Feature Papers in Optical Sensors 2022

Today, optical sensors are the subject of a very significant number of studies and applications [...

Checking diameter uniformity in a prepared graded index polymer optical fiber using a whispering gallery mode technique

This paper experimentally demonstrates a method for measurement of fiber diameter variations with submicron resolution. The fiber sample under test was a short section of graded index polymer optical fiber (GIPOF) with a diameter of 430 μm prepared by an interfacial gel polymerization technique and heat drawn from graded index preforms of known refractive index profiles at 180oC. Measurement results have been verified by SEM microscopic studies. The proposed method can be applied in both manufacturing and quality control of GIPOF

Checking diameter uniformity in a prepared graded index polymer optical fiber using a whispering gallery mode technique

This paper experimentally demonstrates a method for measurement of fiber diameter variations with submicron resolution. The fiber sample under test was a short section of graded index polymer optical fiber (GIPOF) with a diameter of 430 μm prepared by an interfacial gel polymerization technique and heat drawn from graded index preforms of known refractive index profiles at 180oC. Measurement results have been verified by SEM microscopic studies. The proposed method can be applied in both manufacturing and quality control of GIPOF

International journal of innovative computing and applications

This paper investigated the application of FBG sensors in the measurement of scissor blade–tissue interaction forces. Sensor placement at the blade–tissue interaction site provides the basis for increased force measurement accuracy, without compromising the functionality of the instrument. This increased accuracy provided the foundation for in-depth analysis of the force components generated during typical scissor cutting cycles. Theoretical analysis and experimental investigation explored the decoupling of the major forces present during cutting. The isolation of tissue-fracture forces from inter-blade friction forces was carried out. This is useful as knowledge of the fracture properties of biological tissues can be diff cult to obtain. Moreover, the force information obtained can be ref ected to the user in a telerobotic application ensuring a greater sense of user immersion. Scissor cutting force data is of particular relevance to those involved in the development of soft tissue models for medical simulation systems. The motivation behind this work is to develop a smart surgical instrument capable of unobtrusively, and with minimal impact on instrument functionality, detecting tissue– instrument interaction forces. Future work will involve the miniaturization of the current technique enabling the development of a laparoscopic prototype instrument capable of acquiring in vivo force and material fracture propertie

Dithiocarbamates as Effective Reversible Addition–Fragmentation Chain Transfer Agents for Controlled Radical Polymerization of 1-Vinyl-1,2,4-triazole

Narrow dispersed poly(1-vinyl-1,2,4-triazole) (PVT) was synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization of 1-vinyl-1,2,4-triazole (VT). AIBN as the initiator and dithiocarbamates, xanthates, and trithiocarbonates as the chain transfer agents (CTA) were used. Dithiocarbamates proved to be the most efficient in VT polymerization. Gel permeation chromatography was used to determine the molecular weight distribution and polydispersity of the synthesized polymers. The presence of the CTA stabilizing and leaving groups in the PVT was confirmed by 1H and 13C NMR spectroscopy. The linear dependence of the degree of polymerization on time confirms the conduct of radical polymerization in a controlled mode. The VT conversion was over 98% and the PVT number average molecular weight ranged from 11 to 61 kDa. The polydispersity of the synthesized polymers reached 1.16. The occurrence of the controlled radical polymerization was confirmed by monitoring the degree of polymerization over time

Are Kazakhstani Women Satisfied with Antenatal Care? Implementing the WHO Tool to Assess the Quality of Antenatal Services

Women’s satisfaction is a part of the quality assurance process with potential to improve antenatal health services. The objective of this study was to assess the prevalence of women’s satisfaction with antenatal care in an urban Kazakhstani setting and investigate associated factors. A total of 1496 women who delivered in all maternity clinics from 6 February through 11 July 2013 in Semey, East Kazakhstan, filled out a standardized pretested questionnaire on satisfaction with antenatal care. Independent associations between dissatisfaction and its correlates were studied by logistic regression. Ninety percent of the women were satisfied with the antenatal care. Women who were dissatisfied had lower education. These women would have preferred more checkups, shorter intervals between checkups, more time with care providers, and shorter waiting times. The overall dissatisfaction was associated with long waiting times and insufficient information on general health in pregnancy, results of laboratory tests, treatment during pregnancy, and breastfeeding. Although most of the women in the study setting were satisfied with the new antenatal care model, we identified the main sources of dissatisfaction that should be addressed. Given that Semey is a typical Kazakhstani city, the results can be generalized to other Kazakhstani urban settings

Evaluation of branched-chain amino acids in children with autism spectrum disorder and epilepsy

Autism spectrum disorder (ASD) and epilepsy run hand-to-hand in their pathophysiology. Epilepsy is not an uncommon finding in patients with ASD. The aim of the present study was to identify the metabolic abnormalities of BCAAs (leucine, isoleucine, and valine) in children with ASD with and without seizures in comparison with neurotypical controls. Also, this study aimed to investigate the presence of epileptiform discharges on electroencephalography (EEG) in ASD patients and to describe the types and frequency of seizures observed. The study included 90 children aged 2-7 years, 30 of whom were diagnosed with both ASD and epilepsy. The other 30 children were diagnosed as ASD without epilepsy, and a comparable 30 normally developed children served as a control group. The groups were matched by age and gender. All patients were referred to the Autism Disorders Clinic for interviews and examinations. The Childhood Autism Rating Scale (CARS) was applied to all study participants to assess the degree of autism. The present study results show that all types of seizures may be identified in ASD children. The median serum levels of BCAAs were lower in ASD children with and without epilepsy than in neurotypical controls. This opens the door for discussion about new etiologies and better categorizations of ASD based on genotype and genetic abnormalities detected. More studies with larger samples are needed to understand ASD better and to more reliable evaluate the association between ASD, EEG changes, seizures, and BCAAs