1,721,021 research outputs found
Smart Implantable Artificial Bladder: an integrated design for organ replacement
No full textSubstituting the natural bladder with an artificial solution, after cancer and other pathologies, is an ambitious challenge in biomedical engineering. In this work we propose a fully implantable smart artificial bladder system (ABS) that collects urinary fluids and provides the subject with real-time feedback on the implant status. To achieve long term duration, the ABS was designed to be unstretchable in order to be treated with urine resistant coatings and included built-in passive check valves preventing reflux to kidneys. To estimate the amount of fluid collected, the ABS was provided with four electromagnetic distance sensing units and a control unit. An algorithm implemented on an embedded controller enabled the reconstruction of the bladder volume through sensors readings. A wireless data transfer system allows for providing a real-time feedback to the subject. Bench tests validated volume reconstruction accuracy and ex-vivo experiments verified the implantability of the proposed device on a human cadaver, proving the reliability of a Bluetooth data transmission system and paving the way towards an in-body/out-body communication. The proposed solution has the potential to overcome the limitations of currently available replacement strategies towards a new generation of implantable devices for lost organ functions replacement
Millimeter-Scale Magnetic Carrier for On-Demand Delivery of Magnetic and Non-Magnetic Microparticles Suspensions
Full text linkThe use of magnetic microparticles (MMPs) has recently proven a great potential for biomedical applications, i.e. for drug delivery or magnetic hyperthermia. However, MMPs are typically delivered passively through systemic injection or exploiting tethered drug delivery systems which require percutaneous medical procedures. Here we propose an untethered magnetic carrier for MMPs suspension delivery. This wireless millirobot is capable of precisely releasing MMPs that after delivery are completely decoupled from the carrier and can be manipulated independently by separate magnetic sources. Experiments were performed in an aqueous environment to validate carrier locomotion and controlled release capabilities. The prototyped carrier (overall 41 mm long and 10 mm in diameter) can be wirelessly moved by an external magnet at a distance larger than 10 cm, and, when fixed magnetically, can be triggered by another external magnet (around 6 mm apart) to release a cargo. Magnetic navigation and release activation well fit model predictions with actuation distance errors below 10% based on experimental performance. The carrier proved able to perform controlled release of non-magnetic and magnetic cargoes and was recorded to release approximately 25% of the loaded MMPs suspension with no premature release
Indipendent control of magnetic millirobots for targeted drug delivery: simulation-based feasibility study
No full textAdvanced micro-nano-bio systems for future targeted therapies
No full textThis article aims at highlighting the most recent and promising research trends, the open challenges and the possible routes to follow in the field of targeted therapy. A highly interdisciplinary viewpoint has been used, trying to evidence and discuss the different opportunities deriving from recent evolutions of nanotechnology, polymer science, robotics and biotechnology. The most used vectors for nanomedicine applications are described, together with the different action strategies described in the literature, such as passive targeting, site-directed targeting and remotely triggerable drug delivery. Special emphasis is given to magnetically triggered systems and ultrasound-responsive materials, identified as the most promising paradigms. Key competences and system integration strategies derived from robotics are also introduced, focusing the attention on the crucial issue of achieving high controllability of the vector at the micro- and nano-scale. Finally, bio-components are described, highlighting their potential as functional sensing elements or smart mechanisms to be integrated on board of advanced micro-nano therapeutic devices. The conclusion aims at depicting the importance of novel and improved targeted therapy strategies, to be coupled with the emerging world of predicting and personalized medicine. To this aim, a real merging of skills and approaches, derived from the aforementioned research fields, is recognized as highly desirable and rich of opportunities
Toward dosing precision and insulin stability in an artificial pancreas system
No full textA fully implantable artificial pancreas (AP) still represents the holy grail for diabetes treatment. The quest for efficient miniaturized implantable insulin pumps, able to accurately regulate the blood glucose profile and to keep insulin stability, is still persistent. This work describes the design and testing of a microinjection system connected to a variable volume insulin reservoir devised to favor insulin stability during storage. The design, the constitutive materials, and the related fabrication techniques were selected to favor insulin stability by avoiding-or at least limiting-hormone aggregation. We compared substrates made of nylon 6 and Teflon, provided with different surface roughness values due to the employed fabrication procedures (i.e., standard machining and spray deposition). Insulin stability was tested in a worst case condition for 14 days, and pumping system reliability and repeatability in dosing were tested over an entire reservoir emptying cycle. We found that nylon 6 guarantees a higher insulin stability than Teflon and that independent of the material used, larger roughness determines a higher amount of insulin aggregates. A dedicated rotary pump featured by a 1-lL delivery resolution was developed and connected through a proper gear mechanism to a variable volume air-tight insulin reservoir. The microinjection system was also able to operate in a reverse mode to enable the refilling of the implanted reservoir. The developed system represents a fundamental building block toward the development of a fully implantable AP and could be advantageously integrated even in different implantable drug delivery apparatus (e.g., for pain management)
Mechatronic refilling device for long-term implantable artificial organs
No full textObjective: this work introduces a new paradigm for a lifelong-implanted completely automated artificial pancreas (AP) refilled by swallowable pills. We report data about the design and development of an implanted docking system and a refilling mechanism to be interfaced with the gastrointestinal tract, thus allowing long-term maintenance of a chronically implanted mechatronic AP.
Methods: the implanted docking system is based on a miniaturized Magnetic Switchable Device (MSD). Finite element method (FEM) analyses allowed to identify the most appropriate MSD design features and precision machining permitted its fabrication. A rotary DC motor assures MSD activation/deactivation. The swallowable capsule, carrying insulin and fabricated in polydimethilsiloxane, is provided with an RFID tag for its detection by the implanted system and with a ferromagnetic ring for docking. The refilling system is based on a miniaturized linear motor which pushes a needle into the duodenum/stomach internal lumen, in order to punch the docked capsule and to transfer the insulin from the capsule to the internal reservoir, thanks to a miniature pump. A dedicated passive valve integrated in the implantable system is the interface between the device and the body, thus allowing capsule punching and automatically closing after needle retraction.
Results: FEM analyses permitted to identify the best MSD shape which maximizes the contact area with the docked capsule. A Ni-Co-Fe alloy and an N52 NdFeB magnet were employed for achieving an attraction force of 11 N in the “ON” configuration and 1.41e-5 N in the “OFF” configuration. In addition, for a passive valve of 10 x 10 x 2.5 mm3, the maximum opening is ~ 1 mm, thus allowing the use of a 31G insulin needle.
Conclusion: The developed prototype requires further miniaturization, but it demonstrates the feasibility of a mechatronic implantable device for non invasive refilling of artificial organs based on swallowed cargos
Design of a novel magnetic platform for cancer cell manipulation and personalized oncologic treatment
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