Analysis of the profile curves of the menisci for the sapphire capillaries and fibers growth by EFG (Stepanov) technique

Rossolenko, S. N.; Курлов, В. Н.; Asrian, A. A.

doi:10.1002/crat.200900068

Cited by 6 publications

(2 citation statements)

References 10 publications

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“…The approaches for growing sapphire shaped crystals, in particular ribbons, with longitudinal capillary channels, are based on the EFG technique, which implies the crystal growth from a melt formed on the top of a capillary die 34–36 . One of the main problems in growing sapphire crystals with capillary channels of small diameter is the possibility of channel collapse due to an increase in Laplace pressure in the melt meniscus with a decrease in the radius of the mean curvature of the meniscus surface (decrease in the channel diameter) and an increase in the meniscus height 48 . To mitigate this challenge, we optimized the growth rates and temperature regimes in the crystallization zone, as well as applied new approaches to the die design and a system for monitoring the crystallization front state.…”

Section: Methodsmentioning

confidence: 99%

Proof of concept for the sapphire scalpel combining tissue dissection and optical diagnosis

et al. 2021

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Objectives: The development of compact diagnostic probes and instruments with an ability to direct access to organs and tissues and integration of these instruments into surgical workflows is an important task of modern physics and medicine. The need for such tools is essential for surgical oncology, where intraoperative visualization and demarcation of tumor margins define further prognosis and survival of patients. In this paper, the possible solution for this intraoperative imaging problem is proposed and its feasibility to detect tumorous tissue is studied experimentally. Methods: For this aim, the sapphire scalpel was developed and fabricated using the edge-defined film-fed growth technique aided by mechanical grinding, polishing, and chemical sharpening of the cutting edge. It possesses optical transparency, mechanical strength, chemical inertness, and thermal resistance alongside the presence of the as-grown hollow capillary channels in its volume for accommodating optical fibers. The rounding of the cutting edge exceeds the same for metal scalpels and can be as small as 110 nm. Thanks to these features, sapphire scalpel combines tissue dissection with light delivering and optical diagnosis. The feasibility for the tumor margin detection was studied, including both gelatin-based tissue phantoms and ex vivo freshly excised specimens of the basal cell carcinoma from humans and the glioma model 101.8 from rats. These tumors are commonly diagnosed either non-invasively or intraoperatively using different modalities of fluorescence spectroscopy and imaging, which makes them ideal candidates for our feasibility test. For this purpose, fiber-based spectroscopic measurements of the backscattered laser radiation and the fluorescence signals were carried out in the visible range. Results: Experimental studies show the feasibility of the proposed sapphire scalpel to provide a 2-mm-resolution of the tumor margins' detection, along with an ability to distinguish the tumor invasion region, which results from analysis of the backscattered optical fields and the endogenous or exogenous fluorescence data. Conclusions: Our findings justified a strong potential of the sapphire scalpel for surgical oncology. However, further research and engineering efforts are required to optimize the sapphire scalpel geometry and the optical diagnosis protocols to meet the requirements of oncosurgery, including diagnosis and resection of neoplasms with different localizations and nosologies.

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Section: Methodsmentioning

confidence: 99%

Proof of concept for the sapphire scalpel combining tissue dissection and optical diagnosis

et al. 2021

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“…4 показана схема выращивания из расплава сапфирового многоканального стержня требуемой геометрии, которую практически невозможно получить механической обработкой из-за высокой твердости сапфира. Сечение кристалла определяется конструкцией формообразователя, при этом размеры кристалла могут варьироваться лишь в узком диапазоне, определяемом формой мениска расплава [63,64]. Для получения стержня переходного сечения основание мениска расплава отрывается от кромок одной части формообразователя, задающего первоначальную форму (все три канала открыты; рис.…”

Section: выращивание из расплава многоканального сапфирового нейрозондаunclassified

Сапфировый Нейрохирургический Зонд Для Аспирации Опухолей Мозга С Демаркацией Границ С Помощью Спектроскопии-=sup=-*-=/Sup=-

Шикунова¹,

Долганова²,

Катыба³

et al. 2019

Журнал Технической Физики

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A contact sapphire neurosurgical probe for the removal of brain tumors with the possibility of intraoperative exogenous fluorescence diagnostics and laser coagulation of adjacent blood vessels has been developed. The geometry of the sapphire neuroprobe has been optimized to increase the sensitivity of fluorescence diagnostics. For this purpose, a series of computational experiments have been performed using the Monte Carlo method. The technique for growing a sapphire shaped crystal with a variable cross section has been developed. Using this technique, a pilot prototype of the sapphire neuroprobe has been manufactured. The sample has been approbated experimentally.

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3D numerical investigation and improvement to the design of the thermal field before seeding in a multi-die edge-defined film-fed growth system for sapphire ribbon crystals

Liu

Geng

et al. 2014

Journal of Crystal Growth

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Analysis of the profile curves of the menisci for the sapphire capillaries and fibers growth by EFG (Stepanov) technique

Cited by 6 publications

References 10 publications

Proof of concept for the sapphire scalpel combining tissue dissection and optical diagnosis

Proof of concept for the sapphire scalpel combining tissue dissection and optical diagnosis

Сапфировый Нейрохирургический Зонд Для Аспирации Опухолей Мозга С Демаркацией Границ С Помощью Спектроскопии-=sup=-*-=/Sup=-

3D numerical investigation and improvement to the design of the thermal field before seeding in a multi-die edge-defined film-fed growth system for sapphire ribbon crystals

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