Restoration of optical spectrum

This article deals with research of luminous sources which could be applied in indoor Free Space Optic (FSO) networks. Indoor FSO networks have potential to replace standard IEEE 802.11 in the future. Suitable selection and configuration of optical radiation sources can at the same time provide communication and lighting in indoor spaces. This article is engaged in spectral mergence of optical sources, willful suppression of part of emitted visible spectrum and consequential restoration of this optical spectrum

VLC transmitter with plastic optical fibers for indoor free space optic networks

This article deals with the construction design of optical transmitter for indoor Free Space Optic (FSO) networks. This optical transmitter will be able to provide the lighting and communication at the same time. Thanks to special solution in spectral characteristic of transmitted light it is necessary to use two LEDs radiation sources. The light beams of these LEDs have to be spatially overlapped in crisscross direction and then the transmitter can realize both functions. There is described a construction of optical transmitter with plastic optical fibers which merges two LED beams together and provide lighting and communication at the same time

Non-invasive fiber optic probe encapsulated into PolyDiMethylSiloxane for measuring respiratory and heart rate of the human body

This article describes the design and the functional verification of fiber optic system with an innovative non-invasive measuring probe for monitoring respiratory and heart rate. The measuring probe is based on Fiber Bragg Grating (FBG), and it is encapsulated in the PolyDiMethylSiloxane polymer (PDMS). PDMS offers a unique combination of suitable properties for the use in biomedical applications. The main advantages include inert to human skin and immunity to electromagnetic interference. The measuring probe is a part of contact strip which is placed on the chest of the patient. The measurement is based on sensing the movements of the thoracic cavity of the patient during breathing. Movement (mechanical stress) is transferred to FBG using the contact strip. Respiratory and heart rate are analyzed using the spectral evaluation of the measured signals. This monitoring method is fully dielectric; thus the absolute safety of the patient is ensured. The main contributions of the article are a design of non-invasive probe encapsulated into a PDMS polymer and implementation of the probe for humans using a contact strip. This combination forms an essential element of the measuring system. The set of experimental measurements verified functionality with respect to the position of the patient. Performed experiments proved the functionality of the presented solution so it can be utilized for further research in biomedical applications

Perimeter system based on a combination of a Mach-Zehnder interferometer and the Bragg gratings

Fiber optic interferometers and Bragg gratings belong to the group of very precise and sensitive devicesthat allow measuring very small deformation, temperature or vibration changes. The described methodology presentsthe useof a Mach-Zehnder interferometer and Bragg gratings together as a sensor system for detecting and monitoring movement within thedefined perimeter of 2.5×1m. Analyses of the dynamic changes in interferometric patterns were a basis for this method. Also the signal maximum amplitude was measured and compared with the noise background. Perimeter disruptions can be detected by Bragg gratings due to its large deformation sensitivity in transversal or perpendicular directions. The result is then evaluated in the spectral domain. In terms of detected persons it showed very good results. The combination of these sensors was chosen for monitoring both the static and dynamic phenomena. Author's aim is to take advantage of both devices' positive properties. Thus, the system has the abilityto identify people due to frequency analysis in case of interferometers as well as dynamic weighting thanks to Bragg gratings

Time Changes in Resisted Sprinting With a Weighted Vest: 5 % of Body Weight or Back Squat? The Use of the 1RM Back Squat and Body Weight as Load Strategy in Weighted Vest Sprinting

The purpose was to investigate whether runners who do not squat their body weight once will not be overloaded with a weight vest with a load of 5% of BW and will not maintain 95% intensity across ten repetitions of a 20-meter sprint. Eight adult female students (24,05±1,15 years old; body height 168±4,24 cm; body weight 60,39±5,53 kg) from the faculty of sports studies at Masaryk University in the Czech Republic participated in this study. Categories were: 1 = NBW (1RM in the squat is relative body weight ± 5 kg), 2 = LBW (1RM in the squat is lower than BW-5 kg) and 3 = HBW (1RM in the squat is higher than BW +5 kg). The measurements took place on three different days, each day running with another experimental condition: free sprinting, weighted vest sprinting with a 5% load of BW, and weighted vest sprinting with a 5% load of 1RM squat. With a weight vest with resistance at the level of 5% of body weight, during 49 sprints, the intensity decreased by a maximum of 4.82% (participant 4, NBW group, 1st run). Although, with weight vest resistance at the level of 5% of the 1RM back squats, during 68 sprints, the intensity decreased by a maximum of 6.59% (participant 1, NBW group, 8th run). It seems that the level of strength abilities of the lower limbs did not play a role in this, we can calculate 5% intensity from both BW and 1 RM squat. Since the HBW group could maintain the required intensity even at significantly higher weights than 5% BW, further research with a larger research sample is needed

New sophisticated analysis method of crystallizer temperature profile utilizing optical fiber DTS based on the stimulated Raman scattering

Continuous casting is a modern and advanced technology of steel production, whose product is a steel blank as a semifinished product for further manufacturing. It is known that better monitoring and process control of casting improves the steel quality and is able to ensure customers’ requirements in terms of sizes, brands, quantities and properties with lower costs. The crystallizer belongs among the most important parts of this whole process [1]. At present many methods for analysing of the crystallizer temperature profile in operation were published and experimentally verified. In these methods, the thermocouples or Bragg gratings are widely used. New sophisticated analysis method of crystallizer temperature profile is the utilization of the optical fiber DTS based on the stimulated Raman scattering. This paper describes the first experimental measurement and verification of the method, which are necessary for the method deployment into the industrial practices

A non-invasive multichannel hybrid fiber-optic sensor system for vital sign monitoring

In this article, we briefly describe the design, construction, and functional verification of a hybrid multichannel fiber-optic sensor system for basic vital sign monitoring. This sensor uses a novel non-invasive measurement probe based on the fiber Bragg grating (FBG). The probe is composed of two FBGs encapsulated inside a polydimethylsiloxane polymer (PDMS). The PDMS is non-reactive to human skin and resistant to electromagnetic waves, UV absorption, and radiation. We emphasize the construction of the probe to be specifically used for basic vital sign monitoring such as body temperature, respiratory rate and heart rate. The proposed sensor system can continuously process incoming signals from up to 128 individuals. We first present the overall design of this novel multichannel sensor and then elaborate on how it has the potential to simplify vital sign monitoring and consequently improve the comfort level of patients in long-term health care facilities, hospitals and clinics. The reference ECG signal was acquired with the use of standard gel electrodes fixed to the monitored person's chest using a real-time monitoring system for ECG signals with virtual instrumentation. The outcomes of these experiments have unambiguously proved the functionality of the sensor system and will be used to inform our future research in this fast developing and emerging field.Web of Science171art. no. 11

Mapping frameworks and approaches to measuring the quality of transition support services for young people with intellectual and developmental disabilities

Transition to adulthood for young people with intellectual disabilities and developmental disabilities (IDD) has been given significant attention in research, policy development and practice. The aim of this paper was to explore how a recently developed theoretical outcomes-based framework for measuring the quality of services for people with disabilities could potentially be useful in conceptualizing and supporting successful transition to adulthood. The theoretical discussion draws on both the scoping review and template analysis that was used to develop the Service Quality Framework and on a separate study synthesizing expert completed country templates and literature review which included models of and research on successful transition to adulthood. Synthesis identified that using a quality of life outcomes focused framework of Service Quality could be mapped onto and extend current thinking on what is seen as successful transition to adulthood by putting the focus on successful transition as people with IDD moving towards having similar opportunities and quality of life as other adults without disabilities living in the same community/society. Implications of a more wide-ranging definition and holistic view for both practice and future research are discussed

Measuring optimal length of the amplifying fiber in different working conditions of the amplifier

The aim of this article is to highlight possible unwanted behaviour of an EDFA optical amplifier during temperature changes. After a brief introduction dealing with amplifiers and doped fibers in general we focus on the assembly of our own EDFA amplifier with standard construction and the IsoGain I-6 amplifying fiber, and on the parameters of its individual components. Since an erbium doped fiber has usually no direct thermal stabilization, temperature changes can affect performance of the entire amplifier. The next part of the article therefore describes the impacts of such changes on behaviour of our amplifier. At the very end we performed a measurement of the amplifier deployed in the actual WDM-PON the description of which can be found in the last chapter

Magnetic resonance imaging compatible non-invasive fibre-optic sensors based on the Bragg gratings and interferometers in the application of monitoring heart and respiration rate of the human body: A comparative study

The publication presents a comparative study of two fibre-optic sensors in the application of heart rate (HR) and respiratory rate (RR) monitoring of the human body. After consultation with clinical practitioners, two types of non-invasive measuring and analysis systems based on fibre Bragg grating (FBG) and fibre-optic interferometer (FOI) have been designed and assembled. These systems use probes (both patent pending) that have been encapsulated in the bio-compatible polydimethylsiloxane (PMDS). The main advantage of PDMS is that it is electrically non-conductive and, as well as optical fibres, has low permeability. The initial verification measurement of the system designed was performed on four subjects in a harsh magnetic resonance (MR) environment under the supervision of a senior radiology assistant. A follow-up comparative study was conducted, upon a consent of twenty volunteers, in a laboratory environment with a minimum motion load and discussed with a head doctor of the Radiodiagnostic Institute. The goal of the laboratory study was to perform measurements that would simulate as closely as possible the environment of harsh MR or the environment of long-term health care facilities, hospitals and clinics. Conventional HR and RR measurement systems based on ECG measurements and changes in the thoracic circumference were used as references. The data acquired was compared by the objective Bland-Altman (B-A) method and discussed with practitioners. The results obtained confirmed the functionality of the designed probes, both in the case of RR and HR measurements (for both types of B-A, more than 95% of the values lie within the +/- 1.96 SD range), while demonstrating higher accuracy of the interferometric probe (in case of the RR determination, 95.66% for the FOI probe and 95.53% for the FBG probe, in case of the HR determination, 96.22% for the FOI probe and 95.23% for the FBG probe).Web of Science1811art. no. 371