Background: Robotic devices are expected to be widely used in various applications including support for the independent mobility of the elderly with muscle weakness and people with impaired motor function as well as support for nursing care that involves heavy laborious work. We evaluated the effects of a hybrid assistive limb robot suit on the gait of stroke patients undergoing rehabilitation.
Methods: The study group comprised 16 stroke patients with severe hemiplegia. All patients underwent gait training. Four patients required assistance, and 12 needed supervision while walking. The stride length, walking speed and physiological cost index on wearing the hybrid assistive limb suit and a knee–ankle–foot orthosis were compared.
Results: The hybrid assistive limb suit increased the stride length and walking speed in 4 of 16 patients. The patients whose wal-king speed decreased on wearing the hybrid assistive limb suit either had not received sufficient gait training or had an estab-lished gait pattern with a knee–ankle–foot orthosis using a quad cane. The physiological cost index increased after wearing the hybrid assistive limb suit in 12 patients, but removal of the suit led to a decrease in the physiological cost index values to equivalent levels prior to the use of the suit.
Conclusions: Although the hybrid assistive limb suit is not useful for all hemiplegic patients, it may increase the walking speed and affect the walking ability. Further investigation would clarify its indication for the possibility of gait training.

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A haptic feedback system is required to assist telerehabilitation with ro-bot hand. The system should provide the reaction force measured in the robot hand to an operator. In this pa-per, we have developed a force feedback device that presents a reaction force to the distal segment of the operator’s thumb, middle finger, and basipodite of the middle finger when the robot hand grasps an object. The device uses a shape memory alloy as an actuator, which affords a very compact, lightweight, and accurate device.

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The work presents a newly developed safety concept for application of robotic walking simulators based on the principle of programmable footplates in gait rehabilitation. Unlike robotic hand devices or exoskeleton robots for gait training on treadmills, which can be built relatively lightweight and require only small drives which can hardly do harm to the patient, a programmable footplate walking simulator with permanent foot fixture essentially needs to have powerful drives in order to carry and move the full body weight of the patient. The developed safety concept comprises several redundant algorithms and devices in the real-time robot control software, electrical emergency stop circuitry and machine mechanics. The mechanical core is a machine design offering maximum passive security by covering all moving parts (i.e. robot drives and linkages) and a newly developed foot safety release binding, which is mounted on each footplate. The release binding allows a safe release from the footplate in all directions in any degree of freedom in the sagittal plane. It is combined with an ankle goniometer which is equipped with adjustable emergency stop limit switches, thus ensuring that the allowed ankle range-of-motion is not exceeded.

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Insects of the order Diptera have evolved to become prolific flyers able to perform aerial maneuvers that far surpass anything man-made. The Harvard Micro robotics lab has recently demonstrated the first step towards recreating these evolutionary wonders with the world’s first demonstration of an at-scale robotic insect capable of generating sufficient thrust to takeoff (with external power). The mechanics and aerodynamics of this device are quite similar to Dipteran insects. Biologists have recently quantified the complex nonlinear temporal phenomena that give insects their outstanding capabilities. Periodic wing motions consisting of a large stroke and pronation and supination about an axis parallel to the span-wise direction are characteristic of most hovering Dipteran insects. Previous microrobot designs have attempted to concisely control each wing trajectory in these two dimensions. The robot that is shown here has three degrees-of- freedom, only one of which is actuated. Here, a central power actuator drives the wing with as large a stroke as possible and passive dynamics allow the wing to rotate using flexural elements with joint stops to avoid over-rotation. There are four primary components to the mechanical system: the actuator (or ‘flight muscle’), transmission (or ‘thorax’), airframe (or ‘exoskeleton’) and the wings. Each is constructed using a meso- scale manufacturing paradigm called Smart Composite Microstructures. This entails the use of laminated laser-micromachined materials stacked to achieve a desired compliance profile. This prototyping method is inexpensive, conceptually simple, and fast: for example, all components of the fly can be created in less than one week. Additionally, the resulting structures perform favorably when compared to alternative devices: flexure joints have almost no loss, ultra-high modulus links have higher stiffness-to-weight than any other material, and the piezoelectric actuators have similar power density to th- e best DC motors at any scale. After integration, the fly is fixed to guide wires that restrict the motion so that the fly can only move vertically. The wings are then driven open loop to achieve a large angular displacement. This is done at resonance to further amplify the wing motion. The wings exhibit a trajectory nearly identical to biological counterparts. Finally, this 60 mg, 3 cm wingspan system is allowed to freely move in the vertical direction demonstrating thrust that accelerates the fly upwards. Bench-top thrust measurements show that this robotic fly has a thrust-to- weight ratio of approximately two. These results unequivocally confirm the feasibility of insect-sized MAVs. The remaining challenges involve the development of microelectronics appropriate for power conversion, sensing, communication, and control along with the choice of an appropriate power source.

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