28 research outputs found
MINIATURE LOW-COHERENCE FIBER OPTIC ACOUSTIC SENSOR WITH THIN-FILM UV POLYMER DIAPHRAGM
A miniature low-coherence fiber optic acoustic sensor with a thin-film UV polymer diaphragm is developed and studied in this thesis to address the fundamental challenge of miniaturizing acoustic sensors. When miniaturizing an acoustic sensor, there is a critical size limitation at which the transduction mechanism deformation becomes too small for detection. However, a solution to this problem is to utilize a high resolution, low coherence fiber optic interferometric detection system coupled with a soft, thin-film transduction mechanism. A novel fabrication technique was developed to enable the use of elastomers, which inherently exhibit desirably low Young's modulus properties. In addition, the fabrication process enables fabrication of diaphragms at thicknesses on the order of nanometers. The fabrication process also renders highly tunable sensor performance and superior sensing quality at a low cost. The sensor developed exhibits a flat frequency response between 50 Hz and 4 kHz with a useable bandwidth up to 20 kHz, a dynamic range of 117.55 dB SPL, a signal to noise ratio (SNR) of 58 dB, and a sensitivity up to 1200 mV/Pa. In this thesis, it is further demonstrated that by using an array these sensors fabricated from the same batch facilitates accurate directional sound localization by utilizing the interaural phase difference (IPD) exhibited by sensor pairs. Future work is suggested to optimize the sensor performance for a specific application, to carry out studies of more complex array configurations, and to develop algorithms that can help increase the sound localization accuracy
STATISTICAL COMPARISON OF THE KNEE CONTACT FORCES AND KNEE JOINT MOMENTS TO EVALUATE THE LOADING IN THE KNEE WITH FRONTAL PLANE MALALIGNMENT DURING WALKING
In children and adolescent with valgus malalignment the loading is shifted to the lateral compartment. The aim of this study was to investigate the numerical linear relationship between knee joint moments and medial and lateral knee contact forces in children and adolescents with frontal plane malalignment and typically developed controls. In the 2nd half of stance a significant medium linear relationship was found between the knee adduction moment and the medial and lateral knee contact forces. These results lead to the assumption that the loading in the knee joint in children and adolescent should be analyzed by calculating knee contact forces rather than knee joint moments
Identification of Patients with Similar Gait Compensating Strategies Due to Unilateral Hip Osteoarthritis and the Effect of Total Hip Replacement: A Secondary Analysis
Despite good clinical functional outcome, deficits in gait biomechanics exist 2 years after total hip replacement surgery. The aims of this research were (1) to group patients showing similar gait adaptations to hip osteoarthritis and (2) to investigate the effect of the surgical treatment on gait kinematics and external joint moments. In a secondary analysis, gait data of 51 patients with unilateral hip osteoarthritis were analyzed. A k-means cluster analysis was performed on scores derived via a principal component analysis of the gait kinematics. Preoperative and postoperative datasets were statistically tested between clusters and 46 healthy controls. The first three principal components incorporated hip flexion/extension, pelvic tilt, foot progression angle and thorax tilt. Two clusters were discriminated best by the peak hip extension during terminal stance. Both clusters deviated from healthy controls in spatio-temporal, kinematic and kinetic parameters. The cluster with less hip extension deviated significantly more. The clusters improved postoperatively but differences to healthy controls were still present one year after surgery. A poor preoperative gait pattern in patients with unilateral hip osteoarthritis is associated with worse gait kinematics after total hip replacement. Further research should focus on the identification of patients who can benefit from an adapted or individualized rehabilitation program
The first annual meeting of the Nippon Hoken-Gakkai (Insurance Institute of Japan)
The effects of manipulated dental occlusion on body posture has been investigated quite often and discussed controversially in the literature. Far less attention has been paid to the influence of dental occlusion position on human movement. If human movement was analysed, it was mostly while walking and not while running. This study was therefore designed to identify the effect of lower jaw positions on running behaviour according to different dental occlusion positions.Twenty healthy young recreational runners (mean age = 33.9±5.8 years) participated in this study. Kinematic data were collected using an eight-camera Vicon motion capture system (VICON Motion Systems, Oxford, UK). Subjects were consecutively prepared with four different dental occlusion conditions in random order and performed five running trials per test condition on a level walkway with their preferred running shoes. Vector based pattern recognition methods, in particular cluster analysis and support vector machines (SVM) were used for movement pattern identification.Subjects exhibited unique movement patterns leading to 18 clusters for the 20 subjects. No overall classification of the splint condition could be observed. Within individual subjects different running patterns could be identified for the four splint conditions. The splint conditions lead to a more symmetrical running pattern than the control condition.The influence of an occlusal splint on running pattern can be confirmed in this study. Wearing a splint increases the symmetry of the running pattern. A more symmetrical running pattern might help to reduce the risk of injuries or help in performance. The change of the movement pattern between the neutral condition and any of the three splint conditions was significant within subjects but not across subjects. Therefore the dental splint has a measureable influence on the running pattern of subjects, however subjects individuality has to be considered when choosing the optimal splint condition for a specific subject
Prediction of Locally Advanced Urothelial Carcinoma of the Bladder Using Clinical Parameters before Radical Cystectomy - A Prospective Multicenter Study
Introduction: We aimed at developing and validating a pre-cystectomy nomogram for the prediction of locally advanced urothelial carcinoma of the bladder (UCB) using clinicopathological parameters. Materials and Methods: Multicenter data from 337 patients who underwent radical cystectomy (RC) for UCB were prospectively collected and eligible for final analysis. Univariate and multivariate logistic regression models were applied to identify significant predictors of locally advanced tumor stage (pT3/4 and/or pN+) at RC. Internal validation was performed by bootstrapping. The decision curve analysis (DCA) was done to evaluate the clinical value. Results: The distribution of tumor stages pT3/4, pN+ and pT3/4 and/or pN+ at RC was 44.2, 27.6 and 50.4%, respectively. Age (odds ratio (OR) 0.980; p < 0.001), advanced clinical tumor stage (cT3 vs. cTa, cTis, cT1; OR 3.367; p < 0.001), presence of hydronephrosis (OR 1.844; p = 0.043) and advanced tumor stage T3 and/or N+ at CT imaging (OR 4.378; p < 0.001) were independent predictors for pT3/4 and/or pN+ tumor stage. The predictive accuracy of our nomogram for pT3/4 and/or pN+ at RC was 77.5%. DCA for predicting pT3/4 and/or pN+ at RC showed a clinical net benefit across all probability thresholds. Conclusion: We developed a nomogram for the prediction of locally advanced tumor stage pT3/4 and/or pN+ before RC using established clinicopathological parameters
Perencanaan pabrik pengolahan cronut dengan kapasitas bahan baku 25 kg tepung terigu per hari
Cronut merupakan salah satu inovasi produk bakery dengan mengkombinasikan teknik pembuatan donat dan pastry. Beberapa bulan terakhir, cronut mulai populer dan digemari oleh semua kalangan. Cronut belum banyak dihasilkan oleh produsen di Indonesia sehingga peluang usaha untuk mendirikan pabrik cronut cukup besar. Pabrik pengolahan cronut direncanakan memiliki kapasitas bahan baku 25 kg tepung terigu per hari. Lokasi pabrik cronut direncanakan didirikan di Jalan Dinoyo
125A Surabaya, Jawa Timur. Badan usaha yang digunakan pada pabrik cronut adalah swasta perseorangan dengan menggunakan struktur organisasi lini. Pabrik cronut memiliki karyawan sebanyak 2 orang. Utilitas yang digunakan pada pabrik cronut adalah air PDAM (10.352
L/bulan), listrik (18.815kWh/bulan), LPG (17.20 kg/bulan), dan solar. Pabrik cronut memiliki laju pengembalian modal sesudah pajak (ROR) sebesar 24,15% yang lebih besar dari minimum attractive rate of return (MARR) sebesar 16%. Waktu pengembalian modal sesudah pajak adalah
3 tahun 1 bulan. Titik impas atau break even point (BEP) yang diperoleh sebesar 40,64%. Berdasarkan faktor teknis dan ekonomis, pabrik cronut yang direncanakan layak didirikan dan dioperasikan
A systematic review of the associations between inverse dynamics and musculoskeletal modeling to investigate joint loading in a clinical environment
The assessment of knee or hip joint loading by external joint moments is mainly used to draw conclusions on clinical decision making. However, the correlation between internal and external loads has not been systematically analyzed. This systematic review aims, therefore, to clarify the relationship between external and internal joint loading measures during gait. A systematic database search was performed to identify appropriate studies for inclusion. In total, 4,554 articles were identified, while 17 articles were finally included in data extraction. External joint loading parameters were calculated using the inverse dynamics approach and internal joint loading parameters by musculoskeletal modeling or instrumented prosthesis. It was found that the medial and total knee joint contact forces as well as hip joint contact forces in the first half of stance can be well predicted using external joint moments in the frontal plane, which is further improved by including the sagittal joint moment. Worse correlations were found for the peak in the second half of stance as well as for internal lateral knee joint contact forces. The estimation of external joint moments is useful for a general statement about the peak in the first half of stance or for the maximal loading. Nevertheless, when investigating diseases as valgus malalignment, the estimation of lateral knee joint contact forces is necessary for clinical decision making because external joint moments could not predict the lateral knee joint loading sufficient enough. Dependent on the clinical question, either estimating the external joint moments by inverse dynamics or internal joint contact forces by musculoskeletal modeling should be used
Perencanaan pabrik pengolahan cronut dengan kapasitas bahan baku 25 kg tepung terigu per hari
Cronut merupakan salah satu inovasi produk bakery dengan mengkombinasikan teknik pembuatan donat dan pastry. Beberapa bulan terakhir, cronut mulai populer dan digemari oleh semua kalangan. Cronut belum banyak dihasilkan oleh produsen di Indonesia sehingga peluang usaha untuk mendirikan pabrik cronut cukup besar. Pabrik pengolahan cronut direncanakan memiliki kapasitas bahan baku 25 kg tepung terigu per hari. Lokasi pabrik cronut direncanakan didirikan di Jalan Dinoyo
125A Surabaya, Jawa Timur. Badan usaha yang digunakan pada pabrik cronut adalah swasta perseorangan dengan menggunakan struktur organisasi lini. Pabrik cronut memiliki karyawan sebanyak 2 orang. Utilitas yang digunakan pada pabrik cronut adalah air PDAM (10.352
L/bulan), listrik (18.815kWh/bulan), LPG (17.20 kg/bulan), dan solar. Pabrik cronut memiliki laju pengembalian modal sesudah pajak (ROR) sebesar 24,15% yang lebih besar dari minimum attractive rate of return (MARR) sebesar 16%. Waktu pengembalian modal sesudah pajak adalah
3 tahun 1 bulan. Titik impas atau break even point (BEP) yang diperoleh sebesar 40,64%. Berdasarkan faktor teknis dan ekonomis, pabrik cronut yang direncanakan layak didirikan dan dioperasikan
Media 2: Subwavelength optical trapping with a fiber-based surface plasmonic lens
Originally published in Optics Letters on 01 March 2013 (ol-38-5-721
Knee load distribution in hip osteoarthritis patients after total hip replacement
Reduced external knee adduction moments in the second half of stance after total hip replacement have been reported in hip osteoarthritis patients. This reduction is thought to shift the load from the medial to the lateral knee compartment and as such increase the risk for knee osteoarthritis. The knee adduction moment is a surrogate for the load distribution between the medial and lateral compartments of the knee and not a valid measure for the tibiofemoral contact forces which are the result of externally applied forces and muscle forces. The purpose of this study was to investigate whether the distribution of the tibiofemoral contact forces over the knee compartments in unilateral hip osteoarthritis patients 1 year after receiving a primary total hip replacement differs from healthy controls. Musculoskeletal modeling on gait was performed in OpenSim using the detailed knee model of Lerner et al. (2015) for 19 patients as well as for 15 healthy controls of similar age. Knee adduction moments were calculated by the inverse dynamics analysis, medial and lateral tibiofemoral contact forces with the joint reaction force analysis. Moments and contact forces of patients and controls were compared using Statistical Parametric Mapping two-sample t-tests. Knee adduction moments and medial tibiofemoral contact forces of both the ipsi- and contralateral leg were not significantly different compared to healthy controls. The contralateral leg showed 14% higher medial tibiofemoral contact forces compared to the ipsilateral (operated) leg during the second half of stance. During the first half of stance, the lateral tibiofemoral contact force of the contralateral leg was 39% lower and the ratio 32% lower compared to healthy controls. In contrast, during the second half of stance the forces were significantly higher (39 and 26%, respectively) compared to healthy controls. The higher ratio indicates a changed distribution whereas the increased lateral tibiofemoral contact forces indicate a higher lateral knee joint loading in the contralateral leg in OA patients after total hip replacement (THR). Musculoskeletal modeling using a detailed knee model can be useful to detect differences in the load distribution between the medial and lateral knee compartment which cannot be verified with the knee adduction moment