Measurement of object structure from size-encoded images generated by optically-implemented Gabor filters.

We use optical Fourier processing based on two dimensional (2D) Gabor filters to obtain size-encoded images which depict with 20nm sensitivity to size while preserving a 0.36µm spatial resolution, the spatial distribution of structural features within transparent objects. The size of the object feature measured at each pixel in the encoded image is determined by the optimal Gabor filter period, S(max), that maximizes the scattering signal from that location in the object. We show that S(max) (in µm) depends linearly on feature size (also in µm) over a size range from 0.11µm to 2µm. This linear response remains largely unchanged when the refractive index ratio is varied and can be predicted from numerical simulations of Gabor-filtered light scattering. Pixel histograms of the size-encoded images of isolated spheres and diatoms were used to generate highly resolved size distributions ("size spectra") exhibiting sharp peaks characterizing the known major structural features within the studied objects. Dynamic signal associated with changes in selected feature sizes within living cells is also demonstrated. Taken together, our data suggest that a label-free, direct and objective measurement of sample structure is enabled by the size-encoded images and associated pixel histograms generated from a calibrated optical processing microscope based on Gabor filtering.

In-home virtual reality videogame telerehabilitation in adolescents with hemiplegic cerebral palsy.

UNLABELLED: Golomb MR, McDonald BC, Warden SJ, Yonkman J, Saykin AJ, Shirley B, Huber M, Rabin B, AbdelBaky M, Nwosu ME, Barkat-Masih M, Burdea GC. In-home virtual reality videogame telerehabilitation in adolescents with hemiplegic cerebral palsy. OBJECTIVE: To investigate whether in-home remotely monitored virtual reality videogame-based telerehabilitation in adolescents with hemiplegic cerebral palsy can improve hand function and forearm bone health, and demonstrate alterations in motor circuitry activation. DESIGN: A 3-month proof-of-concept pilot study. SETTING: Virtual reality videogame-based rehabilitation systems were installed in the homes of 3 participants and networked via secure Internet connections to the collaborating engineering school and children's hospital. PARTICIPANTS: Adolescents (N=3) with severe hemiplegic cerebral palsy. INTERVENTION: Participants were asked to exercise the plegic hand 30 minutes a day, 5 days a week using a sensor glove fitted to the plegic hand and attached to a remotely monitored videogame console installed in their home. Games were custom developed, focused on finger movement, and included a screen avatar of the hand. MAIN OUTCOME MEASURES: Standardized occupational therapy assessments, remote assessment of finger range of motion (ROM) based on sensor glove readings, assessment of plegic forearm bone health with dual-energy x-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT), and functional magnetic resonance imaging (fMRI) of hand grip task. RESULTS: All 3 adolescents showed improved function of the plegic hand on occupational therapy testing, including increased ability to lift objects, and improved finger ROM based on remote measurements. The 2 adolescents who were most compliant showed improvements in radial bone mineral content and area in the plegic arm. For all 3 adolescents, fMRI during grip task contrasting the plegic and nonplegic hand showed expanded spatial extent of activation at posttreatment relative to baseline in brain motor circuitry (eg, primary motor cortex and cerebellum). CONCLUSIONS: Use of remotely monitored virtual reality videogame telerehabilitation appears to produce improved hand function and forearm bone health (as measured by DXA and pQCT) in adolescents with chronic disability who practice regularly. Improved hand function appears to be reflected in functional brain changes.

Polarisation dynamics of vector soliton molecules in mode locked fibre laser.

Two fundamental laser physics phenomena--dissipative soliton and polarisation of light are recently merged to the concept of vector dissipative soliton (VDS), viz. train of short pulses with specific state of polarisation (SOP) and shape defined by an interplay between anisotropy, gain/loss, dispersion, and nonlinearity. Emergence of VDSs is both of the fundamental scientific interest and is also a promising technique for control of dynamic SOPs important for numerous applications from nano-optics to high capacity fibre optic communications. Using specially designed and developed fast polarimeter, we present here the first experimental results on SOP evolution of vector soliton molecules with periodic polarisation switching between two and three SOPs and superposition of polarisation switching with SOP precessing. The underlying physics presents an interplay between linear and circular birefringence of a laser cavity along with light induced anisotropy caused by polarisation hole burning.

Integrative rehabilitation of elderly stroke survivors: the design and evaluation of the BrightArm™.

PURPOSE: To describe the development of the BrightArm upper extremity rehabilitation system, and to determine its clinical feasibility with older hemiplegic patients. METHOD: The BrightArm adjusted arm gravity loading through table tilting. Patients wore an arm support that sensed grasp strength and communicated wirelessly with a personal computer. Games were written to improve cognitive, psychosocial and the upper extremity motor function and adapted automatically to each patient. The system underwent feasibility trials spanning 6 weeks. Participants were evaluated pre-therapy, post-therapy, and at 6 weeks follow-up using standardized clinical measures. Computerized measures of supported arm reach and game performance were stored on a remote server. RESULTS: Five participants had clinically significant improvements in their active range of shoulder movement, shoulder strength, grasp strength, and their ability to focus. Several participants demonstrated substantially higher arm function (measured with the Fugl-Meyer test) and two were less-depressed (measured with the Becks Depression Inventory, Second Edition). The BrightArm technology was well-accepted by the participants, who gave it an overall subjective rating of 4.1 on a 5 point Likert scale. CONCLUSIONS: Given these preliminary findings, it will be beneficial to evaluate the BrightArm through controlled clinical trials and to investigate its application to other clinical populations.

Long-term hand tele-rehabilitation on the PlayStation 3: benefits and challenges.

Rehabilitation interventions for the hand have shown benefits for children with Hemiplegia due to cerebral palsy or traumatic brain injury. Longer interventions are facilitated if training is provided in the patient's home, due to easier access to care and reduced impact on school or work activities. Providing remote rehabilitation over lengthy periods of time has however its own challenges. This paper presents two pediatric patients with hemiplegia, who practiced virtual hand rehabilitation games using a modified PlayStation 3 and 5DT sensing gloves. Despite severe initial hand spasticity, and occasional technology shortcomings, the subjects practiced for about 14 months, and 6 months, respectively. Game performance data for the second patient is presented. Follow-up evaluations 14 months from the removal of the PlayStation 3 from the home of the child with cerebral palsy showed that the patient had good retention in terms of grasp strength, hand function and bone health. Challenges of long-term home tele-rehabilitation are also discussed.

Maintained hand function and forearm bone health 14 months after an in-home virtual-reality videogame hand telerehabilitation intervention in an adolescent with hemiplegic cerebral palsy.

Virtual reality videogames can be used to motivate rehabilitation, and telerehabilitation can be used to improve access to rehabilitation. These uses of technology to improve health outcomes are a burgeoning area of rehabilitation research. So far, there is a lack of reports of long-term outcomes of these types of interventions. The authors report a 15-year-old boy with hemiplegic cerebral palsy and epilepsy because of presumed perinatal stroke who improved his plegic hand function and increased his plegic forearm bone health during a 14-month virtual reality videogame hand telerehabilitation intervention. A total of 14 months after the intervention ended, repeat evaluation demonstrated maintenance of both increased hand function and forearm bone health. The implications of this work for the future of rehabilitation in children with neurological disabilities are discussed in this article.

Quantifying subcellular dynamics in apoptotic cells with two-dimensional Gabor filters.

We demonstrate an optical Fourier filtering method which can be used to characterize subcellular morphology during dynamic cellular function. In this paper, our Fourier filters were based on two-dimensional Gabor elementary functions, which can be tuned to sense directly object size and orientation. We utilize this method to quantify changes in mitochondrial and nuclear structure during the first three hours of apoptosis. We find that the technique is sensitive to a decrease in particle orientation consistent with apoptosis-induced mitochondrial fragmentation. The scattering signal changes were less pronounced in the nucleus and the remainder of the cytoplasm. Particles in these regions were less oriented than mitochondria and did not change orientation significantly.

Feasibility of modified remotely monitored in-home gaming technology for improving hand function in adolescents with cerebral palsy.

The convergence of game technology, the Internet, and rehabilitation science forms the second-generation virtual rehabilitation framework. This paper presents the first pilot study designed to look at the feasibility of at-home use of gaming technology adapted to address hand impairments in adolescents with hemiplegia due to perinatal stroke or intraventricular hemorrhage. Three participants trained at home for approximately 30 min/day, several days a week, for six to ten months. During therapy, they wore a fifths dimension technologies ultra sensing glove and played custom-developed Java 3D games on a modified PlayStation 3. The games were designed to accommodate the participants' limited range of motion, and to improve finger range and speed of motion. Trials took place in Indiana, while monitoFring/data storage took place at Rutgers Tele-Rehabilitation Institute (New Jersey). Significant improvements in finger range of motion (as measured by the sensing glove) were associated with self- and family-reported improvements in activities of daily living. In online subjective evaluations, participants indicated that they liked the system ease of use, clarity of instructions, and appropriate length of exercising. Other telerehabilitation studies are compared to this study and its technology challenges. Directions for future research are included.