Predicting muscle forces measurements from kinematics data using kinect in stroke rehabilitation

Muscle strength is mostly measured by wearable devices. However, wearing such devices is a tedious, unpleasant, and sometimes impossible task for stroke patients. In this paper, a mathematical model is proposed to estimate the strength of the upper limb muscles of a stroke patient by using Microsoft Kinect sensor. A prototype exergame is designed and developed to mimic real post-stroke rehabilitation exercises. Least-square regression matrix is used to find the relation between the kinematics of the upper limb and the strength of the corresponding muscles. Kinect sensor is used along with a force sensing resistors (FSR) glove and two straps to collect both, real-time upper limb joints data and the strength of muscles of the subjects while they are performing the exercises. The prototype of this system is tested on five stroke patients and eight healthy subjects. Results show that there is no statistically significant difference between the measured and the estimated values of the upper-limb muscles of the stroke patients. Thus, the proposed method is useful in estimating the strength of the muscles of stroke patient without the need to wear any devices.     

SmartPads: a plug-N-play configurable tangible user interface

One common concern with video games today is the lack of physical activity they demand from the user. The design of games and tangible user interfaces (TUIs) that stimulate players and engage them into fun exercising activities is starting to attract the attention of many researchers and companies. This paper presents the software and hardware design and development of a TUI intended for exercise-based games targeted mostly towards children. The proposed TUI, SmartPads, can be constructed using elemental building blocks (pads) into numerous shapes. The pads-which are individually controlled by microcontrollers-are mapped onto a computer screen in real-time. A user interacts with the TUI by stepping on the pads. To evaluate the functionality and efficiency of the TUI, we developed three games in the field of exergaming. The games also have an educational value and are integrated with multimedia output modalities to enrich children’s playing experience.

     

A new iterative method for analysing nonlinear photonic-crystal structures

The article presents an efficient iterative method for analysing non-linear photonic crystals. The new approach is used for analysing a frequency converter constructed with a 2D pillar-type photonic crystal waveguide structure. The considered converter uses the non-linear properties and the compound waveguide structure. The analysis is based on the iterative resolution of two relationships between incident and reflected volume-waves. The reflection operator is expressed using Hankel functions. Numerical results have been obtained with moderate CPU time and memory requirement. Simulations obtained are in agreement with recent published results.     

Synthesis of new silica xerogels based on bi-functional 1,3,4-thiadiazole and 1,2,4-triazole adducts

New transparent Silica-based hybrid materials were synthesized by reaction of polymethylhydrosiloxane (PMHS) and organic compounds: 1,3,4-thiadiazole-2,5-diamine (1), 1,3,4-thiadiazole-2,5-dithiol (2) and 1H-1,2,4-triazole-3-thiol (3), in tetrahydrofuran as solvant using hexachloroplatinic acid (H₂PtCl₆.6H₂O) as a catalyst. PMHS was used as a principal network forming agent, it has been cross-linked via hydrosilylation reaction with bi-functional heterocyclic compounds, leading to the formation of colored gels. These later dried (xerogels) were characterized by numerous techniques, including spectroscopy of (FT–IR) and ¹³C and ²⁹Si CP MAS NMR. The xerogels morphology and texture were studied by scanning electron microscopy and Brunauer–Emmet–Teller method. According to N₂-physisorption results, isotherms are classified as type IV with H₂ type hysteresis loop; then, the xerogels are mesoporous materials. The optic and magnetic properties of the obtained materials were studied by UV–VIS and EPR spectroscopies, respectively. This study showed that all materials are paramagnetic semiconductors.     

Numerical thermal‐hydraulic performance investigations in turbulent curved channel flow with horseshoe baffles

A numerical work is performed to investigate the thermal‐hydraulic performance in a curved channel of a journal bearing equipped with oblique horseshoe baffles. Water, a working fluid, is passed through the curved channel at a constant temperature condition of 358 K. The effects of different parameters of baffles, that is, attack angle (α = 45°, 60°, and 90°) and the number of baffles (NB = 9 and 13 baffles), are examined. Influences of design parameters on heat transfer and friction performances are studied and displayed in terms of the Nusselt number, the friction factor, the Nusselt number enhancement ratio, and the thermal‐hydraulic performance factor (THPF). The numerical simulations present the flow structures of the tested channel in terms of velocity, isotherms, turbulent kinetic energy, and vorticity contours. The numerical results reveal that the adopted geometry of the curved channel with baffles yields a significant enhancement of heat transfer rate over the plain channel (without baffles), which is approximately 2.5 to 3.8 times. Also, the results show that the best condition to achieve maximum heat transfer is at angle α = 90°, NB = 13, and Re = 5000, compared with other conditions. Furthermore, the maximum THPF of the curved channel using baffles is 4.4 at the same condition. The results confirmed that the geometry of the baffles inside the curved channel has a remarkable impact on heat transfer improvement, accompanied by a reasonable increase in friction losses.