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1.
Adv Mater ; 27(10): 1731-7, 2015 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-25641076

RESUMO

Advanced materials and fractal design concepts form the basis of a 3D conformal electronic platform with unique capabilities in cardiac electrotherapies. Fractal geometries, advanced electrode materials, and thin, elastomeric membranes yield a class of device capable of integration with the entire 3D surface of the heart, with unique operational capabilities in low power defibrillation. Co-integrated collections of sensors allow simultaneous monitoring of physiological responses. Animal experiments on Langendorff-perfused rabbit hearts demonstrate the key features of these systems.


Assuntos
Terapia por Estimulação Elétrica/instrumentação , Eletrodos , Coração , Ligas/química , Animais , Elastômeros , Impedância Elétrica , Terapia por Estimulação Elétrica/métodos , Desenho de Equipamento , Fractais , Coração/fisiologia , Coração/fisiopatologia , Irídio/química , Teste de Materiais , Microscopia Eletrônica de Varredura , Nanoestruturas/química , Imagem Óptica , Compostos de Platina/química , Poliestirenos/química , Coelhos , Elastômeros de Silicone , Compostos de Prata/química , Análise Espectral , Tiofenos/química , Titânio/química
2.
Nat Commun ; 5: 4938, 2014 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-25234839

RESUMO

Characterization of temperature and thermal transport properties of the skin can yield important information of relevance to both clinical medicine and basic research in skin physiology. Here we introduce an ultrathin, compliant skin-like, or 'epidermal', photonic device that combines colorimetric temperature indicators with wireless stretchable electronics for thermal measurements when softly laminated on the skin surface. The sensors exploit thermochromic liquid crystals patterned into large-scale, pixelated arrays on thin elastomeric substrates; the electronics provide means for controlled, local heating by radio frequency signals. Algorithms for extracting patterns of colour recorded from these devices with a digital camera and computational tools for relating the results to underlying thermal processes near the skin surface lend quantitative value to the resulting data. Application examples include non-invasive spatial mapping of skin temperature with milli-Kelvin precision (±50 mK) and sub-millimetre spatial resolution. Demonstrations in reactive hyperaemia assessments of blood flow and hydration analysis establish relevance to cardiovascular health and skin care, respectively.


Assuntos
Epiderme/fisiologia , Temperatura Cutânea , Pele/patologia , Algoritmos , Calibragem , Diagnóstico por Imagem , Difusão , Elastômeros , Humanos , Nanotecnologia , Fótons , Reprodutibilidade dos Testes
3.
Nat Commun ; 5: 3329, 2014 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-24569383

RESUMO

Means for high-density multiparametric physiological mapping and stimulation are critically important in both basic and clinical cardiology. Current conformal electronic systems are essentially 2D sheets, which cannot cover the full epicardial surface or maintain reliable contact for chronic use without sutures or adhesives. Here we create 3D elastic membranes shaped precisely to match the epicardium of the heart via the use of 3D printing, as a platform for deformable arrays of multifunctional sensors, electronic and optoelectronic components. Such integumentary devices completely envelop the heart, in a form-fitting manner, and possess inherent elasticity, providing a mechanically stable biotic/abiotic interface during normal cardiac cycles. Component examples range from actuators for electrical, thermal and optical stimulation, to sensors for pH, temperature and mechanical strain. The semiconductor materials include silicon, gallium arsenide and gallium nitride, co-integrated with metals, metal oxides and polymers, to provide these and other operational capabilities. Ex vivo physiological experiments demonstrate various functions and methodological possibilities for cardiac research and therapy.


Assuntos
Algoritmos , Coração/fisiologia , Membranas Artificiais , Modelos Cardiovasculares , Pericárdio/fisiologia , Animais , Elastômeros/química , Eletrocardiografia/instrumentação , Eletrocardiografia/métodos , Eletrodos , Técnicas Eletrofisiológicas Cardíacas/instrumentação , Técnicas Eletrofisiológicas Cardíacas/métodos , Mapeamento Epicárdico/instrumentação , Mapeamento Epicárdico/métodos , Coração/anatomia & histologia , Sistema de Condução Cardíaco/fisiologia , Concentração de Íons de Hidrogênio , Imageamento Tridimensional , Técnicas In Vitro , Pericárdio/anatomia & histologia , Coelhos , Reprodutibilidade dos Testes , Semicondutores , Silicones/química , Temperatura
4.
Adv Healthc Mater ; 3(10): 1597-607, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24668927

RESUMO

Non-invasive, biomedical devices have the potential to provide important, quantitative data for the assessment of skin diseases and wound healing. Traditional methods either rely on qualitative visual and tactile judgments of a professional and/or data obtained using instrumentation with forms that do not readily allow intimate integration with sensitive skin near a wound site. Here, an electronic sensor platform that can softly and reversibly laminate perilesionally at wounds to provide highly accurate, quantitative data of relevance to the management of surgical wound healing is reported. Clinical studies on patients using thermal sensors and actuators in fractal layouts provide precise time-dependent mapping of temperature and thermal conductivity of the skin near the wounds. Analytical and simulation results establish the fundamentals of the sensing modalities, the mechanics of the system, and strategies for optimized design. The use of this type of "epidermal" electronics system in a realistic clinical setting with human subjects establishes a set of practical procedures in disinfection, reuse, and protocols for quantitative measurement. The results have the potential to address important unmet needs in chronic wound management.


Assuntos
Eletrônica Médica/instrumentação , Monitorização Fisiológica/instrumentação , Cicatrização/fisiologia , Idoso , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Silicones , Temperatura Cutânea/fisiologia , Fita Cirúrgica , Termografia/instrumentação
5.
Nat Commun ; 5: 4779, 2014 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-25182939

RESUMO

Research in stretchable electronics involves fundamental scientific topics relevant to applications with importance in human healthcare. Despite significant progress in active components, routes to mechanically robust construction are lacking. Here, we introduce materials and composite designs for thin, breathable, soft electronics that can adhere strongly to the skin, with the ability to be applied and removed hundreds of times without damaging the devices or the skin, even in regions with substantial topography and coverage of hair. The approach combines thin, ultralow modulus, cellular silicone materials with elastic, strain-limiting fabrics, to yield a compliant but rugged platform for stretchable electronics. Theoretical and experimental studies highlight the mechanics of adhesion and elastic deformation. Demonstrations include cutaneous optical, electrical and radio frequency sensors for measuring hydration state, electrophysiological activity, pulse and cerebral oximetry. Multipoint monitoring of a subject in an advanced driving simulator provides a practical example.


Assuntos
Monitorização Transcutânea dos Gases Sanguíneos/instrumentação , Eletrônica/instrumentação , Desenho de Equipamento , Monitorização Fisiológica/instrumentação , Oximetria/instrumentação , Monitorização Transcutânea dos Gases Sanguíneos/métodos , Encéfalo/fisiologia , Elasticidade , Fenômenos Eletrofisiológicos , Humanos , Monitorização Fisiológica/métodos , Oximetria/métodos , Silicones/química , Pele/metabolismo
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