RCEAU-Net: Cascade Multi-Scale Convolution and Attention-Mechanism-Based Network for Laser Beam Target Image Segmentation with Complex Background in Coal Mine.

Accurate and reliable pose estimation of boom-type roadheaders is the key to the forming quality of the tunneling face in coal mines, which is of great importance to improve tunneling efficiency and ensure the safety of coal mine production. The multi-laser-beam target-based visual localization method is an effective way to realize accurate and reliable pose estimation of a roadheader body. However, the complex background interference in coal mines brings great challenges to the stable and accurate segmentation and extraction of laser beam features, which has become the main problem faced by the long-distance visual positioning method of underground equipment. In this paper, a semantic segmentation network for underground laser beams in coal mines, RCEAU-Net, is proposed based on U-Net. The network introduces residual connections in the convolution of the encoder and decoder parts, which effectively fuses the underlying feature information and improves the gradient circulation performance of the network. At the same time, by introducing cascade multi-scale convolution in the skipping connection section, which compensates for the lack of contextual semantic information in U-Net and improves the segmentation effect of the network model on tiny laser beams at long distance. Finally, the introduction of an efficient multi-scale attention module with cross-spatial learning in the encoder enhances the feature extraction capability of the network. Furthermore, the laser beam target dataset (LBTD) is constructed based on laser beam target images collected from several coal mines, and the proposed RCEAU-Net model is then tested and verified. The experimental results show that, compared with the original U-Net, RCEAU-Net can ensure the real-time performance of laser beam segmentation while increasing the Accuracy by 0.19%, Precision by 2.53%, Recall by 22.01%, and Intersection and Union Ratio by 8.48%, which can meet the requirements of multi-laser-beam feature segmentation and extraction under complex backgrounds in coal mines, so as to further ensure the accuracy and stability of long-distance visual positioning for boom-type roadheaders and ensure the safe production in the working face.

Composite Diffraction-Free Beam Formation Based on Iteratively Calculated Primitives.

To form a diffraction-free beam with a complex structure, we propose to use a set of primitives calculated iteratively for the ring spatial spectrum. We also optimized the complex transmission function of the diffractive optical elements (DOEs), which form some primitive diffraction-free distributions (for example, a square or/and a triangle). The superposition of such DOEs supplemented with deflecting phases (a multi-order optical element) provides to generate a diffraction-free beam with a more complex transverse intensity distribution corresponding to the composition of these primitives. The proposed approach has two advantages. The first is the rapid (for the first few iterations) achievements of an acceptable error in the calculation of an optical element that forms a primitive distribution compared to a complex one. The second advantage is the convenience of reconfiguration. Since a complex distribution is assembled from primitive parts, it can be reconfigured quickly or dynamically by using a spatial light modulator (SLM) by moving and rotating these components. Numerical results were confirmed experimentally.

Periodic Surface Structuring of Copper with Spherical and Cylindrical Lenses.

The use of a cylindrical lens in femtosecond laser surface structuring is receiving attention to improve the processing efficiency. Here, we investigate the structures produced on a copper target, in air, by exploiting both spherical and cylindrical lenses for beam focusing, aiming at elucidating similarities and differences of the two approaches. The morphological features of the surface structures generated by ≈180 fs laser pulses at 1030 nm over areas of 8 × 8 mm2 were analyzed. For the spherical lens, micron-sized parallel channels are formed on the target surface, which is covered by subwavelength ripples and nanoparticles. Instead, the cylindrical lens leads to a surface decorated with ripples and nanoparticles with a negligible presence of micro-channels. Moreover, the morphological features achieved by focusing ≈180 fs laser pulses at 515 nm with the cylindrical lens and varying the scanning parameters were also studied. The experimental results evidence a direct effect of the hatch distance used in the scanning process on the target surface that contains dark and bright bands corresponding to regions where the rippled surface contains a richer decoration or a negligible redeposition of nanoparticles. Our findings can be of interest in large area surface structuring for the selection of the more appropriate focusing configuration according to the final application of the structured surface.

Modificaciones del segmento anterior ocular tras extracción del cristalino versus iridotomía periférica láser en el cierre angular primario / Modifications of the ocular anterior segment after lens extraction versus peripheral laser iridotomy in primary angle closure

RESUMEN Introducción: el tratamiento inicial para el cierre angular primario está dirigido a modificar el segmento anterior ocular y a estabilizar la enfermedad. Objetivo: evaluar si existen diferencias entre los pacientes tratados con facoemulsificación o iridotomía periférica láser, en cuanto a mejoría de los parámetros anatómicos del segmento anterior ocular. Materiales y métodos: se realizó un estudio cuasi experimental con un grupo de control histórico en la provincia Pinar del Río, entre enero de 2011 y enero de 2020. El mismo incluyó 196 ojos de 144 pacientes con cierre angular primario, tratados con facoemulsificación o iridotomía periférica láser. El análisis estadístico se realizó a través del programa SPSS. Resultados: en el preoperatorio no hubo diferencias significativas para la amplitud de la cámara anterior. En el postoperatorio sí existieron diferencias muy significativas (p < 0,001) entre los dos procedimientos quirúrgicos para ambos ojos. En la amplitud angular también existieron diferencias muy significativas (p < 0,001) entre el preoperatorio y el postoperatorio de ambos grupos. La presencia de sinequias anteriores periféricas fue escasa, sin diferencias entre los valores basales, y a los dos meses en ambos ojos para cada grupo. La evidencia de cierre angular, al final del período, entre el grupo de facoemulsificación y el de iridotomía, fue de 4,9 % vs. 23,2 % (p = 0,029) en el ojo derecho, y de 2,7 % vs. 29,0 % (p = 0,003) en el izquierdo. Conclusiones: tanto la extracción del cristalino como la iridotomía periférica láser mejoran los parámetros anatómicos del segmento anterior, aunque los resultados son superiores en ojos tratados con facoemulsificación.

ABSTRACT Introduction: initial treatment for the primary angle closure is aimed to modify the anterior ocular segment and to stabilize the disease. Objective: to assess if there are differences between patients treated with phacoemulsification or peripheral laser iridotomy, in terms of improvement of the anatomical parameters of the anterior ocular segment. Materials and methods: a quasi-experimental study was led with a historic control group in the province of Pinar del Rio, between January 2011 and January 2020. It included 196 eyes of 144 patients with primary angular closure, treated with phacoemulsification or laser peripheral iridotomy. The statistical analysis was carried out using SPSS program. Results: in the preoperative period there were not significant differences for the amplitude of the anterior chamber. In the postoperative there were very significant differences (p < 0.001) between the two surgical procedures for both ayes. In angular amplitude there were also very significant differences (p < 0.001) between preoperative y postoperative periods of both groups. The presence of peripheral anterior synechia was scarce, without differences between baseline values, and after two months in both eyes for each group. The evidence of angular closure, at the end of the period, between the phacoemulsification group and the iridotomy one was 4.9 % vs. 23.2 % (p = 0.029) in the right eye, and 2.7 % vs. 29.0 % (p = 0.003) in the left. Conclusions: both, crystalline lens extraction and laser peripheral iridotomy improve the anatomical parameters of the anterior segment, although the results are greater in ayes treated with phacoemulsification.

Calibration of Laser Beam Direction for Inner Diameter Measuring Device.

The laser triangulation method is one of the most advanced methods for large inner diameter measurement. Our research group proposed a kind of inner diameter measuring device that is principally composed of three laser displacement sensors known to be fixed in the same plane measurement position. It is necessary to calibrate the direction of the laser beams that are emitted by laser displacement sensors because they do not meet the theoretical model accurately. For the purpose of calibrating the direction of laser beams, a calibration method and mathematical model were proposed. The inner diameter measuring device is equipped with the spindle of the machine tool. The laser beams rotate and translate in the plane and constitute the rotary rays which are driven to scan the inner surface of the ring gauge. The direction calibration of the laser beams can be completed by the sensors' distance information and corresponding data processing method. The corresponding error sources are analyzed and the validity of the method is verified. After the calibration, the measurement error of the inner diameter measuring device reduced from ± 25 µ m to ± 15 µ m and the relative error was not more than 0.011%.

Avaliação do papel de opioides endógenos na analgesia do laser de baixa potência, 820 nm, em joelho de ratos Wistar / Role of endogenous opioids in 820 nm low power laser analgesia in the knees of Wistar rats

JUSTIFICATIVA E OBJETIVOS: A sensação de dor pode resultar em incapacidade, sendo associada à lesão estrutural. O laser de baixa potência mostra-se útil em terapias que objetivam a redução da dor articular e o reparo tecidual, mas ainda com algumas controvérsias. O objetivo deste estudo foi avaliar se a analgesia produzida pelo laser de baixa potência, 820 nm, sofre interferência pela aplicação de um inibidor de opioides endógenos. MÉTODO: Foram utilizados 24 ratos Wistar submetidos à hiperalgesia e divididos em quatro grupos: G1: não tratados; G2: tratados com laser 820 nm; G3: prévio a lesão, injeção de naloxona e não tratados; G4: naloxona e tratados com laser 820 nm. Para a produção de hiperalgesia foi administrado 100 µL de formalina a 5% no espaço articular tíbio-femoral direito. A avaliação da nocicepção ocorreu pelo tempo de elevação da pata (TEP), em cinco momentos, sendo AV1 (pré-lesão), AV2 (15 min/pós), AV3 (30 min/pós), AV4 (1 hora pós) e AV5 (2 horas pós). RESULTADOS: Todos os grupos apresentaram diferença significativa entre AV1 e AV2, mas, apenas G2 não apresentou diferença entre AV1 e AV3. Para os momentos seguintes não houve diferenças com relação à AV1. CONCLUSÃO: A analgesia oriunda do laser de baixa potência, 820 nm, sofre interferências com aplicação de naloxona.

BACKGROUND AND OBJECTIVES: Pain may result in incapacity when it is associated to structural injury. Low power laser is useful in therapies aiming at decreasing joint pain and at tissue repair, but it is still somewhat controversial. This study aimed at evaluating whether analgesia induced by 820 nm low power laser is affected by the application of an endogenous opioids inhibitor. METHOD: Twenty-four Wistar rats submitted to hyperalgesia were divided into four groups. G1: untreated; G2: treated with 820 nm laser; G3: naloxone injection before injury and untreated; G4: naloxone and treated with 820 nm laser. To induce hyperalgesia, 100 µL of 5% formalin were injected in the right tibiofemoral joint space. Nociception was evaluated by the time for flinching (TFF) in five moments: AV1 (pre-injury), AV2 (15 min/after), AV3 (30 min/after), AV4 (1 hour after) and AV5 (2 hours after). RESULTS: All groups showed significant difference between AV1 and AV2, but only G2 showed no difference between AV1 and AV3. There have been no differences for remaining moments as compared to AV1. CONCLUSION: Low power 820 nm laser analgesia is affected by naloxone.

Tratamento alternativo para neuralgia pós-herpética após transplante pulmonar. Relato de caso / Alternative treatment for post-herpetic neuralgia after lung transplantation. Case report

JUSTIFICATIVA E OBJETIVOS: A neuralgia pós-herpética (NPH) é a dor que permanece após o desaparecimento do episódio agudo de herpes zoster. O objetivo deste estudo foi relatar o tratamento da dor da NPH em paciente transplantado pulmonar. RELATO DO CASO: Paciente do sexo masculino, 73 anos, transplantado pulmonar há três anos, em uso de imunossupressores. Desenvolveu quadro de herpes zoster há um ano, com vesículas no oitavo espaço intercostal do hemitórax direito (HTD). O tratamento foi efetivo com ganciclovir; entretanto, o paciente evoluiu com dor em queimação, intensa, constante, com piora no último mês, com intensidade pela escala visual numérica (EVN) de 9, mesmo com uso de 600 mg/dia de gabapentina. Ao exame físico apresentava uma lesão avermelhada no HTD, hiperestésica. Foi instituído tratamento com gabapentina (900 mg), amitriptilina (25 mg), dipirona (8 g) e oxicodona (20 mg) ao dia. Feita a aplicação de laser de baixa intensidade (LBI) diariamente por uma semana, seguido de tratamento com amitriptilina tópica a 4%. A intensidade da dor diminuiu para 5. A frequência de aplicação do LBI diminuiu para uma vez a cada dois dias com melhora significativa com EVN entre 1 e 2. Teve alta hospitalar, com 25 mg/dia de amitriptilina oral e amitriptilina tópica a 4%. CONCLUSÃO: O uso do LBI e da amitriptilina tópica foi eficaz para remissão do quadro doloroso.

BACKGROUND AND OBJECTIVES: Post-herpetic neuralgia (PHN) is the pain remaining after the resolution of acute herpes zoster episode. This study aimed at reporting a case of PHN pain treatment in lung transplantated patient. CASE REPORT: Male patient, 73 years old, submitted to lung transplantation three years ago and under immunosuppressants. He developed herpes zoster one year ago with vesicles in the eighth intercostal space of the right hemithorax (RHT). Treatment was effective with ganciclovir, however the patient evolved with severe, constant burning pain worsened one month ago with intensity 9 according to the numeric visual scale (NVS), even with 600 mg/day gabapentin. At physical evaluation he presented a hyperesthesic reddish lesion in the RHT. Patient was treated with gabapentin (900 mg), amitriptyline (25 mg), dipirone (8 g) and oxycodone (20 mg) per day. Low intensity laser (LIL) was applied daily for one week, followed by treatment with 4% topic amitriptyline. Pain intensity decreased to 5. LIL frequency was decreased to once every two days with significant NVS improvement to 1 and 2. He was discharged with 25 mg/day oral amitriptyline and 4% topic amitriptyline. CONCLUSION: LIL and topic amitriptyline were effective for pain remission.

Sci-Fri PM: Planning-08: Zero diffusion radiochromic genipin-gelatin dosimeter.

PURPOSE: To develop a zero diffusion radiochromic hydrogel by cross-linking gelatin polymers with genipin, for three-dimensional (3-D) radiation dosimetry. METHOD AND MATERIALS: Gelatin and genipin were dissolved in distilled water and continuously stirred at 40C for thee hours and then sulfuric acid was acid prior to placing gel in containers. Concentrations of genipin, gelatin and sulfuric acid were varied to determine the optimal gel sensitivity for optical computed tomography (CT). Photon beams (4 MV x-rays, 1×1, 2×2, 3×3 cm) irradiated a 10 cm diameter cylinder of gel. Using a cone beam optical CT scanner at λ = 590 nm, zero diffusion was observed by recording sequential 3D scans separated by 18 hours. Additional evidence was provided by sequential transmission photographs of a cuvette containing a sample that had been exposed to a 0.8 mm diameter, 1 mW, 594 nm, He-Ne laser beam and photobleached. RESULTS: Radiochromic bleaching is a fast process, complete within seconds of termination of irradiation. Dose sensitivity increases with cross- linking density and sulfuric acid concentration. The initial optical density limits dose sensitivity, requiring approximately 30 Gy for 10 cm diameter samples to have reasonable contrast. More sensitive but darker gels require smaller samples. A comparison of profiles through 3D reconstructed dose distribution showed identical profiles for a time interval of 18 hours. Visually the sample maintained this image for six months when stored at 4C in a dark refrigerator. Transmission photographs of the laser beam image recorded by photobleaching remained constant when stored a 23 C in the dark for ten months. CONCLUSION: Radiochromic genipin gelatin gels form a permanent and stable image when protected from bright visible light. This result is a new, non-toxic material for 3D dosimetry.