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At least 73 records · Page 4Linked to original sources
PubMed2005

Bioptic telescopes meet the needs of drivers with moderate visual acuity loss.

PURPOSE: Visually impaired people are permitted to use bioptic telescopes for driving in many states in the United States. However, it has been suggested that the telescope is used only to meet the visual acuity criteria for licensure. In this study, a survey was used to establish the extent to which bioptic telescopes are used by and meet the driving needs of people with moderately reduced visual acuity. METHODS: A cross-sectional survey of a convenience sample of 58 bioptic drivers was administered by telephone interview. Bioptic telescope usage patterns were quantified with questions designed specifically for the study. Driving patterns were quantified by use of the Driving Habits Questionnaire. Subjects were recruited from four sources across the United States to ensure a range of bioptic training and driving experience. RESULTS: The majority (74%) rated the bioptic telescope as very helpful, and almost all (90%) would continue to use it for driving, even if it were not required for driving licensure; however, only 62% reported always wearing the bioptic when driving. Subjects had relatively unrestricted driving habits, driving a mean of 222 +/- 211 miles per week, and 85% aged < or =65 years drove to work. With the exception of driving in rain, in bright sunlight, and at night, there was little difficulty with driving in a variety of situations, and levels of driving avoidance due to vision impairment were low (<10%). CONCLUSIONS: The bioptic telescope met the (self-reported) driving needs of the majority of visually impaired drivers in this survey and was found to be a useful aid for tasks requiring resolution of detail.

Adolescent↗
PubMed1993

Stroboscopic videolaryngoscopy: a comparison of fiberscopic and telescopic documentation.

The clinical value of stroboscopic videolaryngoscopy (SVL) for the evaluation of laryngeal disorders has been emphasized. Some investigators advocate the use of a flexible fiberscope, while others recommend the use of a rigid telescope for SVL. In order to determine which procedure is more useful for clinical diagnosis, the senior author (E.Y.) performed both fiberscopic and telescopic SVL on 120 consecutive patients who complained of hoarseness. Equipment used included the Olympus ENF-P3 fiberscope, the Nagashima SFT-1 rigid telescope, the Nagashima LS-3A laryngostroboscope, and color video cameras. Our study indicated that stroboscopic images produced by telescopic SVL were superior to those from fiberscopic SVL in the majority of cases. The purpose of this paper is to compare fiberscopic and telescopic SVL, to evaluate the advantages and disadvantages of fiberscopic and telescopic SVL, and to present the authors' recommendations.

Adult↗
PubMed1997

Telescopic laryngeal and pharyngeal surgery.

Surgery of the hypopharynx and larynx has traditionally been performed with either direct, unaided vision or the operating microscope. We proposed to extend the surgical capability provided by angled Hopkins telescopes to the larynx and hypopharynx. Forty-eight cases in which rigid telescopes were employed primarily for intervention were reviewed. We found significant advantages of the telescopic system when performing procedures on surfaces that were not 90 degrees from the observer, such as the walls of the hypopharynx, the petiole of the epiglottis, the ventricle, and the posterior commissure. Both 30 degree and 70 degree telescopes were found useful, but required complementary instruments. The potassium titanyl phosphate laser's flexible fiber provided a distinct advantage in resecting lesions that presented on vertical surfaces. Telescopes also permitted the use of large instruments designed for intraperitoneal and intrathoracic surgery that blocked the view of the operating microscope. Telescopic pharyngeal and laryngeal visualization allowed surgical procedures complementary to more traditional forms of endoscopic surgery.

Adolescent↗
PubMed1987

Telescopic video-otoscopy using a compact home video color camera.

Our method of telescopic video-otoscopy using a telescope (Hopkins) and a compact home video camera is presented. Telescopic video-otoscopy is a most effective method of demonstrating and documenting the anatomy and pathology of the tympanic membrane, ear canal, and mastoid cavity. It is of considerable value for teaching, patient counseling, and making a permanent record. It obtains instantaneously a video print-out either in black-and-white or in color of video images of telescopic otoscopy. A simple and economical method of telescopic pneumatic otoscopy (pneumatic teleotoscopy) is also described. Telescopic video otoscopy combined with the use of a video printer is a useful addition to the clinical practice of otology.

Data Display↗
PubMed2002

Characterization of the supermirror hard-x-ray telescope for the InFOCmuS balloon experiment.

A hard-x-ray telescope is successfully produced for balloon observations by making use of depth-graded multilayers, or so-called supermirrors, with platinum-carbon (Pt/C) layer pairs. It consists of four quadrant units assembled in an optical configuration with a diameter of 40 cm and a focal length of 8 m. Each quadrant is made of 510 pieces of coaxially and confocally aligned supermirrors that significantly enhance the sensitivity in an energy range of 20-40 keV. The configuration of the telescope is similar to the x-ray telescope onboard Astro-E, but with a longer focal length. The reflectivity of supermirrors is of the order of 40% in the energy range concerned at a grazing angle of 0.2 deg. The effective area of a fully assembled telescope is 50 cm2 at 30 keV. The angular resolution is 2.37 arc min at half-power diameter 8.0 keV. The field of view is 12.6 arc min in the hard-x-ray region, depending somewhat on x-ray energies. We discuss these characteristics, taking into account the figure errors of reflectors and their optical alignment in the telescope assembly. This hard-x-ray telescope is unanimously afforded in the International Focusing Optics Collaboration for muCrab Sensitivity balloon experiment.

Journal Article↗
PubMed2004

Optical phased array configuration for an extremely large telescope.

Extremely large telescopes are currently under consideration by several groups in several countries. Extrapolation of current technology up to 30 m indicates a cost of over dollars 1 billion. Innovative concepts are being explored to find significant cost reductions. We explore the concept of an Optical Phased Array (OPA) telescope. Each element of the OPA is a separate Cassegrain telescope. Collimated beams from the array are sent via an associated set of delay lines to a central beam combiner. This array of small telescope elements offers the possibility of starting with a low-cost array of a few rings of elements, adding structure and additional Cass elements until the desired diameter telescope is attained. We address the salient features of such an extremely large telescope and cost elements relative to more conventional options.

Journal Article↗
PubMed2004

Adaptive-optics performance of Antarctic telescopes.

The performance of natural guide star adaptive-optics systems for telescopes located on the Antarctic plateau is evaluated and compared with adaptive-optics systems operated with the characteristic mid-latitude atmosphere found at Mauna Kea. A 2-m telescope with tip-tilt correction and an 8-m telescope equipped with a high-order adaptive-optics system are considered. Because of the large isoplanatic angle of the South Pole atmosphere, the anisoplanatic error associated with an adaptive-optics correction is negligible, and the achievable resolution is determined only by the fitting error associated with the number of corrected wave-front modes, which depends on the number of actuators on the deformable mirror. The usable field of view of an adaptive-optics equipped Antarctic telescope is thus orders of magnitude larger than for a similar telescope located at a mid-latitude site; this large field of view obviates the necessity for multiconjugate adaptive-optics systems that use multiple laser guide stars. These results, combined with the low infrared sky backgrounds, indicate that the Antarctic plateau is the best site on Earth at which to perform high-resolution imaging with large telescopes, either over large fields of view or with appreciable sky coverage. Preliminary site-testing results obtained recently from the Dome Concordia station indicate that this site is far superior to even the South Pole.

Journal Article↗
PubMed2006

Wide-field Fizeau imaging telescope: experimental results.

A nine-aperture, wide-field Fizeau imaging telescope has been built at the Lockheed-Martin Advanced Technology Center. The telescope consists of nine, 125 mm diameter collector telescopes coherently phased and combined to form a diffraction-limited image with a resolution that is consistent with the 610 mm diameter of the telescope. The phased field of view of the array is 1 murad. The measured rms wavefront error is 0.08 waves rms at 635 nm. The telescope is actively controlled to correct for tilt and phasing errors. The control sensing technique is the method known as phase diversity, which extracts wavefront information from a pair of focused and defocused images. The optical design of the telescope and typical performance results are described.

Journal Article↗
PubMedDate not supplied

Measuring the effectiveness of bioptic telescopes for persons with central vision loss.

PURPOSE: 1) To evaluate a vision rehabilitation program aimed at training persons with central vision loss to use a bioptic telescope for improving life skills, including driving and 2) to compare the outcomes of subjects who are given bioptic telescopes and training, with subjects who are prescribed telescopic lenses without training. METHODS: Twenty-five subjects ranging in age from 16 to 78 years were included in the study. Each subject was randomized to one of three groups: Group 1 received bioptic telescopes and training during the first approximately 3-month-long period of the approximately 6-month-long study; Group 2 received lenses and training during the second approximately 3-month-long period of the study; and Group 3 received the lenses for approximately 3 months without any training. An assessment battery consisting of clinical vision tests, functional tasks evaluated by an orientation and mobility specialist, driving skills evaluated by a kinesiotherapist specializing in driver's education, and psychophysical measures was administered to Groups 1 and 2 at baseline, and at approximately 3 and 6 months, and to Group 3 at baseline and at approximately 3 months. The tasks were categorized into 6 major functional categories: Recognition, Mobility, Peripheral Identification, Scanning, Tracking, and Visual Memory. Training consisted of 5 weeks of laboratory-based training focusing on skills within these 6 categories, and 8 weeks of on-road driving training. RESULTS: There was significant improvement in all task categories with use of the telescopes. There was improvement in all task groups with training, though a significant difference between the trained and untrained groups existed only in the Recognition, Peripheral Identification, and Scanning Categories, but not in Mobility, Tracking, or Visual Memory. When the tasks involving driving-related skills were analyzed separately, training also had a significant effect. CONCLUSION: There was significant improvement in visual skills with the use of a bioptic telescope. This improvement was greater with training in the use of the lenses in a number of visual skills categories including driving-related skills.

Adolescent↗
PubMed2000

Deleterious effects of telescoped bronchial anastomosis in single and bilateral lung transplantation.

PURPOSE: To compare complication rates of telescoped versus end-to-end bronchial anastomoses in single and bilateral lung transplantation. METHODS: One hundred and thirty adult lung transplant recipients were evaluated during a seven-year period for the presence of three types of major bronchial anastomotic complications (ischemia, dehiscence, and severe stenosis). Surgical technique, clinical course, and mortality in all patients were reviewed retrospectively. RESULTS: The three major complications, ischemia, dehiscence, and severe stenosis, were observed in 13 (32%), 10 (24%), and 13 (32%), respectively, of 41 telescoped bronchial anastomoses. In contrast, ischemia, dehiscence, and severe stenosis, occurred in 25 (19%), 14 (10%), and 11 (8%) of 135 end-to end anastomoses. These differences were statistically significant for the occurrence of dehiscence and severe stenosis (p=0.0350 and 0.0004, respectively), and not statistically significant for ischemia (p=0.0846). Five (12%) telescoped anastomoses required stent placement as compared with six (4%) end-to end anastomoses (p=0.1313). Early postoperative pneumonia was more common in the telescoped anastomosis group (57%) as compared to the end-to-end group (35%; p=0.0271). There was a trend to shorter survival in the telescoped anastomosis group (mean survival 1172+/-149 d) as compared to the end-to-end group (mean survival 1542+/-126 d), but these differences did not achieve statistical significance (p=0.2400). CONCLUSION: In single and bilateral lung transplants, telescoped anastomoses are associated with a higher incidence of bronchial anastomotic complications and postoperative pneumonia than end-to-end anastomoses.

Adolescent↗
PubMed2003

Rigid pediatric bronchoscopy for bronchial foreign bodies with and without Hopkins telescope.

This study was undertaken to evaluate the merits and demerits of pediatric bronchoscopy with or without the use of Hopkins telescope in 60 pediatric patients at the Otolaryngology clinic of tertiary level teaching hospital. Group-I comprised of 30 children who underwent a non-telescopic procedure, while Group-II included another 30 who went through a telescopic-guided removal using standard forceps. It was observed that due to better illumination, higher optical resolution and magnification owing to the use of the telescope, foreign body removal using this technique was completed with minimal complications. The precision in foreign body removal using telescopic-guided procedure in Group-II cases was immense though the operative time in comparison to the non-telescopic one was found to be statistically higher (P = 0.0019). This group also had a shorter hospital stay. The use of standard forceps in place of optical forceps gave an easier maneuverability through small-sized pediatric bronchoscopes, thereby giving an edge over the latter.

Bronchi↗
PubMedDate not supplied

Implant-supported mandibular overdentures retained with ball or telescopic crown attachments: a 3-year prospective study.

PURPOSE: The aim of the present study was to evaluate implant survival, peri-implant conditions, and prosthodontic maintenance requirements for implant-supported mandibular overdentures in atrophic mandibles retained with ball or resilient telescopic crown attachments during a 3-year period. MATERIALS AND METHODS: Twenty-five patients with edentulous mandibles each received 2 Camlog root-form dental implants in the mandibular interforaminal (canine) region. The denture attachment system was chosen randomly; 13 patients received ball attachments and 12 patients received resilient telescopic crowns. Implant survival, implant mobility (Periotest values), and peri-implant conditions such as bone resorption, pocket depth, Plaque Index, Gingiva Index, Bleeding Index, and Calculus Index values were assessed for each implant. In addition, detailed prosthodontic maintenance was evaluated during the follow-up period and the 2 retention modalities were compared. RESULTS: There were no differences in implant survival, implant mobility (Periotest values), and peri-implant conditions between the 2 retention modalities. During the 3-year period significantly more complications/interventions for maintenance purposes were registered in the ball group (62 interventions) than in the telescopic crown group (26 interventions; P < .01). CONCLUSION: The results indicate that both ball attachments and resilient telescopic crowns used on isolated implants in the edentulous mandible are viable treatment options. Implant success and peri-implant conditions did not differ between ball attachments and telescopic crowns used as retention modalities for implant overdentures, but the frequency of technical complications was significantly higher with ball attachments than with resilient telescopic crowns.

Crowns↗
PubMedDate not supplied

[Principles of making of external telescope crown].

The functioning of telescope crowns consists of pulling on the external crown by telescope principle on the internal crown due to which a friction is caused, which has a decisive role in retention of each telescope restoration. In order to achieve the greatest friction power of each telescope crown, it is indispensable to make every internal telescope crown in a parallelometer and on milling principle. The external crown may be made by applying several laboratory procedures. By analyzing the friction power, it was concluded that the most proper way for making of external telescope was the principle of "doubler" model of refractory material, while the other methods of making gave poor results.

Crowns↗
PubMed1982

Removal of bronchial foreign bodies in children. Use of a new Minioptical telescope.

New optical telescopes have been introduced for pediatric bronchoscopy and removal of foreign bodies in the bronchi. One is flexible telescope (diameter, 1.8 mm). The other is a rigid telescope (diameter, 1.6 mm). Each contains both image and light channels. Each telescope is easily inserted into the side port of the conventional ventilating bronchoscope. Advantages of using these optical telescopes are magnification of image and achievement of an unobstructed view during manipulation with forceps.

Bronchoscopy↗
PubMed1986

Telescopic videorhinoscopy: a useful addition to the clinical practice of rhinology.

Telescopic videorhinoscopy using a rigid telescope and a color video camera is an effective method of demonstrating and documenting the anatomy and pathology of the nose. Its chief value is in making an accurate diagnosis. It is also an excellent method of teaching endoscopic surgery of the nose and sinuses. The authors present a useful method of telescopic videography of intranasal structures using Hopkins rigid telescopes and a reasonably priced video home system color camera. Telescopic videorhinoscopy is a useful addition to the daily practice and teaching of rhinology.

Endoscopes↗
PubMed1980

Microvascular anastomoses: a comparison of the end-to-end and the telescoped techniques in rats.

The end-to-end anastomotic technique and the telescoped anastomotic technique were compared in a paired experimental study of 200 primarily patent anastomoses in the femoral arteries and veins of rats. It was found that the arterial telescoped anastomosis was faster and simpler to perform and had a significantly lower frequency of late thrombotic deposition (13%) than the arterial end-to-end anastomosis (41%), although the patency rates at 1 week were equal (88%). Aneurysms at the site of the anastomosis were not observed in the arterial telescoped anastomoses, while initial stages of probable aneurysms were observed in 24% of the arterial end-to-end anastomoses. The venous telescoped anastomoses were also less time-consuming and simpler to construct. Although equal patency rates at 1 week were obtained (84%-88%), the venous telescoped anastomoses displayed a significantly more pronounced incidence of thrombotic deposition at the site of the anastomosis.

Anastomosis, Surgical↗
PubMed2000

Tooth-supported telescopic prostheses in compromised dentitions: a clinical report.

This article describes indications for treatment with telescopic restorations on patients with periodontally and endodontically compromised dentitions that require splinting, with special emphasis on treatment that restores the entire dental arch. Stabilization of compromised teeth with fixed splinted restorations is usually inadvisable because of the risk factors involved, such as eventual localized abutment failure. Detachable telescopic prostheses may be preferred as a near equivalent or substitute because they can be detached and repaired without reconstruction of the entire restoration. Retentive and splinting properties of detachable telescopic restorations can be as effective as FPDs. Inner telescopic copings can be cemented as individual crowns to facilitate the procedure. Telescopic restorations can be retrieved by the patient for cleaning and easy access to the entire marginal periodontal circumference of the abutments. This promotes effective home care and oral hygiene. In addition, principles of design and indications, as well as technical and clinical factors, were discussed.

Aged↗
PubMed2005

Telescoping of drinking-related behaviors: gender, racial/ethnic, and age comparisons.

OBJECTIVE: To examine demographic differences in alcohol telescoping-the rate of self-reported movement from regular alcohol consumption to the onset of regular heavy drinking-as well as differences in ages of initiation of regular alcohol use and alcohol use to intoxication. METHOD: The present study compared the retrospective reports of 2037 clients (1252 males, 785 females) enrolled in substance user treatment facilities around the country in 1998 and 1999. RESULTS: Overall, the findings support previous research, indicating that women generally move more rapidly than men from initiation of regular alcohol use to problem use (telescoping). The findings also indicate that African-Americans generally begin regular alcohol use later than their Anglo counterparts and move more rapidly from initiation of regular alcohol use to problem use (telescoping). Examining the sample by older vs. younger age groups demonstrates that gender and racial/ethnic differences in the age of initiation of regular alcohol use and in telescoping may be limited by age group, as these patterns appear in the older but not the younger cohort. CONCLUSIONS: These findings suggest that self-reported regular alcohol use, alcohol abuse, and telescoping differences vary dramatically by gender, race/ethnicity, and age cohort. Furthermore, the pattern of findings suggests that these differences are more likely the result of sociocultural than biological differences between the groups under study.

Adult↗