UV Exposed Optical Fibers with Frequency Domain Reflectometry for Device Tracking in Intra-Arterial Procedures

Shape tracking of medical devices using strain sensing properties in optical fibers has seen increased attention in recent years. In this paper, we propose a novel guidance system for intra-arterial procedures using a distributed strain sensing device based on optical frequency domain reflectometry (OFDR) to track the shape of a catheter. Tracking enhancement is provided by exposing a fiber triplet to a focused ultraviolet beam, producing high scattering properties. Contrary to typical quasi-distributed strain sensors, we propose a truly distributed strain sensing approach, which allows to reconstruct a fiber triplet in real-time. A 3D roadmap of the hepatic anatomy integrated with a 4D MR imaging sequence allows to navigate the catheter within the pre-interventional anatomy, and map the blood flow velocities in the arterial tree. We employed Riemannian anisotropic heat kernels to map the sensed data to the pre-interventional model. Experiments in synthetic phantoms and an in vivo model are presented. Results show that the tracking accuracy is suitable for interventional tracking applications, with a mean 3D shape reconstruction errors of 1.6 +/- 0.3 mm. This study demonstrates the promising potential of MR-compatible UV-exposed OFDR optical fibers for non-ionizing device guidance in intra-arterial procedures

Determination of optimum parameter levels for multi-performance characteristics in conventional milling of beryllium copper alloy by using response surface methodology

Abstract: With the more demands of modern engineering products with utmost precision and productivity, the control of surface roughness (R a ) together with Material Removal Rate (MRR) have become more significant. This paper optimizes the process parameters (spindle speed, feed and depth of cut) for beryllium copper alloy (C17200) in conventional vertical milling operation using a 6 mm carbide end mill. The experiments were conducted by using Response Surface Methodology (RSM) face centered central composite design. The experimental values obtained for quality characteristics (R a and MRR) are empirically related to process parameters by developing a response surface model using Design-Expert version 7 software. The results show that the optimal parameter levels within the selected range for machining a straight groove with both lower R a and higher MRR in the plate of beryllium copper alloy using CNC Vertical Machining Centre (VMC) are 4416 rpm spindle speed, 0.49 mm/rev feed and 2 mm depth of cut

EXPERIMENTAL AND ANALYTICAL STUDIES ON THE DETERMINATION OF HOLE QUALITY IN DRY DRILLING OF GFRP COMPOSITES

In this investigation nonlaminated Glass Fiber Reinforced Plastic (GFRP) composite rods made by pultrusion method with high fiber weight fraction was drilled with a special geometry coated carbide drill. The ovality of the drilled holes were measured using CMM. Taguchi’s orthogonal array and analysis of variance (ANOVA) were employed to study the influence of process parameters such as feed and spindle speed on ovality. The optimum level of process parameters towards minimum ovality were obtained to achieve defect controlled drilling of pultruded GFRP composite rods. Correlation for ovality with process parameters were established using a statistical software MINITAB 16 and found not to be fit. The influence of feed was insignificant and that of speed was significant on ovality of the drilled holes. The optimal process parameter levels within the range examined was identified as 0.05 mm/rev feed and 1000 rpm speed for drilling pultruded GFRP composite rods using 10 mm ratio drill. The influence of process parameters on hole quality in nonlaminated composite rods differs from that of in laminated composites

Evaluation of palliative care training program for medical interns in a tertiary care teaching hospital, South India

Introduction: The Department of Community Medicine has been training medical interns for providing hospital-based palliative care (HBPC) and community-based palliative care (CBPC) services with an interprofessional team. This study was done to evaluate the training program on palliative care developed for medical interns. Material and Methods: It was a retro-pre type of program evaluation done among 172 interns between January 2016 and December 2017. One day program was conducted for the interns by faculty trained in palliative care, followed by placement in HBPC and CBPC program. At the end of training, self-perceived improvement in knowledge was collected on a five-point Likert scale. Certificates were issued on completion. Data were entered and analyzed using Epi Info (version 7.2.2.6) software. Wilcoxon signed-rank test was applied between pre- and post-scores. Manual content analysis was done for open-ended questions. Results: The mean age of the participants was 22.5 ± 0.8 years, with 76 (44.2%) males and 96 (55.8%) females. There was statistically significant improvement in perceived knowledge scores after attending the training. Areas of learning, values learned, and uses of learning in future career and suggestions for improving the training program were the categories obtained. Conclusion: The training program improved the self-perceived knowledge on palliative care among medical interns. The exposure to HBPC and CBPC program had a positive effect on their attitude and perceived skills for caring of chronically ill patients. Such programs can be initiated by other palliative care providing institutions for training medical interns

Microstructure and dry sliding wear resistance evaluation of plasma nitrided austenitic stainless steel type AISI 316LN against different sliders

In this work, Plasma Nitriding was carried out at a temperature of 570 degrees C on nuclear grade austenitic stainless steel type AISI 316 LN (316LN SS) in a gas mixture of 20% N-2-80% H-2 to improve the surface hardness and thereby sliding wear resistance. The Plasma Nitride (PN) treated surface has been characterized by Vickers microhardness measurements, Scanning Electron Microscopic (SEM) examination, X-ray Diffraction (XRD) and sliding wear assessment. The average thickness of the PN layer was found to be 70 mu m. Microhardness measurements showed a significant increase in the hardness from 210 HV25g (unnitrided sample) to 1040 HV25g (Plasma Nitrided sample). The XRD reveals that PN layer consists of CrN, Fe4N and Fe3N phases along with austenite phase. The tribological parameters such as the friction coefficient and wear mechanism have been evaluated at ambient conditions for PN treated ring (PN ring) vs. ASTM A453 grade 660 pin (ASTM pin), PN ring vs. Nickel based alloy hard faced pin (Colmonoy pin), PN ring vs. 316LN SS pin and 316LN SS ring vs. 316LN SS pin. The wear tracks have been analyzed by SEM, Energy Dispersive X-ray Analysis (EDX) and Optical Profilometry. The untreated 316LN SS ring vs. 316LN SS pin produced severe wear and was characterized by a combination of delamination and adhesion wear mechanism, whereas wear mechanism of the PN rings reveals mild abrasion and a transfer layer from pin materials. (C) 2012 Elsevier B.V. All rights reserved

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Not AvailableThe reproductive characteristic of Rhizoprionodon acutus were investigated using 684 specimens collected along Gujarat coast (India) of the north-eastern Arabian Sea. The sex ratio between male and female (1:1.13) was not found to be significantly different. Male and female sharks were found to mature at total lengths of 61.5 cm and 61.3 cm, respectively. Large and ripe follicles were observed throughout the year, which indicates that the breeding season extends all through the year. However, a significant increase in maximum follicle diameter was observed during February and March in the first quarter and during October and November in the last quarter of the year, which indicates that a portion of the population shows temporal preferences for breeding. This is also corroborated by the increase in the number of mature females with visible eggs in their ovary. Increase in the number of ready to spawn pregnant females was observed during March to May, followed by an increase in the number of postpartum females during May to June. The larger mean size of embryos was also recorded during May and, therefore, it can be presumed that a major parturition event happens during May. The uterine fecundity was found to be significantly influenced by maternal body size and varied from three to seven embryos per litter. Unlike male sharks, the female sharks showed significant variation in the monthly hepato-somatic index (HSI) which was significantly higher in January, after which it showed a gradual decreasing trend probably due to maternal nutrient investment during gestation.Not Availabl