Discusses the process of standing from a chair is the first movement to be affected by physical impairment or ageing. That justified the increase of researches around sit-to-stand movements nowadays.This thesis presents the design of a four links wearable device that can assist disable people to stand from a sitting position. The four links are joined at the ankle, the knee and the HAT (Head, Arm and Trunk) where actuators are mounted. The system is built around three controllers. The Goal Controller drives the links along their reference trajectories, the Stability Controller makes sure that the system does not collapse as it is rising, and the last controller combines the signal from the 2 first ones.The reference trajectories are obtained from data recorded from healthy people performing the movement. The main idea behind the present design is that from seat off, the floor projection of the body centre of pressure is evaluated and compared to the most stable position. The stability controller generates the torque necessary to compensate the deviation, while the third controller adjusts the level of participation of that torque to satisfy both the trajectory and the stability objectives. Similar idea was previously found in Prinz (2010).

For millions of individuals, a spinal cord injury has taken away their ability to walk. While wheelchairs and leg braces offer mobility options, none offer a means to stand up and walk. For these individuals, secondary injuries can be prevalent, and special care must be taken to avoid the pain and cost of pressure sores, urinary tract infections, and other such ailments. Furthermore, there is an emotional benefit to being able to stand and walk. Events such as choosing your own seat at the theater or sports game, walking your daughter down the aisle at her wedding, reaching the pasta on the top shelf at the grocery store, or checking out of a hotel at the main counter, are taken for granted by those who can walk, but for those who use a wheelchair for mobility, these are stark reminders of the limitations of the chair. Exoskeletons provide a means by which these individuals can get up again and walk. They offer power joints and a support for the body so that a user with a spinal cord injury can rely on the robot's power to replace what their body no longer provides. While the architecture and design of such an exoskeleton is complex, the control of the exoskeleton offers numerous challenges. This thesis presents the development and testing of a method to allow the user to communicate his desired motion to the robot. For an exoskeleton to truly provide freedom for the user, the user must be able to operate the exoskeleton independently. To do this, the exoskeleton must know what the user wants to do and when and then decide if that maneuver is safe. The user communicates his desired action to the exoskeleton using the Human Machine Interface (HMI). This thesis describes development of the hardware and software for the HMI beginning with the conception of the structure of the HMI based on end-user surveys and observations of users. The hardware was then developed to determine the state transitions and the software was written to determine desired state changes. The Human Machine Interface was then verified using a mockup to test and then was tested on the eLEGS exoskeleton. The software was verified through experiments and theoretically using classifiers. The Human Machine Interface was tested by subjects with a wide range of injuries and abilities to ensure that it performed safely for all users. Based on experience with the Human Machine Interface, improvements in robustness and usability were made. This thesis also presents the development of some of the continuous controllers used to achieve the sitting and standing motions. While traditional control strategies rely on models, control of exoskeletons includes a human in the loop, which can be a sizeable disturbance. Therefore, the controller development must be robust to this disturbance and also take into account the comfort and safety of the user. The results presented here show numerous spinal cord injury patients of varying levels and completeness able to ambulate independently using the HMI developed for eLEGS. They are able to walk, sit, and stand naturally, thus providing wheelchair users a viable means of walking again.

This book reports on the latest advances in concepts and further development of principal component analysis (PCA), discussing in detail a number of open problems related to dimensional reduction techniques and their extensions. It brings together research findings, previously scattered throughout many scientific journal papers worldwide, and presents them in a methodologically unified form. Offering vital insights into the subject matter in self-contained chapters that balance the theory and concrete applications, and focusing on open problems, it is essential reading for all researchers and practitioners with an interest in PCA

Wearable Robotics: Systems and Applications provides a comprehensive overview of the entire field of wearable robotics, including active orthotics (exoskeleton) and active prosthetics for the upper and lower limb and full body. In its two major sections, wearable robotics systems are described from both engineering perspectives and their application in medicine and industry. Systems and applications at various levels of the development cycle are presented, including those that are still under active research and development, systems that are under preliminary or full clinical trials, and those in commercialized products. This book is a great resource for anyone working in this field, including researchers, industry professionals and those who want to use it as a teaching mechanism. Provides a comprehensive overview of the entire field, with both engineering and medical perspectives Helps readers quickly and efficiently design and develop wearable robotics for healthcare applications

The mobility of the lower extremities may be affected by neurological conditions such as stroke or spinal cord injury. When, motor function, gait coordination and muscle strength are impaired. Rehabilitation can improve the autonomy of legs movement in order to carry out everyday tasks such as walking or stand up, also known as a Sit-To-stand. Sit-To-Stand is a task that requires considerable effort for those who have suffered a stroke or other type of injury. To perform the Sit-To-stand movement there are variables such as force, velocities, position angles, among others that can be modeled with the use of robotic exoskeletons. This project develops a Sit-To-Stand control strategy implemented in a robotic exoskeleton. This is based on previous work on the development of control strategies for the rehabilitation of the Sit-ToStand. Where Sit-To-Stand transition phases combined with position and admittance control strategies are used. The objectives of this project are to find optimal values of the angles of the joints involved in the transition of the phases and to propose an improvement in the control strategy to assist people with lower extremities movements.

The majority of powered lower-limb exoskeletons nowadays are designed to rigidly track time-based kinematic patterns, which forces users to follow specific joint positions. This kinematic control approach is limited to replicating the normative joint kinematics associated with one specific task and user at a time. These pre-defined trajectories cannot adjust to continuously varying activities or changes in user behavior associated with learning during gait rehabilitation. Time-based kinematic control approach must also recognize the user’s intent to transition from one task-specific controller to another, which is susceptible to errors in intent recognition and does not allow for a continuous range of activities. Moreover, fixed joint patterns also do not facilitate active learning during gait rehabilitation. People with partial or full volitional control of their lower extremities should be allowed to adjust their joint kinematics during the learning process based on corrections from the therapist. To address this issue, we propose that instead of tracking reference kinematic patterns, kinetic goals (for example, energy or force) can be enforced to provide a flexible learning environment and allow the user to choose their own kinematic patterns for different locomotor tasks. In this dissertation, we focus on an energetic control approach that shapes the Lagrangian of the human body and exoskeleton in closed loop. This energetic control approach, known as energy shaping, controls the system energy to a specific analytical function of the system state in order to induce different dynamics via the Euler-Lagrange equations. By explicitly modeling holonomic contact constraints in the dynamics, we transform the conventional Lagrangian dynamics into the equivalent constrained dynamics that have fewer (or possibly zero) unactuated coordinates. Based on these constrained dynamics, the matching conditions, which determine what energetic properties of the human body can be shaped, become easier to satisfy. By satisfying matching conditions for human-robot systems with arbitrary system dimension and degrees of actuation, we are therefore able to present a complete theoretical framework for underactuated energy shaping that incorporates both environmental and human interaction. Simulation results on a human-like biped model and experimental results with able-bodied subjects across a variety of locomotor tasks have demonstrated the potential clinical benefits of the proposed control approach.

The new technological advances opened widely the application field of robots. Robots are moving from the classical application scenario with structured industrial environments and tedious repetitive tasks to new application environments that require more interaction with the humans. It is in this context that the concept of Wearable Robots (WRs) has emerged. One of the most exciting and challenging aspects in the design of biomechatronics wearable robots is that the human takes a place in the design, this fact imposes several restrictions and requirements in the design of this sort of devices. The key distinctive aspect in wearable robots is their intrinsic dual cognitive and physical interaction with humans. The key role of a robot in a physical human–robot interaction (pHRI) is the generation of supplementary forces to empower and overcome human physical limits. The crucial role of a cognitive human–robot interaction (cHRI) is to make the human aware of the possibilities of the robot while allowing them to maintain control of the robot at all times. This book gives a general overview of the robotics exoskeletons and introduces the reader to this robotic field. Moreover, it describes the development of an upper limb exoskeleton for tremor suppression in order to illustrate the influence of a specific application in the designs decisions.

Circuits, Signals and Systems for Bioengineers: A MATLAB-Based Introduction, Third Edition, guides the reader through the electrical engineering principles that can be applied to biological systems. It details the basic engineering concepts that underlie biomedical systems, medical devices, biocontrol and biomedical signal analysis, providing a solid foundation for students in important bioengineering concepts. Fully revised and updated to better meet the needs of instructors and students, the third edition introduces and develops concepts through computational methods that allow students to explore operations, such as correlations, convolution, the Fourier transform and the transfer function. New chapters have been added on image analysis, noise, stochastic processes and ergodicity, and new medical examples and applications are included throughout the text. - Covers current applications in biocontrol, with examples from physiological systems modeling, such as the respiratory system - Includes revised material throughout, with improved clarity of presentation and more biological, physiological and medical examples and applications - Includes a new chapter on noise, stochastic processes, non-stationary and ergodicity - Includes a separate new chapter featuring expanded coverage of image analysis - Includes support materials, such as solutions, lecture slides, MATLAB data and functions needed to solve the problems