Wearable Monitoring Devices for Assistive Technology: Case Studies in Post-Polio Syndrome

The correct choice and customization of an orthosis are crucial to obtain the best comfort and efficiency. This study explored the feasibility of a multivariate quantitative assessment of the functional efficiency of lower limb orthosis through a novel wearable system. Gait basographic parameters and energetic indexes were analysed during a Six-Minute Walking Test (6-MWT) through a cost-effective, non-invasive polygraph device, with a multichannel wireless transmission, that carried out electro-cardiograph (ECG); impedance-cardiograph (ICG); and lower-limb accelerations detection. Four subjects affected by Post-Polio Syndrome (PPS) were recruited. The wearable device and the semi-automatic post-processing software provided a novel set of objective data to assess the overall efficiency of the patient-orthosis system. Despite the small number of examined subjects, the results obtained with this new approach encourage the application of the method thus enlarging the dataset to validate this promising protocol and measuring system in supporting clinical decisions and out of a laboratory environment

The effects of ankle-foot orthoses on gait deviations associated with untreated developmental dysplasia of the hip during walking: case study

Developmental dysplasia of the hip (DDH) is considered to be one of the most common orthopaedic disorders, referring to a range of conditions from mild to severe dislocation of the hip joint. Knowledge of ankle-foot orthosis (AFO) use in patients with severe developmental dysplasia of the hip bone is crucial and may help improve the gait cycle during walking. The plantar pressure sensing mat and insole plantar sensor pad are ideal low cost alternatives to the force plate for capturing plantar centre pressure excursion during gait. Acquired centre of pressure (COP) traces are favoured by many medical clinicians and allied health professionals evaluating foot loading and body balance with respect to foot biomechanics, foot injury, foot deformation and foot ulceration. Researchers have recommended the use of COP traces for the study of the deformed foot and deformed lower limb to improve orthosis assessment and orthosis performance testing. Knowledge of the COP and plantar pressure characteristics such as peak pressure, contact pressure and pressure time integral during walking can help identify possible foot pathology, help determine the most effective foot orthosis, and allow for the appropriate calculation of balance control and joint kinetics and kinematics during gait. However, there are unclear gait alterations in individuals with DDH which have clinical implications such as the investigation of AFOs and their effect on lower limb kinematics and kinetics, and their impact on the plantar pressure characteristics of the joints during walking and running. This research aimed to provide a better understanding of the gait characteristics of patients with severe DDH. The first set of objectives was to study and evaluate the kinematics and kinetics of the ankle, knee and hip joints during walking in the sagittal plane for a patient aged 27 years (the author of this research) with severe dysplasia of the left hip, using two different types of ankle-foot orthosis (custom-made, and leaf-AFO). The data were collected using ten cameras and one force plate under four conditions: barefoot, custom-made AFO, leaf AFO, and shoes only. The angles between every two segments were calculated using the Euler rotation sequence. An inverse dynamic approach was used to calculate sagittal joint moments and power. The results showed that the planter flexion angle reached its maximum during the time between the toes-off, the ground phase and the initial swing phase with a mean difference of 21.1° and 14°, respectively. Moreover, the results indicated that the fabricated orthosis decreased both the right and left extensor moments significantly during the load-bearing phase in comparison to barefoot by a mean difference of 0.29, and 0.43 Nm/kg respectively for both limbs. Results showed that the custom-orthosis had a higher moment during the late stance of the gait cycle compared to barefoot, with the data showing significant change by a mean difference of 0.1604 Nm/kg. However, the Leaf Spring AFO had little impact on the flexion moment during the late stance phase. The second set of objectives of this study was to evaluate the effect of wearing the two ankle-foot orthosis on the plantar pressure distribution of specific foot regions for the patient with DDH. These objectives were achieved by developing a correlation technique between the COP trajectory and the lower limb trajectory during the three main phases of gait (heel strike, midstance and push off). The lower limb trajectory data were collected using a new close-range photogrammetry system that employed six HD video cameras to capture the lower limb trajectory. The COP trace and pressure data were collected using 3000E F-scan in-shoe sensors sampling at 100 Hz inserted inside the patient’s shoes. Six walking trials (ten steps per trial) were recorded for each condition (barefoot, custom-made orthosis, and Leaf-AFO). The average of the three middle steps was taken out of the ten steps for each trial under each condition. The corresponding results showed that the highest values of the pressure time integral for the left foot barefoot condition were registered under the lateral heel (LH) 115.92±2.91 kPa.sec, medial heel (MH) 101.66±2.55 kPa.sec, first toe (T1) 73.79±1.85 kPa.sec, fourth and fifth toes (T45) 49.90±1.25 kPa.sec and second toe (T2) 42.94±1.08 kPa.sec. The research concluded that the kinematics and kinetics of the ankle and hip joint were improved by the custom-made orthosis more than that of the Leaf AFO-Spring Orthoses. The current work also concluded that both AFOs did not much change the kinematics of the knee joint however, there were some improvements in the moments and power generated. Finally, the researcher concluded that both orthoses enhanced body stability, minimized foot pain, and minimizing the risk of injury beneath specific foot regions. More investigations are required in the future, such as the investigation of the customized Knee-Ankle-Foot Orthosis (KAFOs) and increasing the number of samples

Orthotic management of instability of the knee related to neuromuscular and central nervous system disorders: systematic review, qualitative study, survey and costing analysis

Background Patients who have knee instability that is associated with neuromuscular disease (NMD) and central nervous system (CNS) conditions can be treated using orthoses, such as knee–ankle–foot orthoses (KAFOs). Objectives To assess existing evidence on the effectiveness of orthoses; patient perspectives; types of orthotic devices prescribed in the UK NHS; and associated costs. Methods Qualitative study of views of orthoses users – a qualitative in-depth interview study was undertaken. Data were analysed for thematic content. A coding scheme was developed and an inductive approach was used to identify themes. Systematic review – 18 databases were searched up to November 2014: MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, Cumulative Index to Nursing and Allied Health, EMBASE, PASCAL, Scopus, Science Citation Index, BIOSIS Previews, Physiotherapy Evidence Database, Recal Legacy, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Health Technology Assessment database, Cochrane Central Register of Controlled Trials, Conference Proceedings Citation Index: Science, Health Management Consortium, ClinicalTrials.gov, International Clinical Trials Registry Platform and National Technical Information Service. Studies of adults using an orthosis for instability of the knee related to NMD or a CNS disorder were included. Data were extracted and quality was assessed by two researchers. Narrative synthesis was undertaken. Survey and costing analysis – a web survey of orthotists, physiotherapists and rehabilitation medicine physicians was undertaken. Telephone interviews with orthotists informed a costing analysis. Results Qualitative study – a total of 24 people participated. Potential for engagement in daily activities was of vital importance to patients; the extent to which their device enabled this was the yardstick by which it was measured. Patients’ prime desired outcome was a reduction in pain, falls or trips, with improved balance and stability. Effectiveness, reliability, comfort and durability were the most valued features of orthoses. Many expressed frustration with perceived deficiencies in service provision relating to appointment and administrative systems and referral pathways. Systematic review – a total of 21 studies (478 participants) were included of people who had post-polio syndrome, inclusion body myositis, were post stroke or had spinal cord injury. The studies evaluated KAFOs (mainly carbon fibre), stance control KAFO and hip KAFOs. All of the studies were at risk of bias and, in general, were poorly reported. Survey and costing analysis – in total, 238 health-care professionals responded. A range of orthoses is prescribed for knee instability that is related to NMD or CNS conditions, approximately half being custom-made. At least 50% of respondents thought that comfort and confidence in mobility were extremely important treatment outcomes. The cost of individual KAFOs was highly variable, ranging from £73 to £3553. Conclusions Various types of orthoses are used in the NHS to manage patients with NMD/CNS conditions and knee instability, both custom-made and prefabricated, of variable cost. Evidence on the effectiveness of the orthoses is limited, especially in relation to the outcomes that are important to orthoses users. Limitations The population included was broad, limiting any in-depth consideration of specific conditions. The response rate to the survey was low, and the costing analysis was based on some assumptions that may not reflect the true costs of providing KAFOs. Future work Future work should include high-quality research on the effectiveness and cost-effectiveness of orthoses; development of a core set of outcome measures; further exploration of the views and experiences of patients; and the best models of service delivery. Study registration This study is registered as PROSPERO CRD42014010180. The qualitative study is registered as Current Controlled Trials ISRCTN65240228. Funding The National Institute for Health Research Health Technology Assessment programme

After Stroke Movement Impairments: A Review of Current Technologies for Rehabilitation

This chapter presents a review of the rehabilitation technologies for people who have suffered a stroke, comparing and analyzing the impact that these technologies have on their recovery in the short and long term. The problematic is presented, and motor impairments for upper and lower limbs are characterized. The goal of this chapter is to show novel trends and research for the assistance and treatment of motor impairment caused by strokes

Development of a two-dimensional biomechanical multibody model for the analysis of the human gait with an ankle-foot orthosis

Dissertação de mestrado integrado em Biomedical Engineering (área de especialização em Biomaterials, Biomechanics and Rehabilitation)Ankle-foot orthoses are orthotic devices that support the ankle joint and are appropriate for several pathologies, mostly the ones that cause dropfoot, which is caused by an ankle joint deficiency. In the present work, a planar multibody model of the human body in the sagittal plane was developed. For this purpose, the MOBILE computational program was utilized. The model simulates the lower limbs and is made of 9 rigid bodies. It has 12 DOFs and is prepared for reproducing kinematic data acquired in a gait lab. Kinematic measurements were obtained in a gait lab from a healthy subject, with and without plastic ankle foot orthoses worn on both feet. The results obtained showed that with the orthoses, the ankle joint behavior is similar to a linear torsional spring, with almost no hysteresis. Ankle kinematics, measured in the gait lab with and without orthoses, were successfully reproduced by forward dynamics using the multibody model developed, which allows for the validation of the presented approach. Furthermore, it was concluded that ankle foot orthoses can be modeled as a spring element acting at the ankle joint, and the use of an ankle foot orthosis reduces the muscle activation at the ankle in about 15%.Knöchel-Fuß-Orthesen sind orthopädische Geräte, die das Sprunggelenk zu unterstützen und sind für verschiedene Erkrankungen, vor allem diejenigen, die dropfoot, die von einer Sprunggelenks-Mangel verursacht wird dazu führen, angemessen. In der vorliegenden Arbeit wurde ein planarer Multibody Modell des menschlichen Körpers in der Sagittalebene entwickelt. Zu diesem Zweck wurde das MOBILE Rechenprogramm verwendet. Das Modell simuliert die unteren Extremitäten und wird von 9 starren Körpern. Es verfügt über 12 Freiheitsgrade und ist für die Wiedergabe kinematische Daten in einer Ganglabors erworbenen vorbereitet. Kinematische Messungen wurden in einem Ganglabors von einer gesunden Person erhalten, mit und ohne Kunststoff Sprunggelenk Orthesen an beiden Füßen getragen. Die erhaltenen Ergebnisse zeigten, dass mit den Orthesen, das Sprunggelenk Verhalten ähnlich einer linearen Torsionsfeder ist, fast ohne Hysterese. Knöchel Kinematik, in der Ganglabors mit und ohne Orthesen gemessen wurden erfolgreich von Vorwärtsdynamikanalyse Verwendung der Multibody Modell entwickelt, das für die Validierung der dargebotenen Ansatz ermöglicht reproduziert. Darüber hinaus wurde festgestellt, dass Sprunggelenk Orthesen als Feder wirkende Element am Sprunggelenk modelliert werden können, und die Verwendung eines Fußheberorthese verringert die Muskelaktivität am Knöchel in etwa 15%.As ortóteses do tornozelo são dispositivos ortopédicos que apoiam a articulação do tornozelo e são indicados para uma variedade de patologias, nomeadamente as que causam pé pendente, que é uma deficiência na mobilidade do tornozelo. No presente trabalho, um modelo multibody planar do corpo humano no plano sagital foi criado. Para tal, o software MOBILE foi usado. O modelo simula os membros inferiores e é composto por nove corpos rígidos. Possui 12 graus de liberdade e está preparado para usar dados cinemáticos adquiridos num laboratório de análise da marcha humana como restrições de guiamento. Dados cinemáticos foram obtidos num laboratório de análise da marcha humana, a partir de um indivíduo saudável, com e sem ortóteses plásticas em ambos os pés. Os resultados mostraram que, com a ortótese, o comportamento da articulação do tornozelo é semelhante a uma mola de torção linear, praticamente sem histerese. Os dados cinemáticos do tornozelo, medidos no laboratório de marcha, com e sem ortótese, foram reproduzidos com sucesso por uma dinâmica direta, utilizando o modelo multibody desenvolvido, o que validou a abordagem utilizada. Todas as metodologias encontram-se descritas e explicadas nesta tese e concluiuse que a ortóteses do tornozelo podem ser modeladas como uma mola de torsão que actua na articulação do tornozelo. Concluiu-se também que a utilização de uma ortótese do tornozelo por uma pessoa saudável reduz a activação muscular do mesmo em cerca de 15%

Design of a knee orthosis locking system

Dissertação de mestrado em Engenharia MecatrónicaThe main goal of this work was to design a mechatronic locking system for a Stance Control Knee Ankle Foot Orthosis (SCKAFO). This mechanism should be able to perform two different functions. The first one is to lock the orthosis during the stance phase of human gait, in which contact between the foot and the ground exists. The second function deals with the unlock of the orthosis during the swing phase, in which there is no contact between the foot and the ground, allowing the flexion of the knee. Biomechanics of human gait play an important role in the mechanical design of the locking system, since the motion characteristics associated with pathological and nonpathological exhibit different behaviors. Thus experimental gait studies was considered for pathological and non-pathological, in order to analyze the kinematic properties(joint angles and trajectories) and kinetic (ground reaction forces, joint forces and moments) of the human gait. In the context of the present work sensors were used to detect the key points that characterize the human gait, allowing for the correct mechanism performance. These sensors are placed in anatomical relevant locations and calculate, not only the joint angles, but also the angular acceleration. The data read by these sensors is interpreted by a microcontroller that controls the actuation system in order to lock or unlock the mechanism. An innovative solution is presented here, which differs from the currently available solutions or in the scientific literature. The new approach is able to work without foot sensors and cables used with the purpose to lock/unlock the orthosis. With this approach it is expected that the locking/unlocking operation will be effective, safe and quick for the user.O objetivo principal deste projeto foi desenvolver um sistema mecatrónico para ortóteses do tipo Stance Control Knee Ankle Foot Orthosis (SCKAFO). Este mecanismo permite realizar duas funções distintas. A primeira consiste no bloqueio da ortótese durante a fase de apoio da marcha humana, onde se verifica contacto entre o pé e o solo. A segunda função incide no desbloqueio da ortótese durante a fase de balanço da marcha humana, onde não se verifica contacto entre o pé e o solo, permitindo a flexão do joelho. Os conceitos biomecânicos da marcha humana assumem uma elevada importância no projeto mecânico deste mecanismo, uma vez que as características associadas à marcha natural e patológica demonstram comportamentos distintos. Por isso serão consideradas análises experimentais, com o objetivo de caracterizar cinematicamente (ângulos e trajetórias das articulações e segmentos anatómicos) e cineticamente (forças de contacto entre o pé e o solo, momentos e forças nas articulações) a marcha humana. No contexto do presente trabalho foram utilizados sensores de forma a detetar pontoschave da marcha humana, permitindo um correto funcionamento do mecanismo. Os sensores serão colocados nos segmentos anatómicos de maior interesse para este estudo e irão possibilitar o cálculo dos ângulos das articulações e as suas acelerações angulares. A informação gerada pelos sensores será interpretada por um microcontrolador, que irá controlar um sistema de atuação, permitindo bloquear ou desbloquear a ortótese. Com este trabalho, pretende-se desenvolver uma abordagem inovadora, que difere de todas as soluções comerciais e apresentadas na literatura científica. Esta solução permite um funcionamento sem a necessidade de recorrer a sensores plantares (colocados no pé) e sem presença de cabos ao longo do membro inferior. Com esta abordagem pretende-se desenvolver um mecanismo que realize a operação de bloqueio e desbloqueio de modo eficaz, seguro e rápido para o seu utilizador

Design and Evaluation of AIRGAIT Exoskeleton\u27s Leg Orthosis: Development of a Control Scheme and Strategy for a Noble Control of Antagonistic Mono- and Bi-Articular Actuators

芝浦工業大学201

Design and Evaluation of a Knee-Extension-Assist

Quadriceps muscle weakness is a condition that can result from a wide variety of causes, from diseases like polio and multiple sclerosis to injuries of the head and spine. Individuals with weakened quadriceps often have difficulty supplying the knee-extension moments required during common mobility tasks. Existing powered orthoses that provide an assistive knee-extension moment are large and heavy, with power supplies that generally last less than two hours. A new device that provides a knee-extension-assist moment was designed to aid an individual with quadriceps muscle weakness to stand up from a seated position, sit from a standing position, and walk up and down an inclined surface. The knee-extension-assist (KEA) was designed as a modular component to be incorporated into existing knee-ankle-foot-orthoses (KAFO). The KEA consists of three springs that are compressed, as the knee is flexed under bodyweight, by cables that wrap around a sheave at the knee. The KEA returns the stored energy from knee flexion as an extension moment during knee extension. During swing or other non-weight bearing activities, the device is disengaged from the KAFO by decoupling the sheave from the KAFO knee joint, allowing free knee joint motion. A prototype was built and mechanically tested to determine KEA behaviour during loading and extension and to ensure proper KEA function. For biomechanical evaluation, able-bodied subjects used the prototype KEA while performing sit-to-stand, stand-to-sit, ramp ascent, and ramp descent tasks. The KEA facilitated sitting and standing, providing an average of 53 % of the required extension moment for the two participants, which allowed one participant to reduce quadriceps usage by 38 % and the other to perform sit-to-stand in a slower and more controlled manner that was not possible without the KEA. KEA use during ramp gait caused an overall increase in quadriceps activation by 76 %, on average, with use. Future efforts will be made to modify the design to improve functionality, especially for ramp gait, and to reduce device size and weight

Hybrid walking therapy with fatigue management for spinal cord injured individuals

In paraplegic individuals with upper motor neuron lesions the descending path for signals from central nervous system to the muscles are lost or diminished. Motor neuroprosthesis based on electrical stimulation can be applied to induce restoration of motor function in paraplegic patients. Furthermore, electrical stimulation of such motor neuroprosthesis can be more efficiently managed and delivered if combined with powered exoskeletons that compensate the limited force in the stimulated muscles and bring additional support to the human body. Such hybrid overground gait therapy is likely to be more efficient to retrain the spinal cord in incomplete injuries than conventional, robotic or neuroprosthetic approaches. However, the control of bilateral joints is difficult due to the complexity, non-linearity and time-variance of the system involved. Also, the effects of muscle fatigue and spasticity in the stimulated muscles complicate the control task. Furthermore, a compliant joint actuation is required to allow for a cooperative control approach that is compatible with the assist-as-needed rehabilitation paradigm. These were direct motivations for this research. The overall aim was to generate the necessary knowledge to design a novel hybrid walking therapy with fatigue management for incomplete spinal cord injured subjects. Research activities were conducted towards the establishment of the required methods and (hardware and software) systems that required to proof the concept with a pilot clinical evaluation. Speciffically, a compressive analysis of the state of the art on hybrid exoskeletons revealed several challenges which were tackled by this dissertation. Firstly, assist-as-needed was implemented over the basis of a compliant control of the robotic exoskeleton and a closed-loop control of the neuroprosthesis. Both controllers are integrated within a hybrid-cooperative strategy that is able to balance the assistance of the robotic exoskeleton regarding muscle performance. This approach is supported on the monitoring of the leg-exoskeleton physical interaction. Thus the fatigue caused by neuromuscular stimulation was also subject of speciffic research. Experimental studies were conducted with paraplegic patients towards the establishment of an objective criteria for muscle fatigue estimation and management. The results of these studies were integrated in the hybrid-cooperative controller in order to detect and manage muscle fatigue while providing walking therapy. Secondly closed-loop control of the neuroprosthesis was addressed in this dissertation. The proposed control approach allowed to tailor the stimulation pattern regarding the speciffic residual motor function of the lower limb of the patient. In order to uncouple the closed-loop control from muscle performance monitoring, the hybrid-cooperative control approach implemented a sequential switch between closed-loop and open-loop control of the neuroprosthesis. Lastly, a comprehensive clinical evaluation protocol allowed to assess the impact of the hybrid walking therapy on the gait function of a sample of paraplegic patients. Results demonstrate that: 1) the hybrid controller adapts to patient residual function during walking, 2) the therapy is tolerated by patients, and 3) the walking function of patients was improved after participating in the study. In conclusion, the hybrid walking therapy holds potential for rehabilitate walking in motor incomplete paraplegic patients, guaranteeing further research on this topic. This dissertation is framed within two research projects: REHABOT (Ministerio de Ciencia e Innovación, grant DPI2008-06772-C03-02) and HYPER (Hybrid Neuroprosthetic and Neurorobotic Devices for Functional Compensation and Rehabilitation of Motor Disorders, grant CSD2009-00067 CONSOLIDER INGENIO 2010). Within these research projects, cutting-edge research is conducted in the eld of hybrid actuation and control for rehabilitation of motor disorders. This dissertation constitutes proof-of concept of the hybrid walking therapy for paraplegic individuals for these projects. ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------En individuos parapléjicos con lesiones de la motoneurona superior, la conexión descendente para la transmisión de las señales del sistema nervioso central a los músculos se ve perdida o disminuida. Las neuroprótesis motoras basadas en la estimulación eléctrica pueden ser aplicadas para inducir la restauración de la función motora en pacientes con paraplejia. Además, la estimulación eléctrica de tales neuroprótesis motoras se puede gestionar y aplicar de manera más eficiente mediante la combinación con exoesqueletos robóticos que compensen la generación limitada de fuerza de los músculos estimulados, y proporcionen soporte adicional para el cuerpo. Dicha terapia de marcha ambulatoria puede ser probablemente más eficaz para la recuperación de las funciones de la médula espinal en lesiones incompletas que las terapias convencionales, robóticas o neuroprotesicas. Sin embargo, el control bilateral de las articulaciones es difícil debido a la complejidad, no-linealidad y la variación con el tiempo de las características del sistema en cuestión. Además, la fatiga muscular y la espasticidad de los músculos estimulados complican la tarea de control. Por otra parte, se requiere una actuación robótica modulable para permitir un enfoque de control cooperativo compatible con el paradigma de rehabilitación de asistencia bajo demanda. Todo lo anterior constituyó las motivaciones directas para esta investigación. El objetivo general fue generar el conocimiento necesario para diseñar un nuevo tratamiento híbrido de rehabilitación marcha con gestión de la fatiga para lesionados medulares incompletos. Se llevaron a cabo actividades de investigación para el establecimiento de los métodos necesarios y los sistemas (hardware y software) requeridos para probar el concepto mediante una evaluación clínica piloto. Específicamente, un análisis del estado de la técnica sobre exoesqueletos híbridos reveló varios retos que fueron abordados en esta tesis. En primer lugar, el paradigma de asistencia bajo demanda se implementó sobre la base de un control adaptable del exoesqueleto robótico y un control en lazo cerrado de la neuroprótesis. Ambos controladores están integrados dentro de una estrategia híbrida cooperativa que es capaz de equilibrar la asistencia del exoesqueleto robótico en relación con el rendimiento muscular. Este enfoque se soporta sobre la monitorización de la interacción física entre la pierna y el exoesqueleto. Por tanto, la fatiga causada por la estimulación neuromuscular también fue objeto de una investigación específica. Se realizaron estudios experimentales con pacientes parapléjicos para el establecimiento de un criterio objetivo para la detección y la gestión de la fatiga muscular. Los resultados de estos estudios fueron integrados en el controlador híbrido-cooperativo con el fin de detectar y gestionar la fatiga muscular mientras se realiza la terapia híbrida de rehabilitación de la marcha. En segundo lugar, el control en lazo cerrado de la neuroprótesis fue abordado en esta tesis. El método de control propuesto permite adaptar el patrón de estimulación en relación con la funcionalidad residual específica de la extremidad inferior del paciente. Sin embargo, con el n de desacoplar el control en lazo cerrado de la monitorización del rendimiento muscular, el enfoque de control híbrido-cooperativo incorpora una conmutación secuencial entre el control en lazo cerrado y en lazo abierto de la neuropr otesis. Por último, un protocolo de evaluación clínica global permitido evaluar el impacto de la terapia híbrida de la marcha en la función de la marcha de una muestra de pacientes parapléjicos. Los resultados demuestran que: 1) el controlador híbrido se adapta a la función residual del paciente durante la marcha, 2) la terapia es tolerada por los pacientes, y 3) la funci on de marcha del paciente mejora despu es de participar en el estudio. En conclusión, la terapia de híbrida de la marcha alberga un potencial para la rehabilitación de la marcha en pacientes parapléjicos incompletos motor, garantizando realizar investigación más profunda sobre este tema. Esta tesis se enmarca dentro de los dos proyectos de investigación: REHABOT (Ministerio de Ciencia e Innovación, referencia DPI2008-06772-C03-02) y HYPER (Hybrid Neuroprosthetic and Neurorobotic Devices for Functional Compensation and Rehabilitation of Motor Disorders, referencia CSD2009-00067 CONSOLIDER INGENIO 2010). Dentro de estos proyectos se lleva a cabo investigación de vanguardia en el campo de la actuación y el control híbrido de la combinación robot-neuroprótesis para la rehabilitación de trastornos motores. Esta tesis constituye la prueba de concepto de la terapia de híbrida de la marcha para individuos parapléjicos en estos proyectos.This dissertation is framed within two research projects: REHABOT (Ministerio de Ciencia e Innovación, grant DPI2008-06772-C03-02) and HYPER (Hybrid Neuroprosthetic and Neurorobotic Devices for Functional Compensation and Rehabilitation of Motor Disorders, grant CSD2009-00067 CONSOLIDER INGENIO 2010

Biped locomotion control through a biologically-inspired closed-loop controller

Dissertação de mestrado integrado em Engenharia BiomédicaCurrently motor disability in industrialized countries due to neural and physical impairments is an increasingly worrying phenomenon and the percentage of patients is expected to be increasing continuously over the coming decades due to a process of ageing the world is undergoing. Additionally, rising retirement ages, higher demand of elderly people for an independent, dignified life and mobility, huge cost in the provision of health care are some other determinants that motivate the restoration of motor function as one of the main goals of rehabilitation. Modern concepts of motor learning favor a task-specific training in which all movements in daily life should be trained/assisted repetitively in a physically correct fashion. Considering the functional activity of the neuronal circuits within the spinal cord, namely the central pattern generator (CPG), as the foundation to human locomotion, motor relearning should be based on intensive training strategies directed to the stimulation and reorganization of such neural pathways through mechanisms addressed by neural plasticity. To this end, neuromodelings are required to simulate the human locomotion control to overcome the current technological challenges such as developing smaller, intelligent and cost-effective devices for home and work rehabilitation scenarios which can enable a continuous therapy/ assistance to guide the impaired limbs in a gentle manner, avoiding abrupt perturbations and providing as little assistance as necessary. Biomimetic models, taking neurological and biomechanical inspiration from biological animals, have been embracing these challenges and developing effective solutions on refining the locomotion models in terms of energy efficiency, simplicity in the structure and robust adaptability to environment changes and unexpected perturbations. Thus, the aim target of this work is to study the applicability of the CPG model for gait rehabilitation, either for assistance and/or therapy purposes. Focus is developed on the locomotion control to increase the knowledge of the underlying principles useful for gait restoration, exploring the brainstem-spinal-biomechanics interaction more fully. This study has great application in the project of autonomous robots and in the rehabilitation technology, not only in the project of prostheses and orthoses, but also in the searching of procedures that help to recuperate motor functions of human beings. Encouraging results were obtained which pave the way towards the simulation of more complex behaviors and principles of human locomotion, consequently contributing for improved automated motor rehabilitation adapted to the rehabilitation emerging needs.Actualmente a debilidade motora em países industrializados devido a deficiências neurais e físicas é um fenómeno crescente de apreensão sendo expectável um contínuo aumento do rácio de pacientes nas próximas décadas devido ao processo de envelhecimento. Inclusivé, o aumento da idade de reforma, a maior procura por parte dos idosos para uma mobilidade e vida autónoma e condigna, o elevado custo nos cuidados de saúde são incentivos para a restauração da função motora como um dos objectivos principais da reabilitação. Conceitos recentes de aprendizagem motora apoiam um treino de tarefas específicas no qual movimentos no quotidiano devem ser treinados/assistidos de forma repetitiva e fisicamente correcta. Considerando a actividade funcional dos circuitos neurais na medula, nomeadamente o gerador de padrão central (CPG), como a base da locomoção, a reaprendizagem motora deve-se basear em estratégias intensivas de treino visando a estimulação e reorganização desses vias neurais através de mecanismos abordados pela plasticidade neural. Assim, são necessários modelos neurais para simular o controlo da locomoção humana de modo a superar desafios tecnológicos actuais tais como o desenvolvimento de dispositivos mais compactos, inteligentes e económicos para os cenários de reabilitação domiciliar e laboral que podem permitir uma terapia/assistência contínua na guia dos membros debilitados de uma forma suave, evitando perturbações abruptas e fornecendo assistência na medida do necessário. Modelos biomiméticos, inspirando-se nos princípios neurológicos e biomecânicos dos animais, têm vindo a abraçar esses desafios e a desenvolver soluções eficazes na refinação de modelos de locomoção em termos da eficiência de energia, da simplicidade na estrutura e da adaptibilidade robusta face a alterações ambientais e perturbações inesperadas. Então, o objectivo principal do trabalho é estudar a aplicabilidade do modelo de CPG para a reabilitação da marcha, para efeitos de assistência e/ou terapia. É desenvolvido um foco no controlo da locomoção para maior entendimento dos princípios subjacentes úteis para a recuperação da marcha, explorando a interacção tronco cerebral-espinal medula-biomecânica de forma mais detalhada. Este estudo tem potencial aplicação no projecto de robôs autónomos e na tecnologia de reabilitação, não só no desenvolvimento de ortóteses e próteses, mas também na procura de procedimentos úteis para a recuperação da função motora. Foram obtidos resultados promissores susceptíveis de abrir caminho à simulação de comportamentos e princípios mais complexos da marcha, contribuindo consequentemente para uma aprimorada reabilitação motora automatizada adaptada às necessidades emergentes