In stroboscopic measurement of rotational speed, the observed pattern is stationary at everyrotational speed which is multiple of primary speed. Since suitable multiple measuring method hasnot been known, there has been serious troubles in measuring. On the other hand, suitable measuring device is useful not only for removing such troubles but for extending measurable speedrange of the stroboscope.
In this paper two practical methods, method 1 and method 2 are discussed. Operating principlesof these methods are quite different from each other; the former makes use of mathematical natureof series of flush frequency when single stationary pattern appears, but the latter makes use of therelation between the phase difference of two flushes with equal frequency, and the angular differenceof double stationary patterns.
Biased multivibrators modified for the above two methods are presented, and satisfactory result hasbeen obtained. The electronic circuit for method 2 is a little more complicated than that for method 1, but it was proved by experiments that the former is much more convenient for mesuring operation.

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球軸受等が製作されたる場合其の良,不良を簡單に檢査する爲に圓盤に或囘轉を與へ圓盤の囘轉速度の減衰を方法に依て測定する方法が便利である.著者は此の方法に依て球軸受に就て研究し,球軸受に與へる給油量に從ひ目掛けの摩擦係數が著しく變化する状況を測定した.次に同樣な方法を用ひ,テーパ軸受の檢査器に應用して好結果を得た.テーパ軸受は旋盤等の工作機械に多く使用されて居るが,テーパ軸受の締工合を數量的に檢査出來る方法は必要である.即ちテーパ軸受に於てテーパブッシュの締工合が適確でなければ囘轉軸及軸受面が焼付いたり又は破損したりする恐れがある.この事は從來テーパ軸受の締付程度を工員等の感に依て行つたからで,熟練工員でもテーパ軸受の適確なる調整は相當面倒である.斯樣に工員等の感又は熟練に頼らずしてテーパ軸受の滑動面に作用する接觸壓力及摩擦係數を簡易に檢出出來る測定理論を明かにした.各異のテーパブッシュの締程度に依て接觸壓力及摩擦係數を測定して好結果を得た.著者のテーパ軸受檢査器は方法を應用し實用に供し得る事を確めた.
著者の提案せる軸受檢査器による測定結果を綜合すれば球軸受,テーパ軸受の性能試驗に適することを明かにした.の點滅周波數を豫め正確に較正して置けば,測定の際に入り得る誤差の因子少くして所要の摩擦係數μを比較的精度大にして檢出することが出來た.從つて各種の球軸受,ローラー軸受等の製品檢査に適するものと思はれる.

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At our E. N. T. Clinic in Keio University Hospital, a visual observation is regarded as an especially important factor in making a diagnosis. An observation is made by enlarging the vocal fold image on a CTR using a laryngoscope.
It is essential that an examination should not only be performed but that the acquired results be utilized both effectively and efficiently.
To this end, all the examination results are recorded on a VTR and at the same time input in the form of digital video records into our personal computer. The computer used is widely used type and our own application software is developed for operating.
The method is as follows :
# 1 Register the patient's data to be used as a data base.
# 2 Label each VTR of patient's data.
# 3 Search the patient's past data and display the visual Image.
# 4 Search the patient's past data as it progresses over time, and display the visual image.
# 5 Analyze the results of stroboscopic imaging using fuzzy logic.
# 6 Display a demonstration video of laryngeal disorders.
# 7 Perform a phonetic screening test using fuzzy logic.
This method proves to be useful in making a diagnosis with regard to progress over time. It is also quite useful in informing patients and teaching students. Our report is an example of applying personal computers in medical treatment.

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Laryngo-stroboscopy is a common clinical tool used to observe vocal fold oscillation, yet it is not appropriate for visualizing the oscillations that contain sub-harmonic waves that often appear in pathological vocal folds. Here, we propose a novel technique based on stroboscopy in which such pathological vocal fold oscillations can be observed by applying FFT (fast Fourier transformation) analysis. We tested two algorithms to determine the stroboscopic illumination frequency : Illuminations on the basis of (i) beat frequency and (ii) multi-light sources. A vocal fold oscillation model with two different fundamental frequencies mimicking pathological conditions such as nodular vocal folds was used to evaluate the performance of the algorithms. The beat frequency was extracted from the sound wave by FFT analysis and used to stroboscopically illuminate the oscillations, demonstrating that the algorithm is useful for observing pathological oscillations, but may be inapplicable to clinical cases because of its low light intensity. In contrast, the alternative algorithm using multi-light sources to illuminate each fundamental oscillation simultaneously showed good performance visualizing the pathological oscillations as well as in the level of clarity, demonstrating that the newly designed laryngo-stroboscopy system is valuable for observing pathological vocal fold oscillations.

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A portable stroboscope, using a simple cold cathode fluorescent tubeas the light source, was made and its electrical and optical properties were measured. It has following advantages compared to those made as yet,
(1) upper limit of the stroboscopic frequency is high,
(2) the light source tube has asimple structure and the vacuum tubes used in the electri-cal circuit are popular radio receiving tubes,
(3) the life of the light source tube is long,
(4) the color of the stroboscopic light is approximately white because of using fluorescent material,
(5) the light intensity is, strong enough to take photograph in a dark room.

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目的:喉頭のmicrosurgeryは拡大視下に確実な手術ができるため,ひろく一般に行なわれるようになつた.喉頭のmicrosurgeryの大きな目的の一つに術後の発声機能をできるだけ正常にすることがある.従来の喉頭のmicrosurgeryの方法では術中に喉頭の発声機能を知ることとは難かしかつた.この点を解決するためを使用して,手術の経過と共に発声時の声帯振動の状態を観察し,声帯振動ができるだけ正常に近い状態で手術を終了すれば術後の音声も最良の結果をうると考えて,その方法を試みた.
方法:従来の喉頭のmicrosurgeryの光源としての光源を使用する方法をとつた.すなわち,の発光管のより明るいものを試作し,その両端よりグラスフアイバーを導光用として喉頭鏡の両側先端まで導き,手術用顕微鏡を介して喉頭鏡下に発声時の声帯の振動を観察しうると共に,同じ光源でスイツチの操作一つで最高発光がでるようにして,手術も行ないうるようにを改造した.手術の実際は,1. 麻酔は発声が必要であるため,Neuroleptanalgesiaに咽喉頭局所噴霧麻酔,もしくは局所塗布注入麻酔のみで行ない,2. 喉頭を展開し,3. 手術用顕微鏡下に局所所見を観察し,4. 術前の声帯振動を観察し,5. 手術を施行し,6. 声帯振動観察の順に行なう.必要に応じて5.6. を繰返し声振帯動が正常に最も近いと考えられる状態で手術を終了する.
結果:昭和47年1月より12月の1年間に喉頭の器質的疾患152例に本法を施行した.多くの疾患において手術の進行と共に声帯振動は改善され正常に近い振動が観察されるものが多かつた.
その経験から:
1. 術前の声帯振動の状態で手術方法を選択しうる.
2. 声帯振動の観察から手術の終了時を決定しうる.
3. 声帯振動が最もよい状態で手術を終了するため,術後の音声改善が確実である.以上のような利点があり,声帯の器質的疾患の手術法として非常に有効な方法と考えられる。その方法及び代表症例について述べた.

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A portable stroboscope which has a good colour rendition has been constructed. Two fluorescent lamps using Mg-tungstate (Argon gas 3.0mmHg and Mercury one drop) and a Neon-Argon lamp (total pressure 3.3mmHg, Argon percentage 20%) are operated synchroni-cally. Chief advantages of this stroboscope are considered as follows:-
(1) a good colour rendition is obtained.
(2) stable stroboscopic operation is available at the frequency range of 100c/m-15, 000c/m for a long time.
(3) only about 300 V d.c. source obtained by an ordinary eliminator is sufficient for the operating circuit.
(4) the apparatus is small enough to be portable (total weight 17Kg), but the light intensity is strong enough to take photographs in darkness (50 lux at the point 50cm distant when operated at 3, 000c/m).
(5) the life of the light source tubes is long.

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We fabricated a visual observation system for a rotating object with an automatic synchronizing function using a ferroelectric liquid crystal (FLC) cell. Stroboscopic vision was achieved not using a flash light but using a FLC cell as a fast-response optical shutter. A reflective photosensor was used for sensing a rotating object. For the drive of the liquid crystal shutter synchronized with the rotating object, an electric circuit mainly composed of a microcontroller and a H bridge unit, which were made up of easily available electric parts, was designed. The automatic synchronizing function was evaluated from the visibility of a character on the center of the propeller. The results indicate the automatic synchronizing function can work over 6.2 × 10³rpm.

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This 59-year-old male was initially treated by a general practioner under a diagnosis of acute laryngitis because the patient developed hoarseness after an upper respiratory infection.
In about one month, the patient was seen by an otolaryngologist who found the cause of his hoarseness was left recurrent nerve paralysis which was considered to be due to viral infection and was treated conservatively for about three months without improvement.
The patient visited the authors' hospital three and a half months after the onset of the disease. He was then found to have tuberculous lesions in the upper lobes of both lungs.
Culture of his sputum showed a positive result for tuberculous bacilli.
The tuberculous lesion was taken into consideration as a possible cause of his recurrent paralysis. Meanwhile, the patient developed severe pain in the chest, which was found to be due to deformans of the cervical spine. Traction of the cervical spine relieved the symptom rapidly.
A few months later the patient developed fracture of the left iliac bone, for which canvas traction was used. The patient developed dyspnea one night lasting for about 30 minutes, which was later found to have been caused by bilateral vocal cord paralysis.
The patient died due to cardiac arrest two days after a tracheostomy was perfomed.
The autopsy revealed concurrent adenocarcinoma of the left lung.
It was difficult to identity the true cause of the vocal cord paralysis because the lung tumor was concealed by the pulmonary tuberculous lesion and the patient did not show any significant symptoms suggesting the lung cancer.

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