The use of clinical analysis of movements in evaluation of motor functional status of patients after total hip replacement

Aim: to estimate functional status of coxarthrosis in patients requiring total hip replacement of the two hip joints. Material and methods. The biomechanical examination of 94 patients with bilateral primary coxarthrosis before and after total hip replacement was performed using clinical stabilometric software complex. The ability to perceive the mechanical load during standing and walking was evaluated at different stages of the treatment. The difference between the samples was estimated with the use of Mann — Whitney U-test. The rank correlation of biomechanical parameters was measured by Spearman coefficient. Results. It was revealed that the most responsive indicators are the transfer period, the first and second periods of double support and the deviation of the center of pressure relative to the average position in the frontal plane. Conclusion. After surgical treatment there was observed some improvement: the-left-and-right-step asymmetry decrease, rhythm rate increase, improved ability to maintain body balance, jog reactions increase

Optimization, fabrication and characterization of a binary subwavelength cylindrical terahertz lens

A problem of optimizing the subwavelength microrelief of a binary cylindrical transmissive diffractive lens (DL) with a 300-mm focal length for a wavelength of λ=141 μm was considered. High-resistivity silicon was chosen as the DL substrate material. The angle of incidence of the illuminating beam was taken to be π/6. The optimization parameters were the height of the DL profile and the fill factor of the groove. The main goal of optimizing the design was to increase the diffraction efficiency of the lens. The DL diffraction efficiency was calculated using a Fourier mod method. The DL was fabricated by plasma-chemical etching (Bosch process) of the surface of a silicon substrate. The diffraction efficiency of the calculated lens was estimated to be 70%. However, a full-scale experiment showed the real efficiency to be much lower. These differences are related to both errors in the manufacturing process of the DL and non-ideal thickness parameters of the silicon wafers