Ciencias Exactas y Ciencias de la Salud

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Development of a 3-DOF exoskeleton for rehabilitation and training of human wrist in combination with a virtual interface
(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-07-31) García Leal, Roderico Alfredo; Huegel West, Joel Carlos; puemcuervo, emipsanchez; O'Malley, Marcia K; Cruz Ortiz, David; Salgado Ramos, Iván de Jesús; González de Alba, Alejandro; School of Engineering and Sciences; Campus Monterrey; Ballesteros Escamilla, Mariana Felisa
Rehabilitation therapies produce positive outcomes by recovering the lost brain plasticity after a cerebrovascular accident or stroke; such therapies can be applied by physiotherapists with the assistance of rehabilitation devices; among these devices, robots have shown the capability of providing consistent and measurable routines for long periods. In the physiotherapy process, the upper limbs are the first parts of the body to receive rehabilitation by playing a key role in performing activities of daily living (ADL) again. In that sense, wrist rehabilitation robots are the most common device with that purpose. The thesis presented herein describes the development of an exoskeleton robot for wrist rehabilitation with three degrees of freedom (DOFs). It was designed to have the capability of proving the forces and ranges of motion required to generate wrist rehabilitation routines. The device DOFs consist of three rotational joints in series, allowing the user to effectuate the natural wrist movements: pronation/supination, flexion/extension, and radial/ulnar deviation. The exoskeleton joints are actuated directly by quasi-direct drive actuators that provide sufficient torque and speed at each DOF to replicate wrist ADLs movements. Actuator's low inertia and low friction allow the joints to be back-drivable, enhancing the transparency of the device. Robust state feedback control algorithms are implemented to achieve position control and trajectory tracking at each DOF without implementing the system's mathematical model. System characterization is obtained through the frequency response and static friction tests over each joint. The effect of the robot dynamics on the user was measured by analyzing the kinematic data of healthy participants when performing wrist movements when using and not the exoskeleton, validating the transparency of the exoskeleton joints by observing smooth velocity profiles when using the device. Finally, a pilot test is performed to demonstrate the capability of interacting with a two-dimensional virtual interface (VI) through the wrist movements performed over the exoskeleton, validating the possibility of future implementation of game-based therapies to encourage participants to perform wrist movements for their rehabilitation. The obtained results provide meaningful data demonstrating the potential of the developed exoskeleton to be used as a wrist rehabilitation device.
Lab-scale modular platform to study coiled-flow inverters (CFI) as candidates for continuous-flow photoreactor units: A case study based on the oxidative degradation of fluorescein induced by visible light in the presence of ZnO-APTMS-Au micro/nano-particles in aqueous suspension
(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-12-04) Tiwari, Chinmay Pramodkumar; Aguirre Soto, Héctor Alán; tolmquevedo; Gallo Villanueva, Roberto Carlos; Contreras Cruz, David Atahualpa; López Guajardo, Enrique Alfonso; School of Engineering and Sciences; Campus Monterrey
Visible light-driven continuous-flow photochemistry has gained widespread recognition lately and is employed in many innovatively designed photoreactors. Out of the two main categories, slurry reactors are found to have a better reputation in terms of achieving competitive photon efficiencies when compared to immobilized catalyst type reactor designs. However, several obstacles had stalled the broad-scale implementation of this beneficial process. A few of the main imminent challenges include combating light attenuation by better mixing in continuous-flow of the suspension to allow the use of the higher photocatalyst content and require lower photon consumption. Also, the difficulties in the fabrication of intricate glass-based photoreactor designs are one of the significant challenges. An inherently better-designed reactor which deals with the common problems of conventional photoreactors is required. This thesis presents a flexible platform to study photoreactors, where a coiled flow inverter—a well-established static mixer design— is used as a micro/milli-fluidic device. The CFI is incorporated as a photoreactor for the first time for a continuous flow photodegradation study of an organic model pollutant, fluorescein, with ZnO catalyst functionalized with APTMS and Au nanoparticles to make it visible-light absorptive. Flow inversions leading to chaotic advection occurring in the CFI combats light attenuation. Due to superlative mixing coupled with a highly efficient visible light source, our photo-CFI stands to be in top slurry reactor designs as per the recently established PSTY benchmark, valued at 2.97×10^−2 (m^3 treated water day^-1 m^-3 reactor kW^-1). A brief study on the uni- and multi-axial light arrangement for complex geometries was used to analyze the effect of geometry/lighting arrangement and ensure uniform irradiation of the photo-CFI. A discussion of dye-degradation products surface interaction with photocatalyst was carried out to analyze possible explanations for an observed destabilization of the suspension during reaction, leading to depositions in the reactor. SLA based additive manufacturing is tested and projected to be a superior alternative for rapid prototyping of intricate transparent photoreactor designs in lieu of conventional glass blowing techniques of complex geometries such as those required for static mixers like the photo-CFI.

Ciencias Exactas y Ciencias de la Salud

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