Chlorin E6-photodynamic therapy basal cell carcinoma

Purpose of the study. Evaluation of the therapeutic efficacy of chlorin E6-photodynamic therapy (PDT) with photosensitizers (PS) photoditazine, photolone and photoran in patients suffering basal cell skin carcinoma.Materials and methods. The efficacy of chlorin E6-PDT was studied in 532 patients with basal cell skin cancer (BCC) aged 28 to 93 years. PhS Photoditazine was used in 72 (13,5 %) patients at a dose of 0.5-1.0 mg/kg, PhS Photolon - in 281 (52,8 %) patients at a dose of 1.1-1.6 mg/kg and PhS Photoran - in 179 (33,6 %) people at a dose of 1.1-1.6 mg/kg.Sessions of local irradiation of tumor foci were performed on a laser device "Latus-2" (662 nm) with a power density of 200-500 mW/cm2, light energy was applied to the tumors at a dose of 100-300-600 J/cm2.Results. During the follow-up period from 6 months to 5 years, 16.2 % of cases of relapse were diagnosed in the study group. When analyzing the results, it was found that the percentage of relapses was minimal when using all PhS in patients who underwent PDT for the first time established BCC of the initial stages (neoplasms up to 2.0 cm) and amounted to 2.2 % (4 patients out of 183), and with a prevalence of the process of more than 2.0 cm and up to 4.0 cm, 9.5 % (10 patients out of 105) of relapses were found. In the results of treatment of recurrent skin malignancies with PDT using derivatives of chloride E6, depending on the prevalence of the process, a similar trend was observed: with the size of tumor foci up to 2.0 cm, the percentage of repeated relapses was less and amounted to 17.1 % (18 patients out of 105) than in the treatment of neoplasms more than 2.0 cm and up to 4.0 cm (28.8 % of relapses - 21 patients out of 73).Conclusions. Chlorin E6-PDT makes it possible to effectively treat primary and recurrent BCC in an independent variant, and the results of treatment depend on a number of factors, including the prevalence of the disease and the presence or absence of previous treatment.

Laser therapy in the complex treatment of patients with compression-ischemic neuropathy

Material and methods. Twenty-two patients with compression-ischemic neuropathy were included into the study. Low-level laser device “ALOK-1” was used for laser therapy. Its beam impacts tissues directly; its power is 1 mW, wavelength – 0.63 μm, spot diameter – 0.8 mkm.Results. Subjective, objective and instrumental findings became significantly better, if to compare with the pre-operative period.Conclusion. The developed technique has shown its good efficiency. The intraoperative laser therapy CIN patients decreased the severity of symptoms up to their complete regression; patients were highly satisfied with their postoperative outcomes.

Regulador de distância para pesquisa de laser de Er:YAG sem contato

Aims: develop a distance regulator for the Er:YAG laser. Methods: a metallic device adaptable to the 2051 handpiece was developed. Interchangeable metallic pieces, with diferent lengths, are adaptable to the regulator's body. Results: this laser device allows standard distances for laser delivering, from 08 to 20 millimetres from target tissue. Conclusions: the use of this new device allows a standard evaluation of the Er:YAG laser effects in experimental surgery, when emitted from different distances of the target tissue.

Navigated, Robot-Driven Laser Craniotomy for SEEG Application Using Optical Coherence Tomography in an Animal Model

Objectives: We recently introduced a navigated, robot-driven laser beam craniotomy for use with stereoelectroencephalography (SEEG) applications. This method was intended to substitute the hand-held electric power drill in an ex vivo study. The purpose of this in vivo non-recovery pilot study was to acquire data for the depth control unit of this laser device, to test the feasibility of cutting bone channels, and to assess dura perforation and possible cortex damage related to cold ablation.Methods: Multiple holes suitable for SEEG bone channels were planned for the superior portion of two pig craniums using surgical planning software and a frameless, navigated technique. The trajectories were planned to avoid cortical blood vessels using magnetic resonance angiography. Each trajectory was converted into a series of circular paths to cut bone channels. The cutting strategy for each hole involved two modes: a remaining bone thickness mode and a cut through mode (CTR). The remaining bone thickness mode is an automatic coarse approach where the cutting depth is measured in real time using optical coherence tomography (OCT). In this mode, a pre-set measurement, in mm, of the remaining bone is left over by automatically comparing the bone thickness from computed tomography with the OCT depth. In the CTR mode, the cut through at lower cutting energies is managed by observing the cutting site with real-time video.Results: Both anesthesia protocols did not show any irregularities. In total, 19 bone channels were cut in both specimens. All channels were executed according to the planned cutting strategy using the frameless navigation of the robot-driven laser device. The dura showed minor damage after one laser beam and severe damage after two and three laser beams. The cortex was not damaged. As soon as the cut through was obtained, we observed that moderate cerebrospinal fluid leakage impeded the cutting efficiency and interfered with the visualization for depth control. The coaxial camera showed a live video feed in which cut through of the bone could be identified in 84%.Conclusion: Inflowing cerebrospinal fluid disturbed OCT signals, and, therefore, the current CTR method could not be reliably applied. Video imaging is a candidate for observing a successful cut through. OCT and video imaging may be used for depth control to implement an updated SEEG bone channel cutting strategy in the future.

LASER IN PERIODONTOLOGY- A REVIEW

Lasers are used in implant and periodontal field practices. Laser has various periodontal applications including calculus removal, decontamination of root and implant surfaces and bio stimulation, incision and ablation, osseous surgery, excision of the soft tissue, and bacterial reduction. There is a strong evidence that laser is used for surgical and nonsurgical periodontal therapies including root bio modification, bacterial decline and decontamination of infected implant surface, and removal of the pocket epithelium.Waterlase® and Periowave™ systems are recent devices that have further revolutionized the laser technology for its favorable clinical applications; however, the procedural cost with the laser device constitutes an obstacle for its routine application. Keywords: laser, biomodulation, fluorencence, LANAP

The number of intracorneal ring segments in asymmetric and central cones

Background To compare the results of single versus double intracorneal ring segment (ICRS) (KeraRing) implantation in keratoconus with respect to different cone locations. Methods Twenty-two eyes of 18 patients with totally asymmetric cones (20–80% or 0–100% distribution along steep axis) were implanted with single ICRS (Group 1), 38 eyes of 32 patients with central or partially asymmetric cones (50–50% or 40–60% distribution along steep axis) were implanted with double ICRS (Group 2), at a depth of 80% of the site of implantation, in channels created with femtosecond laser device. All patients had uncorrected and corrected distance visual acuities (UDVA and CDVA, respectively) of ≤ 0.3 Snellen lines. Results In both groups, patients had median UDVA and CDVA gain of 3 Snellen lines (P > 0.05). Postoperative improvement in indices of vertical asymmetry and height decentration in Group 1; simulated keratometry, corneal astigmatism and anterior corneal asphericity values in Group 2 were greater (P < 0.05). A total of 10 eyes (45.5%) in Group 1 were recommended double ring implantation by the manufacturer’s nomogram, but underwent single ICRS implantation and achieved visual, refractive, tomographic outcomes comparable to that in Group 2, although corneal cylindrical correction was less and final topographic astigmatism was greater. Conclusion Double ICRS implantation seems to be superior in terms of keratometry, corneal astigmatism and anterior corneal asphericity improvement. Single ICRS implantation in totally asymmetric cones seems to provide satisfactory visual, refractive and tomographic results, similar to double ICRS implantation in central and partially asymmetric cones, by inducing central shift of the cone.

Performance of open-path GasFinder3 devices for CH₄ concentration measurements close to ambient levels

Open-path measurements of methane (CH4) with the use of GasFinder systems (Boreal Laser Inc, Edmonton Canada) have been frequently used for emission estimation with the inverse dispersion method (IDM), particularly from agricultural sources. It is common to many IDM applications that the concentration enhancement related to CH4 sources is small, typically between 0.05 and 0.5 ppm, and accurate measurements of CH4 concentrations are needed at concentrations close to ambient levels. The GasFinder3-OP (GF3) device for open-path CH4 measurements is the latest version of the commercial GasFinder systems by Boreal Laser Inc. We investigated the uncertainty of six GF3 devices from side-by-side intercomparison measurements and comparisons to a closed-path quantum cascade laser device. The comparisons were made at near-ambient levels of CH4 (85 % of measurements below 2.5 ppm) with occasional phases of elevated concentrations (max. 8.3 ppm). Relative biases as high as 8.3 % were found, and a precision for half-hourly data between 2.1 and 10.6 ppm-m (half width of the 95 % confidence interval) was estimated. These results deviate from the respective manufacturer specifications of 2 % and 0.5 ppm-m. Intercalibration of the GF3 devices by linear regression to remove measurement bias was shown to be of limited value due to drifts and step changes in the recorded GF3 concentrations.

Detect caterpillar, grasshopper, aphid and simulation program for neutralizing them by laser

The protection of crops from pests is relevant for any cultivated crop. But modern methods of pest control by pesticides carry many dangers for humans. Therefore, research into the development of safe and effective pest control methods is promising. This manuscript presents a new method of pest control. We used neural networks for pest detection and developed a powerful laser device (5 W) for their neutralization. In the manuscript methods of processing images with pests to extract the most useful feature are described in detail. Using the following pets as an example: aphids, grasshopper, cabbage caterpillar, we analyzed various neural network models and selected the optimal models and characteristics for each insect. In the paper the principle of operation of the developed laser device is described in detail. We created the program to search a pest in the video stream calculation of their coordinates and transmission data with coordinates to the device with the laser.