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Toshio Chiba - One of the best experts on this subject based on the ideXlab platform.
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The development of a composite-type optical Fiberscope system for fetoscopic laser photocoagulation of chorionic plate anastomosing vessels (FLPC)
Minimally invasive therapy & allied technologies : MITAT : official journal of the Society for Minimally Invasive Therapy, 2010Co-Authors: Kiyoshi Oka, Takeshi Seki, Akihiro Naganawa, Hiromasa Yamashita, Keri Kim, Toshio ChibaAbstract:We developed a new laser device using a composite-type optical Fiberscope for laser surgery to treat twin-twin transfusion syndrome. The composite-type optical Fiberscope (2.2 mm in external diameter) consists of a centrally located single fiber for laser treatment (0.1 mm in diameter) and its surrounding fibers for diagnosis. This Fiberscope enables transmission of 40-W Yb fiber laser. The Yb fiber laser can be focused to 10mm focal length using two lenses on the tip of the Fiberscope. In this research, we emitted the laser to in vivo porcine mesenteric vessel with blood flow both with an established laser fiber of 0.6-mm diameter (0.6-mm normal fiber) and with our composite-type optical Fiberscope to compare the cautery performance of those devices. According to the experimental results, the composite-type optical Fiberscope has a cautery efficiency equal to that of a 0.6-mm normal fiber, and it can contract the vein diameter about 35% as compared to the vein diameter before laser irradiation.
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composite type optical Fiberscope for laser surgery for twin to twin transfusion syndrome
international conference on Medical Imaging and Augmented Reality, 2008Co-Authors: Kiyoshi Oka, Akihiro Naganawa, Hiromasa Yamashita, Tetsuya Nakamura, Toshio ChibaAbstract:We present our new laser device for prospective human fetoplacental surgery including that of twin-twin transfusion syndrome. We developed a composite-type optical Fiberscope (2.2-mm in diameter) that enables transmission of 40-W Yb fiber laser light alongside of coaxial fetoscopic images. Using a laser condensing lens on the Fiberscope tip, Yb fiber laser light can be focused 10-mm off. Using porcine liver tissue, despite changes in delivered laser energy, the diameter and depth of cauterized areas remained constant when the liver position agreed with the laser focal point, although the laser output altered the extent of tissue ablation. In conclusion, the performance of the Fiberscope can be well controlled with accurate and efficient ablation of the target tissue. This Yb fiber laser Fiberscope is expected to work much better if mounted on a miniature bending manipulator and if provided with additional functions (real-time distance and blood flow measurements).
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MIAR - Composite-Type Optical Fiberscope for Laser Surgery for Twin-to-Twin Transfusion Syndrome
Lecture Notes in Computer Science, 1Co-Authors: Kiyoshi Oka, Akihiro Naganawa, Hiromasa Yamashita, Tetsuya Nakamura, Toshio ChibaAbstract:We present our new laser device for prospective human fetoplacental surgery including that of twin-twin transfusion syndrome. We developed a composite-type optical Fiberscope (2.2-mm in diameter) that enables transmission of 40-W Yb fiber laser light alongside of coaxial fetoscopic images. Using a laser condensing lens on the Fiberscope tip, Yb fiber laser light can be focused 10-mm off. Using porcine liver tissue, despite changes in delivered laser energy, the diameter and depth of cauterized areas remained constant when the liver position agreed with the laser focal point, although the laser output altered the extent of tissue ablation. In conclusion, the performance of the Fiberscope can be well controlled with accurate and efficient ablation of the target tissue. This Yb fiber laser Fiberscope is expected to work much better if mounted on a miniature bending manipulator and if provided with additional functions (real-time distance and blood flow measurements).
Kiyoshi Oka - One of the best experts on this subject based on the ideXlab platform.
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Design and Preclinical Validation of the Composite-Type Optical Fiberscope for Minimally Invasive Procedures of Intrauterine Disease.
Journal of minimally invasive gynecology, 2015Co-Authors: Hiroshi Shigetomi, Kiyoshi Oka, Takeshi Seki, Hiroshi KobayashiAbstract:Abstract Study Objective Because of the rapid growth of minimally invasive surgical procedures, we developed an ultrathin fiberscopic imaging system for laser surgery that could be an important instrument for clinical use in an office setting. Methods and Main Results A new device, consisting of a custom 1.1-mm diameter flexible Fiberscope and ytterbium laser-supported ablation system (composite-type optical Fiberscope), has been developed to achieve accurate laser irradiation for minimally invasive procedures of intrauterine disease. This system was validated ex vivo with successful laser ablation under observation. This study provides the design, characterization, performance, and preclinical validation of an optimized composite-type optical Fiberscope system. The validation of this Fiberscope for endometrial ablation was performed in 12 hysterectomy samples. The irradiated spot diameter and depth were (mean ± SD) 2.80 ± 0.28 mm and 1.53 ± 0.58 mm, respectively, in the range of 185 to 400 J. The effects of the laser on endometrial tissue depended strongly on the combined effects of the output power density and duration of irradiation. The new device makes it possible to perform accurate ablation, because our technology concentrated on combining the 2 subsystems into a single prototype capable of simultaneously observing both the endometrial lesion and the laser spot on a monitor. Conclusions In conclusion, the feasibility and performance of the composite-type Fiberscope system were demonstrated in preclinical studies.
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A composite-type optical Fiberscope system with hybrid functions of diagnosis and medical treatment
JSAP-OSA Joint Symposia 2014 Abstracts, 2014Co-Authors: Kiyoshi Oka, Takeshi SekiAbstract:A composite-type optical Fiberscope which has furthered technical development in Japan Atomic Energy Agency (JAEA) is a special Fiberscope which can treat both a high energy laser light and image information [1]. This composite type optical Fiberscope was born as a specific tool which is useful for the maintenance technical development in a nuclear fusion reactor and a large-sized nuclear installation [2][3]. This Fiberscope is useful in narrow parts, such as a fuel bundle of reactor internal, and piping of a heat exchanger. Since this technology has high flexibility, at the present, the application to the medical field is under promotion as diagnostic and treatment equipment. In this report, the basic structure of a composite-type optical Fiberscope and the example of the medical application are introduced.
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The development of a composite-type optical Fiberscope system for fetoscopic laser photocoagulation of chorionic plate anastomosing vessels (FLPC)
Minimally invasive therapy & allied technologies : MITAT : official journal of the Society for Minimally Invasive Therapy, 2010Co-Authors: Kiyoshi Oka, Takeshi Seki, Akihiro Naganawa, Hiromasa Yamashita, Keri Kim, Toshio ChibaAbstract:We developed a new laser device using a composite-type optical Fiberscope for laser surgery to treat twin-twin transfusion syndrome. The composite-type optical Fiberscope (2.2 mm in external diameter) consists of a centrally located single fiber for laser treatment (0.1 mm in diameter) and its surrounding fibers for diagnosis. This Fiberscope enables transmission of 40-W Yb fiber laser. The Yb fiber laser can be focused to 10mm focal length using two lenses on the tip of the Fiberscope. In this research, we emitted the laser to in vivo porcine mesenteric vessel with blood flow both with an established laser fiber of 0.6-mm diameter (0.6-mm normal fiber) and with our composite-type optical Fiberscope to compare the cautery performance of those devices. According to the experimental results, the composite-type optical Fiberscope has a cautery efficiency equal to that of a 0.6-mm normal fiber, and it can contract the vein diameter about 35% as compared to the vein diameter before laser irradiation.
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composite type optical Fiberscope for laser surgery for twin to twin transfusion syndrome
international conference on Medical Imaging and Augmented Reality, 2008Co-Authors: Kiyoshi Oka, Akihiro Naganawa, Hiromasa Yamashita, Tetsuya Nakamura, Toshio ChibaAbstract:We present our new laser device for prospective human fetoplacental surgery including that of twin-twin transfusion syndrome. We developed a composite-type optical Fiberscope (2.2-mm in diameter) that enables transmission of 40-W Yb fiber laser light alongside of coaxial fetoscopic images. Using a laser condensing lens on the Fiberscope tip, Yb fiber laser light can be focused 10-mm off. Using porcine liver tissue, despite changes in delivered laser energy, the diameter and depth of cauterized areas remained constant when the liver position agreed with the laser focal point, although the laser output altered the extent of tissue ablation. In conclusion, the performance of the Fiberscope can be well controlled with accurate and efficient ablation of the target tissue. This Yb fiber laser Fiberscope is expected to work much better if mounted on a miniature bending manipulator and if provided with additional functions (real-time distance and blood flow measurements).
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MIAR - Composite-Type Optical Fiberscope for Laser Surgery for Twin-to-Twin Transfusion Syndrome
Lecture Notes in Computer Science, 1Co-Authors: Kiyoshi Oka, Akihiro Naganawa, Hiromasa Yamashita, Tetsuya Nakamura, Toshio ChibaAbstract:We present our new laser device for prospective human fetoplacental surgery including that of twin-twin transfusion syndrome. We developed a composite-type optical Fiberscope (2.2-mm in diameter) that enables transmission of 40-W Yb fiber laser light alongside of coaxial fetoscopic images. Using a laser condensing lens on the Fiberscope tip, Yb fiber laser light can be focused 10-mm off. Using porcine liver tissue, despite changes in delivered laser energy, the diameter and depth of cauterized areas remained constant when the liver position agreed with the laser focal point, although the laser output altered the extent of tissue ablation. In conclusion, the performance of the Fiberscope can be well controlled with accurate and efficient ablation of the target tissue. This Yb fiber laser Fiberscope is expected to work much better if mounted on a miniature bending manipulator and if provided with additional functions (real-time distance and blood flow measurements).
Kazuo Sanada - One of the best experts on this subject based on the ideXlab platform.
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Applied Fiber Optics
2016Co-Authors: Keiji Kaneda, T Ohashi, Takashi Tsumanuma, Kazuo SanadaAbstract:Endoscope for stereoscopic vision is in great demand for medical field to diagnose and treat disease parts of patients more precisely. The authors are convinced that the silica based imagefiber is suitable for making a thinner Fiberscope for streoscopic vision. The structure of the Fiberscope and the quality of transmitted image have been investigated. It has been found that stereognosis depends on the magnification of eyepiece, distance between left and right objective lenses and the image quality between two transmitting systems. On the basis of this results, the ultrathin Fiberscope with silica based imagefibers for stereoscopic vision have been developed. The diameter of Fiberscope is only 2mm with two transmitting systems that consist of two imagefibers with 10000 pixels and lightguide for illumination and objective lenses. This Fiberscope for stereoscopic vision can be used for the micro surgery, such as the laparoscopic surgery and the thoracoscopic surgery required for the thin diameter. 1
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TH][S PAPER i:s ALSO PUBLISHED IN VOLUME 1893 AS PAPER 1893-5. Ultrathin Fiberscope for Stereoscopic Vision
2016Co-Authors: Keiji Kaneda, T Ohashi, Takashi Tsumanuma, Kazuo SanadaAbstract:Endoscope for stereoscopic vision is in great demand for medical field to diagnose and treat disease parts of patients more precisely. The authors are convinced that the silica based imagefiber is suitable for making a thinner Fiberscope for streoscopic vision. The structure of the Fiberscope and. the quality of transmitted image have been investigated. It has been found that siereognosis depends on the magnification of eyepiece, distance between left and right objective lenses and the image quality between two transmitting systems. On the basis of this results, the ultrathin Fiberscope with silica based imagefibers for stereoscopic vision have been developed. The diameter of Fiberscope is only 2mm with two transmitting systems that consist of two imagefibers with 10000 pixels and lightguide for illumination and objective lenses. This Fiberscope for stereoscopic vision can be used for the micro surgery, such as the laparoscopic surgery and the thoracoscopic surgery required for the thin diameter. 1
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Silica-based rod lens for the medical Fiberscope
Biomedical Fiber Optic Instrumentation, 1994Co-Authors: Kenichi Nakatate, Takashi Tsumanuma, Naoki Shamoto, Tateuki Oohashi, Kazuo SanadaAbstract:The ultrathin Fiberscope, in which the outer diameter is under 1.0 mm, has made possible the direct observation of narrow portions within the human body. The Fiberscope mainly consists of the imagefiber, the objective lens, and the illumination fiber, and each advance of these devices has brought the reduction of the scope-diameter. We have investigated the silica based rod lens for the following merits: (1) The Fiberscope can be sterilized by the (gamma) -ray instead of ethylene oxide gas which has the problem of carcinogenicity, because the silica glass has high radiation resistant characteristics. (2) The silica based rod lens can be spliced with the imagefiber without any adhesive agent by using the arc fusion splicing machine. As a result, the reliability of the Fiberscope can be significantly improved. The silica based rod lens with 125 micrometers in diameter was fabricated by drawing from preform rod made by the vapor phase axial deposition method. The characteristics of their images were evaluated by the modulation transfer function method. This paper presents the details of the fabrication technique of the silica based rod lens and its characteristics.
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Ultrathin Fiberscope for stereoscopic vision
Proceedings of SPIE, 1993Co-Authors: Keiji Kaneda, T Ohashi, Takashi Tsumanuma, Kazuo SanadaAbstract:Endoscope for stereoscopic vision is in great demand for medical field to diagnose and treat disease parts of patients more precisely. The authors are convinced that the silica-based imagefiber is suitable for making a thinner Fiberscope for stereoscopic vision and have developed an ultrathin Fiberscope with silica-based imagefibers for stereoscopic vision. The diameter of Fiberscope is only 2 mm with two transmitting systems that consist of two imagefibers with 10000 pixels and lightguide for illumination and objective lenses. This Fiberscope for stereoscopic vision can be used for the microsurgery, such as the laparoscopic surgery and the thoracoscopic surgery required for the thin diameter.
Sameh Fathy El-tamboly - One of the best experts on this subject based on the ideXlab platform.
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Endotracheal intubation: ultrasound-guided versus Fiberscope in patients with cervical spine immobilization
Journal of Anesthesia, 2017Co-Authors: Moustafa Abdelaziz Moustafa, Emad A. Arida, Ola M. Zanaty, Sameh Fathy El-tambolyAbstract:Background Ultrasound has growing applications in airway management during anesthesia. The aim of the present study was to evaluate the feasibility of real-time ultrasound-guided tracheal intubation in patients with cervical spine immobilization relative to Fiberscope-guided tracheal intubation. Patients and methods This randomized controlled study was carried out on 266 adult patients who have a rigid neck collar in place for cervical spine immobilization and were randomly allocated into two equal groups. All patients were subjected to the same anesthetic protocol. After full neuromuscular blockade, neck collar was removed and tracheal intubation was done in the neutral position. In group A, the trachea was intubated guided by a 5–12-MHz linear ultrasound probe attached to a Sonoscape A5 ultrasound machine. In group B, the trachea was intubated by an endotracheal tube mounted over a Fiberscope (Karl Storz, working length 65 cm, distal tip diameter 5.6 mm). Hemodynamic measurements and oxygen saturation were recorded. Tracheal intubation criteria for both groups including duration of the intubation procedure, number of intubation attempts, success rate at each attempt, and the lowest oxygen saturation recorded during tracheal intubation were recorded. Results Ultrasound and Fiberscope achieved comparable time for tracheal intubation (57 ± 12 vs. 55 ± 10 s), respectively. Success rate of tracheal intubation at the first attempt was higher in the Fiberscope group than the ultrasound group, with a P value of 0.032. The overall success rate was not significantly different between the two groups. Conclusions Ultrasound-guided tracheal intubation showed a lower first attempt success rate in patients with cervical spine immobilization compared to Fiberscope-guided tracheal intubation but the overall success rates were comparable. Ultrasound can be an alternative technique for guiding tracheal intubation in patients with cervical spine immobilization. Registry number PACTR201602001476292.
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Endotracheal intubation: ultrasound-guided versus Fiberscope in patients with cervical spine immobilization.
Journal of anesthesia, 2017Co-Authors: Moustafa Abdelaziz Moustafa, Emad A. Arida, Ola M. Zanaty, Sameh Fathy El-tambolyAbstract:Ultrasound has growing applications in airway management during anesthesia. The aim of the present study was to evaluate the feasibility of real-time ultrasound-guided tracheal intubation in patients with cervical spine immobilization relative to Fiberscope-guided tracheal intubation. This randomized controlled study was carried out on 266 adult patients who have a rigid neck collar in place for cervical spine immobilization and were randomly allocated into two equal groups. All patients were subjected to the same anesthetic protocol. After full neuromuscular blockade, neck collar was removed and tracheal intubation was done in the neutral position. In group A, the trachea was intubated guided by a 5–12-MHz linear ultrasound probe attached to a Sonoscape A5 ultrasound machine. In group B, the trachea was intubated by an endotracheal tube mounted over a Fiberscope (Karl Storz, working length 65 cm, distal tip diameter 5.6 mm). Hemodynamic measurements and oxygen saturation were recorded. Tracheal intubation criteria for both groups including duration of the intubation procedure, number of intubation attempts, success rate at each attempt, and the lowest oxygen saturation recorded during tracheal intubation were recorded. Ultrasound and Fiberscope achieved comparable time for tracheal intubation (57 ± 12 vs. 55 ± 10 s), respectively. Success rate of tracheal intubation at the first attempt was higher in the Fiberscope group than the ultrasound group, with a P value of 0.032. The overall success rate was not significantly different between the two groups. Ultrasound-guided tracheal intubation showed a lower first attempt success rate in patients with cervical spine immobilization compared to Fiberscope-guided tracheal intubation but the overall success rates were comparable. Ultrasound can be an alternative technique for guiding tracheal intubation in patients with cervical spine immobilization. PACTR201602001476292.
Koki Shimoji - One of the best experts on this subject based on the ideXlab platform.
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A new approach for observing cerebral cisterns and ventricles via a percutaneous lumbosacral route by using fine, flexible Fiberscopes.
Journal of neurosurgery, 2009Co-Authors: Koki Shimoji, Satoru Fukuda, Mai Ogura, Sanae Gamou, Seki Yunokawa, Hidetoshi Sakamoto, Shigeho MoritaAbstract:Object To establish a new method for the diagnosis of central nervous system diseases, the authors visualized the cerebral cisterns and ventricles via a percutaneous lumbosacral route by using newly developed fine, flexible Fiberscopes. Methods Fine, flexible Fiberscopes, 0.9 and 1.4 mm in diameter, were introduced up to the cerebral cisterns and ventricles through a percutaneous lumbosacral route in awake patients with chronic headache and/or neck pain or those undergoing spinal surgery and in whom MR imaging did not disclose any particular abnormalities in the brain. A lumbosacral subarachnoid puncture was made with a modified method of a continuous epidural block. Results In 25 of 31 patients tested, the cerebellomedullary and/or pontine/interpeduncular cisterns were easily and safely reached, and the brainstem structures were visualized. Advancement of the Fiberscope beyond the spinal level was abandoned in 6 patients with adhesive spinal arachnoiditis, because the Fiberscopes encountered resistance s...
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Observation of spinal canal and cisternae with the newly developed small-diameter, flexible Fiberscopes.
Anesthesiology, 1991Co-Authors: Koki Shimoji, H. Fujioka, Mayumi Onodera, T. Hokari, Satoru Fukuda, Naoshi Fujiwara, Tsuruo HatoriAbstract:Small-diameter (0.5-, 0.9-, and 1.4-mm) flexible Fiberscopes were developed for visual diagnosis of spinal canal diseases. The Fiberscopes were introduced via a Tuohy needle into the subarachnoid and epidural spaces of ten patients with various pain syndromes. Clear visualization of the subarachnoid space was achieved using the Fiberscopes. The epidural space could be visualized only during withdrawal of the Fiberscope. In five cases, the Fiberscope could be advanced up to the level of the cisternae without causing the patient any discomfort. A slight headache and transient fever were noted after the examination in five and two cases, respectively, but no other complications occurred. Interestingly, preexisting pain diminished (two cases) or disappeared (one case) after the myeloscopy in three of five cases in which the myeloscopy revealed aseptic adhesive arachnoiditis. Further studies should be carried out to evaluate the usefulness of this technique.