Assistive Robotic Exoskeleton for Helping Limb Girdle Muscular Dystrophy Salomón Castro, Esther Lugo, Pedro Ponce and Arturo Molina EDIA-Cátedra de Ingeniería Mecatrónica Tecnológico de Monterrey Campus Ciudad de México Distrito Federal, México A0094678@itesm.mx; Esther.lugo@itesm.mx; pedro.ponce@itesm.mx; arturo.molina@itesm.mx Abstract—The Limb Girdle Muscular Dystrophy (LGMD) is a heterogeneous group of muscle diseases; this is manifested by a progressive loss of the strength of the muscles of the pelvic and shoulders girdles. Several devices that can compensate for the loss of some motors skills have been developed in support for the activities of patients presenting such dystrophy. Those devices include the pole or treadmill that can be used with an exoskeleton to improve the phase of displacement among other activities. This work shows a new mechanical design for a robotic-exoskeleton with seven movement axis, having as purpose to help people, with certain LGMD dystrophy or diseases characteristics, in generate movements of flexion/extension in the lower extremity joints and realize the gait cycle. All of the design movement’s analysis is simulated in Solidworks® and OpenSim® software. Keywords-LGMD; simulation; exoskeleton; Solidworks®; OpenSim® I. INTRODUCTION Robotic-exoskeleton research and development were originated by the military in the 1960s. In the research of Reinkensmeyer [1], mentioned that initial work has focused on therapeutic applications of robotic exoskeletons with a Lokomat gait-training robot. A recent review realized by [2, 3] identified four characteristics which robotic-exoskeletons must have their maximal rehabilitative and assistive technology potential: 1) robust human-robot multimodal cognitive interaction; 2) safe and dependable physical interaction; 3) true wear ability and portability and 4) user-centered aspects such as acceptance and usability. Significant advances in the robotic- exoskeletons have been achieved, but the technology has many limitations related to physical and cognitive interaction, for example, the difficulty of aligning the principal axes of motion correctly between human joints and exoskeleton joints [4]. But robotic-exoskeleton has some advantages, such as support to muscles or helps to maintain functionality in muscles affected for some diseases or dystrophy (rehab application). The use of these devices is important because can keep patients ambulatory longer, minimize crippling contractures and prevent or delay scoliosis (curvature of the spine). The objective of this paper is to present an robotic- exoskeleton, determine the movement relation between human joints and exoskeleton joints, and simulate the movement during typical gait for people with LGMD type 1C, 2A and 2B [5, 6, 7, 8]. The work is divided in the following way to get to the simulation of the movements required in the human gait with LGMD, begins with a description of the study case, subsequently it is the analysis of motion to determine the movements that should make the robotic-exoskeleton to help the patient to generate the basic flexion/extension alone. Based on this information, it raises the design considerations of the robotic-exoskeleton, which subsequently transferred to the conceptual design of the same and the simulation to validate the optimum operation based on the needs of the LGMD patient. II. LIMB GIRDLE MUSCULAR DYSTROPHY Constitutes a group of genetically determinate, progressive disorders of muscles, in which the pelvic o shoulder girdle musculature is predominantly or primarily involved [9]. The variation seen in the LGMDs is caused by differences in the type of gene alteration. Early symptoms can include difficulty walking, running and rising from the floor [10, 11]. A. Effects of muscular dystrophy Clinical onset of the disease occurs anywhere from the first to the third decade of life, LGMD is progressive, affected person´s muscles continue to get weaker throughout their lifetime. Generally, over time, a person with LGMD loses muscle bulk and strength [10]. In these muscles become shortened and lose elasticity, causing the joints are being tightened little by little, losing mobility; this restricts their mobility increases the effects of physical decline. B. Assistive devices for LGMD For more stability and less fatigue, is possible to use an exoskeleton with the cane or walker, because this cause differences in support muscle and organ development, it improves their health because the body is meant to work in an upright posture, help to maintain function and comfort, and can make things easier as weakness progresses [11]. An electric wheelchair or scooter becomes convenient when weakness in the pelvic girdle and upper legs causes frequent falls but have troubles such as use on rough terrain or stairs or difficulty of transportation. However, patients using devices such as exoskeleton that transmits to the lower limb the assist force which is generated by the actuator and must supply all of the power needed by exerting forces with other muscles to compensate that is weak or injured. For LGMD the robotic-exoskeleton device is useful when the level of 2013 International Conference on Mechatronics, Electronics and Automotive Engineering 978-1-4799-2252-9/13 $31.00 © 2013 IEEE DOI 10.1109/ICMEAE.2013.9 27 2013 International Conference on Mechatronics, Electronics and Automotive Engineering 978-1-4799-2252-9/13 $31.00 © 2013 IEEE DOI 10.1109/ICMEAE.2013.9 27 2013 International Conference on Mechatronics, Electronics and Automotive Engineering 978-1-4799-2252-9/13 $31.00 © 2013 IEEE DOI 10.1109/ICMEAE.2013.9 27 2013 International Conference on Mechatronics, Electronics and Automotive Engineering 978-1-4799-2253-6/13 $31.00 © 2013 IEEE DOI 10.1109/ICMEAE.2013.9 27