Design of a Rise Support to be integrated in the HOBBIT Robot

The purpose of the thesis work is to analyze the possibility to integrate a sit-to-stand functionality into the HOBBIT service robot for elderly people while keeping the stability of the robot. A prototype with a knee support and a handle was used in combination with a motion capture system to capture joints angles and forces during the sit-to-stand movement. A skeletal model was created using the OpenSim software where data and a CAD model of the robot were imported and analyzed. Matlab was used to calculate the stability of the robot and optimize the positions of the knee support and handle. Finally, the prototype was tested with four elderly people. The forces necessary to rise up did not compromise the stability of the robot and the users found the prototype useful, comfortable and necessary

Human Activity Recognition and Control of Wearable Robots

abstract: Wearable robotics has gained huge popularity in recent years due to its wide applications in rehabilitation, military, and industrial fields. The weakness of the skeletal muscles in the aging population and neurological injuries such as stroke and spinal cord injuries seriously limit the abilities of these individuals to perform daily activities. Therefore, there is an increasing attention in the development of wearable robots to assist the elderly and patients with disabilities for motion assistance and rehabilitation. In military and industrial sectors, wearable robots can increase the productivity of workers and soldiers. It is important for the wearable robots to maintain smooth interaction with the user while evolving in complex environments with minimum effort from the user. Therefore, the recognition of the user's activities such as walking or jogging in real time becomes essential to provide appropriate assistance based on the activity. This dissertation proposes two real-time human activity recognition algorithms intelligent fuzzy inference (IFI) algorithm and Amplitude omega ($A \omega$) algorithm to identify the human activities, i.e., stationary and locomotion activities. The IFI algorithm uses knee angle and ground contact forces (GCFs) measurements from four inertial measurement units (IMUs) and a pair of smart shoes. Whereas, the $A \omega$ algorithm is based on thigh angle measurements from a single IMU. This dissertation also attempts to address the problem of online tuning of virtual impedance for an assistive robot based on real-time gait and activity measurement data to personalize the assistance for different users. An automatic impedance tuning (AIT) approach is presented for a knee assistive device (KAD) in which the IFI algorithm is used for real-time activity measurements. This dissertation also proposes an adaptive oscillator method known as amplitude omega adaptive oscillator ($A\omega AO$) method for HeSA (hip exoskeleton for superior augmentation) to provide bilateral hip assistance during human locomotion activities. The $A \omega$ algorithm is integrated into the adaptive oscillator method to make the approach robust for different locomotion activities. Experiments are performed on healthy subjects to validate the efficacy of the human activities recognition algorithms and control strategies proposed in this dissertation. Both the activity recognition algorithms exhibited higher classification accuracy with less update time. The results of AIT demonstrated that the KAD assistive torque was smoother and EMG signal of Vastus Medialis is reduced, compared to constant impedance and finite state machine approaches. The $A\omega AO$ method showed real-time learning of the locomotion activities signals for three healthy subjects while wearing HeSA. To understand the influence of the assistive devices on the inherent dynamic gait stability of the human, stability analysis is performed. For this, the stability metrics derived from dynamical systems theory are used to evaluate unilateral knee assistance applied to the healthy participants.Dissertation/ThesisDoctoral Dissertation Aerospace Engineering 201

The development of test action bank for active robot learning

A thesis submitted to the University of Bedfordshire, in fulfilment of the requirements for the degree of Master of Science by researchIn the rapidly expanding service robotics research area, interactions between robots and humans become increasingly cornmon as more and more jobs will require cooperation between the robots and their human users. It is important to address cooperation between a robot and its user. ARL is a promising approach which facilitates a robot to develop high-order beliefs by actively performing test actions in order to obtain its user's intention from his responses to the actions. Test actions are crucial to ARL. This study carried out primary research on developing a Test Action Bank (TAB) to provide test actions for ARL. In this study, a verb-based task classifier was developed to extract tasks from user's commands. Taught tasks and their corresponding test actions were proposed and stored in database to establish the TAB. A backward test actions retrieval method was used to locate a task in a task tree and retrieve its test actions from TAB. A simulation environment was set up with a service robot model and a user model to test TAB and demonstrate some test actions. Simulations were also perfonned in this study, the simulation results proved TAB can successfully provide test actions according to different tasks and the proposed service robot model can demonstrate test actions

The influence of peripheral neuropathy on walking kinematics and physical function

The 108th Congress (2005) has reported that 20 million U.S. citizens suffer from Peripheral Neuropathy (PN). Characterized by sensory nerve deterioration, PN reduces somatosensation (Padua et al., 2005) and increases the risk of fall-related injury (Richardson et al., 1992). The purpose of this dissertation was to provide insight into 1) the effects of acute loss of foot sole sensation on locomotor system health, 2) the effects of PN on locomotor system health, and 3) the underlying impairments associated with reduced physical function within the older adult and PN populations. Locomotor system health was assessed by the magnitude of stride-to-stride variability and local instability contained in the kinematics of treadmill walking. In healthy young adults, ice-induced reduction of foot sole sensation did not alter the magnitude of stride-to-stride variability during treadmill walking. It did, however, increase lower-extremity joint local instability, or the sensitivity to small scale perturbations. Compared to controls, individuals with PN walked with similar local instability yet increased variability, at relatively slow speeds. When walking at relatively fast speeds, individuals with PN exhibited exaggerated increases in local instability. In healthy older adults, locomotion-based physical function (LBPF), as defined by 6-minute walk and Timed Up-and-Go performance, was correlated to leg strength and measures of locomotor system health. However, only measures of locomotor system health provided independent predictive information of LBPF. The PN group exhibited reduced LBPF. As opposed to healthy old adults, correlates of LBPF were not leg strength but instead standing balance variables. Multiple variables of leg strength, standing balance, and locomotor system health provided independently predictive information regarding each test of LBPF. The opposing effects of ice-induced reduction in foot sole sensation and PN on locomotor system health suggest that the chronic nature of PN allows for the implementation of partially effective compensatory strategies. Yet, the inability to adapt to relatively fast speeds suggests that falls likely occur during challenging situations. The fundamentally different correlates and predictors of LBPF between older adults and those with PN highlight the uniqueness of the movement disorder associated with PN

Functional and coordination determinants of gait in older adults

Os idosos têm padrão de marcha prejudicado, diminuição da velocidade, fraqueza muscular, controle motor prejudicado, coordenação dos membros prejudicada, ângulos e comprimento da passada diminuídos, aumento do tempo de apoio duplo e deficiências posturais. No entanto, ainda não há uma compreensão clara dos efeitos do envelhecimento sobre os principais determinantes da marcha. O objetivo geral desta Tese foi, portanto, examinar os determinantes funcionais e de coordenação da marcha em idosos. Para atingir esse objetivo, três estudos originais foram desenvolvidos: 1) explorar os determinantes físicos do declínio da velocidade da marcha em 187 idosos ativos (72,2±6,8 anos). O desempenho da caminhada foi caracterizado por 2 parâmetros: índice de reabilitação locomotora (IRL) e índice de caminhada (RC). Com o avançar da idade, as velocidades auto selecionadas e máximas diminuíram em até 26%, assim como as variáveis de aptidão física pioraram com o envelhecimento. Encontramos a RC e o equilíbrio corporal como preditores da velocidade máxima, sugerindo que seria necessário diminuir a RC para evitar o desequilíbrio. Reduções excessivas nos parâmetros analisados indicam perda da homeostase na mecânica da marcha. 2) compreender até que ponto os mecanismos de controle do membro superior estão presentes durante a marcha. 20 idosos e 13 jovens caminharam em diferentes velocidades em esteira e foi calculada a fase relativa contínua (FRC) média e contínua para os pares cotovelo-ombro e ombro-quadril. Os idosos têm FRC média e estabilidade reduzida em comparação com adultos mais jovens, e a velocidade afeta a FRC ao longo do tempo. A estabilidade da coordenação dos membros superiores foi maior para os idosos nas velocidades de caminhada preferidas e rápidas. 3) verificar a relação entre coordenação bilateral e coordenação intersegmentar em 24 idosos saudáveis (66,3±4,4 anos) e as relações entre os fatores. Medimos a coordenação da marcha através do índice de coordenação de fase (ICF), fase relativa contínua (FRC) e sua variabilidade. Os idosos têm ajustes na FRC, principalmente entre quadril e joelho, para melhorar a ICF. O controle intersegmentar desempenha um papel crucial na coordenação bilateral. Os resultados mostraram que os determinantes da coordenação parecem ser os principais determinantes da marcha do idoso por meio do equilíbrio corporal que é influenciado por diferentes aspectos. As habilidades físicas também podem determinar a marcha de idosos, apoiada pela velocidade da marcha, que aparece indiretamente como determinante da capacidade de condicionamento por meio do IRL.Older adults have impaired gait pattern, decreased speed, muscle weakness, impaired motor control, impaired limb coordination, decreased angles and stride length, increased double support time, and postural impairments. However, there is still no clear understanding of the effects of aging on the main determinants of gait. The overall aim of this Thesis was therefore to examine the functional and coordination determinants of gait in older adults. To achieve this goal, three original studies were developed: 1) explore the physical determinants of the decline in gait speed in 187 active older adults (72.2±6.8 years). Walking performance was characterized by 2 parameters: locomotor rehabilitation index (LRI) and walking ratio (WR). With advancing age, the self-selected and maximum speeds decreased by up to 26%, as well as the physical fitness variables worsened with aging. We found WR and body balance as predictors of maximum velocity, suggesting that it would be necessary to decrease WR to avoid imbalance. Excessive reductions in the analyzed parameters indicate loss of homeostasis in gait mechanics. 2) understand the extent to which upper limb control mechanisms are present during gait. 20 older adults and 13 young people walked at different speeds on a treadmill and mean and continuous relative phase stability (CRP) were calculated for the elbow-shoulder and shoulderhip joint pairs. Older adults have reduced mean CRP and stability compared to younger adults, and speed affects CRP over time. The stability of upper limb coordination was greater for the older adults at preferred and fast walking speeds. 3) verify the relationship between bilateral coordination and intersegmental coordination in 24 healthy older adults (66.3±4.4 years) and the relationships between the factors. We measured gait coordination through the phase coordination index (PCI), continuous relative phase (CRP) and their variability. Older adults have adjustments in CRP, especially between hip and knee, to improve PCI. Intersegmental control plays a crucial role in bilateral coordination. The results showed that the coordination determinants seem to be the main determinants of the older adults' gait through body balance that is influenced by different aspects. Physical abilities can also determine the gait of older adults, supported by gait speed, which appears indirectly as a determinant of conditioning ability through the LRI

Age Related Changes in Balance and Gait

abstract: Gait and balance disorders are the second leading cause of falls in the elderly. Investigating the changes in static and dynamic balance due to aging may provide a better understanding of the effects of aging on postural control system. Static and dynamic balance were evaluated in a total of 21 young (21-35 years) and 22 elderly (50-75 years) healthy subjects while they performed three different tasks: quiet standing, dynamic weight shifts, and over ground walking. During the quiet standing task, the subjects stood with their eyes open and eyes closed. When performing dynamic weight shifts task, subjects shifted their Center of Pressure (CoP) from the center target to outward targets and vice versa while following real-time feedback of their CoP. For over ground walking tasks, subjects performed Timed Up and Go test, tandem walking, and regular walking at their self-selected speed. Various quantitative balance and gait measures were obtained to evaluate the above respective balance and walking tasks. Total excursion, sway area, and mean frequency of CoP during quiet standing were found to be the most reliable and showed significant increase with age and absence of visual input. During dynamic shifts, elderly subjects exhibited higher initiation time, initiation path length, movement time, movement path length, and inaccuracy indicating deterioration in performance. Furthermore, the elderly walked with a shorter stride length, increased stride variability, with a greater turn and turn-to-sit duration. Significant correlations were also observed between measures derived from the different balance and gait tasks. Thus, it can be concluded that aging deteriorates the postural control system affecting static and dynamic balance and some of the alterations in CoP and gait measures may be considered as protective mechanisms to prevent loss of balance.Dissertation/ThesisM.S. Bioengineering 201

Movement Variability and the Use of Nonlinear Tools: Principles to Guide Physical Therapist Practice

Fields studying movement generation, including robotics, psychology, cognitive science and neuroscience utilize concepts and tools related to the pervasiveness of variability in biological systems. The concepts of variability and complexity, and the nonlinear tools used to measure these concepts open new vistas for physical therapy practice and research in movement dysfunction of all types. Because mounting evidence supports the necessity of variability for health and functional movement, we argue in this perspective for changes in the way therapists view variability both in theory and in action. By providing clinical examples, as well as applying existing knowledge about complex systems, we hope to create a springboard for new directions in physical therapy research and practice

Associating Frailty and Dynamic Dysregulation between Motor and Cardiac Autonomic Systems

Frailty is a geriatric syndrome associated with the lack of physiological reserve and consequent adverse outcomes (therapy complications and death) in older adults. Recent research has shown associations between heart rate (HR) dynamics (HR changes during physical activity) with frailty. The goal of the present study was to determine the effect of frailty on the interconnection between motor and cardiac systems during a localized upper-extremity function (UEF) test. Fifty-six older adults aged 65 or older were recruited and performed the UEF task of rapid elbow flexion for 20-seconds with the right arm. Frailty was assessed using the Fried phenotype. Wearable gyroscopes and electrocardiography were used to measure motor function and HR dynamics. Using convergent cross-mapping (CCM) the interconnection between motor (angular displacement) and cardiac (HR) performance was assessed. A significantly weaker interconnection was observed among pre-frail and frail participants compared to non-frail individuals (p<0.01, effect size=0.81$\pm$0.08). Using logistic models pre-frailty and frailty were identified with sensitivity and specificity of 82% to 89%, using motor, HR dynamics, and interconnection parameters. Findings suggested a strong association between cardiac-motor interconnection and frailty. Adding CCM parameters in a multimodal model may provide a promising measure of frailty.Comment: 16 pages, 3 tables, 4 figure

EFFECT OF THE SMARTSTEP\u3csup\u3eTM\u3c/sup\u3e STABILIZATION SYSTEM ON BALANCE IN OLDER ADULTS IN AN INDEPENDENT LIVING RESIDENCE

An increase in postural sway is one of the risk factors that have been linked to an increased incidence of falls in the older adult population. Researchers have shown that peripheral sensation is crucial in maintaining a static posture for adults of all ages. It has been reported that older adults have decreased tactile sensation of the plantar surface of their feet. and when the sensory feedback was increased older adults had improved postural control. It was hypothesized that facilitation of the sole of the foot with the use of a semirigid foot orthotic would result in improved postural stability in older adults. Twenty-seven volunteers (19 females, 8 males, mean age: 87 ± 5 yrs) were recruited as subjects from a retirement community. All subjects were supplied with the SmartStep™ Stabilization System. There were a total of 5 Test Days for each subject. The first 2 Test Days were performed while the subjects wore their own shoes, while the last 3 Test Days were performed while the subjects wore the SmartStep™. Test Days 1 and 2 were performed 48 hours apart. Test Day 3 occurred 2 to 4 weeks after Test 2. Test Days 4 and 5 occurred 4-weeks after the prior Test Day. During the 8-weeks between Test Days 3 and 5, subjects were asked to wear the SmartStep™ as their daily shoe. Clinical measures of balance, force plate measurements, sensation testing, and confidence and activity scales were collected on all subjects throughout the eight week test period. Statistical significance was found for 3 of the clinical measures. The Timed “Up & Go” improved from 17.25 to 15.47 sec. The Functional Reach and Lateral Reach Tests demonstrated a decline in scores during the eight weeks. There was only 1 statistically significant finding for the force plate measures. The center of pressure displacement in the anteriorposterior direction was increased from 4.6 to 5.3 cm. No significant differences where reported for any other dependent variable. The results did not indicate statistically that the in-shoe orthotic enhanced postural stability in this group of subjects. However, there were indications that there was a subset of the current population that benefited from the intervention and this needs to be investigated further

Using the Microsoft Kinect to assess human bimanual coordination

Optical marker-based systems are the gold-standard for capturing three-dimensional (3D) human kinematics. However, these systems have various drawbacks including time consuming marker placement, soft tissue movement artifact, and are prohibitively expensive and non-portable. The Microsoft Kinect is an inexpensive, portable, depth camera that can be used to capture 3D human movement kinematics. Numerous investigations have assessed the Kinect\u27s ability to capture postural control and gait, but to date, no study has evaluated it\u27s capabilities for measuring spatiotemporal coordination. In order to investigate human coordination and coordination stability with the Kinect, a well-studied bimanual coordination paradigm (Kelso, 1984, Kelso; Scholz, & Schöner, 1986) was adapted. ^ Nineteen participants performed ten trials of coordinated hand movements in either in-phase or anti-phase patterns of coordination to the beat of a metronome which was incrementally sped up and slowed down. Continuous relative phase (CRP) and the standard deviation of CRP were used to assess coordination and coordination stability, respectively.^ Data from the Kinect were compared to a Vicon motion capture system using a mixed-model, repeated measures analysis of variance and intraclass correlation coefficients (2,1) (ICC(2,1)).^ Kinect significantly underestimated CRP for the the anti-phase coordination pattern (p \u3c.0001) and overestimated the in-phase pattern (p\u3c.0001). However, a high ICC value (r=.097) was found between the systems. For the standard deviation of CRP, the Kinect exhibited significantly higher variability than the Vicon (p \u3c .0001) but was able to distinguish significant differences between patterns of coordination with anti-phase variability being higher than in-phase (p \u3c .0001). Additionally, the Kinect was unable to accurately capture the structure of coordination stability for the anti-phase pattern. Finally, agreement was found between systems using the ICC (r=.37).^ In conclusion, the Kinect was unable to accurately capture mean CRP. However, the high ICC between the two systems is promising and the Kinect was able to distinguish between the coordination stability of in-phase and anti-phase coordination. However, the structure of variability as movement speed increased was dissimilar to the Vicon, particularly for the anti-phase pattern. Some aspects of coordination are nicely captured by the Kinect while others are not. Detecting differences between bimanual coordination patterns and the stability of those patterns can be achieved using the Kinect. However, researchers interested in the structure of coordination stability should exercise caution since poor agreement was found between systems