RESUMEN
BACKGROUND: In recent years, health monitoring systems (HMS) have aroused great interest due to their broad prospects in preventive medicine. As an important component of HMS, flexible force sensors (FFS) with high flexibility and stretch-ability can monitor vital health parameters and detect physical movements. AIM OF REVIEW: In this review, the novel materials, the advanced additive manufacturing technologies, the selective sensing mechanisms and typical applications in both wearable and implantable HMS are discussed. KEY SCIENTIFIC CONCEPTS AND IMPORTANT FINDINGS OF REVIEW: We recognized that the next generation of the FFS will have higher sensitivity, wider linear range as well as better durability, self-power supplied and multifunctional integrated. In conclusion, the FFS will provide powerful socioeconomic benefits and improve people's quality of life in the future.
RESUMEN
BACKGROUND: Artificial meniscal implants can be used to replace a severely injured meniscus after meniscectomy and restore the normal functionality of a knee joint. The aim of this paper was to design porous meniscal implants and assess their biomechanical properties. METHODS: Finite element simulations were conducted on eight different cases including intact healthy knees, knee joints with solid meniscal implants, and knee joints with meniscal implants with two types of triply periodic minimal surfaces. Compression stresses, shear stresses, and characteristics of stress concentrated areas were evaluated using an axial compressive load of 1150 N and an anterior load of 350 N. RESULTS: Compared to the solid meniscal implant, the proposed porous meniscal implant produced lower levels of compression and shear stresses on the cartilage, which facilitated the cartilage to retain a semilunar characteristic similar to the natural meniscus. Moreover, both compression and shear stresses on the artificial cartilage were found to be sensitive to the pore properties of the meniscal implant. The meniscal implants with primitive surfaces (porosity: 41%) showed a better performance in disseminating stresses within the knee joint. CONCLUSION: The present commercial meniscal implant has the problem of equivalent biomechanical properties compared to natural menisci. The main advantage of the proposed porous structure is that it can be used to prevent excessive compression and shear stresses on the articular cartilages. This structure has advantages both in terms of mechanics and printability, which can be beneficial for future clinical applications.
Asunto(s)
Menisco/fisiopatología , Prótesis e Implantes , Adulto , Fenómenos Biomecánicos , Análisis de Elementos Finitos , Humanos , Imagenología Tridimensional , Articulación de la Rodilla/patología , Articulación de la Rodilla/fisiopatología , Masculino , Menisco/patología , Porosidad , Estrés Mecánico , Propiedades de SuperficieRESUMEN
Heterogeneous biomaterials that simultaneously mimic the topological and mechanical properties of nature bone tissues are of great interest in recent years. In this study, multi-morphology porous scaffolds based on the triply periodic minimal surfaces (TPMS) were designed and 3D printed with spatially changing pore patterns. Experiments and numerical analyses were carried out to assess the mechanical properties of the multi-morphology graded porous scaffold. As can be seen from the results, the multi-morphology structure showed a combination of relatively low elastic moduli and high yield strength. This combination allows for simultaneously minimizing the bone damage and increasing the stability of bone-implant interface. Thus the 3D printed multi-morphology porous Ti6AlV scaffold had shown significant promise for orthopedic application.