Volume 1 Issue 1
Authors: Yury.V. Kulakov; Eugenia V. Kir’yanova; Veronika V. Malaeva; Anatoly Ye. Kostiv; Irina А. Pochekutova; Vladimir I. Korenbaum
Abstract: Computer analysis of respiratory noises provides a precise estimation of acoustic forced expiratory noises time (FETa). The objective is to analyze FETa diagnostic capability in revealing bronchial obstruction. A group of patients with bronchial asthma involved 50 males (16-24 years). Selection criteria: (a) diminution of FEV1/FVC (VC) relation; (b) bronchodilator response to salbutamol; (c) diurnal variability of PEF. A group of 52 healthy volunteers was recruited as the control one. Spirometry and forced expiratory tracheal noises recording were sequentially accomplished for each person. FETa values were estimated by means of developed semiautomated procedure, including bandpass filtration (200–2000 Hz), waveform envelope calculation with accumulation period of 0.01 sec, measurement of FETa at 0.5% level from the peak value of the waveform. The value of FETa was significantly larger in BA patients group than in control one. Based on ROC-analysis the cutoff point FETa > 1.86 s was chosen as a sign of bronchial obstruction. Areas under ROC-curves of FETa and baseline spirometric index FEV1/FVC (VC) did not differ significantly. The mean intrasubject variability of FETa constituted 8.3% in the control group. Thus FETa is a reasonably sensitive, specific and quite repeatable test of bronchial obstruction in young men.
Keywords: computer analysis, respiratory noises, forced exhalation, signal processing, expiratory time, bronchial obstruction
Authors: Urbano D; Bravo R; Rupcich M; Cerrolaza M
Abstract: Energy expenditure is considered an essential tool for assessing functional ability. However in most motion analysis laboratories this is not routinely measured. When the goal of surgical treatment is to functionality or to make easier the task effort, energy assessment provides a unique and important tool. An energy consumption index which can be highly correlated with metabolic energy expenditure is presented in this work. It would enable physicians and researchers to evaluate physical performance on an individual basis and to perform retrospective studies. Since by definition concentric contraction of muscles is power generating while eccentric contraction is power absorbing, this work is focused on the concentric (positive) power intervals. It is assumed that energy cost increase during pathological gait due to the high percentage of concentric contractions. Then, concentric areas of power generation in the kinetic power graphs of hip, knee and ankle in children with cerebral palsy were calculated and then normalized with respect to subject weight, thus obtaining the Normalized Concentric Energy (NCE) index. The concentric energy obtained from NCE calculation on kinetic data from 42 diplegic children with the metabolic energy expenditure (oxygen consumption) were analyzed and compared. Four regression models (linear, exponential, quadratic and cubic) were carried out and a model validation was performed. The cubic regression model showed the best fit to dataset.
Keywords: kinetic variables, energy index, oxygen consumption, joint power
Authors: Ehsan Taheri; Behrooz Sepehri; Reza Ganji; Cyrus Nasirai
Abstract: Locking Compression Plates(LCP) are useful fixation devices for tibia and other human long bones. Orthopedists use LCPs with various numbers of holes to fix bone fractures . Not all of holes on plates are often used with Screws so various screw positioning is possible in operations. In this research, a 3D model of tibia is created with the exact geometry of the real bone by using CT scan images of the human right leg .It was materialized by MIMIX and developed in ABAQUS software. This was done considering whole bone material including bone marrow and cancellous bone that have been mostly ignored in previous researches . The model is mechanically validated and verified in comparison with response and behavior of previous cadaveric bone studies . Comparing the stress and stiffness in various positioning of screws on a stainless steel 11 holes LCP used for fixating tibia with a medial transverse fracture in various treatments and finding the optimized screw omission, was the purpose of this paper which results can help orthopedists to choose the suitable cases of screws positioning of fixation devices.
Keywords: ; Screw placement; transverse fracture ; finite element analysis (fea); stress analysis