Small-Incision new generation implantable miniature telescope surgical technique and patient outcomes.

BACKGROUND: Various ocular implants were suggested as a means of enhancing vision in patients with advanced age related macular degeneration. Recently, a new generation of implantable telescopes has been released. The purpose of this study is to report the surgical technique of implantation along with patient outcomes. METHODS: This work focuses on the surgical technique. Crucial surgical steps are carefully reported along with discussion on main drawbacks and limitations. RESULTS: This approach uses a preloaded delivery system with improved features and requires a smaller incision. First patient outcomes are also reported. CONCLUSIONS: Surgical steps to implant this preloaded intraocular telescope are easier than previous versions, however this remains a complex procedure. Initial patient functional outcomes look promising.

Bessel light beam for a surgical laser focusing telescope-a novel approach.

As the demand for CO[Formula: see text] laser surgeries continues to grow, the quality of their main instrument, the laser micromanipulator, becomes increasingly important. However, in many surgery systems, a large ratio of the laser power is wasted due to the reflection from the mirror of a telescopic system, like a Cassegrain telescope, back to the laser side, which not only decreases the system's efficiency but can also damage the system itself. In this article, we introduce a new design of the micromanipulator telescope for CO[Formula: see text] laser surgery, which employs a Bessel beam to improve the system efficiency. As in the propagation of a Bessel beam, the power of the light beam can be transferred from the center to a ring shape, the whole power reflected from the first mirror can reach the second mirror and no power goes back to the second mirror hole. The micromanipulator telescope design and optimization are carried out using Zemax Optics Studio, and the integration of the Bessel beam into the system is implemented using MATLAB. Our simulation results show that by applying the appropriate Bessel beam, the system efficiency can reach more than 96%, and the normalized peak irradiance can increase by 40 to 73% for various working distances. In addition to increasing the system efficiency and normalized peak irradiance, resulting in a sharper surgical blade, the use of the Bessel beam enhances the depth of focus, making the system less sensitive to depth misalignment.

Reflective multi-immersion microscope objectives inspired by the Schmidt telescope.

Imaging large, cleared samples requires microscope objectives that combine a large field of view (FOV) with a long working distance (WD) and a high numerical aperture (NA). Ideally, such objectives should be compatible with a wide range of immersion media, which is challenging to achieve with conventional lens-based objective designs. Here we introduce the multi-immersion 'Schmidt objective' consisting of a spherical mirror and an aspherical correction plate as a solution to this problem. We demonstrate that a multi-photon variant of the Schmidt objective is compatible with all homogeneous immersion media and achieves an NA of 1.08 at a refractive index of 1.56, 1.1-mm FOV and 11-mm WD. We highlight its versatility by imaging cleared samples in various media ranging from air and water to benzyl alcohol/benzyl benzoate, dibenzyl ether and ethyl cinnamate and by imaging of neuronal activity in larval zebrafish in vivo. In principle, the concept can be extended to any imaging modality, including wide-field, confocal and light-sheet microscopy.

Auge y declive de la tecnología española de instrumentos ópticos: el telescopio del Instituto de Óptica Daza de Valdés (1940-1970) / Rise and decline of spanish optical instrument technology: the telescope of the Institute of Optics Daza de Valdés (1940-1970)

El desarrollo científico-tecnológico de instrumentos ópticos en España tuvo una época de florecimiento en la década de los cuarenta y cincuenta del siglo XX. Esto fue debido al impulso de, primero, la Sección de Óptica del Instituto de Física Alonso de Santa Cruz, y, posteriormente, del Instituto de Óptica Daza de Valdés, fundado en 1946; ambas instituciones pertenecientes al Consejo Superior de Investigaciones Científicas. Sin embargo, la década de los sesenta supuso un declive de las capacidades y potencialidades adquiridas durante el periodo anterior. La historia de un telescopio, de tipo Maksutov, cuyo diseño y fabricación se realizaron en el Instituto de Óptica, nos sirve de hilo conductor para explicar el auge y declive de la óptica instrumental en España desde los años cuarenta a los setenta. Analizamos los factores involucrados, tanto internos (científicos y tecnológicos), como externos (condicionantes políticos y económicos) que determinaron este singular desarrollo que acabaría convirtiendo a la óptica instrumental en una de las áreas más relevantes en el panorama científico-tecnológico del primer franquismo.(AU)

The scientific-technological development of optical instruments in Spain had a flourishing period in the 1940s and 1950s. This was due to the impulse of, first, the Optics Section of the Institute of Physics Alonso de Santa Cruz, and later the Institute of Optics Daza de Valdés, founded in 1946; both institutions belonging to the Spanish National Research Council. However, during the 1960s, the capabilities and potential acquired during the previous period began to decline. The history of a Maksutov-type telescope, whose design and manufacture were carried out at the Institute of Optics, serves as a guiding thread to explain the rise and fall of optical instrumentation in Spain from the 40s up to the 70s. We analyze the factors involved, both internal (scientific and technological) and external (political and economic conditioning factors) which determined this singular development that would eventually turn optical instrumentation into one of the most relevant areas in the scientific-technological panorama of Early Francoism.(AU)

[VITOM 3D exoscopic system compared to microsurgical technique in spinal surgery]. / Rezul'taty ispol'zovaniya 3D-ekzoskopii VITOM v sravnenii s mikrokhirurgicheskoi tekhnikoi v spinal'noi khirurgii.

3D exoscopy based on Video Telescope Operating Monitor (VITOM) technology provides good visualization quality and portability. There are few data on comparison of extracorporeal telescoping with microsurgical techniques in spinal surgery. OBJECTIVE: To compare the effectiveness of VITOM 3D exoscopy and microsurgical techniques in spinal surgery. MATERIAL AND METHODS: A prospective study included 80 patients (54 men and 26 women). Two groups were distinguished: group 1 (ES, n=40) - VITOM 3D exoscopy, group 2 (SM, n=40) - Pentero 900 surgical microscope. We analyzed surgery time, postoperative rehabilitation, hospital-stay and complications. ES and microsurgical technique were compared using the questionnaire by Takahashi S. and rapid upper limb assessment (RULA). RESULTS: Conventional microsurgical technique was characterized by less surgery time (p<0.05) and morbidity (p=0.02). Postoperative rehabilitation and hospital-stay were similar (p=0.26 and p=0.39, respectively). Image quality in ES was comparable to microsurgical technique in shallow accesses and manipulations perpendicular to skin incision. Availability of neurosurgical instruments at different depths of the wound channel was comparable in both groups. The limitation of ES was length of skin incision, depth of the wound and its visualization at certain angle. These features required expansion of surgical approach or conversion of intervention. In general, surgeons rated intraoperative posture comfort as comparable in both groups that was consistent with the RULA scale. CONCLUSION: VITOM 3D exoscopy is an alternative to traditional microscopy and more ergonomically beneficial in spinal surgery in case of manipulations perpendicular to skin incision and shallow wide accesses. There are several important limitations of this device including difficult manipulations in narrow deep wounds and visualization under certain angle.

An improved camera model for oblique-viewing laparoscopes: high reprojection accuracy independent of telescope rotation.

Objective. Oblique-viewing laparoscopes are popular in laparoscopic surgeries where the target anatomy is located in narrow areas. Their viewing direction can be shifted by telescope rotation without changing the laparoscope pose. This rotation also changes laparoscope camera parameters that are estimated by camera calibration to be able to reproject an anatomical model onto the laparoscopic view, creating augmented reality (AR). The aim of this study was to develop a camera model that accounts for these changes, achieving high reprojection accuracy for any telescope rotation.Approach. Camera parameters were acquired by calibrations encompassing a wide telescope rotation range. For those parameters showing periodic changes upon rotation, interpolation models were created and used to establish an updatable camera model. With this model, corner points of a tracked checkerboard were reprojected onto the checkerboard laparoscopic images, at random rotation angles. Root-mean-square reprojection errors (RMSEs) were calculated between the reprojected and imaged corner points.Main results. Reprojection RMSEs were low and approximately independent on telescope rotation angle, over a wide rotation range of 320°. The mean reprojection RMSE was 2.8±0.7 pixels for a conventional laparoscope and 3.6±0.7 pixels for a chip-on-the-tip (COTT) laparoscope, corresponding to 0.3±0.1 mm and 0.4±0.1 mm in world coordinates respectively. Worst-case reprojection errors were about 9 pixels (0.8 mm) for both laparoscopes.Significance. The camera model developed in this study improves on existing models for oblique-viewing laparoscopes because it provides high reprojection accuracy independent of the telescope rotation angle and is applicable for conventional and chip-on-a-tip oblique-viewing laparoscopes. The work presented here is an important step towards creating accurate AR in image-guided interventions where oblique-viewing laparoscopes are used while simultaneously providing the surgeon the flexibility to rotate the telescope to any desired rotation angle.Acronyms. CC: camera coordinates; CCToolbox: camera calibration toolbox; COTT: chip-on-the-tip; CS: camera sensor; DD: decentering distortion; FL: focal length; OTS: optical tracking system; PP: principal point; RD: radial distortion; SI: supplementary information;tHE:hand-eye translation component.

Video telescope operating monitor-assisted surgery is equivalent to conventional surgery in treatment of cervical intervertebral disc herniation in dogs.

OBJECTIVE: To compare the use of the video telescope operating monitor (VITOM) and use of a conventional unassisted surgical method for treatment of cervical intervertebral disc herniation in dogs. ANIMALS: 39 dogs with cervical intervertebral disc disease. METHODS: Prospective study. Dogs were prospectively nonrandomly assigned to either the VITOM (n = 19) or conventional surgery (20) group depending on VITOM system availability. Signalment and preoperative neurologic status were recorded for all dogs. Preoperative and postoperative CT myelography was performed to compare intervertebral space location, spinal cord dimensions at the decompression level, ventral slot dimensions, and residual disc material. Surgical complications and postoperative neurologic outcomes were recorded. Data were compared between the 2 groups using fixed-effects or mixed-effects models to consider double reading of CT myelography images. RESULTS: No significant differences were noted between the 2 groups regarding the decompression ratio (P = .85), vertebral length body ratio (P = .13), ventral slot width ratio (P = .39), residual disc material (P = .30), and sinus bleeding (P = .12). No significant differences were found between the 2 groups regarding postoperative neurologic grade (P = .17). CLINICAL RELEVANCE: VITOM-assisted ventral slot decompression is equivalent to conventional surgery in treatment of cervical intervertebral disc herniation in dogs. The use of VITOM remains a good alternative to the conventional surgical method.

Precise and Efficient Pointing Control of a 2.5-m-Wide Field Survey Telescope Using ADRC and Nonlinear Disturbance Observer.

Linear active disturbance rejection control (LADRC) has been widely used to improve the tracking accuracy and anti-disturbance performance of telescope servo control under disturbances. However, the linear extended state observer (LESO) is sensitive to noise, and its bandwidth is limited by the resonant frequency of the telescope. To enhance the LARDC's ability to attenuate disturbances, a novel cascade anti-disturbance structure (NCADS) with LADRC on the outer speed loop and a nonlinear disturbance observer (NDOB) on the inner current loop is proposed. The NDOB compensates for the dominant disturbance through feedforwarding the q-axis current reference, and the LESO compensates for the residual disturbance on the outer speed loop. First, the NCADS is introduced in a three-closed-loop control framework of PMSM. Then, the design method of the controller for each loop and the NDOB are presented, the parameter-tuning method based on bandwidth is demonstrated, and the convergence of the NDOB is proved. Furthermore, to improve the searching and tracking efficiency of wide-field survey telescopes, the nonlinear tracking differentiator (NTD) was modified to plan the transition process of the position loop, which only needs to set the maximum speed and acceleration of the telescope. Finally, simulations and experiments were performed on a 2.5-m-wide field survey telescope. The experimental results verify that the proposed NCADS method has a better anti-disturbance performance and higher tracking precision than the conventional method, and the improved NTD method does not need to tune parameters and achieved a fast and smooth transition process of the position loop.

Charge-Sign Dependent Cosmic-Ray Modulation Observed with the Calorimetric Electron Telescope on the International Space Station.

We present the observation of a charge-sign dependent solar modulation of galactic cosmic rays (GCRs) with the Calorimetric Electron Telescope onboard the International Space Station over 6 yr, corresponding to the positive polarity of the solar magnetic field. The observed variation of proton count rate is consistent with the neutron monitor count rate, validating our methods for determining the proton count rate. It is observed by the Calorimetric Electron Telescope that both GCR electron and proton count rates at the same average rigidity vary in anticorrelation with the tilt angle of the heliospheric current sheet, while the amplitude of the variation is significantly larger in the electron count rate than in the proton count rate. We show that this observed charge-sign dependence is reproduced by a numerical "drift model" of the GCR transport in the heliosphere. This is a clear signature of the drift effect on the long-term solar modulation observed with a single detector.

New evidence of the Hoyle-like structure in 16O.

An experiment of 12C(16O,16O → 4α)12C was performed at a beam energy of 96 MeV. A large number of 4-α events were recorded in coincidence and with full particle identification (PID). This was made possible by employing a series of silicon-strip-based telescopes that provided excellent position and energy resolutions. Four narrow resonances just above the 15.1 MeV state were firmly identified in the α + 12C(7.65 MeV; Hoyle state) decay channel. Combined with the theoretical predictions, these resonant states provide new evidence for the predicted possible Hoyle-like structure in 16O above the 4-α separation threshold. Some very high-lying 4-α resonant states have also been observed and need to be further investigated.

How Digital Technologies Enhance Telescopic and Conical Clinical Case Workflows.

Telescopic and conical dental solutions for tooth-borne, implant-borne, and combination tooth/implant-borne removable dental prosthetics have a long and rich history. Traditionally, these restorations have been based on analog techniques. The integration of digital technologies, however, has had a profound impact on these solutions in numerous ways, helping to facilitate efficient fabrication of many technical and clinical facets of these dental prosthetics. This article examines how digital technologies impact telescopic and conical clinical case workflows and technical protocols. It discusses such aspects as intraoral scanning, photogrammetry, primary and secondary telescopes and cones, tertiary structures, and temporary restorations.

Detection system of the lobster eye telescope with large field of view.

The lobster eye telescope is promising for large-field x ray imaging in astronomy. The special structure of the lobster eye system makes the focal plane a sphere, resulting in detector defocus when the field is large. In this study, we established a model based on the principle of lobster eye imaging and simulated the imaging at different image distances. The results reveal the relationship between the defocus and position accuracy and angular resolution. To ensure the optical performance of the large field lobster eye telescope, we propose a detection system design method using multiple detectors stitched together to form a spherical-like surface and apply it to the development of the Einstein Probe/wide-field x ray telescope (EP/WXT) submodule. About 70% of the detection area is out of focus within 0.5 mm. The scanning image of the integrated WXT submodule shows good uniformity of the point spread function (PSF) for various incident angles, and the effect of defocus on imaging is acceptable.