This paper presents the design of a 3-DOF prosthetic wrist for transradial myoelectric upper limb prosthesis that allows the orientation of a prosthetic hand to reduce compensatory movements that cause musculoskeletal problems mainly in the back and shoulder. The device is capable of perform passively abduction-adduction movements and actively flexion-extension and pronation-supination movements. The system has a DC motor that transmits power to the active movements and a solenoid for the choice of the type of movement to be performed. In order to validate the design of the components of the device, calculations and simulations were carried out by finite elements method to determine deformations, mechanical resistance and fatigue to define the critical components and maintenance periods. © 2019 IEEE.

This paper presents the implementation of a Finger force detection platform capable to measure the exerted forces by the index, middle, ring and little finger in single-axis direction (flexion); and in dual-axis direction (flexion/adduction) by the thumb. It can be adapted to different sizes in both right or left hand. A test protocol is established. Also, a Graphical User Interface (GUI) is developed in order to assist the subject during the test. The results show the maximum forces developed by each finger among Peruvian participants.

This work describes the development of a prosthesis hand prototype with an active wrist. The Octa Hand can perform at least six grasping shapes: rest, tip, tripod, power, spherical and extension. Cables and pulley mechanism was used on each finger to enable the flexion/extension and under-actuated abduction/adduction movement while worm drive and internal helical gear mechanisms were used on the wrist to enable the flexion/extension and pronation/supination movements. To obtain an anthropomorphic, compact, low-weight and low-cost result, the prototype was designed based on a CAD model using 3D scanner technology, and the prototype was manufactured with 3D printed technology with a total weight of 950g. A control algorithm was tested for speed and fingertips force evaluation of each degree of freedom and the force in the fingertips. As a result, the average speed of the fingers was 140 de...

Partial hand and transradial amputations are among the most common levels of amputation. In the former case, a mechanical prosthesis is prescribed, while in the latter case either a mechanical or a myoelectric one are used depending on the patient’s preference and access to the technology. While a variety of prostheses designs are aimed to transradial amputees and plenty others are for partial hand amputations, like the 3D-printed open-source concepts that are activated by the user’s wrist, for a faster and more efficient treatment of hand amputations, one design should be adaptive for different levels of amputation without compromising the prosthesis performance. This work describes a powered prosthesis design with modular fingers and space constraints that allow it to be adapted to different levels of amputation. The prosthesis finger lengths could also be customized to user-specif...

Se propone un diseño de una prótesis de mano destinada a amputados transmetacarpianos y propulsada por micromotores de CC. Además, se muestra un método para personalizar los dedos protésicos para que coincidan con una antropometría específica del usuario. Finalmente, se explica la selección de sensores y actuadores, y se prueba un esquema de control básico en el prototipo.

Se presenta un diseño de una prótesis de mano impresa en 3D para amputados transmetacarpianos y accionada por micromotores de CC. Se utilizaron mecanismos de articulación de cuatro barras para los movimientos de flexión de los dedos índice, medio, anular y meñique, mientras que para el pulgar se utilizó un mecanismo de engranajes cilíndricos y tracción helicoidal. Finalmente, se probó un esquema de control básico en el prototipo para la evaluación de velocidad y fuerza.

This paper presents the development and validation of a tridimensional 7-DOF human body model for the representation and study of closed kinetic chain exercises (CKCE) performed with the feet fixed in space, i.e. low posture exercises. The biomechanical model, a link-segment model, is based on an Euler-Lagrange formulation and employs a generalized joint coordinate system. A top-down mechanical analysis provides an estimation of the internal joint moments, along with the vertical ground reaction forces, using kinematical data collected by inertial sensors. The model is validated by correlating estimated ground reaction forces to kinetic experimental data from force plates. Pearson correlation coefficients were calculated for four CKCE types (150 trials in total). In all cases, a median correlation r > 0.90 was found, hence proving that the proposed model is quite satisfactory for CKCE mo...