Development of a Dynamic Goniometer with an Incremental Encoder

Angle dynamic measurements of body joints have become an important parameter to know for sportsmen, physicians and analysts of rehabilitation processes. The development of devices that allows those measurements turns out to be a hard work for biomedical engineers because during the acquisition process the mechanical system usually affects the natural joints movements. Digital goniometers have been constructed using different electronic principles, especially using resistance variations in potentiometers. In this paper we propose the construction of a dynamic goniometer with an incremental encoder using a mechanical transmission between a hinge and a pulley connected to an optical disk. The rotation is detected with an infrared led and a phototransistor. Calculations are done through a microcontroller and finally shown in real time using a liquid crystal display (LCD).La medición dinámica de los ángulos articulares se ha convertido en un parámetro fundamental para deportistas, médicos y analistas de los procesos de rehabilitación. El desarrollo de dispositivos para estas aplicaciones ha presentado retos importantes debido a la imposibilidad de implementar los sistemas mecánicos requeridos para la medición, sin afectar el movimiento natural de las articulaciones. Los goniómetros digitales se han construido a partir de diferentes principios electrónicos, particularmente basados en las variaciones resistivas de potenciómetros. Este trabajo muestra el desarrollo e implementación de un goniómetro dinámico basado en un encoder incremental con un sistema de transmisión mecánico entre una articulación de tipo bisagra y una polea conectada a un disco óptico. La rotación se detecta con un LED infrarrojo y un fototransistor. El cálculo del movimiento angular en la articulación se realiza con un microcontrolador. Finalmente los datos se muestran en tiempo real en una pantalla de cristal líquido (LCD)

IMU Validation Apparatus for Human Joints

ME450 Capstone Design and Manufacturing Experience: Fall 2020Inertial measurement units (IMUs) are small sensor packs that include accelerometers, gyroscopes, and magnetometers that are used to conduct movement analysis outside of a laboratory setting. IMUs use an integration process to determine absolute orientation and location of the object they are attached to, so error in their output is vulnerable to discrepancies from the effects of long-term data collection. Additional error can also be introduced through magnetic interference with the magnetometer readings. To combat this, calibration and post-processing algorithms can be made to adjust for these measurement errors, but ground truth angle data is needed to quantify their performance. This report outlines the requirements, specifications, evaluated concepts, verification methods, and developed solution for a device that is capable of measuring ground truth angles for comparison with angles derived from different IMU algorithms.Dr. Stephen Cain, Mechanical Engineering, University of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/164441/1/IMU_Validation_Apparatus_for_Human_Joints.pd

Development of Finger ContracturePrevention System For Early Post StrokeRehabilitation

芝浦尾工業大学2016年

A decade of user operation on the macromolecular crystallography MAD beamline ID14-4 at the ESRF

The improvement of the X-ray beam quality achieved on ID14-4 by the installation of new X-ray optical elements is described

Diseño de un encoder magnético usando efecto Hall

We present the design of a magnetic encoder to measure angular position. The proposed encoder includes two Hall sensors in quadrature in a fixed platform. In addition, and over the sensors, there are two permanent magnets in a shaft. The relative motion between the fixed and the movable components generate a voltage variation in the sensors, which serve to generate the approximation of the angular position. We detail the acquisition process and the linearization method, because we consider that these are the most important contributions of this work. Lastly, we show the application of the encoder in the position control of a direct current motor to show the performance of the encoder estimating fast and slow angular position changes.En este artículo se presenta el diseño de un encoder magnético para la medición de la posición angular. El encoder está compuesto por dos sensores de efecto Hall en cuadratura en una plataforma fija. Además, sobre los sensores, y en el eje a medir se ubican dos imanes permanentes con magnetización axial. El movimiento relativo entre el componente fijo y el móvil del encoder genera una variación de voltaje en los sensores. Esta variación da lugar a la aproximación de la posición angular. Se detallan los procesos de adquisición y linealización de los datos, dado que son los aportes más importantes de esta propuesta. Para finalizar se muestra la aplicación del encoder en el control de posición angular del eje de un motor de corriente directa, con lo que se muestra el trabajo del encoder ante cambios lentos y rápidos de posición

A Design Methodology for Development of Clinically Compliant Upper Limb Spasticity Part-Task Trainer

芝浦工業大学201

Application of precision engineering for nanometre focussing of hard X-rays in synchrotron beam lines

This thesis was submitted for the degree of Master of Philosophy and awarded by Brunel University.Many modern synchrotron beamlines are able to focus X-rays to a few microns in size. Although the technology to achieve this is well established, performing routine experiments with such beams is still time consuming and requires careful set up. Furthermore there is a need to be able to carry out experiments using hard X-ray beams with even smaller beams of between 100nm and 10nm. There are focussing optics that are able to do this but integrating these optics into a stable and a usable experimental set up are challenging. Experiments can often take some hours and any change in position of the beam on the sample will adversely affect the quality of the results. Experiments will often require scanning of the beam across the sample and so mechanisms suitable for high resolution but stable scanning are required. Performing routine experiments with nanometre sized beams requires mechanical systems to be able to position the sample, focussing optics, detectors and diagnostics with significantly higher levels of stability and motion resolution than is required from so called micro focus beam lines. This dissertation critically reviews precision engineering and associated technologies that are relevant for building nano focus beamlines, and the following key issues are explored: • Long term position stability due to thermal effects • Short term position stability due to vibration • Position motion with nanometre incremental motion • Results of some tests are presented and recommendations given. Some test results are presented and guidance on designing nano focus beamlines presented.Diamond Light Sourc