A Passive Variable Impedance Control Strategy with Viscoelastic Parameters Estimation of Soft Tissues for Safe Ultrasonography

In the context of telehealth, robotic approaches have proven a valuable solution to in-person visits in remote areas, with decreased costs for patients and infection risks. In particular, in ultrasonography, robots have the potential to reproduce the skills required to acquire high-quality images while reducing the sonographer's physical efforts. In this paper, we address the control of the interaction of the probe with the patient's body, a critical aspect of ensuring safe and effective ultrasonography. We introduce a novel approach based on variable impedance control, allowing real-time optimisation of a compliant controller parameters during ultrasound procedures. This optimisation is formulated as a quadratic programming problem and incorporates physical constraints derived from viscoelastic parameter estimations. Safety and passivity constraints, including an energy tank, are also integrated to minimise potential risks during human-robot interaction. The proposed method's efficacy is demonstrated through experiments on a patient dummy torso, highlighting its potential for achieving safe behaviour and accurate force control during ultrasound procedures, even in cases of contact loss.Comment: 7 pages, 7 figures, submitted to ICRA 202

Synthetic and bio-artificial tactile sensing: a review

This paper reviews the state of the art of artificial tactile sensing, with a particular focus on bio-hybrid and fully-biological approaches. To this aim, the study of physiology of the human sense of touch and of the coding mechanisms of tactile information is a significant starting point, which is briefly explored in this review. Then, the progress towards the development of an artificial sense of touch are investigated. Artificial tactile sensing is analysed with respect to the possible approaches to fabricate the outer interface layer: synthetic skin versus bio-artificial skin. With particular respect to the synthetic skin approach, a brief overview is provided on various technologies and transduction principles that can be integrated beneath the skin layer. Then, the main focus moves to approaches characterized by the use of bio-artificial skin as an outer layer of the artificial sensory system. Within this design solution for the skin, bio-hybrid and fully-biological tactile sensing systems are thoroughly presented: while significant results have been reported for the development of tissue engineered skins, the development of mechanotransduction units and their integration is a recent trend that is still lagging behind, therefore requiring research efforts and investments. In the last part of the paper, application domains and perspectives of the reviewed tactile sensing technologies are discussed

Brain Tumour Classification Using Deep Features from Structural MRI

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Robotic simulators for tissue examination training with multimodal sensory feedback

Tissue examination by hand remains an essential technique in clinical practice. The effective application depends on skills in sensorimotor coordination, mainly involving haptic, visual, and auditory feedback. The skills clinicians have to learn can be as subtle as regulating finger pressure with breathing, choosing palpation action, monitoring involuntary facial and vocal expressions in response to palpation, and using pain expressions both as a source of information and as a constraint on physical examination. Patient simulators can provide a safe learning platform to novice physicians before trying real patients. This paper reviews state-of-the-art medical simulators for the training for the first time with a consideration of providing multimodal feedback to learn as many manual examination techniques as possible. The study summarizes current advances in tissue examination training devices simulating different medical conditions and providing different types of feedback modalities. Opportunities with the development of pain expression, tissue modeling, actuation, and sensing are also analyzed to support the future design of effective tissue examination simulators

Medical robots with potential applications in participatory and opportunistic remote sensing: A review

Among numerous applications of medical robotics, this paper concentrates on the design, optimal use and maintenance of the related technologies in the context of healthcare, rehabilitation and assistive robotics, and provides a comprehensive review of the latest advancements in the foregoing field of science and technology, while extensively dealing with the possible applications of participatory and opportunistic mobile sensing in the aforementioned domains. The main motivation for the latter choice is the variety of such applications in the settings having partial contributions to functionalities such as artery, radiosurgery, neurosurgery and vascular intervention. From a broad perspective, the aforementioned applications can be realized via various strategies and devices benefiting from detachable drives, intelligent robots, human-centric sensing and computing, miniature and micro-robots. Throughout the paper tens of subjects, including sensor-fusion, kinematic, dynamic and 3D tissue models are discussed based on the existing literature on the state-of-the-art technologies. In addition, from a managerial perspective, topics such as safety monitoring, security, privacy and evolutionary optimization of the operational efficiency are reviewed

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

Advanced Sensing and Image Processing Techniques for Healthcare Applications

This Special Issue aims to attract the latest research and findings in the design, development and experimentation of healthcare-related technologies. This includes, but is not limited to, using novel sensing, imaging, data processing, machine learning, and artificially intelligent devices and algorithms to assist/monitor the elderly, patients, and the disabled population

3D printing PhycoTrix™ for wound healing

With the advent of additive manufacturing and its recent use in regenerative medicine, bioprinting has become a promising technology for tissue engineering applications. PhycoTrix™, a sulphated marine-derived polysaccharide, taken from the cell wall of a DNA barcoded green algal spp., (Chlorophyta), has a chemical structure similar to mammalian glycosaminoglycans found within the dermal skin layer extracellular matrix. This sustainable, under-utilised source of biomaterial was developed into a bioink for use in bioprinting. Specifically, a dual-network hydrogel was engineered through ionic and chemical means. This hydrogel was characterised following methacrylation through 1H NMR, FT-IR, and circular dichroism. The physical properties, printability, and crosslinking kinetics were all assessed through rheology and mechanical properties through micro-indentation. Preliminary cytocompatibility studies were evaluated using fibroblasts and adipose-derived stem cells. The results indicated relatively high cell binding affinity and proliferation compared to other alginate studies, suggesting this novel biomaterial could be useful for wound healing applications, such as wound dressings and matrices for tissue repair and regeneration

Desenho e processamento de estruturas porosas de fosfatos de cálcio por robocasting para engenharia de tecido ósseo

Doutoramento em Ciência e Engenharia de MateriaisA presente dissertação teve como foco principal o desenvolvimento de estruturas 3D porosas (scaffolds) para regeneração óssea por robocasting. Esta técnica de fabrico aditivo permite a produção de scaffolds com morfologia e estrutura predefinidas e sem a necessidade de maquinagem subsequente, podendo ser usada para o fabrico de implantes personalizados com estrutura interna semelhante à do osso que se pretende substituir. Como materiais de partida, foram utilizados pós de fosfatos de cálcio bifásicos (hidroxiapatite + β-fosfato tricálcico) não dopados, e dopados com diferentes iões (Sr, Ag, Cu, Mg e Zn), obtidos por precipitação em meio aquoso. A substituição parcial de iões Ca pelos iões dopantes induziu alterações na composição de fases cristalinas e resultou em partículas com características morfológicas distintas e em materiais com desempenhos biológicos diferentes. Os pós foram dispersos em meio aquoso com a ajuda de aditivos de processamento adequados (um dispersante e um ligante) de modo a obter suspensões com elevada concentração de sólidos, requisito essencial para o fabrico de componentes por robocasting. O tamanho e a morfologia das partículas e a concentração dos aditivos de processamento desempenharam os papéis cruciais no comportamento reológico das suspensões. A adição de agente floculante modificou drasticamente as propriedades reológicas do sistema e permitiu a obtenção de pastas com comportamento viscoelástico adequado para o processo de extrusão. Os scaffolds com diferentes tamanhos de poro foram produzidos pela deposição de um filamento com 410 μm de diâmetro. A resistência à compressão dos scaffolds sinterizados a 1100°C foi comparável ou mesmo superior à do osso esponjoso. Scaffolds com diferentes tamanhos de poro (120-500 μm) foram testados in vitro usando células estaminais mesenquimais humanas (hMSCs). Pretendeu-se avaliar a influência do tamanho dos poros na adesão celular inicial, na atividade metabólica e no potencial osteogénico. Os resultados obtidos mostraram que os poros com maior dimensão proporcionam condições favoráveis para a diferenciação osteogénica das hMSCs. Além disso, os fosfatos de cálcio co-dopados com Sr e Zn melhoraram o desempenho biológico, incluindo adesão, atividade metabólica e proliferação das hMSC. A última parte da tese foi dedicada à preparação de scaffolds não sinterizados incorporando um fármaco (levofloxacina) de forma a obter componentes com capacidade de regeneração óssea e de tratamento local de infeções. A pasta utilizada foi obtida através da dispersão dos pós de CaP numa solução de quitosano na presença do fármaco e de um agente de reticulação (genipin). Os scaffolds 3D à base de fosfatos de cálcio produzidos por robocasting no âmbito desta tese revelaram-se muito promissores para aplicações na engenharia de tecidos, particularmente regeneração de tecido ósseo e administração de fármacos.The main focus of this thesis was the development of novel 3D porous scaffolds for bone regeneration by robocasting. This additive manufacturing technique allows the production of scaffolds with predefined morphology and structure without the need for subsequent machining and can be used for the manufacture of customized implants with an internal structure similar to that of the bone to be replaced. Biphasic calcium phosphates (hydroxyapatite + β-tricalcium phosphate), undoped and doped (with Sr, Ag, Cu, Mg and Zn), obtained through aqueous precipitation process were used as starting powders. The partial substitution of Ca ions by doping ions induced changes in the crystalline phase assemblages and resulted in particles with distinct morphological characteristics and in materials with different biological outcomes. The powders were dispersed in aqueous medium with the aid of suitable processing additives (a dispersant and a binder) in order to obtain suspensions with high solids loading, an essential requirement for the manufacture of components by robocasting. The size and morphology of the particles and the concentration of the processing additives played crucial roles in the rheological behaviour of the suspensions. The addition of a flocculating agent drastically modified the rheological properties of the systems and allowed obtaining pastes with viscoelastic behaviour suitable for the extrusion process. The scaffolds with different pore sizes were produced by the controlled deposition of filaments with 410 μm in diameter. The compressive strength of scaffolds sintered at 1100 ° C was comparable or even superior to that that of spongy bone. Scaffolds with different pore sizes (120-500 μm) were tested in vitro using human mesenchymal stem cells (hMSCs). The aim was to evaluate the influence of pore size on initial cell adhesion, metabolic activity and osteogenic potential. The results showed that larger pores provide favourable conditions for osteogenic differentiation of hMSCs. In addition, calcium phosphates codoped with Sr and Zn improved the biological performance, including adhesion, metabolic activity and proliferation of hMSC. The last part of the thesis was devoted to the preparation of sintering-free scaffolds incorporating a drug (levofloxacin) in order to obtain components with capacity for bone regeneration and local treatment of infections. The paste used was obtained by dispersing the CaP powders in a solution of chitosan in the presence of the drug and a crosslinking agent (genipin). The 3D scaffolds produced by robocasting in the frame of this thesis program revealed to be very promising for tissue engineering applications, particularly bone tissue regeneration and drug delivery