SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "AMNE:(TEKNIK OCH TEKNOLOGIER Medicinteknik Medicinsk material- och protesteknik) "

Sökning: AMNE:(TEKNIK OCH TEKNOLOGIER Medicinteknik Medicinsk material- och protesteknik)

  • Resultat 1-10 av 515
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Bondesson, Johan, 1991, et al. (författare)
  • Definition of Tubular Anatomic Structures from Arbitrary Stereo Lithographic Surface
  • 2017
  • Ingår i: Initiative Seminar Engineering Health, 8-9 November 2017, Chalmers.
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • An accurate description of anatomies and dynamics of vessels is crucial to understand their characteristics and improve surgical techniques, thus it is the basis, in addition to surgeon experience, on which stent design and operation procedures rely. The process of producing this description is user intensive, and recent improvement in image processing of medical3D imaging allows for a more automated workflow. However, there is a need to bridge the gap from a processed geometry to a robust mathematical computational grid. By sequentially segmenting a tubular anatomic structure, here defined by a stereo lithographic (STL) surface, an initial centerline is formed by connecting centroids of orthogonal cross-sectional contours along the length of the structure. Relying on the initial centerline, a set of non-overlapping 2D cross sectional contours are defined along the centerline, a centerline which is updated after the 2D contours are produced. After a second iteration of producing 2D contours and updating the centerline, a full description of the structure is created. Our method for describing vessel geometry shows good coherence to existing method. The main advantages of our method include the possibility of having arbitrary triangulated STL surface input, automated centerline definition, safety against intersecting cross-sectional contours and automatic clean-up of local kinks and wrinkles.
  •  
2.
  • Palmquist, Anders, 1977, et al. (författare)
  • Complex geometry and integrated macro-porosity: Clinical applications of electron beam melting to fabricate bespoke bone-anchored implants
  • 2023
  • Ingår i: Acta Biomaterialia. - : Elsevier BV. - 1742-7061 .- 1878-7568. ; 156, s. 125-145
  • Forskningsöversikt (refereegranskat)abstract
    • The last decade has witnessed rapid advancements in manufacturing technologies for biomedical implants. Additive manufacturing (or 3D printing) has broken down major barriers in the way of producing complex 3D geometries. Electron beam melting (EBM) is one such 3D printing process applicable to metals and alloys. EBM offers build rates up to two orders of magnitude greater than comparable laser-based technologies and a high vacuum environment to prevent accumulation of trace elements. These features make EBM particularly advantageous for materials susceptible to spontaneous oxidation and nitrogen pick-up when exposed to air (e.g., titanium and titanium-based alloys). For skeletal reconstruction(s), anatomical mimickry and integrated macro-porous architecture to facilitate bone ingrowth are undoubtedly the key features of EBM manufactured implants. Using finite element modelling of physiological loading conditions, the design of a prosthesis may be further personalised. This review looks at the many unique clinical applications of EBM in skeletal repair and the ground-breaking innovations in prosthetic rehabilitation. From a simple acetabular cup to the fifth toe, from the hand-wrist complex to the shoulder, and from vertebral replacement to cranio-maxillofacial reconstruction, EBM has experienced it all. While sternocostal reconstructions might be rare, the repair of long bones using EBM manufactured implants is becoming exceedingly frequent. Despite the various merits, several challenges remain yet untackled. Nevertheless, with the capability to produce osseointegrating implants of any conceivable shape/size, and permissive of bone ingrowth and functional loading, EBM can pave the way for numerous fascinating and novel applications in skeletal repair, regeneration, and rehabilitation. Statement of significance: Electron beam melting (EBM) offers unparalleled possibilities in producing contaminant-free, complex and intricate geometries from alloys of biomedical interest, including Ti6Al4V and CoCr. We review the diverse range of clinical applications of EBM in skeletal repair, both as mass produced off-the-shelf implants and personalised, patient-specific prostheses. From replacing large volumes of disease-affected bone to complex, multi-material reconstructions, almost every part of the human skeleton has been replaced with an EBM manufactured analog to achieve macroscopic anatomical-mimickry. However, various questions regarding long-term performance of patient-specific implants remain unaddressed. Directions for further development include designing personalised implants and prostheses based on simulated loading conditions and accounting for trabecular bone microstructure with respect to physiological factors such as patient's age and disease status.
  •  
3.
  • Johansson, Martin L, et al. (författare)
  • Non-invasive sampling procedure revealing the molecular events at different abutments of bone-anchored hearing systems–A prospective clinical pilot study
  • 2022
  • Ingår i: Frontiers in Neuroscience. - : Frontiers Media SA. - 1662-4548 .- 1662-453X. ; 16
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To investigate the molecular activities in different compartments around the bone-anchored hearing system (BAHS) with either electropolished or machined abutments and to correlate these activities with clinical and microbiological findings. Materials and methods: Twelve patients received machined or electropolished abutments after implant installation of BAHS. Peri-abutment fluid and tissue were collected from baseline to 12 months. Gene expression of cytokines and factors related to tissue healing and inflammation, regeneration and remodelling, as well as bacterial recognition were determined using quantitative-polymerase chain reaction (qPCR). The clinical status was evaluated using the Holgers scoring system, and bacterial colonisation was investigated by culturing. Results: The gene expression of inflammatory cytokines (IL-8, IL-1β, and IL-10) and bacteria-related Toll-like receptors (2 and 4) was higher in the peri-abutment fluid than at baseline and in the peri-abutment tissue at 3 and 12 months. Conversely, the expression of genes related to tissue regeneration (Coll1a1 and FOXO1) was higher in the tissue samples than in the peri-abutment fluid at 3 and 12 months. Electropolished abutments triggered higher expression of inflammatory cytokines (IL-8 and IL-1β) (in peri-abutment fluid) and regeneration factor FOXO1 (in peri-abutment tissue) than machined abutments. Several cytokine genes in the peri-abutment fluid correlated positively with the detection of aerobes, anaerobes and Staphylococcus species, as well as with high Holger scores. Conclusion: This study provides unprecedented molecular information on the biological processes of BAHS. Despite being apparently healed, the peri-abutment fluid harbours prolonged inflammatory activity in conjunction with the presence of different bacterial species. An electropolished abutment surface appears to be associated with stronger proinflammatory activity than that with a machined surface. The analysis of the peri-abutment fluid deserves further verification as a non-invasive sampling and diagnostic procedure of BAHS.
  •  
4.
  • Pirozzi, Ileana, et al. (författare)
  • Circulatory Support : Artificial Muscles for the Future of Cardiovascular Assist Devices
  • 2023
  • Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095.
  • Tidskriftsartikel (refereegranskat)abstract
    • Artificial muscles enable the design of soft implantable devices which are poised to transform the way we mechanically support the heart today. Heart failure is a prevalent and deadly disease, which is treated with the implantation of rotary blood pumps as the only alternative to heart transplantation. The clinically used mechanical devices are associated with severe adverse events, which are reflected here in a comprehensive list of critical requirements for soft active devices of the future: low power, no blood contact, pulsatile support, physiological responsiveness, high cycle life, and less-invasive implantation. In this review, we investigate and critically evaluate prior art in artificial muscles for their applicability in the short and long term. We highlight the main challenges regarding the effectiveness, controllability, and implantability of recently proposed actuators and explore future perspectives for attachment, physiological responsiveness, durability, and biodegradability as well as equitable design considerations.
  •  
5.
  • Lammi, Mikko J., 1961-, et al. (författare)
  • Regulation of oxygen tension as a strategy to control chondrocytic phenotype for cartilage tissue engineering and regeneration
  • 2024
  • Ingår i: Bioengineering. - : MDPI. - 2306-5354. ; 11:3
  • Forskningsöversikt (refereegranskat)abstract
    • Cartilage defects and osteoarthritis are health problems which are major burdens on health care systems globally, especially in aging populations. Cartilage is a vulnerable tissue, which generally faces a progressive degenerative process when injured. This makes it the 11th most common cause of global disability. Conservative methods are used to treat the initial phases of the illness, while orthopedic management is the method used for more progressed phases. These include, for instance, arthroscopic shaving, microfracturing and mosaicplasty, and joint replacement as the final treatment. Cell-based implantation methods have also been developed. Despite reports of successful treatments, they often suffer from the non-optimal nature of chondrocyte phenotype in the repair tissue. Thus, improved strategies to control the phenotype of the regenerating cells are needed. Avascular tissue cartilage relies on diffusion for nutrients acquisition and the removal of metabolic waste products. A low oxygen content is also present in cartilage, and the chondrocytes are, in fact, well adapted to it. Therefore, this raises an idea that the regulation of oxygen tension could be a strategy to control the chondrocyte phenotype expression, important in cartilage tissue for regenerative purposes. This narrative review discusses the aspects related to oxygen tension in the metabolism and regulation of articular and growth plate chondrocytes and progenitor cell phenotypes, and the role of some microenvironmental factors as regulators of chondrocytes.
  •  
6.
  • Ortiz Catalan, Max Jair, 1982, et al. (författare)
  • Patterned Stimulation of Peripheral Nerves Produces Natural Sensations With Regards to Location but Not Quality
  • 2019
  • Ingår i: IEEE Transactions on Medical Robotics and Bionics. - 2576-3202. ; 1:3, s. 199-203
  • Tidskriftsartikel (refereegranskat)abstract
    • Sensory feedback is crucial for dexterous manipulation and sense of ownership. Electrical stimulation of severed afferent fibers due to an amputation elicits referred sensations in the missing limb. However, these sensations are commonly reported with a concurrent “electric” or “tingling” character (paresthesia). In this paper, we examined the effect of modulating different pulse parameters on the quality of perceived sensations. Three subjects with above-elbow amputation were implanted with cuff electrodes and stimulated with a train of pulses modulated in either amplitude, width, or frequency (“patterned stimulation”). Pulses were shaped using a slower carrier wave or via quasi-random generation. Subjects were asked to evaluate the natural quality of the resulting sensations using a numeric rating scale. We found that the location of the percepts was distally referred and somatotopically congruent, but their quality remained largely perceived as artificial despite employing patterned modulation. Sensations perceived as arising from the missing limb are intuitive and natural with respect to their location and, therefore, useful for functional restoration. However, our results indicate that sensory transformation from paresthesia to natural qualia seems to require more than patterned stimulation.
  •  
7.
  • Cardemil, Carina, et al. (författare)
  • Strontium-doped calcium phosphate and hydroxyapatite granules promote different inflammatory and bone remodelling responses in normal and ovariectomised rats.
  • 2013
  • Ingår i: PLosOne. - : Public Library of Science (PLoS). - 1932-6203. ; 8:12
  • Tidskriftsartikel (refereegranskat)abstract
    • The healing of bone defects may be hindered by systemic conditions such as osteoporosis. Calcium phosphates, with or without ion substitutions, may provide advantages for bone augmentation. However, the mechanism of bone formation with these materials is unclear. The aim of this study was to evaluate the healing process in bone defects implanted with hydroxyapatite (HA) or strontium-doped calcium phosphate (SCP) granules, in non-ovariectomised (non-OVX) and ovariectomised (OVX) rats. After 0 (baseline), six and 28d, bone samples were harvested for gene expression analysis, histology and histomorphometry. Tumour necrosis factor-α (TNF-α), at six days, was higher in the HA, in non-OVX and OVX, whereas interleukin-6 (IL-6), at six and 28d, was higher in SCP, but only in non-OVX. Both materials produced a similar expression of the receptor activator of nuclear factor kappa-B ligand (RANKL). Higher expression of osteoclastic markers, calcitonin receptor (CR) and cathepsin K (CatK), were detected in the HA group, irrespective of non-OVX or OVX. The overall bone formation was comparable between HA and SCP, but with topological differences. The bone area was higher in the defect centre of the HA group, mainly in the OVX, and in the defect periphery of the SCP group, in both non-OVX and OVX. It is concluded that HA and SCP granules result in comparable bone formation in trabecular bone defects. As judged by gene expression and histological analyses, the two materials induced different inflammatory and bone remodelling responses. The modulatory effects are associated with differences in the spatial distribution of the newly formed bone.
  •  
8.
  • Enejder, Annika, 1969, et al. (författare)
  • SHG Imaging for Tissue Engineering Applications
  • 2016
  • Ingår i: Second Harmonic Generation Imaging. - : CRC Press. - 9781439849156 - 9781439849149 ; , s. 409-426
  • Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
    • Treatment of lost tissue oen relies on transplantations, either of donor or of autologous tissue. Both alternatives have limitations; there is for example a limited supply of donor transplants, which also require immunosuppression therapy with possible side eects. Transplanted autologous tissue may lack some of the functions of the original tissue and the procedure may also introduce complications at the donor site. In some cases, articial substitutes manufactured from nonbiological materials can be used, for example, synthetic polymer blood vessels or joint replacement prostheses. However, these replacements have drawbacks such as risk for infections, limited material durability, and lack of mechanisms for repair, growth, and remodeling. For these reasons, development of advanced articial tissue constructs with adaptive capabilities is desirable.
  •  
9.
  • Isaksson-Daun, Johan (författare)
  • A Sound Approach Toward a Mobility Aid for Blind and Low-Vision Individuals
  • 2023
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Reduced independent mobility of blind and low-vision individuals (BLVIs) cause considerable societal cost, burden on relatives, and reduced quality of life for the individuals, including increased anxiety, depression symptoms, need of assistance, risk of falls, and mortality. Despite the numerous electronic travel aids proposed since at least the 1940’s, along with ever-advancing technology, the mobility issues persist. A substantial reason for this is likely several and severe shortcomings of the field, both in regards to aid design and evaluation.In this work, these shortcomings are addressed with a generic design model called Desire of Use (DoU), which describes the desire of a given user to use an aid for a given activity. It is then applied on mobility of BLVIs (DoU-MoB), to systematically illuminate and structure possibly all related aspects that such an aid needs to aptly deal with, in order for it to become an adequate aid for the objective. These aspects can then both guide user-centered design as well as choice of test methods and measures.One such measure is then demonstrated in the Desire of Use Questionnaire for Mobility of Blind and Low-Vision Individuals (DoUQ-MoB), an aid-agnostic and comprehensive patient-reported outcome measure. The question construction originates from the DoU-MoB to ensure an encompassing focus on mobility of BLVIs, something that has been missing in the field. Since it is aid-agnostic it facilitates aid comparison, which it also actively promotes. To support the reliability of the DoUQ-MoB, it utilizes the best known practices of questionnaire design and has been validated once with eight orientation and mobility professionals, and six BLVIs. Based on this, the questionnaire has also been revised once.To allow for relevant and reproducible methodology, another tool presented herein is a portable virtual reality (VR) system called the Parrot-VR. It uses a hybrid control scheme of absolute rotation by tracking the user’s head in reality, affording intuitive turning; and relative movement where simple button presses on a controller moves the virtual avatar forward and backward, allowing for large-scale traversal while not walking physically. VR provides excellent reproducibility, making various aggregate movement analysis feasible, while it is also inherently safe. Meanwhile, the portability of the system facilitates testing near the participants, substantially increasing the number of potential blind and low-vision recruits for user tests.The thesis also gives a short account on the state of long-term testing in the field; it being short is mainly due to that there is not much to report. It then provides an initial investigation into possible outcome measures for such tests by taking instruments in use by Swedish orientation and mobility professionals as a starting point. Two of these are also piloted in an initial single-session trial with 19 BLVIs, and could plausibly be used for long-term tests after further evaluation.Finally, a discussion is presented regarding the Audomni project — the development of a primary mobility aid for BLVIs. Audomni is a visuo-auditory sensory supplementation device, which aims to take visual information and translate it to sound. A wide field-of-view, 3D-depth camera records the environment, which is then transformed to audio through the sonification algorithms of Audomni, and finally presented in a pair of open-ear headphones that do not block out environmental sounds. The design of Audomni leverages the DoU-MoB to ensure user-centric development and evaluation, in the aim of reaching an aid with such form and function that it grants the users better mobility, while the users still want to use it.Audomni has been evaluated with user tests twice, once in pilot tests with two BLVIs, and once in VR with a heterogenous set of 19 BLVIs, utilizing the Parrot-VR and the DoUQ-MoB. 76 % of responders (13 / 17) answered that it was very or extremely likely that they would want use Audomni along with their current aid. This might be the first result in the field demonstrating a majority of blind and low-vision participants reporting that they actually want to use a new electronic travel aid. This shows promise that eventual long-term tests will demonstrate an increased mobility of blind and low-vision users — the overarching project aim. Such results would ultimately mean that Audomni can become an aid that alleviates societal cost, reduces burden on relatives, and improves users’ quality of life and independence.
  •  
10.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-10 av 515
Typ av publikation
tidskriftsartikel (313)
konferensbidrag (125)
doktorsavhandling (24)
forskningsöversikt (16)
bokkapitel (12)
annan publikation (10)
visa fler...
patent (7)
licentiatavhandling (6)
rapport (1)
bok (1)
visa färre...
Typ av innehåll
refereegranskat (426)
övrigt vetenskapligt/konstnärligt (80)
populärvet., debatt m.m. (9)
Författare/redaktör
Persson, Cecilia (94)
Engqvist, Håkan (78)
Engqvist, Håkan, 197 ... (32)
Xia, Wei (26)
Öhman, Caroline (18)
Andersson, Martin, 1 ... (18)
visa fler...
Öhman-Mägi, Caroline (17)
Lidgren, Lars (14)
Procter, Philip (14)
Thomsen, Peter, 1953 (13)
Isaksson, Hanna (13)
Ajaxon, Ingrid (13)
Ginebra, Maria-Pau (13)
Ortiz Catalan, Max J ... (12)
Tägil, Magnus (12)
Palmquist, Anders, 1 ... (12)
Shah, Furqan A. (12)
Larsson, Sune (11)
Pujari-Palmer, Micha ... (11)
Strömme, Maria (10)
Lopez, Alejandro (10)
Karlsson Ott, Marjam (10)
Raina, Deepak Bushan (10)
Mijakovic, Ivan, 197 ... (9)
Pandit, Santosh, 198 ... (9)
Strømme, Maria, 1970 ... (9)
Pettersson, Maria (9)
Hulsart Billström, G ... (9)
Welch, Ken (8)
Skjöldebrand, Charlo ... (8)
Unosson, Erik (8)
Rising, Anna (7)
Xia, Wei, Associate ... (7)
Isaksson, Per (7)
Bredenberg, Susanne (7)
Lilja, Mirjam, 1981- (7)
Montazerolghaem, Mar ... (7)
Gatenholm, Paul, 195 ... (6)
Johansson, Jan (6)
Jimbo, Ryo (6)
Schmidt, Susann (6)
Diez-Escudero, Anna (6)
Brånemark, Rickard, ... (6)
Fu, Le (6)
Hedhammar, My (6)
Grishenkov, Dmitry, ... (6)
Joffre, Thomas (6)
Hoess, Andreas (6)
Lewin, Susanne (6)
Thesleff, Alexander, ... (6)
visa färre...
Lärosäte
Uppsala universitet (235)
Chalmers tekniska högskola (107)
Lunds universitet (68)
Kungliga Tekniska Högskolan (54)
Göteborgs universitet (44)
Linköpings universitet (33)
visa fler...
Karolinska Institutet (30)
RISE (21)
Sveriges Lantbruksuniversitet (15)
Umeå universitet (14)
Malmö universitet (14)
Högskolan i Borås (10)
Mittuniversitetet (8)
Stockholms universitet (7)
Linnéuniversitetet (4)
Luleå tekniska universitet (3)
Mälardalens universitet (2)
Högskolan i Halmstad (1)
Högskolan i Gävle (1)
Högskolan Väst (1)
Örebro universitet (1)
Gymnastik- och idrottshögskolan (1)
Karlstads universitet (1)
visa färre...
Språk
Engelska (513)
Svenska (1)
Odefinierat språk (1)
Forskningsämne (UKÄ/SCB)
Teknik (515)
Medicin och hälsovetenskap (177)
Naturvetenskap (80)
Lantbruksvetenskap (5)
Humaniora (2)
Samhällsvetenskap (1)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy