A Magnetic Drug Delivery Capsule Based on a Coil Actuation Mechanism

Current Wireless Capsule Endoscopic systems (WCE) provide only diagnostic tools, but in the future, advanced functionalities such as controllable drug delivery could be available for clinicians. This work introduces a Magnetic Drug Delivery Capsule (MDDC). The MDCC is based on a coil actuation mechanism that enables the deployment of a drug chamber from the device body. In this work, we present the prototype design and the results of bench trials that demonstrated the device ability to trigger the drug deployment by characterizing the magnetic field and resulting force

An FPGA-based flexible demo-board for endoscopic capsule design optimization

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Doctor of Philosophy

dissertationThis dissertation explores the design and use of an electromagnetic manipulation system that has been optimized for the dipole-eld model. This system can be used for noncontact manipulation of adjacent magnetic tools and combines the eld strength control of current electromagnetic systems with the analytical modeling of permanent-magnet systems. To design such a system, it is rst necessary to characterize how the shape of the eld source aects the shape of the magnetic eld. The magnetic eld generated by permanent magnets and electromagnets can be modeled, far from the source, using a multipole expansion. The error associated with the multipole expansion is quantied, and it is shown that, as long as the point of interest is 1.5 radii of the smallest sphere that can fully contain the magnetic source, the full expansion will have less than 1% error. If only the dipole term, the rst term in the expansion, is used, then the error is minimized for cylindrical shapes with a diameter-to-length ratio of 4=3 and for rectangular-bars with a cube. Applying the multipole expansion to electromagnets, an omnidirectional electromagnet, comprising three orthogonal solenoids and a spherical core, is designed that has minimal dipole-eld error and equal strength in all directions. Although this magnet can be constructed with any size core, the optimal design contains a spherical core with a diameter that is 60% of the outer dimension of the magnet. The resulting magnet's ability to dextrously control the eld at a point is demonstrated by rotating an endoscopic-pill mockup to drive it though a lumen and roll a permanent-magnet ball though several trajectories. Dipole elds also apply forces on adjacent magnetized objects. The ability to control these forces is demonstrated by performing position control on an orientation-constrained magnetic oat and nally by steering a permanent magnet, which is aligned with the applied dipole eld, around a rose curve

Wireless Robotic Capsule for Releasing Bioadhesive

A novel, miniature wireless robotic capsule for releasing bioadhesive patches in the gastrointestinal (GI) tract was designed, fabricated, and preliminarily tested. In particular, the assembled prototype was successfully navigated in a GI phantom, up to a target site where the release mechanism was verified. Then, deployment of a bioadhesive patch onto ex vivo porcine tissue was accomplished, and patch adhesion strength was verified. The main application of the present system is the deployment of anchoring patches for miniature robotic modules to be operated in the targeted anatomical domain. Such an innovative application stems from the wise blend of robotics and bioadhesion. Obtained results, which are consistent with previous investigations by the group, confirm the viability of the adopted bioadhesives for the envisaged anchoring tasks. The present feasibility study complies with the spirit of minimally invasive, wireless diagnosis, and therapy, and provides a preliminary contribution for their advancement

Mapeo de la vía del sistema digestivo por localización híbrida de una cápsula endoscópica microrobótica

Este proyecto propone un sistema para la localización de la ubicación de una cápsula endoscópica dentro del cuerpo humano con precisión. Para ello se vale de la tecnología y conocimiento utilizado en los sistemas de captación y tratamiento de señales, y también de algoritmos utilizados para el procesamiento de señales. Finalmente se presentan los resultados obtenidos.Se trata de un método de localización híbrida en el que la información de ambos procedimientos, que se presentan a continuación, se interpreta para dar una respuesta única y de mayor precisión que por los métodos por separados.El primer método consiste en tratar de medir la intensidad de una señal electromagnética a una frecuencia determinada emitida por la cápsula, a través de varios sensores de radiofrecuencia dispuestos de formas diversas en la zona abdominal.El segundo método busca tratar las imágenes captadas por la cápsula localizando partes o zonas peculiares de la imagen y comparándolas con las de las siguientes imágenes, calculando a través de distintos algoritmos la distancia que se ha recorrido, así como la dirección que se sigue.Ambos procedimientos proporcionan un resultado del recorrido seguido por la cápsula, similares, pero con errores de precisión, no siendo los mismos errores para las mismas zonas. Así se implementan métodos de fusión sensorial para aunar la información obtenida de ambos procedimientos buscando que se corrijan el uno al otro y conseguir un resultado más preciso.<br /

Energy-Efficient Design and Control of a Vibro-Driven Robot

Vibro-driven robotic (VDR) systems use stick-slip motions for locomotion. Due to the underactuated nature of the system, efficient design and control are still open problems. We present a new energy preserving design based on a spring-augmented pendulum. We indirectly control the friction-induced stick-slip motions by exploiting the passive dynamics in order to achieve an improvement in overall travelling distance and energy efficacy. Both collocated and non-collocated constraint conditions are elaborately analysed and considered to obtain a desired trajectory generation profile. For tracking control, we develop a partial feedback controller which for the pendulum which counteracts the dynamic contributions from the platform. Comparative simulation studies show the effectiveness and intriguing performance of the proposed approach, while its feasibility is experimentally verified through a physical robot. Our robot is to the best of our knowledge the first nonlinear-motion prototype in literature towards the VDR systems

Endoscopic Tactile Capsule for Non-Polypoid Colorectal Tumour Detection

An endoscopic tactile robotic capsule, embedding miniaturized MEMS force sensors, is presented. The capsule is conceived to provide automatic palpation of non-polypoid colorectal tumours during colonoscopy, since it is characterized by high degree of dysplasia, higher invasiveness and lower detection rates with respect to polyps. A first test was performed employing a silicone phantom that embedded inclusions with variable hardness and curvature. A hardness-based classification was implemented, demonstrating detection robustness to curvature variation. By comparing a set of supervised classification algorithms, a weighted 3-nearest neighbor classifier was selected. A bias force normalization model was introduced in order to make different acquisition sets consistent. Parameters of this model were chosen through a particle swarm optimization method. Additionally, an ex-vivo test was performed to assess the capsule detection performance when magnetically-driven along a colonic tissue. Lumps were identified as voltage peaks with a prominence depending on the total magnetic force applied to the capsule. Accuracy of 94 % in hardness classification was achieved, while a 100 % accuracy is obtained for the lump detection within a tolerance of 5 mm from the central path described by the capsule. In real application scenario, we foresee our device aiding physicians to detect tumorous tissues

A Review of Locomotion Systems for Capsule Endoscopy

Wireless capsule endoscopy for gastrointestinal (GI) tract is a modern technology that has the potential to replace conventional endoscopy techniques. Capsule endoscopy is a pill-shaped device embedded with a camera, a coin battery, and a data transfer. Without a locomotion system, this capsule endoscopy can only passively travel inside the GI tract via natural peristalsis, thus causing several disadvantages such as inability to control and stop, and risk of capsule retention. Therefore, a locomotion system needs to be added to optimize the current capsule endoscopy. This review summarizes the state-of-the-art locomotion methods along with the desired locomotion features such as size, speed, power, and temperature and compares the properties of different methods. In addition, properties and motility mechanisms of the GI tract are described. The main purpose of this review is to understand the features of GI tract and diverse locomotion methods in order to create a future capsule endoscopy compatible with GI tract properties