Mobile robotic assistive balance trainer - an intelligent compliant and adaptive robotic balance assistant for daily living.

Balance control probably has the greatest impact on independence in activities of daily living (ADL), because it is a fundamental motor skill and prerequisite to the maintenance of a myriad of postures and mobile activities. We propose a new rehabilitation therapy to administer standing and mobile balance control training, enabled by a Mobile Robotic Assistive Balance Trainer (MRABT). The targeted group for this initial work is post stroke patients, although it can be extended to subjects with other neurological insults in the future.

Compact Sensing Design of a Handheld Active Tremor Compensation Instrument.

Active physiological tremor compensation instruments have been under research and development recently. The sensing unit of the instruments provides information on three degrees-of-freedom (DOF) motion of the instrument tip using accelerations provided by accelerometers placed inside the instruments. A complete vector of angular acceleration of the instrument needs to be known to obtain information on three DOF motions of the tip.

Tracking Control of Hysteretic Piezoelectric Actuator using Adaptive Rate-Dependent Controller.

With the increasing popularity of actuators involving smart materials like piezoelectric, control of such materials becomes important. The existence of the inherent hysteretic behavior hinders the tracking accuracy of the actuators. To make matters worse, the hysteretic behavior changes with rate.

Filtering of intended motion for real-time tremor compensation in human upper limb using surface electromyography.

The recorded motion from (pathological) tremor patient may consist of the involuntary tremulous component and the intended motion. These two components have to be separated so that the actuation part will be able to suppress only the tremor. This paper proposes an algorithm to remove the intended motion by using an extended Kalman filter with the help of adaptive high-pass filter.

Feedforward Controller of Ill-Conditioned Hysteresis Using Singularity-Free Prandtl-Ishlinskii Model.

Piezoelectric, magnetostrictive, and shape memory alloy actuators are gaining importance in high-frequency precision applications constrained by space. Their intrinsic hysteretic behavior makes control difficult. The Prandtl-Ishlinskii (PI) operator can model hysteresis well, albeit a major inadequacy: the inverse operator does not exist when the hysteretic curve gradient is not positive definite, i.

Estimating Displacement of Periodic Motion With Inertial Sensors.

Inertial sensors, like accelerometers and gyroscopes, are rarely used by themselves to measure displacement. Accuracy of inertial sensors is greatly handicapped by the notorious integration drift, which arises due to numerical integration of the sensors zero bias error. A solution is proposed in this paper to provide drift free estimation of displacement from inertial sensors.

Position control using 2D-to-2D feature correspondences in vision guided cell micromanipulation.

Conventional camera calibration that utilizes the extrinsic and intrinsic parameters of the camera and the objects has certain limitations for micro-level cell operations due to the presence of hardware deviations and external disturbances during the experimental process, thereby invalidating the extrinsic parameters. This invalidation is often neglected in macro-world visual servoing and affects the visual image processing quality, causing deviation from the desired position in micro-level cell operations. To increase the success rate of vision guided biological micromanipulations, a novel algorithm monitoring the changing image pattern of the manipulators including the injection micropipette and cell holder is designed and implemented based on 2 dimensional (2D)-to 2D feature correspondences and can adjust the manipulator and perform position control simultaneously.

Mitochondrial DNA hypervariable region 1 polymorphism in Singapore Chinese population.

Sequence polymorphisms of hypervariable region 1 were analyzed in 100 unrelated Singaporean Chinese. Ninety-five different haplotypes resulting from 113 variable sites were found between nucleotide positions 16045 and 16364. Single nucleotide polymorphism at nucleotide positions 16223, 16045, 16129, 16362 and 16189 was amongst the five highest frequencies observed in the sequences, whilst the most frequent haplotype was 16045-16223.