Correction Device Research Articles

Understanding the clinical management of co-occurring sleep-related bruxism and obstructive sleep apnea in adults: A narrative and critical review.

Sleep-related bruxism (SRB) is a motor oral behavior characterized by tooth grinding and jaw clenching activity, reported by 8%-12% of the adult general population and 3% of older individuals. The frequency of one of its biomarkers, rhythmic masticatory muscle activity (RMMA), remains elevated across ages. Obstructive sleep apnea (OSA) is associated with the brief and repetitive pause of breathing (apnea) and with transient reduction in oxygen (hypoxia). OSA is observed at all ages and in about 50% of older individuals with a male preponderance. SRB clinical assessment is based on self-reporting of tooth grinding sound, awareness of clenching, jaw pain or headache, and clinical observation of tooth damage. OSA clinical assessment is based on sleepiness and fatigue, snoring, sleep quality, and awareness of breathing cessation, plus clinical examination of anatomical factors (e.g., obesity, retrognathia, large tonsil, macroglossia), age, gender, and body mass. Although the literature does not support association or causality between these two conditions, the co-occurrence is reported in about 30%-50% of adults. To confirm a diagnosis of co-occurring SRB and OSA, home sleep testing (HST) may be indicated. A sleep test is performed using electromyography (EMG) of jaw muscle (masseter or temporalis) and cardio-respiratory variables (e.g., air flow, respiratory effort, oxygen level, heart rate). The management of co-occurring SRB and OSA for individuals with prosthodontic needs is challenging to prevent compromising the oro-pharyngeal space and breathing efficiency. OSA treatment in the presence of SRB includes continuous positive airway pressure (CPAP) use alone or with an occlusal splint or mandibular advancement device (MAD). In addition, the following may be considered: supine sleep correction device, myofuncional therapy, medications, and surgeries. All have limitations and risks. Individual variability suggests that phenotyping is mandatory to select the most efficient and personalized treatment.

Urinary Continence Restoration Through an Endourethral Device: A 3-Month Pilot Study on 10 Patients.

Background: Stress urinary incontinence (SUI) is a widespread and frustrating condition that affects millions of people worldwide, with severe consequences on patients' quality of life and health care systems' costs. Currently, the most severe cases of SUI are treated using implanted (and rather invasive) extraurethral artificial sphincters. The authors propose an innovative, minimally invasive endourethral device for the treatment of SUI. Methods: Ten patients with SUI were enrolled in three Italian centers and underwent device implantation. After 10, 30, 60, and 90 days, correct device position was confirmed by ultrasonography. Improvements in continence and quality of life were evaluated through a 24-hour pad-test, an International Consultation on Incontinence Questionnarie-Short Form (ICI-Q) and a custom checklist. The device was explanted after 90 days. Results: The proposed device was successfully implanted and explanted in 8 out of 10 patients. The results of the pad-test, ICI-Q, and custom checklist demonstrated remarkable improvements in continence (median improvement: 82% with respect to the initial condition) and quality of life (mean reduction of the impact of urine losses on the quality of life: 61%). No major pain or discomfort was reported. Conclusions: The results demonstrate the efficacy of the proposed endourethral artificial sphincter in addressing SUI. The proposed device was successfully implanted and explanted in a short time (∼10 minutes) without intrinsic side effects and without triggering pain or discomfort.

Development of Best Practice Guideline for the management of hot holes in surface coal mines

Surface coal operations in which mining activities are conducted above old underground workings experience hot holes after drilling. In a coal mine, hot holes are defined as shot holes, which after being drilled have an in-hole ambient temperature of 40°C or above or show a temperature increase of 3°C or more during monitoring. Hot holes and other cavities, such as cracks, pose health and safety risks to workers, such as exposure to hot air and high concentrations of noxious gases released from these holes. In addition, workers may be exposed to premature detonation of explosives caused by in-hole temperature increases and chemical reactions. To this end, Coaltech Research Association commissioned a project to develop a Best Practice Guideline for the management of hot holes. This paper is a compilation of the activities conducted in the development of the Best Practice Guideline between 2021 and 2022. The activities included a review of standard operating procedures and hot-hole temperature-measuring and -monitoring devices, and the assessment of current hot-hole procedures at selected mines. The results indicated that management of hot holes requires a focus on pre-emptive risk assessment of mining blocks, identification of hot holes using the correct temperature-measuring devices, and continuous monitoring of hot holes from the time of drilling until just before blasting. Hot-hole management accessories, such as polyvinyl chloride sleeves, were found to be effective in insulating the hot-hole emulsion from the rock mass temperature, thus preventing the potential for premature detonation.

The impact of cellulose nanocrystals on the properties of poly(2‐hydroxyethyl methacrylate)‐based contact lenses

AbstractContact lenses are widely used corrective devices for addressing vision impairments. In addition to their traditional role, these lenses are increasingly applied in personalized care, biosensing, and drug release, thus broadening their application as multifunctional devices. Nanoparticles are often used to introduce new functionalities to these materials. In this context, the role played by different nanoparticles requires attention to ensure that lens manufacture and patient comfort meet the desired criteria. This study investigates the properties of contact lenses prepared by incorporating cellulose nanocrystals into the poly(2‐hydroxyethyl methacrylate) matrix. Using photopolymerization reactions, polyHEMA‐based lenses and nanocomposites containing freeze‐dried and never‐dried nanoparticles were obtained. Fundamental properties of these lenses were evaluated to verify whether the nanoparticles could have a negative effect on the materials. Subsequently, the potential impact of these nanoparticles on the adsorption of model amino acids was investigated. Our findings reveal that the presence of cellulose nanocrystals modifies on lens thickness, light transmittance, mechanical properties, refractive index (RI), and the uptake of amino acids by the contact lenses. This could potentially affect patient comfort and modify the uptake and release of pharmaceutical ingredients by the material. Additionally, it could impact how these materials interact with biomolecules present in the lacrimal fluid.

Efficacy of a Modified Thoracolumbosacral Orthosis in Adult Idiopathic Scoliosis: A Case Study

Background and Objectives: Adult patients with late-onset idiopathic scoliosis (LIS) presents with cosmetic concerns, back pain, muscle fatigue and the psychological effects of living with a visible deformity. The purpose of this study was to evaluate the effectiveness of modified thoracolumbosacral orthosis on adult female patient with LIS who had been suffering from chronic back pain still refusing for spinal surgery. Case Report: A 27-year-old female patient clinically diagnosed with late onset left LIS with apex at T8 level reported to our institute for spinal rehabilitation with orthotic management. She was completely examined for radiographic findings and treated with physiotherapy and modified thoracolumbosacral orthosis with anterior corset and turn buckle device for gradual correction of deformity and spinal alignment. At a 12-month follow-up, the patient no longer suffered from daily low back pain (LBP) (with heavy lifting only) and was fully active. Additionally, her post intervention radiographs showed an improvement in left thoracic scoliosis and coronal balance. Conclusion: This study suggests that the new modified custom-made design of spinal orthosis may be effective in the management of adult LIS and it represents an acceptable alternative to surgery for patients who refused for surgery.

Development of Image Pre-Processing Methods for Software Compensation of Anomal Refraction of the Observer’s Eyes

In recent decades, the practice of demonstrating various static and video images to users using digital, processor-controlled, most often self-luminous devices (computer monitors, smartphone and tablet screens, etc.) has spurred the development of various methods to improve the perception of such images by means of computerized image preprocessing. This also applies to methods of preprocessing images shown to users with various refractive anomalies of the eye(s) (e.g., myopia or astigmatism) in situations where they are not armed with glasses or other corrective devices. Over the past 20+ years, researchers have published dozens of papers on this task, referred to as the precompensation task. In our opinion, the time has come to reflect on the development of scientific thought in this direction and to highlight the most important milestones in realizing the problems on the way to achieving “ideal” precompensation and in approaches to their successful solution. This is the focus of the first part of this review. In the second part, we focus on the current state of research in the stated area, highlight the problems not solved so far, and try to catch the trends of further development of image precompensation methods, paying maximum attention to neural network approaches.

Turbulence image correction using focused light field camera

Under turbulent conditions, the images of objects may be severely blurred and become unrecognizable because of the complex aberrations introduced by turbulence. Using adaptive optics (AO) to compensate for these wavefront aberrations can theoretically solve the problem of image blurring under turbulent conditions. However, due to its small field of view and high cost, the AO system is difficult to widely use. In recent years, using the technology of light field photography to correct turbulence images has been proposed. However, the current studies are either based on the structure of the non-focused light field camera, which makes it hard to achieve good image quality, or on the need to redesign the core sensor of the non-focused light field camera, which greatly increases the cost and complexity. We believe that the structure of a focused light field camera has a good potential for turbulence image correction and propose a new method of achieving a corrected focused image using a focused light field camera in this paper. We propose to use phase estimation instead of depth estimation for a focused light field camera and phase maps instead of a depth map as the basis for achieving a focused image. By the proposed method, a corrected focused image with a large field of view under turbulent conditions is achieved without using independent wavefront correction devices or redesigning the light field camera. The experiments are given to verify the effectiveness of the proposed method under strong turbulent conditions in the laboratory and real turbulent conditions in the outdoors. The proposed method in this paper provides a new and low-cost solution for image correction for optical imaging systems under turbulent conditions, so it has a high application value.

TELEMONITORING IN PATIENTS WITH CHRONIC HEART FAILURE: EXPERIENCE FROM THE TELECUORE PROJECT IN PIACENZA

Abstract Background Starting from February 2023, the Piacenza’s Hospital has approved the use of a cardiological telemonitoring system called ‘TeleCuore’ project. This system, through the monitoring of various vital parameters which are frequently sent by patients via a dedicated platform, allows for remote assessment of the clinical status of 250 individuals with chronic heart failure (CHF). Objectives The objective of this study is to analyze the number and nature of alerts in the data sent by patients and the consequences on patient’s management derived from the alerts received through the telemedicine system. Materials and Methods 250 patients with CHF identified following recent episodes of clinical instability have been equipped with a home monitoring device (Adilife system). This involves collecting the following data: body weight, temperature, blood pressure, heart and respiratory rate, oxygen saturation, and single–lead EKG. These data are daily filtered by perfusionist technicians (TFCPC) and dedicated nurses, reviewed by the Case Manager and cardiologists. In case of recognition of altered parameters, the platform generates alerts according to pre–set clinical parameters, enabling proactive and personalized interventions on patients. In the 9 months of the TeleCuore project, 494 alerts were received, with 119 (24%) judged not clinically relevant, while 375 (76%) required operator intervention. Of these, 99 were due to weight gain (26%), 40 to low blood pressure (11%), 42 to high blood pressure (11%), 33 to tachycardia episodes (9%), 30 to bradycardia (8%), 49 for technic issues with the weight scale (13%), 78 for EKG artifacts (21%), and 4 for previously unknown atrial fibrillation (1%). 25 patients (8%) were invited for ambulatory clinical evaluation, 28 (7%) were managed through teleconsultation, and the remaining majority (85%) was handled via telephone contact for therapy adjustments (60.5%). 39.4% underwent re–training on the correct device use in the first month. Conclusions The TeleCuore Project is a pilot cardiological telemedicine initiative. Initial data confirm the utility of this system in optimizing the follow–up of patients with CHF, allowing for instant therapeutic adjustments based on the patient’s clinical progress. Teamwork of different healthcare professionals have emerged as crucial for the proper management of alerts. Further data will be needed to assess whether TeleCuore also helps reduce hospitalizations related to CHF.

PERCUTANEOUS CLOSURE OF PATENT FORAMEN OVALE AFTER A FAILED DEVICE–CLOSURE ATTEMPT: A HIGH–VOLUME SINGLE CENTRE EXPERIENCE

Abstract Introduction Persistence of patent foramen ovale (PFO) has been associated with cryptogenic stroke due to a paradoxical systemic embolism. In these cases, a percutaneous closure allows to decrease the risk of redo cerebral ischemic events. However, the presence of a complex anatomy might prevent a correct device–deployment with a high–risk o residual shunt and/or device embolization. We describe our experience about alternative technique after a failed device closure attempt. Methods We reviewed six cases wherein the device was not able to close effectively the PFO. In these cases, alternative techniques and skills were adopted to close the PFO. Results From 2021 to 2023, 194 PFO were closed in the congenital catheterization laboratory of Monaldi Hospital (Naples). In the most of cases (188/194 pts, 96.9%) an effective device closure was obtained. However, in 6 cases (3.1%) the device failed to have a PFO closure. In these 6 patients, the PFO anatomy was characterized by: a severe hypertrophy of the septum secundum (2 cases, 33%), an aneurysmatic interatrial septum (3 cases, 50%), a long stiff tunnel (6 cases, 100%). In three cases a deviceless suture–mediated system (NoblestichTM) was effective to achieve a complete PFO closure; whereas, in two cases a combined approach (suture–mediated system followed by a device deployment) allowed to achieve a complete PFO closure. In a patient with Ebstein anomaly and significant cyanosis due to right–to–left PFO shunt, a partial PFO closure (with mild residual right–to–left shunt) was obtained after NoblestichTM deployment. In this setting, the partial PFO closure was effective to achieve a significant improvement of the patient’s arterial saturation and the procedure stopped without to complete the PFO closure with a device. Conclusion Trans–catheter device closure is often effective to achieve a complete PFO closure. However, in some circumstances, the device was unable to have an appropriate PFO closure. A suture–mediated system or a combined approach (suture–mediated system with concomitant device deployment) are effective to achieve the PFO closure in these complex scenarios.

Evaluation of the Effectiveness of Customized Postural Correction Device for Motorcyclist

Evaluation of the Effectiveness of Customized Postural Correction Device for Motorcyclist

PASAT: pathfinder in solar adaptive telescope

In the forefront of quantitative solar physics research using large-aperture ground-based solar optical telescopes, high-contrast observation along with high-accuracy polarimetric measurement in the solar active region are required. In this paper, we propose a novel high-contrast imaging telescope construction with a 60 cm medium aperture, namely, the PAthfinder in Solar Adaptive Telescope (PASAT), in which a deformable secondary mirror is used as the adaptive optical correction device and a symmetrical optical path design is employed, leading to the least Muller matrix polarization instruments. The telescope can provide a high-resolution magnetic field with high accuracy for the solar active regions, as well as high-contrast images with a superior signal-to-noise ratio and photometric accuracy of the solar photosphere and chromosphere. These data will be directly used for a better understanding of the evolution and release of magnetic energy, which will help in improving space weather forecasting. Meanwhile, PASAT will accumulate the relevant techniques for constructing similar, larger solar telescopes in the future.

Automatic Power Factor Correction

With the mining industry moving from traditional manual methods to the advanced mechanised mining, the focus is also shifting to the energy efficiency of the equipment and system being employed. Most of the equipment used in mining like shovel, drill, elevator, continues miner, conveyor, pumps etc. runs on electricity. Electric energy being the only form of energy which can be easily converted to any other form plays a vital role for the growth of any industry. The Power Factor gives an idea about the efficiency of the system to do useful work out of the supplied electric power. A low value of power factor leads to increase is electric losses and also draws penalty by the utility. Significant savings in utility power costs can be realized by keeping up an average monthly power factor close to unity. To improve the power factor to desired level, reactive power compensators are used in the substations. The most common used device is capacitor bank which are switched on and off manually based on the requirement. If automatic switching can be employed for the correction devices, not only it will improve the response time but also removes any scope for error. The work carried out is concerned with developing power factor correction equipment based on embedded system which can automatically monitor the power factor in the mining electrical system and take care of the switching process to maintain a desired level of power factor which fulfils the standard norms. The Automatic Power Factor Correction (APFC) device developed is based on embedded system having 89S52 microcontroller at its core. The voltage and current signal from the system is sampled and taken as input to measure the power factor and if it falls short of the specified value by utility, then the device automatically switch on the capacitor banks to compensate for the reactive power. Keywords:- Automatic, Power factor, Single phase, Domestic, TRIAC, Capacitor Bank etc.

Power Signal Analysis for Early Fault Detection in Brushless DC Motor Drivers Based on the Hilbert–Huang Transform

Brushless DC machines have demonstrated significant advantages in electrical engineering by eliminating commutators and brushes. Every year, these machines increase their presence in transportation applications. In this sense, early fault identification in these systems, specifically in the electronic speed controllers, is relevant for correct device operation. In this context, the techniques reported in the literature for fault identification based on the Hilbert–Huang transform have shown efficiency in electrical systems. This manuscript proposes a novel technique for early fault identification in electronic speed controllers based on the Hilbert–Huang transform algorithm. Initially, currents from the device are captured with non-invasive sensors in a time window during motor operation. Subsequently, the signals are processed to obtain pertinent information about amplitudes and frequencies using the Hilbert–Huang transform, focusing on fundamental components. Then, estimated parameters are evaluated by computing the error between signals. The existing electrical norms of a balanced system are used to identify a healthy or damaged driver. Through amplitude and frequency error analysis between three-phase signals, early faults caused by system imbalances such as current increasing, torque reduction, and speed reduction are detected. The proposed technique is implemented through data acquisition devices at different voltage conditions and then physical signals are evaluated offline through several simulations in the Matlab environment. The method’s robustness against signal variations is highlighted, as each intrinsic mode function serves as a component representation of the signal and instantaneous frequency computation provides resilience against these variations. Two study cases are conducted in different conditions to validate this technique. The experimental results demonstrate the effectiveness of the proposed method in identifying early faults in brushless DC motor drivers. This study provides data from each power line within the electronic speed controller to detect early faults and extend different approaches, contributing to addressing early failures in speed controllers while expanding beyond the conventional focus on motor failure analysis.

Improving Fish Quality and Yield: An Automated Monitoring System for Intensive Aquaculture

The growing interest in the fish farming industry is driven by the depletion of natural fish stocks in the market. However, intensive aquaculture systems, which involve raising fish in artificial tanks and cages, can lead to challenges such as low-quality fish and increased mortality rates, depending on the species being cultivated. To address these issues and maximize yield, this paper proposes a fish quality monitoring system with automatic correction. The system focuses on monitoring and maintaining critical water quality parameters essential for fish growth, including temperature, water level, and pH level. The system comprises an Arduino connected to sensors and a web-based application for data collection and monitoring. Correction devices such as an aquarium heater, a valve, and a water pump are integrated into the system to maintain these parameters at optimal levels for fish development. To assess the system's efficiency and reliability, two fish monitoring setups were compared: one using the proposed controlled system and the other using a traditional setup. Results indicate that the controlled system increased efficiency, reduced stress on fish farmers, decreased fish mortality rates, and improved product quality compared to the traditional setup.

Wearable apparatus for correction of visual alignment under torsional strabismus.

A wearable optical apparatus that compensates for eye misalignment (strabismus) to correct for double vision (diplopia) is proposed. In contrast to prism lenses, commonly used to compensate for horizontal and/or vertical misalignment, the proposed approach is able to compensate for any combination of horizontal, vertical, and torsional misalignment. If the action of the extraocular muscles is compromised (e.g., by nerve damage), a patient may lose their ability to maintain visual alignment, negatively affecting their binocular fusion and stereo depth perception capability. Torsional misalignment cannot be mitigated by standard Fresnel prism lenses. Surgical procedures intended to correct torsional misalignment may be unpredictable. A wearable device able to rectify visual alignment and restore stereo depth perception without surgical intervention could potentially be of great value to people with strabismus. We propose a novel lightweight wearable optical device for visual alignment correction. The device comprises two mirrors and a Fresnel prism, arranged in such a way that together they rotationally shift the view seen by the affected eye horizontally, vertically, and torsionally. The extent of the alignment correction on each axis can be arbitrarily adjusted according to the patient's particular misalignment characteristics. The proposed approach was tested by computer simulation, and a prototype device was manufactured. The prototype device was tested by a strabismus patient exhibiting horizontal and torsional misalignment. In these tests, the device was found to function as intended, allowing the patient to enjoy binocular fusion and stereo depth perception while wearing the device for daily activities over a period of several months. The proposed device is effective in correcting arbitrary horizontal, vertical, and torsional misalignment of the eyes. The results of the initial testing performed are highly encouraging. Future study is warranted to formally assess the effectiveness of the device on multiple test patients.

IMPROVING THE QUALITY OF REGULATION OF CONTROL SYSTEMS WITH UNCLEAR INITIAL INFORMATION

This article presents a study of the properties of an automatic control system with a fuzzy controller, which includes a fuzzy pseudo-linear correction device with phase advance and a PID controller.One of the promising and effective approaches of the modern theory of control of complex technological systems in conditions of uncertainty caused by the fuzziness of initial information is an approach based on the use of expert assessment methods and the theory of fuzzy sets [1,2]. Technological processes characterized by multi-criteria function mainly in a fuzzy environment. Therefore, for optimal control of the operating modes of such systems, it is necessary to take into account the vectors of criteria and the fuzziness of the initial information. One of the alternative methods of building control and regulation systems for objects that are indistinctly defined from the point of view of classical theory is the use of so-called fuzzy logic controllers.Therefore, the development of fuzzy control controllers based on existing microcontrollers is a very urgent task, since a pseudo-linear fuzzy controller built on the basis of fuzzy sets and fuzzy logical I/O, under the condition of uncertainty of the disturbing effect, is able to provide higher quality indicators of the transient process than a traditional PID controller.As pseudolinear correction devices (PKU) we use: Amplitude-suppressed, phase-ahead, and with separate channels for amplitude and phase, since one of the main disadvantages of the PID controller is the presence of a phase delay and high sensitivity to interference in the measuring channel.

Estimation of the lost productivity to the GDP and the national cost of correcting visual impairment from refractive error in Kenya.

In developing countries such as Kenya, minimal attention has been directed towards population based studies on uncorrected refractive error (URE). However, the absence of population based studies, warrants utilization of other avenues to showcase to the stakeholders in eye health the worth of addressing URE. Hence this study estimated the lost productivity to the Gross Domestic Product (GDP) as a result of URE and the national cost required to address visual impairment from URE in Kenya. The lost productivity to the GDP for the population aged 16-60 years was calculated. Thereafter the productivity loss of the caregivers of severe visual impaired individuals was computed as a product of the average annual productivity for each caregiver and a 5% productivity loss due to visual impairment. The productivity benefit of correcting refractive error was estimated based on the minimum wage for individuals aged between 16-60 years with URE. Estimation of the national cost of addressing URE was based on spectacle provision cost, cost of training functional clinical refractionists and the cost of establishing vision centres. A cost benefit analysis was undertaken based on the national cost estimates and a factor of 3.5 times. The estimated lost productivity to the GDP due to URE in in Kenya is approximately US$ 671,455,575 -US$ 1,044,486,450 annually for population aged between 16-60 years. The productivity loss of caregivers for the severe visually impaired is approximately US$ 13,882,899 annually. Approximately US$ 246,750,000 is required to provide corrective devices, US$ 413,280- US$ 108,262,300 to train clinical refractionists and US$ 39,800,000 to establish vision centres. The productivity benefit of correcting visual impairment is approximately US$ 41,126,400 annually. Finally, a cost benefit analysis showed a return of US$ 378,918,050 for human resources, US$ 863,625,000 for corrective devices and US$ 139,300,000 for establishment of vision centres. The magnitude of productivity loss due to URE in Kenya is significant warranting prioritization of refractive error services by the government and all stakeholders since any investment directed towards addressing URE has the potential to contribute a positive return.

A novel sliding double flexible intramedullary nail technique for the management of lower extremity long bone fractures and deformities in osteogenesis imperfecta.

This study aimed to investigate the effectiveness of the sliding double flexible intramedullary nail technique (SDFIN) in managing lower extremity long bone fractures and deformities in patients with osteogenesis imperfecta (OI) based on radiographic measurements. This study was conducted involving type III or IV Silence OI patients who underwent treatment with SDFIN for fractures, deformity correction, or previous device failure. The surgical technique involved the insertion of two straight flexible intramedullary nails in each bone segment, with one inserted from the caudal epiphysis and the other from the proximal region. Clinical and radiological outcomes were evaluated with a mean follow-up of 62.8 ± 20.3 months. Among the 33 lower extremity long bone segments treated with SDFIN, revision was required in 12 segments, resulting in an overall complication rate of 51.5%. Complications included nail migrations observed in 10 cases, decreased joint range of motion in seven, refractures and malrotations in five, nail fracture, and nail extrusion in one case were observed. The femur group had a complication rate of 50%, while the tibia group had a rate of 53.3%. The SDFIN technique demonstrated satisfactory outcomes in managing leg fractures and deformities in OI patients. The technique showed comparable results to newly designed Faisser-Duval rods at a lower cost. Further research and refinement of the technique are necessary to reduce complications and improve patient outcomes.

Modal Phase Modulators Based on Liquid Crystals with 3D-Printed Polymer Microstructures: Increasing Size and Complexity

We present extended capabilities in simple liquid crystal-based devices that are applicable to adaptive optics and other related fields requiring wavefront manipulation. The laser-written devices can provide complex phase profiles, but are extremely simple to operate, requiring only a single electrode pair tuned between 0 and 10 V RMS. Furthermore, the devices operate in the transmissive mode for easy integration into the optical path. We present here as examples three such devices: the first device reproduces the defocus Zernike polynomial; the second device reproduces a seventh-order Zernike polynomial, tertiary coma; and the last example is of a primary spherical aberration. All devices offer wavelength-scale wavefront manipulation up to more than 2π radians peak-to-peak phase at a wavelength of 660 nm. The coma correction device is significantly more complex, reproducing a mode two orders higher than previous demonstrations, while the spherical device is nearly a full order of magnitude larger, measuring 2 mm in diameter.

Systematic analysis of anthropobiomechanical and pathological conditions of dancers’ feet

The article examines the anthropometric, biomechanical and pathological conditions of dancers’ feet, which are taken into account when designing shoes for various purposes and their corrective devices. An analysis of the work of the lower limbs of classical choreography dancers is presented. The basis of ballet movements is the inversion of the legs (rotation of the legs in the hip joints with the feet turned outward), characterized by high-amplitude hip retraction, unfoldment of the knee and ankle joints, which contradicts the natural vertical position of the human body, reduces the area of foot support, but at the same time gives a feeling of greater stability of ballet posture. The qualities of the «ballet foot» due to professional necessity are considered: flexibility, elasticity, sufficient strength and strength endurance. In the process of studying body movement when performing various elements of classical ballet dance, information about the features of the basic positions of most dance movements is systematized. Due to the specific loads constantly acting on the foot, injuries and pathologies inherent in ballet dancers arise. Biomechanical disorders, occupational injuries and pathological conditions of dancers’ feet, characteristic only for ballet dancers, have been studied: thickening of the compact substance of the metatarsal bones, valgus deviation of the thumb (deformation of the first ray of the foot, characterized by reduction of the first metatarsal bone (inside) and deviation of the big (first) toe (outside), deforming arthrosis of the first metatarsal joint, the development of cyst-like restructuring of the head of the I-th metatarsal bone, etc. The connection of the occurrence of transverse and longitudinal flat feet with the constant wearing of soft or rigid ballet shoes is presented. A systematic analysis of occupational injuries and pathological conditions of ballet dancers’ feet is presented, including the cause, methods of diagnosis and prevention, and a schematic image. It is determined that in almost every case, the prevention of the occurrence of certain pathological conditions is the wearing of rational shoes, orthopedic and shoes with corrective devices, including the processes of rehabilitation of the dancer. The systematized information about the work of the lower extremities, pathological conditions, injuries and deformations of the dancers’ feet allowed us to identify the necessary parameters of everyday shoes for the prevention of various diseases. The article is part of a series of publications within the framework of scientific work