The Journal of Japan Society for Laser Surgery and Medicine
Online ISSN : 1881-1639
Print ISSN : 0288-6200
ISSN-L : 0288-6200
Volume 1, Issue 1
Displaying 1-50 of 99 articles from this issue
  • Y. Nakajima, M. Yonekawa, T. Tamaki, J. Meguro, A. Kitano, F. Sano, Y. ...
    1980 Volume 1 Issue 1 Pages 1-6
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    Liver resection with the carbon dioxide laser was carried out in mongrel dogs and compared with the other methods of removing liver.
    The group of liver resection with the carbon dioxide laser had earlier recovery of postoperative hepatic function than the other groups, and had only slight histological changes of the liver.
    It is considered that the carbon dioxide laser knife is useful to perform hepatic resection.
    It is the important problem that hemostatic capability was decreased when the radiated field was covered with blood. It is, therefore, important to have the dry field for hemostasis with the laser radiation.
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  • Wataru Ishii, Keizo Kawai, Makoto Tomizawa, Kazuo Matai, Tetsu Wratanu ...
    1980 Volume 1 Issue 1 Pages 7-11
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    The carbon dioxide laser (Medilaser-S having 60w. max. power) was first installed at Jikei Hospital in 1977. Since the time it was used on various operation in general surgery and we have experienced over two hundred cases.
    This study presents the results of laser indication in general surgery by examination of our clinical cases.
    1. Surgery for body surface
    Most of the tumors of the body surface were good indication for laser surgery. Laser irradiation therapy was also effective for debridement of wet wound with infection. 20-25w. focused or defocused laser beam was usually used for vaporization or laser cutting extirpation and the results were all satisfactory.
    2. Surgery for ano-rectal diseases
    Fistula-in-ano was the best indication among the ano-rectal diseases. Radical operation for fistula-in-ano was performed by means of irradiation of 20-25w. focused or defocused laser beam, and pathological tissue of the fistula was completely vaporized without bleeding. Postoperative course was quite smooth under painless condition and the wound healing was satisfactory without keloid formation.
    3. Surgery for hepatectomy
    To the parenchymal organ with a lot of blood supply, laser cutting method is very useful because of its haemo-static effect.
    S cases of hepatectomy were performed by means of laser cutting method, 60w. defocused beam from 2.0mm to 1.0mm in spot diameter was most suitable for laser cutting, and we acknowledged that the most effective procedure was to control blood supply at the root before laser resection and to ligate the blood vessel over 1mm in diameter. The result was that bleeding volume during operation decreased significantly and the liver surface cut with laser was kept dry without oozing of blood as well as bile juice.
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  • T. Ohtani, R. Amemiya, K. Hayakawa, O. Taira, I. Ogawa, K. Oho, Y. Hay ...
    1980 Volume 1 Issue 1 Pages 12-18
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    The authors compared the results of partial pulmonary resection using 3 types of laser cutters in a total of 32 adult mongrels. The laser cutters consisted of a carbon dioxide gas laser, an argon ion laser and a YAG laser. The results were compared macroscopically and microscopically and on their basis the instruments were employed in clinical cases and their characteristics further evaluated.
    The CO2 gas cutter at a power output of 40W showed cutting characteristics resembling those of the conventional scalpel and had the least effect on surrounding tissue of the three. However its hemostatic ability was limited and the jointed surgical arm has the drawback of rendering it difficult to manipulate easily intrathoracically. Although the argon ion laser provided effective hemostasis its cutting characteristics were poor and it did not qualify for employment as a cutting instrument. While the YAG laser was slightly less effective than the CO2 laser in terms of cutting characteristics it provided excellent hemostasis and the effect on surrounding tissue was also low. It was recognized as the most suitable instrument of the three types of lasers for employment in lung surgery.
    On the basis of clinical experience the following points were recognized to be important when performing pulmonary resection with laser cutters:
    1. The blood vessels in the hilar region should be compressed to reduce blood flow.
    2. The vessels which are roentgenologically recognized as being involved with the tumor should be occluded as quickly as possible.
    3. Alveoli and bronchioles are cauterized easily but larger bronchi and blood vessels remain in a string-like condition. They should be ligated then transected.
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  • Masakazu TSUZUKI, Kazuhiko ATSUMI, Masaharu NAKAJIMA, Akio IHARA
    1980 Volume 1 Issue 1 Pages 19-21
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    Clinical application of laser surgery using CO2Lasery 60 have been used for 29 cases of various surgical fields in the Surgical Center, University of Tokyo Hospital. These cases include 10 cases of liver surgery, 5 cases of brain tumor, 6 cases of hemangioma and lymphangioma and others.
    The effect for cutting and coagulating are satisfactory, when surgeons are accustomed how to use laser surgical apparatus.
    Several problems concerning the clinical application in many surgical fields are discussed. The first desired point is to obtain the easier operability of the hand piece and manipulator of the machine.
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  • Akinori Nagasawa, Katsushi Arai, Hiroyuki Ojimi, Kouji Nishikawa, Kazu ...
    1980 Volume 1 Issue 1 Pages 22-32
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    The therapeutic effects of laser irradiation attract much attention of surgeons.
    The most interest focussed on the soft tissue including skin, mucosal membrane, muscle and visceral organs and hard tissue including dentin and osseous tissue. The above-mentioned tissues are quite different in optic property and the reaction to laser irradiation differs in each tissue or in each organ. In this view point, the author has investigated the therapeutic effect of laser. A particular attention has been paid an deepness and thermal alteration based in laser irradiation. Moreover for the confirmation of the safety against to the laser irradiation, the study of similitude with a trial irradiation has been performed.
    The result indicates that the depth of the incision and the extent of the thermal injury were coincidental with cases of reversed Coefficient of incisional velocity and liberating power of laser irradiation. And single pulse irradiation and continuous wave irradiation reveal that the thermal injury in the peripheral region remained to be little extent respectively.
    Simultaneously, the tissue reaction for laser irradiation in case of normal saline injection in the subcutaneous tissue and so on have been investigated.
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  • Takao NAKAGAWA, Masato TAKAGI, Toshio SIRATORI, Tadashi SUZUKI, Hidema ...
    1980 Volume 1 Issue 1 Pages 33-37
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    The authors used the CO2 laser knife in 19 cases of general surgical operations for the past 9 months, and confirmed its advantage such as the bloodless incision of an open wound.
    Additionally, we Produced a handpiece with a Laser absorption plate attached and used it on a trial basis with the result that the range of safety and the effectiveness of the Laser knife was largely extended.
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  • Musaru Iwasaki, T. Konishi, N. Murata, Y. Tanaka, M. Sasago, Y. Maruya ...
    1980 Volume 1 Issue 1 Pages 38-40
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    The Nd-YAG laser is now considered to have the most powerful hemostatic effect among three lasers now used in the medical field. So we applied this laser to the hemostasis in general surgery, and investigated its effect.
    The medical laser system “Molectron 8000” was used for treatment. The laser beam was transmitted to the operation field through a flexible fiber.
    Following operations were performed with the Nd-YAG laser at the 2nd Dep. of Sur. of University of Tokyo from Dec., 1979 to June, 1980.
    We could get good results in almost all cases, especially in cases of the solid organs, such as the liver and the spleen. But at the bleeding from arteries which had a relatively large size of diameter (more than lmm), it was often impossible to cease bleeding with the laser alone.
    From this research. we knew that the irradiation of the laser at a high power (70-90 watts) with a short duration (0.5-1.0 sec.) was more effctive than that at a low power with a long duration, and tha assisted gas jet was necessary for good hemostasis. We think that the Nd-YAG laser can be used in a lot of surgical cases, such as the liver resection, the splenic rupture, and pperations with hemorragic diathesis.
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  • T. IKEDA, K. ENOMOTO, H. ASADO, H. ISHIKAWA, T. TAKESHITA, O. ABE
    1980 Volume 1 Issue 1 Pages 41-46
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    The advantages of using the laser surgery are in the sharp dissection, prevention from scattering of cancer cells, and so forth. To adopt laser scalpel to vascular surgery and to dissection of the lymph nodes, we have used it in the experimental condition in dog surgery researching for:
    1. The influence of the laser scalpel on the vascular flow.
    2. The suitable power of it for vascular dissection.
    3. Histological change of vascular wall after irradiation.
    The conclusions are as follows:
    1. Laser scalpel is available on vascular dissection without influence on vascular flow.
    2. Suitable condition for vascular dissection was in 10 W 0.07 sec. with pulse wave in power.
    3. Histological study revealed that sharp dissection of laser scalpel seems to be favorable to the wound healing.
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  • Takefumi Okada, Katsuro Takahashi, Yasuhiko Onoe, Seiji Itoh, Yu Maruy ...
    1980 Volume 1 Issue 1 Pages 47-50
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    A laser acupuncture system using a diode laser was developed and more than 60 clinical cases were obtained. Since the laser beam emitted by the diode is in the range of the infrared, which enables deep penetration into the skin, and also the modulation of the beam is easily controled by the electronic circuit, the system is quite simple with remarkable effects. Good results were obtained in those cases where the pain point is in a rather shallow area, such as knee joint pain. A basic study should be made to clarify the mechanism of laser acupuncture phenomena. Also, efforts to find out the optimum parameters for exposure will be made as a next step.
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  • Kazumasa Chiyoda, Kimiharu Noyori
    1980 Volume 1 Issue 1 Pages 51-57
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    The development of laser photocoagulation in the ophthalmology has been originated from Prof. Meyer-Schwickeraths clinical application of xenon photo-coagulation in 1949. Later in 1971, Dr L'Esperance put argon laser hotocoagulation into practical use and nowadays it has become to be indispensable tool for the therapy of retinal disease.
    This time, we carried out argon laser photocoagulation on retinal vascular disease; diabetic retinopaty, retinal vein occlusion, Coats' disease, macroan eurysm etc. And it has been confirmed that the argon laser photocoagulation is one of the most effective treatment for retinal disease.
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  • Ikuo Tobari
    1980 Volume 1 Issue 1 Pages 58-63
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    In May 1969, Zweng and others began their clinical argon laser photocoagulation studies with a slit lamp photocoagulator. Since argon laser photocoagulation systems were introduced in Japan in 1974, argon laser photocoagulation therapy was one of the important treatments for various ocular fundus diseases.
    This is a report on the results of argon laser photocoagulation therapy performed over the past 6 years on 2.265 eyes with 20 kinds of ocular abnormalities. 87 percent of these reported ocular diseases were composed of (1) Central serous retinopathy (708 eyes), (2) Retinal detachment, retinal tear and peripheral lattice degeneration (480 eyes), (3) Retinal branch vein occlusion (462 eyes) and (4) Diabetic retinopathy (326 eyes). In the typical cases of the above ocular diseases there were shown indication and photocoagulation approach of argon laser photocoagulation.
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  • Takaaki Fujiwara, Machiko Wada, Tamako Nagao
    1980 Volume 1 Issue 1 Pages 64-67
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    Ocular photocoagulation is now indispensable for treatment of many kinds of retino-choroidal diseases. We adopted this therapeutic method with an argon laser photocoagulator(Coherent System 900) at Tokai University in May,1979. In the following 13 months, 74 eyes(66 cases) were treated with this method. The authors reported here statistical studies of these cases. They included diabetic retinopathy 34 eyes(27 cases), occlusion of branch of central retinal vein 14 eyes(14 cases), occlusion of central retinal vein 2 eyes (2 cases), retinal detachment 16 eyes (16 cases), central serous choroidopathy 4 eyes (3 cases), Eales disease one eye, Coats disease one eye and others 2 eyes (2 cases). Good results were obtained in 35 eyes (34 cases). We did not experienced immediate complications, but experienced 3 late complications(increased macular edema 2, enlarging of retinal hole 1).
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  • KAYOKO KASHIMA, SHIGEKUNI OKISAKA, TAIRO KIMURA, TIPPAWAN DEVAHUTI, AK ...
    1980 Volume 1 Issue 1 Pages 68-75
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    Since introduction of xenon photocoagulator and argon laser coagulator in ophthalmology, a great deal of advancement is seen in some ocular conditions, such as retinal diseases.
    We recently developed Nd-YAG laser photocoagulator aiming the new powerful coagulator. Its light pump which emits 50 W of 1060 nm being connected with photoslitlamp by a glass fiber optics as to send a beam into human eye. 530 nm of second harmonic wave is also available from the coagulator. Histopathological changes of monkey retina by each laser were examined.
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  • Mitsuru SAWA, Yoshihiko UMAZUME, Tadashi TAMURA, Tetsuma OZAWA
    1980 Volume 1 Issue 1 Pages 76-78
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    A quantative and histological study was conducted of ocular damage in the rabbit eye from carbon dioxide (wave length 10.6μm) and WC (1.3μm) laser radiation.
    A certain corneal opacity was found to occur following irradiation by a continuous wave carbon dioxide laser with energy doses of 0.1W/0.2mm2/5 sec, although shorter than 5 sec. irradiation caused corneal impact or opacity case by case. Tine serial study after irradiation revealed irregular alignment of the corneal collagen fiber.
    Irradiation effect to the cornea by YAG laser was found to be moderate.
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  • Shinseiro OKAMOTO, Tetsuma OZAWA
    1980 Volume 1 Issue 1 Pages 79-82
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    The laser doppler velocimetry was applied to the measurement of the velocity of the retinal blood flow using a fundus camera. This method allowed efficient measurements of the light scattered by the erythrocytes flowing in the vessels. With a computer which is triggered by an electrocardiogram, the autocorrelation function was calculated. Then the pulsation of blood flow velocity in the human retinal artery was shown as being synchronized to the heartbeat. There was no pulsatile flow in the retinal vein.
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  • -TRANSURETHRAL DESTRUCTION OF STONES IN DOG BLADDER-
    YOSHIKATSU TANAHASHI, KAZUYA HARADA, ISAO NUMATA, [in Japanese], HIROS ...
    1980 Volume 1 Issue 1 Pages 83-85
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    An unfocused continous-wave Nd: YAG laser guided through flexible fibers was used in dogs to disintegrate human urinary calculi inserted into their bladder.
    The fiber was delivered into baldder through an endoscope introduced urethrally. Stones were entirely disintegrated by multiple laser radiations (40-50W, 2 sec).
    Elevation of temperature of the bladder wall was controlled under 40°C by changing irrigated water in the bladder.
    Specimen of the bladder wall showed neither macroscopic nor microscopic change except slight edema, immediately or 1-2 weeks after radiation.
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  • Yasuhide Murakami, Nobuo Kawamura
    1980 Volume 1 Issue 1 Pages 86-90
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    The possibility of breakdown of calculi of the urinary treat by the use of the CO2 laser knife and Nd-YAG laser beam was tested using calculi extracted by surgical operation.
    It was felt on the whole that the CO2 laser had a strong perforating power and it was possible to perforate the calculus but its destroying power was weak and the Nd-YAG laser broke down the surface and the perforating power was weak.
    It was considered that these actions would decrease in water.
    It was also considered that the vesical wall would be damaged even if perforation takes place, so the use of the laser appears to be limited and still restricted to experimental stage for the time being.
    We have tried the CO2 laser knife in renal lithotomy and operation for phimosis and others and found union of the sections was good and the scar of the incision line was small but the hemostatic effect was not so marked as had been anticipated.
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  • T. Hoshino, M. Nakajima, S. Nakamura, M. Niizuma, T. Niijima, A. Ihara ...
    1980 Volume 1 Issue 1 Pages 91-94
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    We investigated the effect of the Argon laser on the bladder of rabbits and dogs. The bladder of rabbits was irradiated by 2, 4, 6 and 8 watts for 1 to 5 seconds at the distance about 1 cm. The wall was not perforated under these irradiations. The muscularis propria was affected, but not vaporized. The canine bladder was irradiated by 3 watts for 5 to 20 seconds under three conditions, i. e. in the air, in the water and in the current water. The energy was absorbed more effectively in the air than in the water. The bleeding from the irradiated area was negligible. The bladder wall was completely re-epithelized three weeks after the irradiation.
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  • -INFLUENCE OF Nd: YAG LASER RADIATION TO THE WALL OF CANINE URINARY TRACT-
    ISAO NUMATA, YOSHIKATSU TANAHASHI, KAZUYA HARADA, YUTAKA CHIBA, SEIICH ...
    1980 Volume 1 Issue 1 Pages 95-98
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    Change of canine bladder wall was studied macroscopically and microscopically after radiation of CW Nd: YAG laser.
    Laser output used was ranged from 18 to 72W. Radiation time was 2 or 4 sec. The distance between bladder mucosa and the tip of optical fiber were 0, 1 and 2mm. Experiments were performed on 1) extracted bladder and ureter immersed in the saline; 2) bladder opened surgically and filled with saline, which was removed immediately or 3 days after radiation.
    Seventy-two W., 2 sec radiation makes no perforation on the bladder wall. Perforation was seen when laser power exceeded 36W, 4sec (in vitro).
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  • TATSUO AMAGAI, TADANORI SAITOH, YASUHIKO ONOYE, KIYOKI OKADA, TAKASHI ...
    1980 Volume 1 Issue 1 Pages 99-104
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    Nine bladder tumors of seven patients were treated by endoscopical irradiation of Nd: YAG Laser.
    Open resection or transurethral electro resection were also performed to the cases with the unsatisfactory Laser surgery. Cystoscopic photographs were shown in 2 cases before, soon after and 2 weeks after irradiation.
    Surgical bleeding by Laser therapy was a little or none and was easily controlled. There were no complications as for as bleeding and perforation were concerned.
    Because of the short period of post operative course and small number of the cases, we could not evaluate the value of Trans Urethral Laser Surgery by Nd: YAG Laser. However, it would be convinced that Trans Urethral Laser Surgery was a new effective therapy of bladder tumor if the operative field could get widely and safety through endoscopy.
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  • Seimei TANIMURA, Yoshio TAGUCHI, Takao KUNORI, Takashi SASAKI, Kazuaki ...
    1980 Volume 1 Issue 1 Pages 105-112
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    An automated biological cell sorting system (ABCS) based on laser light scattering method have been designed and constructed for clinical applications. Using the ABCS, the sizes of various lands of cells were measured and cells were separated on their sizes. Daily morphological changes in lymphocytes after stimulation of mitogen or mixed lymphocyte culture were cautiously examined.
    In 10 cases of renal patients, the daily morphological changes in lymphocytes before and after renal transplantations have been measured, Marked changes of size of lymphocytes were observed during acute rejection crisis, especially the changes were observed just before rejection episodes. Thus, acute rejection crisis could be predicted rapidly and easily by the ABCS.
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  • Shigenobu MIHASHI, Minoru HIRANO, Kiyoshi ITO
    1980 Volume 1 Issue 1 Pages 113-119
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    This paper describes our current model of CO2 laser apparatus. It was designed and produced under a close co-operation between the ENT Department of Kurume University Hospital and Asahi Optic Company. The apparatus is our third model and much improvement with respect to safety, stability and maneuverbility was brought about in it as compared to the previous models.
    The apparatus can be used for both gross surgeries and microsurgeries. The output power is 25 Watt at the distal end of the manipulator. The mode structure is single mode. The entire apparatus is small (110cm×69cm×55cm) because the cooling, the gas supplying and the electric systems are all built in a single console. Therefore, it does not take much space in the operating room and it is moved easily.
    A great maneuverbility of the manipulator was obtained by employing an electric motor drive system and a counter-balanced multi-articulated arm.
    For the purpose of security, an automatic check system was employed. When any important problem occurs in the laser production system, the high voltage electric circuit is automatically turned off immediately. There are several alarm lamps which indicate varying problems. Corresponding to the problems, some of the lamps are lighted on forthwith.
    The power indicator depicts the effective power at the distal end of the manipulator. A built-in power meter and a micro computer were adopted for this function. When the distal end of the manipulator is coupled to the built-in power meter, the ratio of the power at the end to that of the generator is calculated and memorized in the micro computer. Then, the computer always calculates value of the power at the end of the manipulator from the value of the power of the generator.
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  • OTOHIKO TAKAYAMA, NORIO MIZUSHIMA, MINORU UCHIDA, MIKIO TAKEDA, HIROSH ...
    1980 Volume 1 Issue 1 Pages 120-124
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    We investigated effects of laser beam surgery on the bronchial cilia using CO2 gas laser and YAG laser.
    Scanning electron microscopic observation reveled that the YAG laser had a stronger effect to the surrounding tissues. YAG laser can be expected more dehydration of the tissue fissure and tear of the tissue. YAG laser is also significant for the promotion of the coagulation of the tissue.
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  • Shigenobu MIHASHI, Hiroshi KAWASAKI, Katsuhiko MIHASHI, Minoru HIRANO
    1980 Volume 1 Issue 1 Pages 125-130
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    Two cases of tracheal stenosis were successfully treated with the use of a specially designed laser bronchoscope.
    Case 1. A 32-year-old male.
    The patient met with a traffic accident in October, 1978. Tracheotomy was performed for lung complication. The tracheostoma was closed two months after the operation.
    In April, 1980, he was admitted to our hospital as an emergency patient because of severe dyspnea. Cicatricial stenosis of the trachea was observed at the distance of 3cm from the carina. The inside diameter was only 3mm at the stenosis. No traditional procedures were thought to be useful to obtain a good air way. Therefore, we vaporized the cicatricious tissue with the use of the laser bronchoscope.
    After the vaporization, the lumen of the stenotic area became 6.5cm in diameter, resulting in a normalrange of respiratory function. He has been free from the symtome for 6 months since the operation.
    Case 2. An 84-year-old female.
    The patient was a case of recurrent papillary adenocarcinoma of the thyroid gland. She first developed a mass of the thyroid gland in 1957. She had a hemithyroidectomy in 1969. Since then, she had had local recurrence twice and neck metastasis twice, each being surgically treated. In 1980, a recurrent tumor was developed from the anterior wall of the trachea. It occupied a half of the lumen. The tumor was located 3cm below the vocal folds extending 1.3 cm downward.
    Because of the advanced age and the very slow proliferation of the tumor vaporization of the intra-tracheal mass was performed under the laser broncho-scope as a palliative treatment. Since the operation, she has been free from recurrence for 6 months.
    On the bases of the clinical experiences described above, we can conclude that laser vaporization under the specially designed bronchoscope is the choice of treatment for some stenotic lesion of the trachea.
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  • R. Amemiya, K. Oho, T. Ohtani, K. Hayakawa, O. Taira, I. Ogawa, Y. Hay ...
    1980 Volume 1 Issue 1 Pages 131-137
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    The authors have conducted a number of basic studies on order to establish the basis of laser surgery via the fiberoptic bronchoscope as a clinical procedure. We compared the effects of photoirradiation using two lasers, a Nd-YAG laser, and an argon ion laser, via a quartz fiber inserted through the instrumentation channel of the Olympus 1T in position in the trachea or bronchus of mongrel dogs. After a series of basic studies, the importance of a classification to categorize the effects of photo-irradiation became clear. As a result we formed the following classification system: Grade 1, grayish white appearance of the mucosa with slight swelling; Grade II, blackening of the mucosal epithelium due to carbonization; Grade III, formation of a shallow ulcer; Grade IV, formation of a deep ulcer; Grade V, perforation. A comparison of the power and penetration characteristics, and among other results it was shown that the argon ion laser required about 1/5 of the energy of the Nd-YAG laser to reach Grade V. Photodynamic effects of laser surgery indicated that in laser photoirradiation of clinical cases via the fiberoptic bronchoscope maximum photo-dynamic effect will be obtained in red colored material with the argon ion laser and black colored material with the Nd-YAG laser.
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  • k. Hayakawa, S. Takei, R. Yamada, O. Taira, R. Amemiya, T. Ohotani, K. ...
    1980 Volume 1 Issue 1 Pages 138-145
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    The authors have conducted basic experiments using laser photoirradiation via the fiberoptic bronchoscope to study the applicability of this method in cases of tumors of the trachea and bronchus. The Nd-YAG laser was transmitted via a Teflon covered quartz fiber 4mm in diameter inserted through the instrumentation channel of an Olympus 1T fiberscope.
    The sternomastoid muscle was inserted through the tracheotomy incision to simulate a tumor causing stenosis of the trachea. Photoirradiation was performed with YAG laser to resect the “tumor”.
    The authors have employed this method successfully in 3 clinical cases. After photoirradiation, dyspnea disappeared and patients became eligible for chemotherapy and irradiation.
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  • MORIYOSHI IMAKIIRE, TAKEO HIROKAWA, TERUHIKO TOKASHIKI, TETSURO HONDA, ...
    1980 Volume 1 Issue 1 Pages 146-152
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    The authors have used since March, 1980 a high-powered carbon dioxide laser surgical unit (MEDILASER-S, MODEL MEL-442, maximum output 60W) for experimental, histomorphological observations and clinical purposes. Up to now, laser surgery has been applied to 19 cases in total. Namely, it was performed in 6 cases for the purposes of radical or quantity-reducing operations of cancer in the head and neck, that is, 2 cases of cancer of the tongue and the oral cavity, 1 case of cancer of the pharynx and 3 cases of cancer of the nasal and paranasal cavities. It was also applied to 3 cases of D-P skin-flap formation, 7 cases of diseases of the oral mucosa such as leukoplakia, papilloma and intractable ulcer and 3 cases of verruca in the external of the auditory meatus and the nasal vestibule. Since laser surgery is often effective for the lesions which are difficult to control by conventional methods and has a mechanism of action quite different from those of conventional operations and X-ray irradiation, it seems to play a unique role especially in the treatment system of head and neck cancer.
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  • Mitsuo Nakata, Sanetomi Eguchi, Nobuo Yoshie
    1980 Volume 1 Issue 1 Pages 153-159
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    20 cases (14 patients) of head and neck tumors were treated by CO2 laser surgery in ENI clinic, the University of Tsukuba, during the period from Nov. 1, 1979 to Aug. 15, 1980.
    It was thought that laser surgery is a powerful treatment for benign tumors and local recurrence of malignant tumors.
    It was speculated that laser surgery will be desirable treatment for malignant melanoma and small, superficial cancer.
    It was concluded that 50W-60W, defocused beam vaporization (1 mm-2 mm) for benign tumors, and 1 mn-0.5 mm beam vaporization for malignant tumors are recommendable laser conditions for the head and neck tumors.
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  • Yoshihiko Murakami, Norio Mizushima, Hiroshi Tomita
    1980 Volume 1 Issue 1 Pages 160-167
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    The carbon dioxide surgical laser has initially been introduced to our clinical practice in Sept., 1977; since then, we have used two types of the CO2 surgical laser unit (Coherent CO2 surgical laser system 400 and Pentax SLC-1 surgical laser).
    We have experienced 167 patients with neoplastic lesions or non-neoplastic diseases in the aerodigestive tract or head and neck region, and treated them almost successfully with above mentioned CO2 surgical laser units, although there have been some problems or limitations in the treatment of the head and neck malignancies.
    As experience accumulated in the absence of significant complications in the CO2 laser surgery, our special concern has been directed to the treatment of the head and neck malignancies with the CO2 laser surgery. As of August 1980, the CO2 laser has been used in 47 patients with head and neck cancers of various portions and the total number of operations has been close to 90.
    In this paper an analysis of effectiveness of the CO2 laser surgery in these 47 patients was made as compared with the conventional surgical procedures, and advantages and disadvantages of the CO2 laser surgery were discussed in connection with evaluation of the CO2 surgical laser instruments now available.
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  • Norimasa Miyakogawa, Tetsuzo Inouye, Eiichi Tanaka, Masami Ogura, Fumi ...
    1980 Volume 1 Issue 1 Pages 168-174
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    LASER Beam was applied to various organs of canine and biophysical changes were photographed by a high speed camera, 4,000 frames per second. Laser Beam was set constant 17, 5 Joules (=35 watts with 0.5 seconds duration) to irradiate organs. Very instantaneous phenomenon were photographed and recorded by ultra high speed camera, John Hadland Mfg Co., make 16 mm Camera and films were analyzed frame to measure filmlength of each biophysical change. Organs applied were, Vocal cord, Tongue, Skin, Cartilage and Bone. These are categorized into mucous membrane group, dry tissue group and group in between. Time length between certain points was precisely calculated by a motion analyzer. A): Onset of irradiation to tissue B): Onset of vacuole C): Peak of vacuolization & erupt ion & eruption (=evaporation) D):Onset of vacuoles E): Onset of carbonization F): Completion F): Completion of carbonization at bottom of crater G): End of carbonization
    Vacuolization was observed clearly in mucous membrane of tongue and vocal cord, and fashion of vaporization and eruption were found to be same in each mucous membrane. On the other hand, very little vaporization and eruption were observed over the periostium of bone and perichondrium of cartilage. Instead, rapid detuochment of periostium and perichondrium were observed. Skin showed react ion of the these in between ultra high speed camera enabled to prove the difference of instantaneous reaction of tissues among the various organs.
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  • Takashi YAMAMOTO, Shinsuke KOBAYASHI, Mignon PARK, Ichiro FUKUMOTO
    1980 Volume 1 Issue 1 Pages 175-178
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    In this paper we describe the feedback controlled safety system whose function is to prevent the mis-irradiation caused by the human errors.
    The distance between the handpiece and the object is measured by detecting the reflected light from the object which is irradiated by He-Ne laser. If the measured distance becomes longer than the preset value,the irradiation of high energy laser is automatically stopped by the shutter.
    The experimental results are following.
    1. The preset region in which the laser irradiation was permitted is not affected by the difference of the reflectivity or the surface slope of the objects.
    2. In the case of specular object such as a mirror, the irradiation of the laser beam is almost perfectly stopped even if the specular object is within the preset region.
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  • Akio IHARA, Kazuhiko ATSUMI, Tsuyoshi NISHISAKA, Seiji SUGIYAMA, Norih ...
    1980 Volume 1 Issue 1 Pages 179-184
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    There are several kinds of medical laser treatment system, that is Nd:YAG, CO2, Argon Ion and etc., which are begun to use for animal experiments and clinical case.
    The important things to use appropriately the medical laser system are as follows.
    One is safety of laser system itself, another is method of maintenance, that is, safety control by user.
    In this paper, safety of laser system (YAG laser and CO2 laser) and how to control it were studied.
    As for hard-ware, it is concluded that following 4 items are thought to be necessary for safety of medical laser system
    1. System trouble is detectable before it is use.
    2. In case of appearance unusual conditions in the system, laser irradiation must be stopped automatically.
    (Interlock system)
    3. Alarm should be continued to ring during laser irradiation.
    4. In case of stand-by mode, whatever laser irradiation's switch become “ON”, laser beam must not be irradiated.
    In addition to these, general notices of use and safety control or soft-ware
    Ware also reported in this paper.
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  • Uichi KUBO, Yuichi HASHISHIN
    1980 Volume 1 Issue 1 Pages 185-191
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    The stable light power guide system is useful problem in the medical laser apparatus. The light communication use quartz fiber is powerful light guide for near infrared radiation with YAG laser. However, in contract to low power propagation at the light communication, light power propagation is a prerequisite for the medical laser. In the case of high power propagation, the occurrence of thermal damage was confirmed on the both end surfaces of quartz fiber. Therefore, the method to overcome this defect was investigated. In our present experiments, we found that the effective method was the forced water cooling at the both end part of fiber.
    In our present experiments, a fiber of diameter 0.6mm and length ca.4 m was used as test fiber.
    From the our experimental results, this confirms that the method of forced water cooling on coupling parts has made it possible to YAG laser power transmission (ca. cw 80W) and the efficency dose not decrease after a long time continuous operation (above a hour).
    On the other hand, we have investigated on the light guide for CO2 laser. As the light guide was used rectangular hollow metal tube. The present experimental results show that,in the coupling, the most suitable condition is one dimensional focus.
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  • Masane SUZUKI, Takayuki SAITO, Kinjiro IWATA, Saburo WATANABE, Sadayuk ...
    1980 Volume 1 Issue 1 Pages 192-197
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    In the last session, we presented a method to get stereoscopic observation of computed tomograms or ultrasonic tomograms using holographic multiplexing. But in this method, following weak points are found.
    1) Necessity of laser
    2) Inferior image caused by speckle noise of laser
    3) Impossibility to stick on a case history sheet
    Combining wellknown binocular stereogram with this method, these weak points will be taken off. In this paper, the whole system for stereoscopic observation of serial tomograms is discussed.
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  • Makoto Kikuchi, Eisuke Nakasu, Akira Sano, Yasahisa Sakurai
    1980 Volume 1 Issue 1 Pages 198-205
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    We have developed a laser absorption spectroscopy for blood glucose measurement based on the use of carbonic gas laser which permits the glucose density of human tissues to be measured continuously without taking blood samples.
    As compared with conventional types of infrared spectroscopes, the newly developed laser absorption spectroscope features a higher light sources brightness and combined use of laser beam displaying excellent wavelength resolution and attenuated total reflection (ATR) plate. The ATR plate is an attenuated total reflection prism with high refraction index containing arsonium selenide.
    Regarding its principle of measurement, the ATR plate is press against the patients lips or other viscous membrane tissue and the carbonic gas laser beam made, to penetrate to a depth of about 30 microns in the tissue for multiplexed. reflection. The absorbed spectrum is measured and fed into a minicomputer for direct readout of glucose density.
    Conventional methods for measuring the kinds or densities of molecules in human tissues optically require the use of visible light rays. However, the newly developed laser absorption spectroscope employs the ATR prism, by which it is possible to use a carbonic gas laser lying in the range of infrared rays for measuring the absorbed spectrum.
    Since this new spectroscope permits the glucose density in the blood to measured in real time and very accurately without extraction of blood serum from the body as with conventional great value in this field.
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  • Shigeto IKEDA, Ryoshuke ONO
    1980 Volume 1 Issue 1 Pages 206-213
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    For the purpose for determining the safety of endoscopic laser irradiation, basic studies are performed.
    Laser irradiation was applied on the liver of pig, filet of chicken and the trachea and bronchi of dog in various watts, duration of time, its continuation and pulse waves to obtain their experimental results.
    We have found the fact that, when the joule number is constant, the higher the watt is, the higher a deep approachability to the organ becomes, and also, even if the carbonization occurs on the surface and perforates deeper, the thickness of protein degeneration is always unchanged.
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  • Shoji Izawa, Akio Yamagishi, Humio Inaba
    1980 Volume 1 Issue 1 Pages 214-221
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    The laser light scattering patterns from various biological cells in a wide solid-angle were measured and analyzed using the light scattering pattern analyzing system developed for this purpose. The system was designed and constructed using a microscope, a He-Ne laser, a photodiode array, a transient recorder, a mini-computer and some optics. For the single cell analyzing method in a short time which enables us to realize automated real time cell discrimination, we developed two scattering pattern analyzing methods. One is to detect the scattered light intensity distribution as a function of the scattering angle θ, which contains useful informations concerning the outer size of the cell as well as the average size of the internal or surface structures. The another one is to detect the scattered light intensity distribution as a function of the azimuthal angle ψ, which includes mostly informations of the asymmetry of the cell itself or its internal structure.
    Based on these two schemes, we have analyzed the wide-angle laser light scattering patterns of various biological cells and thus obtained results which could be used to discriminate, for instance, lymphocyte from granulocyte, lymphocyte from red blood cell and T-lymphocyte from B-lymphocyte.
    This novel technique should provide shape and morphological informations of various single biological cells which allows one to perform desirable discrimination among cell types and properties. Moreover, it is to be noted that employing a simple data processing system for the short-time analysis of the wide-angle laser scattering pattern developed in this work, we could apply this method to the flowing automated cytology system.
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  • NAKAJIMA M., IHARA A., ATSUMI K., KUROKI T.
    1980 Volume 1 Issue 1 Pages 222-230
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    Effect of argon laser irradiation on cultured cell was investigated. From the point of morphological and growth curve examination, Argon laser irradiation alone did not make any significant change at energy density tested this time.(1.6-102.0 J/cm2 )
    Argon laser irradiation on Acridine Orange pretreated cells showed marked suppression of growth and cell death at the moderate concentrations of AO (1μg/ml).
    The mechanism of combined AO and Laser irradiation is unknown but nucleic acid and lysosomal level damage is suspected.
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  • Hiroyuki Nakata, Toshiteru Ohnishi, Kiyoo Kamikawa
    1980 Volume 1 Issue 1 Pages 231-236
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    Experiment was designed to clarify the effects of near-UV laser irradiation on cultured cells. Mouse Mbroblast cells (3T3 cell) were irradiated by N2-laser (wavelength: 337nm, pulse width: 10ns, 40Hz). This cells showed a decrease in cell number after treatment, but growth rates were found to be equivalent to that of control cell population. The survival curve of this cells suggested that this cell-line were reacting to a multihit or multitarget phenomenon for near UV-laser radiation. When this cells treated by vitamin A, the effects of UV-laser radiation was remarkably enhanced.
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  • Y. Ozawa, A. Onuma, K. Kashima, T. Amano, T. Nishisaka
    1980 Volume 1 Issue 1 Pages 237-240
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    Recently Nd: YAG laser is used clinically for the purpose of hemostasis and coagulation. To know the temperature distribution in the tissue, at which Nd: YAG laser was irradiated to the tissue, is important as to determine irradiation time and power. Then we simulated the temperature distribution in the tissue as to CW and repeated pulse irradiation by computer when Nd: YAG laser was irradiated to the tissue. Power density of laser in the tissue was calculated as the sum of direct beam and internal beam (scattered beam). Power density by internal scattering with higher order scattering (third order) was calculated. At the method of numerical analysis which used the 2-dimension heat conduction equation with heat source term of power density. At repeated pulse irradiation, the rise of temperature was calculated from the power density is time of pulse duration, and in time of pulse interval the temperature distribution was calculated by the method of numerical analysis which was used the 2-dimensional heat conduction equation without heat source of power density. Two beam modes (Gaussian and rectangular profile) were used to calculate the rise of temperature in the tissue. Each two combinations were analysed and discussed.
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  • Noboru TAMURA, Michiaki HIRAMOTO, Yoshinobu TANAKA, Hisaaki YAMAMOTO
    1980 Volume 1 Issue 1 Pages 241-244
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    For the determination of the LASER power and irradiation time to treat hemangioma simplex it is important to know the absorbent characteristics of the LASER beam into the skin. 3 cases of hemangioma simplex were examined to know them. Our hypothetic is that we can gain the absorbent coefficient in appearance if Lambert-Beer's equation is true apparently. After the strict tape fixation to the LASER beam receiver made by silicon photocell LASER beam keeps on straight at the intervals of 0.5mm from the edge of the photocell to the spot unable to measure. In these data we can get the absorbent coefficient in appearance. But it is too dangerous to discuss the results, because they are too poor cases. It is necessary for us to examine more cases. And a simulation of optic measurement is also necessary to theorize. We assume that this method will become as valuable as other methods such as histological examinations and reflectance spectrogram.
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  • Further Analysis of the Relationships among Incision Depth, Cutting Velocity, Laser Power and Power Density in CO2 Laser Incision
    Kumio Hishimoto
    1980 Volume 1 Issue 1 Pages 245-250
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    This series of reports entitled “Biophysical Studies on CO2 Laser Surgery” is based upon the CO2 laser surgical research which we performed from 1969 thru 1970 at the Laser Laboratory of the University of Cincinnati Medical Center.
    Experiments were undertaken to quantitate depth of incision by CO2 laser system as a function of laser output, power density and cutting velocity. An American Optical CO2 laser with surgical manipulator was used for focal incision of liver and skin. Experimental data are shown in Figure 1, 3, 4, 5 & 6.
    (1) Graphical analysis of the relationship among laser power (P), incision depth (X) and cutting speed (v) indicates functional relationship of the form: X=k√P/v, where k is a constant. (Hishimoto-Rockwell's formula)
    (2) Further graphical analyses of the relationship of power density (H), cutting velocity (v) and incision depth (X) suggest a relationship of the form: H=KvNXn, where K is a constant.
    (3) Non-linear curve, suggestive of a functional relationship of H=Aebv, at higher cutting velocities for skin incisions in Figure 5 must be attributed to increases in focal spot size and quasi-CW nature of energy delivery of the CO2 laser scalpel.
    (4) A problem that arises in applying the above formulas for deeper incision depth is abrupt reduction of the power density beyond the focal waist of the laser beam as the beam diverges. This variation in power density in deeper layer of the tissue may lead to deviation in mathematically expected values from the true ones.
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  • Akira Hakuba, Shuro Nishimura, Ken Fujitani, Junsuke Katsuyama, Hirosh ...
    1980 Volume 1 Issue 1 Pages 251-258
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    Either total or radical removal of 34 brain tumors was performed by the conventional microsurgical technique combined with CO2 laser beam without causing undue damage of surrounding structures. Three representative cases were presented. One of them was a sphenoid wing meningioma in which attachment of the tumor to the skull base was approached by vaporizing the tumor tissue by CO2 laser beam, followed by bloodless removal of the tumor by the usual microsurgical technique. The second was a cystic ependymoma of the left cerebral hemisphere. The cyst wall of the tumor was easily removed by a laser beam without significant damage to the surrounding brain substance. The last one was a hard calcified astrocytoma in which internal decompression was accomplished by a laser beam without any traction of the surrounding brain substance, and the remaining tumor was then removed by the conventional technique. All these 3 patients took uneventful post-operative course. The nature and properties of the beam and its surgical applications are discussed briefly.
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  • Toshiaki TAKIZAWA, Takashi YAMAZAKI, Masahisa MATSUMOTO, Nobuo MOCHIDA ...
    1980 Volume 1 Issue 1 Pages 259-268
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    We performed surgery on 11 cases of brain tumor using the CO2 laser surgical unit in combination with the ultrasonic surgical aspirator. The CO2 laser scalpel which we used is the Medilaser-S Model MEL-442 which was developed by T. Takizawa and his team for neurosurgery. And the ultrasonic surgical aspirator which we used is the Cavitron Ultrasonic Surgical Aspirator (CUSA) which was developed by E. S. Flamm. The CO2 laser scalpel can bloodlessly vaporize brain tumor with minimal damage to the neural tissue surrounding the tumor. But in cases where the vital arteries or veins run through the tumor, it is very dangerous to vaporize the tumor tissue blindly because this might lead to an inadvertent lasing of vital blood vessels. In such cases, the CUSA system is very useful because it leaves the arteries intact during removal of tumor tissue. In this paper the the surgical techniques to remove brain tumors using the CO2 laser scalpel in combination with the CUSA system are shown together with the 16 mm movie film and the slides. The advantages and disadvantages of the CO2 laser scalpel and the CUSA system are discussed in the case presentation.
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  • Y. Yonekawa, W. Taki, H. Handa, H. Miyake, Y. Oda
    1980 Volume 1 Issue 1 Pages 269-278
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    Twenty eight brain tumors, i. e. nine meningiomas, eight gliomas, two cavernomas, two teratomas, one edipermoid, two pituitary adenomas, two acoustic neurinomas, one hemangioblastoma and one metastatic brain tumor, were removed by laser microsurgery. As the laser surgical apparatuses, cavitron AO-300 and Medilaser were used. The operative microscope was Zeiss 1. Since the laser beam occluded small vessels no more than 1 mm in outside diameter, relatively bloodless removal of the brain tumors could be performed. Laser microsurgery is effective in the removal of such tumors as follows; 1) vascular rich tumors, 2) deeply seated and non-suckable tumors, and 3) relatively large tumors. At present, there are slight restraints in free movement of the operative microscope and also in the operative field caused by attached laser manipulator. This should be resolved in future.
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  • Tsukasa Fujimoto, Yutaka Inaba, Toshihiko Kuroiwa
    1980 Volume 1 Issue 1 Pages 279-286
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    For the operation in neurosurgical field, CO2-laser Combined with operating microscope is quite useful, especially for the excavation of hypervascular tumors, firm consistent tumors and deeply seated tumors. It seems to have boundless Potentiality in the neurosurgical operation in future. And for the progression of micro-laser surgery, accumulation of the basic studies are indispensable. We have used CO2 surgical-Laser. Model 400 from Coherent Company in U. S. A. and the effect of the CO2-laser beam on the brain under various conditions were investigated. Moreover, we created benign tumor like mass-lesion on the rabbits brain using its temporal muscles. The effect of the laser beam on this mass lesion was also investigated and the discussion about the way of laser irradiation was done.
    1 The thermal damage was related with time, but it seemed relatively independent from the strength of the out-put power. The depth of evaporated crater seemed to be corresponded with both of exposure time and out-put power.
    2 Under the ischemic condition, the thickness of the thermal damage was slightly lesser.
    3 Under the hypertensive condition, the thermal damage was significantly increased. This result suggest the importance of the control of blood pressure during and post operative period.
    4 Even if the brain tissue get damage by laser beam, morphological change does not necessarily follow immediately after the exposure. We noticed remarkable brain tissue damage and blood-brain-barrier destruction at late phase.
    5 The effect of the laser beam on the brain of alive animal, seemed to be relatively complicated and it might not correspond with the result from removed brain or other organs. The main effect of the laser beam is undoubtly heat, but the brain damage might be affected by other conditions.
    6 As a model of benign cerebral tumor, temporal muscles were attached to the brain surface. CO2-laser beam was irradiated on this mass lesion, and the discussion was done about the best way of laser irradiation.
    7 Accumulation of the basic studies are needed to progress “micro-laser-surgery”, especially when the procedure will be applied in the area close to important vital organs, such as brain stem and others.
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  • Kouji NISHIKAWA, Akinori NAGASAWA, Kazuichi KATO, Yoshiaki HIRATSUKA, ...
    1980 Volume 1 Issue 1 Pages 287-293
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    This paper reports on dental laser safety investigation and CO2 laser protectors for dentistry
    1) The laser protect effects of the experimental materials. 2) Reflection and heat product ion on the surface of metal instruments after CO2 laser irradiation. 3) Development of prototype of CO2 laser protectors for dental use. This protector i s composed of “WASHI”(Japanese paper) filled with water and aluminum foil.
    Results
    1) Both “WASHI” contained water and aluminum foil showed excel lent laser inhibition effects. 2) Black coated metal surface with various materials was effective to prevent reflection of CO2 laser, while the temperature on it was elevated. 3) The prototype laser protectors were able to inhibit soft and hard tissues from CO2 laser energy, even in 30 watts for 2 seconds.
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  • Kazuichi KATO, Akinori NAGASAWA, Kouji NISHIKAWA, Yoshiaki HIRATSUKA, ...
    1980 Volume 1 Issue 1 Pages 294-300
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    An extracted premolar with single root was irradiated CO2 pulse laser on it's cusp. Then the change of the surface temperature of the cusp and root, and the change of the temperature of the pulp cavity and root canal of this tooth after irradiation of laser were measured and recorded by a medical thermometer and thermocouples.
    For example, when a pulse laser of 10W in power and 1 second in pulse width irradiated on the cusp, temperature in the pulp cavity started elevating 2.5 seconds after irradiation to reach 6.7°C in peak 17.5 seconds after.
    According to these results, it is considered that pulp will free from irreversible damage after irradiation of these quantity of laser energy.
    But additional investigation is necessary to confirm the correlation pain and heat production in lasered tooth.
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  • -Analysis of Tooth Movement used for Laser Holography-
    Haruka Kusakari, Kaoru Yoshida, Hitoshi Iihara
    1980 Volume 1 Issue 1 Pages 301-306
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    Recently, in the dental field, some studies on the measurement of displacement and deformation by means of laser holography have been reported. Most of them, however, have described only the observation of interference fringes formed on the objects, and very few have done the quantitative analysis.
    In the present investigation, authors developed the method of quantitative analysis of three dimensional displacement used for laser holography, measured the three dimensional displacement of teeth by the occlusal force, and obtained some interesting results.
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  • Akinori NAGASAWA, Kazuichi KATO, Kouji NISHIKAWA, Yoshiaki HIRATSUKA, ...
    1980 Volume 1 Issue 1 Pages 307-316
    Published: 1980
    Released on J-STAGE: September 24, 2012
    JOURNAL FREE ACCESS
    Almost the same effects of CO2 laser on objects will be expected after absorption of a quantity of laser energy by irradiation at one time of single pulse or continuous wave, as irradiations dividing it into short pulses. One of the available dividing laser irradiations is repetition pulse laser method which the short laser pulses with the same character irradiate repeatedly. The factors of repetition pulse laser are power, pulse width, repetition cycle, duty, amount of irradiation time and, in addition to them, scanning speed in incision. In clinical application of this technique, these factors must be selected according to practical use. This techniques have many practically available merits as mentioned below. 1) Laser radiation and its effects can be controlled easily. 2) Operation can be controlled easily. 3) The degree of effects of laser on tissues could be controlled easily. 4) Laser therapy without pain is possible.
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