els avenços tecnològics, diferents instruments clínics han estat desenvolupats per realitzar mesures de les qualitats visuals abans de la seva implantació. Tots ells, es basen en simular-li al pacient la visió que tindria després de ser implantat. Per un altre cantó, alguns prototips experimentals iaberrometres o sistemes de doble-pas comercials han estat utilitzats per dur a terme la caracterització de la qualitat in vim en pacients implantats o adaptats amb sistemes multifocals, pero diferents problemes han estat plantejats. Tenint en compte tota aquesta informació, el principal objectiu d'aquesta tesi ha estat la de dissenyar i muntar un nou sistema de doble-pas d'enfocament asimètric de camp obert que fos capaç de fer una caracterització de la qualitat òptica in vivo de pacients implantats o adaptats amb lents de contacte o intraoculars multifocals. I per arribar a aquest objectiu, s'han dut a terme els següents passos: Revisió de les correccions per a la presbícia i caracterització d'elles (Estudi clínic de la sobre-refracció objectiva de pacients adaptats amb lents de contacte multifocals); Validació de la capacitat de mesura d'un simulador comercial (Estudi clínic amb el simulador comercial VirtlOL (1OLens S.L); Disseny i muntatge del sistema de doble-pas amb enfocament asimètric (Disseny opto-mecànic/ Validació de tots els components del sistema/ Validació òptica del sistema); Programació dels programes informàtics que gestionen el sistema i processenPostprint (published version