What is the “ultrasound” in the ultrasonic therapy device? We often hear the term "ultrasound", but we don't really know much about what it is or what it actually entails. What is "ultrasound"? And, while introducing the history of the development of ultrasonic therapy equipment, we will introduce its features in detail.
Application of ultrasound to ophthalmology is a demand of the times!
Generally, the range of frequencies that humans can hear (audible range) is between 20 Hz for low sounds and 20,000 Hz for high sounds. These sounds that humans can hear are called audible frequencies.
Sound waves with a higher frequency than this, that is, "high-frequency sound waves that cannot be detected by the human auditory system" are called ultrasound.
Conversely, sound waves with a frequency lower than the audible frequency, that is, "low-frequency sound waves that cannot be detected by the human auditory system" are called low frequencies. However, in a broader sense, ultrasound refers to "sound waves that are not intended to be heard directly by the human ear." In other words, even sound waves below 20,000 hertz are ultrasonic if they are not intended to be heard directly.
In other words, even if the sound waves used are in the audible range, the application of sound waves that are not intended for human hearing is defined as ultrasound technology and is called "low-band ultrasound." is. (You can hear a beeping sound from the ultrasonic therapy device "I-Power". This is because it uses 12,000 Hz ultrasonic waves in a broad sense.)
Sound travels by vibrating through the air. The vibration wave has a wide range from high vibration waves to low vibration waves and has various characteristics. Therefore, it has been researched and used in many fields.
Typical examples are fish finders used in fishing, medical scanners for externally diagnosing the internal condition of the body, and massage devices that use vibration waves. Ultrasound was initially used in the field of physical therapy as a massage device, but it was considered difficult to apply it to ophthalmology.
Since the eyeball to be treated is an extremely delicate tissue and the eyeball itself is very small, the projection of ultrasonic waves was considered to be dangerous.
After all, very high frequency ultrasound can be destructive. You have to identify what is the right amount of vibration for your eyeballs. A control technique is also required to ensure that the appropriate and specified ultrasound waves are projected onto the cells of the eyeball.
However, application to ophthalmology was a request of the times.
Dr. Yamamoto completes the "hand-held ultrasonic treatment device for ophthalmology".
A group led by Dr. Yukio Yamamoto, a world-renowned authority on ophthalmology, began using ultrasound to treat myopia.
In 1962, Dr. Yamamoto, with the cooperation of Associate Professor Matsuno Iwatake and Lecturer Hiroshi Ishida of Shibaura Institute of Technology, finally completed a hand-held ultrasonic treatment device for ophthalmology. Research on this "hand-held ultrasonic therapeutic device" was presented at the 16th Congress of the Japanese Society of Clinical Ophthalmology and then at the 1st International Society of Myopia in 1964, and received a great response not only in Japan but also overseas.
According to Dr. Yamamoto's research paper, in his clinical experiments at that time, patients aged 10 years or older with pseudomyopia and true myopia for more than 2 years were treated 20 times at intervals of 1 to 2 days. It is said that the treatment was performed by projecting ultrasonic waves to one eye for 10 minutes each time. As a result, improvement in visual acuity was seen in 2 to 3 weeks, and many people said that their visual acuity improved immediately after the first projection.
A follow-up study of subsequent treatment effects has also been added. According to it, as a result of observation over a period of more than a year after the start of ultrasound, it was found that the refractive index of the eyeball improved as well as the visual acuity of myopic patients.
The fact that the refractive index of the cornea has improved means that the improvement in myopia is not temporary, and furthermore, it can be said that there is a fundamental therapeutic effect to stop the progression of myopia. In this way, the Handheld Ophthalmic Ultrasound Therapy Device received the first approval from the Ministry of Health and Welfare.
Safe and free of side effects, this is a must!
The eye is a very fine organ.
That is why ultrasonic waves used for treatment by projecting directly onto the eyes must be absolutely safe and free of side effects. This is a mandatory condition. In 2003, the government approved the ultrasonic therapy device "I-Power", which uses low-frequency longitudinal wave ultrasound with the following characteristics.
- The acoustic output is extremely weak even in ultrasonic waves.
- The oscillation frequency is an appropriate low-band frequency oscillation frequency corresponding to the natural oscillation frequency of human living tissue cells.
- Vibrations are deeply absorbed by tissue cells without resistance and cause no damage.
This means it is safe and has no side effects.
As a side note, it is very interesting to note that the same effect appears not only in the eye that projects ultrasound, but also in the other eye that does not project ultrasound. It is often said that both eyes are connected, and that if one eye goes bad the other will go bad, but the opposite can also happen.
Interview with Hiroshi Asai
Unleash the charm of ultrasonic therapy from homeostasis and hormesis!
Myopia is an unhealthy state of homeostasis.
"Homeostasis and hormesis are important keywords when considering the efficacy of the ultrasonic therapy device 'i-power,'" says Dr. Hiroshi Asai. Professor Emeritus of Waseda University, Doctor of Science.
The physiological term “homeostasis” appears surprisingly often in information about health and the body.
If you look it up in the Kojien dictionary, (homeo means the same, stasis means a state of rest), internal organs of living organisms respond to changes in the external environment (temperature, humidity, etc.) and subjective conditions (posture, movement, etc.). The state and function of maintaining the body environment (body temperature, blood flow, blood components, etc.) within a certain range in a unified and purposeful manner.
In mammals, autonomic nerves and endocrine glands play a central role. Later, he began to talk about the inner balance of the mind.
a. Simply put, it is "constancy" that maintains a constant state. A constant state is the work of always trying to maintain the body even under the influence of external factors such as the environment.
“For example, the human body temperature is maintained at about 37°C. When it gets cold, the metabolism activates to keep the body warm, and when it gets hot, the body sweats to cool down. This is homeostasis.” and Mr. Asai.
In more detail, it is a dynamic equilibrium state in which the state of the body always fluctuates within a relatively narrow range. Even if the outside world is constantly changing, the internal state is kept relatively stable.
Conversely, most illnesses are the result of homeostasis malfunction. In other words, the inability to maintain homeostasis (a stable and constant internal state of the human body) leads to illness.
The human body repeats constant contraction (activity) and relaxation (rest) in accordance with a certain biological rhythm, but changes in the social environment, irregular lifestyle habits, and stress conditions continue to cause errors in the biological rhythm. becomes larger, homeostasis cannot be corrected, and you feel unwell, making it difficult to maintain your health.
“In terms of eyesight, myopia is an unhealthy state of homeostasis. If you overwork your eyes with computers, smartphones, etc., blood flow will be poor, oxygen supply will be poor, and the cells in your eyes will become inactive. As a result, homeostasis malfunctions and focus adjustment does not work well, and if this state continues, an unhealthy state of homeostasis occurs. and return it to a state of healthy homeostasis.”
An ultrasound therapy device with beneficial effects is a good example of hormesis.
A word that contrasts with "homeostasis" is "hormesis". Hormesis is a phenomenon in which a substance that is toxic when used in high or large concentrations stimulates biological activity or produces beneficial effects when used in low or trace amounts. .
Low radiation hormesis (low dose radiation) is well known.
Radiation is widely recognized as harmful to the human body. It is true that exposure to large doses of radiation is harmful to the body. However, a small amount of radiation is always emitted on the earth. It has been found that exposure to radiation 10 to 100 times higher than natural radiation is good for health.
For example, natural radium ore used in bedrock baths and hot springs emits radiation called radon when placed in water. A small amount of radon enters the body, stimulating cells and improving metabolism. It has been proven in experiments and clinical applications that it increases immunity and natural healing power.
“It’s easier to understand if you think of this as chili peppers, which are essential to kimchi, a pickle, rather than radiation. Capsaicin, the main ingredient in chili peppers, is said to be toxic. However, in small amounts, it has the effect of activating energy metabolism and promoting the breakdown of body fat.”
"The Japanese translation of homeostasis, 'constant', uses the same kanji as the fixed star, meaning that it does not move or change. On the other hand, hormesis is difficult to find a Japanese translation, but if you translate it, It is easier to understand if we call it ``stimulation activation.'' The meaning of activation is to give vitality, to activate the function or action of a substance.”
“Humans have to be stimulated. If you are alone in a closed room without sound, you will go insane in three days. You cannot live without external stimulation.”
The function of the ultrasonic waves used in the ultrasonic therapy device "I-Power" is easy to understand from the perspective of this hormesis.
Ultrasound at very high frequencies can be dangerous, even destructive, but low-intensity ultrasound can have beneficial effects, such as stimulating cellular activity in humans. By applying weak ultrasonic waves from an ultrasonic therapy device, blood flow improves and cells are activated.
Eyepower, an ultrasonic therapy device, restores the eyes to a healthy homeostasis state by providing a small amount of stimulation (hormesis) that does not reach a harmful amount to the eyes in an unhealthy homeostasis state. Indeed, the ultrasonic therapeutic device is a good example to explain “homeostasis” and “hormesis”.
Professor Emeritus, Waseda University (Department of Physics). 1961 Graduated from Graduate School of Science, Nagoya University. Doctor of Science. Postdoctoral and senior biophysics researcher at the Cardiovascular Institute, University of California, USA, for a total of three and a half years, 1961-1967. His main research field is cell biophysics. Received the Order of the Sacred Treasure, in the fall 2014 conferment of decorations.