Application of the ultrasonic Doppler method to medical diagnosis was first made in 1955 by Shigeo Satomura. At first he measured the small vibration and motion of the human body in the heart, the eye ball and blood vessels by the Doppler method with microwave and ultrasound. Accidentally in 1958 Satomura found Doppler noise of the blood stream in the process of measuring the microvibration of the blood vessel wall. The next clinical application of this ultrasonic flowmeter was developed by Satomura and Kaneko. Descriptions of the first report at the Society of Acoustics and medical meeting, the first paper in Japanese and English, the first equipment, recording system, the first commercial Doppler flowmeter, the naming of the ultrasonic blood rheograph and further studies on cerebral circulation were also provided in this paper.

抄録全体を表示

In this dissertation the author explains that the intrecardiac phonocardiogram is an important weapon for the diagnosis of the congenital heart-diseases. At the same time the author examines the Doppler method and arrives at the conclusion that besides the valvular vibration the blood flow influences upon the high frequency signal and that we must be careful in the analysis of the Doppler signal, because the intrathoracic and intracardiac vibration mechanism is complicated and the anatomical position of valve shows individual variety. To apply the Doppler method to the clinical diagnosis it is necessary in the present state of study that some indicator, e.g. intracardiac pressure and intracardiac phonocardiogram or other ultrasonic pulse method should be in parallel used. The so-called Mps and Tps which appear after the P wave can be explained not as a reflection of the movement of atrial ventricular vulve itself, but as blood vibration by atrial contraction. The Mps and Tps have the same mechanism as IV tone. Even at the case when auscultation and record of IV tone at the chestwall is difficult, the IV tone can be recorded in the Doppler signal. So in the study of IV tone a new field can be exploited by the Doppler signal method. The Doppler method enables us, without giving no pain to the patients, to get results that cannot be received by the phonocardiogram and other methods. The Doppler method will supplement the insufficient points which phonocardiogram and other methods have. This method was born, as the intracardiac phonocardiogram, in Japan and is highly evaluated in foreign countries. It is hoped that this method be further developed in the right direction by the Japanese scholars.

抄録全体を表示

This is a theoretical treatment of a mechanical filter consisting of disc resonators vibrating in bending mode coupled by longitudinally vibrating bars. The equivalent mechanical circuit for a certain mode(i. e. , the 1st mode) of vibration of the resonator is obtained. General equivalent electrical network for the mechanical filter including the electromechanical transducers is presented. Terminal matching, specific band, and other characteristic features, which are important for the design of mechanical filters are discussed.

抄録全体を表示

When an ultrasonic beam is radiated into the body by a transducer placed on the suface of the chest wall, the motion of the heart causes the so-called Doppler effect on the wave reflected from it. Thus, several kinds of beat tones whose frequencies are proportional to the speed of the heart motion are perceived at the earphones of the receiving apparatus. Designating the frequency of these beat as fd(c/s), the speed of the reflecting area as u_0(cm/sec), the ultrasonic wavelength in the body as λ(cm), the following relation holds between them. u_0=λ/2fd. Since λ is determined by the frequency of the ultrasound which is being used, the knowledge of fd makes it possible to investigate the behaviour of the reflecting region of the heart in motion. In the same way, the minute vibration of the heart surface or of the valvular structures which would be developed by the blood flow would cause the vibrational alterations in the phase of the reflected wave. Hence they can be detected as the vibrational tones of the same kind (in this case, chiefly, heart noises). The principal parts of the apparatus consist of a HF-oscillator, an ultrasonic transducer for the purpose of both transmission and reception, a detector-amplifier, an earphone and a recorder. The transducer is of barium-titanate, 1 cm in diameter. The positive electrode is separated into two concentric parts, the inner disc of 3 mm in diameter being used for transmission and the outer circular ring for reception. The sensitive range proves to be a beam of approximately 1 cm in diameter. Therefore, the investigations of the heart is performed on the distinct parts of this small extension. By supplying a frequency-selecter of bandpass type for the amplifier, it becomes possible to separate and select the movements of the particular parts of the heart. The HF-oscillator is realized by a 6V6 type tube, operating as a self-oscillator. The ultrasonic power output is calculated to be 20 mW/cm^2. In practice, the ultrasonic transducer, attached to the end of a flexible cable, is placed at the various positions on the chest wall, and the Doppler beat due to the movements of the corresponding parts are made audible or recorded. There are three kinds in these tones: 1. Higher Doppler beat. (Movements of the valves) 2. Lower Doppler beat. (Movements of the surface of the heart) 3. Doppler heart noises. (Heart noises)

抄録全体を表示

We firstly recorded a human fetal heart tone after tone stimulus was given to maternal abdominal surface of third trimester by using of fetal heart rate meter and ultrasonic Doppler method, and the heart tone signal was converted into a train pulse which comprised only the initial beats by using of band-pass filter and photocell-lamp.
Further we observed the change of fetal heart rate and fetal movement used by digital computer to obtain sequencial controlled interval variation.
The results were as follows:
1) It was approved that the fetal movement was recognized within 10 seconds after tone stimulus was given and heart rate was increased within 20 seconds. The heart rate recovered within approximately 40 seconds.
2) We considered it was a good method to use Doppler method to find the hard of hearing of fetus at first trimester.

抄録全体を表示

本稿では, われわれが開発した高周波数超音波パルスドプラ血流速計について述べる. 本法により, 高分解能でヒト冠動脈などの比較的細い血管での実時間での血流速度プロフィルの計測が可能となった. カテーテル型プローブの併用により, 外科領域だけでなく内科領域でも本法の応用が可能である.

抄録全体を表示

A total of 152 precordial detections of decompression bubbles was carried out in 91 caisson workers with the Doppler Ultrasonic Bubble Detector.
The results were as follows:
1) Most of the bubble signals appeared and attained to their maximum grade within 60 minutes after decompression.
2) The appearance or increase of blood bubbles was accelerated by clenching the fist or raising arms above the shoulder height. Many workers, however, dislike these movements for fear of suffering from decomperession sickness.
3) Of 152 detections, bubble signals were heard in 88 (58%). They were heard in all cases of decompression sickness which requires treatment (13 bends and 3 chokes). On the other hand, 48 cases with bubble signals were asymptomatic.
4) The occurrence and grade of decompression bubble signals at successive jobs seemed to depend on the decompression schedules.

抄録全体を表示