低重心型平行二輪ビークルにおける質量移動機構を用いた車体傾斜制御設計に関する研究

豊橋技術科学大

Fiber Optic-Based Pressure Sensing Surface for Skin Health Management in Prosthetic and Rehabilitation Interventions

Applied physic

Applications of Advanced Control Interface Technology for Individuals with Upper Limb Impairments

There are likely a quarter of a million individuals who cannot use power wheelchairs because of an inability to use control interfaces. There are likely even more who desire computer access and whose impairments preclude them from being effective users. Historically, isometric controls were thought to have limited application for individuals with movement disorders due to their sensitivity to unintentional movements. The work in this thesis is a series of studies that demonstrate the potential of an alternative method of control—isometric technology. Our work shows that individuals with upper limb impairments can perform just as well with isometric controls as with conventional proportional control, and in some cases individuals with tremor actually perform better with isometric controls. We also introduce work on adaptive control algorithms that can correct errors in movement made with control interfaces and improve performance

The TAO Project: Intelligent wheelchairs for the handicapped

Abstract An R&D project to build a series of intelligent autonomous wheelchairs is discussed. A standardized autonomy management system that can be installed on commercially available well-engineered power chairs has been developed and tested. A behavior-based approach was used to establish sufficient on-board autonomy at minimal cost and material usage, while achieving high efficiency, maximum safety, Iransparency in appearance, and extendability. So far, the add-on system has been installed and tried on two power wheelchair models. Initial results are highly encouraging. Introduction In recent years, with the concept of applying robots to service tasks [Gomi, 92] and with the accelerated rate of aging of the population being reported in many post-industrial countries, demand for more robotic assistive systems for people with physical ailments or loss of mental control is expected to increase. This is a seemingly major application area of service robots in the near future. For the past five years, we have been developing a range of autonomous mobile robots and their software using the behavior-based approach [Brooks, 86] [Gomi, 96a]. In Cartesian robotics, on which most conventional intelligent robotics approaches are based, planning for the generation of motion sequence and calculation of kinematics and dynamics for each planned motion occupy the center of both theoretical interest and practice. By adopting a behavior-based approach, I felt, wheelchairs which can operate daily in complex real-world environments with increased performance in efficiency, safety, and flexibility, and greatly reduced computational requirements can be built at less cost. In addition, improvements in the robustness and graceful degradation characteristics were expected. In the summer of 1995, an autonomy management system for a commercially available Canadian-made power wheelchair was successfully designed and implemented. The system looks after both longitudinal (forward and backward) and angular (left and right) movements of the chair as well limited vocal interactions with the user. The results were exhibited in August 1995 at the Intelligent Wheelchair Even

A survey on bio-signal analysis for human-robot interaction

The use of bio-signals analysis in human-robot interaction is rapidly increasing. There is an urgent demand for it in various applications, including health care, rehabilitation, research, technology, and manufacturing. Despite several state-of-the-art bio-signals analyses in human-robot interaction (HRI) research, it is unclear which one is the best. In this paper, the following topics will be discussed: robotic systems should be given priority in the rehabilitation and aid of amputees and disabled people; second, domains of feature extraction approaches now in use, which are divided into three main sections (time, frequency, and time-frequency). The various domains will be discussed, then a discussion of each domain's benefits and drawbacks, and finally, a recommendation for a new strategy for robotic systems

Magneto-rheological fluid orthosis for suppressing tremor

Tremor is a common movement disorder that occurs with specific neurological conditions. This condition may seriously impact daily living activities. The aim of the present study is to evaluate the possibility of the development of a wearable technology that is capable of exerting torques at a user\u27s joints for suppressing tremor. This thesis is based on the concept of smart structures which are made of Magneto-Rheological (MR) fluid that can dynamically alter its viscosity under magnetic field. The wearable tremor suppressing orthosis needs several conditions. It should be safe, light weight, simple and small in structure, and easily attachable. An MR fluid orthosis satisfies these conditions. This thesis shows the physical properties of MR fluid and the basic concept of a rotational MR fluid damper for suppressing tremor. Specifically, an MR fluid friction damper experimentally provides a damping coefficient capable of suppressing tremor. A simulation confirms that the damping moment of the MR fluid friction damper is sufficient to suppress that of the wrist tremor, with realistic peak to peak torque 0.022 Nm. This allows slower intentional movement to occur with only moderate attenuation. The results of this work show that it is possible to design an MR fluid orthosis that is wearable and capable of suppressing tremors at the wrist. The proportionality of the tremor-reducing torque to electric current allows the potential for both user adjustment as well as automatic feedback control

Investigations into the design of a wheelchair-mounted rehabilitation robotic manipulator

This research describes the steps towards the development of a low-cost wheelchair-mounted manipulator for use by the physically disabled and elderly. A detailed review of world rehabilitation robotics research has been conducted, covering fifty-six projects. This identified the main areas of research, their scope and results. From this review, a critical investigation of past and present wheelchair-mounted robotic arm projects was undertaken. This led to the formulation of the key design parameters in a final design specification. The results of a questionnaire survey of fifty electric wheelchair users is presented, which has for the first time established the needs and abilities of this disability group. An analysis of muscle type actuators, which mimic human muscle, is presented and their application to robotics, orthotics and prosthetics is given. A new type of rotary pneumatic muscle actuator, the flexator, is introduced and through extensive testing its performance characteristics elucidated. A review of direct-drive rotary pneumatic, hydraulic and electrical actuators has highlighted their relative performance characteristics and has rated their efficiency in terms of their peak torque to motor mass ratio, Tp/MM. From this, the flexator actuator has been shown to have a higher Tp/MM ratio than most conventional actuators. A novel kinematic arrangement is presented which combines the best features of the SCARA and vertically articulated industrial robot geometries, to form the 'Scariculated' arm design. The most appropriate actuator for each joint of this hybrid manipulator was selected, based on the criteria of high Tp/MM ratio, low cost, safety and compatibility. The final design incorporates conventional pneumatic linear double-acting cylinders, a vane type rotary actuator, two dual flexator actuators, and stepping motors for the fme control of the wrist/end effector. An ACSL simulation program has been developed which uses mass flow rate equations, based on one-dimensional compressible flow theory and suppressed critical pressure ratios, to simulate the dual flexator actuator. Theoretical and empirical data is compared and shows a high degree of correlation between results. Finally, the design and development work on two prototypes is discussed. The latest prototype consists of a five-axis manipulator whose pneumatic joints are driven by pulse width modulated solenoid valves. An 8051 microprocessor with proportional error feedback modilles the mark to space ratio of the PWM signal in proportion to the angular error of the joints. This enables control over individual joint speeds, reprogrammable memory locations and position monitoring of each joint. The integration of rehabilitation robotic manipulators into the daily lives of the physically disabled and elderly will significantly influence the role of personal rehabilitation in the next century

Die Wirksamkeit von Feedback und Trainingseffekten während der Alphaband Modulation über dem menschlichen sensomotorischen Cortex

Neural oscillations can be measured by electroencephalography (EEG) and these oscillations can be characterized by their frequency, amplitude and phase. The mechanistic properties of neural oscillations and their synchronization are able to explain various aspects of many cognitive functions such as motor control, memory, attention, information transfer across brain regions, segmentation of the sensory input and perception (Arnal and Giraud, 2012). The alpha band frequency is the dominant oscillation in the human brain. This oscillatory activity is found in the scalp EEG at frequencies around 8-13 Hz in all healthy adults (Makeig et al., 2002) and considerable interest has been generated in exploring EEG alpha oscillations with regard to their role in cognitive (Klimesch et al., 1993; Hanselmayr et al., 2005), sensorimotor (Birbaumer, 2006; Sauseng et al., 2009) and physiological (Lehmann, 1971; Niedermeyer, 1997; Kiyatkin, 2010) aspects of human life. The ability to voluntarily regulate the alpha amplitude can be learned with neurofeedback training and offers the possibility to control a brain-computer interface (BCI), a muscle independent interaction channel. BCI research is predominantly focused on the signal processing, the classification and the algorithms necessary to translate brain signals into control commands than on the person interacting with the technical system. The end-user must be properly trained to be able to successfully use the BCI and factors such as task instructions, training, and especially feedback can therefore play an important role in learning to control a BCI (Neumann and Kübler, 2003; Pfurtscheller et al., 2006, 2007; Allison and Neuper, 2010; Friedrich et al., 2012; Kaufmann et al., 2013; Lotte et al., 2013). The main purpose of this thesis was to investigate how end-users can efficiently be trained to perform alpha band modulation recorded over their sensorimotor cortex. The herein presented work comprises three studies with healthy participants and participants with schizophrenia focusing on the effects of feedback and training time on cortical activation patterns and performance. In the first study, the application of a realistic visual feedback to support end-users in developing a concrete feeling of kinesthetic motor imagery was tested in 2D and 3D visualization modality during a single training session. Participants were able to elicit the typical event-related desynchronisation responses over sensorimotor cortex in both conditions but the most significant decrease in the alpha band power was obtained following the three-dimensional realistic visualization. The second study strengthen the hypothesis that an enriched visual feedback with information about the quality of the input signal supports an easier approach for motor imagery based BCI control and can help to enhance performance. Significantly better performance levels were measurable during five online training sessions in the groups with enriched feedback as compared to a conventional simple visual feedback group, without significant differences in performance between the unimodal (visual) and multimodal (auditory–visual) feedback modality. Furthermore, the last study, in which people with schizophrenia participated in multiple sessions with simple feedback, demonstrated that these patients can learn to voluntarily regulate their alpha band. Compared to the healthy group they required longer training times and could not achieve performance levels as high as the control group. Nonetheless, alpha neurofeedback training lead to a constant increase of the alpha resting power across all 20 training session. To date only little is known about the effects of feedback and training time on BCI performance and cortical activation patterns. The presented work contributes to the evidence that healthy individuals can benefit from enriched feedback: A realistic presentation can support participants in getting a concrete feeling of motor imagery and enriched feedback, which instructs participants about the quality of their input signal can give support while learning to control the BCI. This thesis demonstrates that people with schizophrenia can learn to gain control of their alpha oscillations recorded over the sensorimotor cortex when participating in sufficient training sessions. In conclusion, this thesis improved current motor imagery BCI feedback protocols and enhanced our understanding of the interplay between feedback and BCI performance.Die Wirksamkeit von Feedback und Trainingseffekten während der Alphaband Modulation über dem menschlichen sensomotorischen Corte

Neuromodulation and rehabilitation with brain-computer interfaces and Spinal Cord Stimulation

Consequences of spinal cord injury (SCI) are often severe and life-altering. Recovery of hand and arm function is consistently reported by SCI individuals as their greatest priority in terms of rehabilitation. Yet current strategies provide poor-to-modest outcomes. Innovation is required to improve traditional approaches to upper limb rehabilitation. The current view is that, due to the multi-faceted nature of SCI pathology, effective treatment will take a combinational approach. This thesis brings together two emerging and promising technologies—transcutaneous spinal cord stimulation (tSCS) and brain-computer interfaces (BCIs)—in order to judge their complimentary nature as tools for neurophysiological assessment and rehabilitation following SCI. There is growing evidence that cervical tSCS combined with intensive physical training can lead to lasting functional improvements in individuals with chronic SCI. The mechanisms underpinning tSCS-facilitated recovery, however, are still a matter of ongoing research, with conflicting reports of the impact of tSCS on cortical and spinal excitability. Evoked and reflexes have so far been the primary method of quantifying corticospinal excitability. The research undertaken in this thesis first explores electroencephalography (EEG) as a potential complementary method for assessing neuromodulation following tSCS. Due the novelty of the research, a preliminary investigation was undertaken to establish the feasibility of EEG monitoring during cervical tSCS. In a cohort of twenty-one able-bodied individuals, it was demonstrated that tSCS presented as low-latency, high-amplitude artefacts in EEG time series, at a rate equal to the stimulation frequency. Descriptive statistics were used to characterise the impact of tSCS, and judge the effectiveness of noise-attenuation techniques. Results showed that, with artefact-suppression, EEG recorded during tSCS could be returned to levels statistically similar to that of EEG acquired without tSCS interference. Additionally, it was established that neural components, such as the individual alpha frequency, were recoverable, demonstrating the feasibility of EEG as a tool for tracking cortical activity during tSCS. A subsequent study was conducted to investigate the neuromodulatory potential of tSCS on cortical activity. EEG was recorded during upper limb movements in 30 individuals both with and without concurrent cervical tSCS. Stimulation was delivered to the cervical region of the neck at intensities matching the individual’s highest tolerance without causing pain. It was found that cortical oscillatory dynamics were unaffected over a cohort of neurologically intact participants. However, a weak inhibitory effect was measured amoing individuals who received the highest stimulation intensities. A final study was devised to explore the potential of movement priming for tSCS-facilitated upper limb therapy in an individual with chronic AIS A cervical SCI. Movement priming was achieved by encouraging the participant to engage in repetitive bimanual hand movements with respect to their sensorimotor cortical activity as measured with EEG. A BCI provided real time feedback of the participant’s motor engagement in the form of a computer game, allowing them to actively engage regardless of impairment level. The participant first underwent an initial phase of 15 sessions of tSCS training alone followed by a second phase of 15 sessions of BCI priming and tSCS training. The participant’s strength and dexterity improved across both phases of the study. BCI priming may have contributed to an enhanced effect in some measures such as improved bilateral finger strength, but due to mixed results across functional measures no firm conclusions can be drawn. Nevertheless, the functional improvements lend greater credibility to cervical tSCS as a strategy for upper limb rehabilitation