The effects of Tai-Chi in conjunction with thera-band resistance exercise on functional fitness and muscle strength among community-based older people.

AIMS AND OBJECTIVES: The aim of this study was to investigate the effects of Tai-Chi in conjunction with thera-band resistance exercise on functional fitness and muscle strength in community-based older people. BACKGROUND: Tai-Chi is known to improve functional fitness in older people. Tai-Chi is usually performed with free hands without resistance training and usually focuses on training lower limbs. To date, no study has examined the use of Tai-Chi in conjunction with thera-band resistance exercise in this population. DESIGN: Cluster randomised trial design. METHODS: Older people at six senior day care centres in Taiwan were assigned to thera-band resistance exercise or control group using a cluster randomisation. The thera-band resistance exercise group (n = 48) received sixty minute thera-band resistance exercise twice weekly for a period of 16 weeks. The control group (n = 47) underwent routine activities in the day care centre, receiving no Tai-Chi or resistance exercise. RESULTS: After receiving the thera-band resistance exercise, intervention participants displayed a significant increase in muscle strength of upper and lower extremities. Significant improvements were recorded on most measures of the Senior Fitness Test, with the exception of the chair-stand and back-scratch test. CONCLUSION: Thera-band resistance exercise has the potential to improve functional fitness and muscle strength in community-based older people. RELEVANCE TO CLINICAL PRACTICE: Thera-band resistance exercise potentially offers a safe and appropriate form of physical activity that nursing staff can easily incorporate into the daily routine of older people in day care centres, potentially improving functional performance and muscle strength.

Optical interconnect transmitter based on guided-wave silicon optical bench.

An optical interconnect transmitter based on guided-wave silicon optical bench is demonstrated. The guided-wave silicon optical bench (GW-SiOB) is developed on a silicon-on-insulator (SOI) substrate. The three-dimensional guided-wave optical paths on the silicon optical bench are realized using trapezoidal waveguides monolithically integrated with 45° micro-reflectors. Such three-dimensional guided-w ave optical paths of SiOB would simplify and shrink the intra-chip optical interconnects located on a SOI substrate. The clearly open eye patterns operated at a data rate of 5 Gbps verifies the proposed GW-SiOB is suitable for intra-chip optical interconnects.

SOI-based trapezoidal waveguide with 45° microreflector for noncoplanar optical interconnect.

A silicon on insulator (SOI)-based trapezoidal waveguide with a 45° reflector for noncoplanar optical interconnect is demonstrated. The proposed waveguide is fabricated on an orientation-defined (100) SOI substrate by using a single-step anisotropic wet-etching process. The optical performances of proposed waveguides are numerically and experimentally studied. Transmittance of -4.51 dB, alignment tolerance of ±20 µm, cross talk of -53 dB, and propagation loss of -0.404 dB/cm are achieved The proposed waveguide would be a basic element and suitable for the future intrachip optical interconnects.

Monolithic integration of elliptic-symmetry diffractive optical element on silicon-based 45 degrees micro-reflector.

A monolithically integrated micro-optical element consisting of a diffractive optical element (DOE) and a silicon-based 45 degrees micro-reflector is experimentally demonstrated to facilitate the optical alignment of non-coplanar fiber-to-fiber coupling. The slanted 45 degrees reflector with a depth of 216 microm is fabricated on a (100) silicon wafer by anisotropic wet etching. The DOE with a diameter of 174.2 microm and a focal length of 150 microm is formed by means of dry etching. Such a compact device is suitable for the optical micro-system to deflect the incident light by 90 degrees and to focus it on the image plane simultaneously. The measured light pattern with a spot size of 15 microm has a good agreement with the simulated result of the elliptic-symmetry DOE with an off-axis design for eliminating the strongly astigmatic aberration. The coupling efficiency is enhanced over 10-folds of the case without a DOE on the 45 degrees micro-reflector. This device would facilitate the optical alignment of non-coplanar light coupling and further miniaturize the volume of microsystem.

Compact and passive-alignment 4-channel x 2.5-Gbps optical interconnect modules based on silicon optical benches with 45 degrees micro-reflectors.

Compact and passive-alignment 4-channel x 2.5-Gbps optical interconnect modules are developed based on the silicon optical benches (SiOBs) of 5 x 5 mm2. A silicon-based 45 degrees micro-reflector and V-groove arrays are fabricated on the SiOB using anisotropic wet etching. Moreover, high-frequency transmission lines of 4 channel x 2.5 Gbps, and bonding pads with Au/Sn eutectic solder are also deposited on the SiOB. The vertical-cavity surface-emitting laser (VCSEL) array and photo-detector (PD) array are flip-chip assembled on the intended positions. The multi-mode fiber (MMF) ribbons are passively aligned and mounted onto the V-groove arrays. Without the assistance of additional optics, the coupling efficiencies of VCSEL-to-MMF in the transmitting part and MMF-to-PD in the receiving part can be as high as -5.65 and -1.98 dB, respectively, under an optical path of 180 microm. The 1-dB coupling tolerance of greater than +/- 20 microm is achieved for both transmitting and receiving parts. Eye patterns of both parts are demonstrated using 15-bit PRBS at 2.5 Gbps.

Non-mechanical sub-pixel image shifter for acquiring super-resolution digital images.

A sub-pixel image shifter is presented, for use in enhancing the spatial resolution of digital image sensors by combining multiple displaced sub-images using a super-resolution (SR) algorithm. The device uses the walk-off phenomenon in birefringent crystals to separate images with opposite polarizations by a sub-pixel displacement. A liquid crystal (LC) waveplate plus a polarizer can then select the specific image to be exposed, with fast, non-mechanical control. This cascaded device, comprising two sapphire crystals, two LCs, and a single polarizer, is capable of 2-dimensional image shift with displacements of 0.5 pixels. The experimental results show that the image registration stability can be precisely controlled within 0.05 pixels and the contrast transfer function ratio of the SR image is enhanced by up to 1.36 times compared to the original captured image. Moreover, based on the fast transition time of LCs, the displaced sub-images can be recorded in video form with a frame rate of 40 fps.

Authentication labels based on guided-mode resonant filters.

A guided-mode resonance (GMR) filter with wide angular tolerances is experimentally demonstrated as an authentication label illuminated with unpolarized white light. The proposed filter, based on a free-standing silicon nitride membrane suspended on a silicon substrate, is fabricated by using anisotropic wet etching to remove the substrate beneath the silicon nitride layer. Both grating and waveguide structures without a lower cladding layer, i.e., a substrate, are fabricated simultaneously on a silicon nitride membrane. Since the silicon nitride is transparent within the spectra of visible and infrared light, such suspended-membrane-type GMR filters are well suited for applications within the visible spectrum. Moreover, the high refractive index of silicon nitride allows the proposed filters to have strongly modulated gratings and an immunity to high angular deviation. The measured reflection resonance has an angular tolerance up to +/-5 degrees under normal incidence for the wavelength of 629.5 nm.

Homogenized LED-illumination using microlens arrays for a pocket-sized projector.

We present an LED-based ultra-mini DMD projector with a size of 75 mm x 67 mm x 42 mm. A compact homogenizer consisting of a double-side microlens array and two condensers was proposed to reduce the size of the pocket-sized projector. The homogenizer not only allowed for a reduction in the total track length of the system, but also reduced the angle of the rays emitted from the LED with the micro field lens array. The double-side well-aligned 124 x 146 microlens array was fabricated using backside alignment and hot embossing techniques. The microlens array was square-arranged and the fill-factor was extremely high. The uniformity and total throughput of this projector were higher than those of the current pocket-sized projectors. Moreover, the optical performances of the projector such as color difference and the LED alignment tolerance were also measured and discussed.