Applications of Infra and Ultrasound Practical Applications of Ultrasound and Infrasound in Medicine or Other Areas RAJARAM BHAGAVATHULA, VirginiaPolytechnic Institute and State University, Blacksburg, Virginia INTRODUCTION 1 Sound can be defined as vibration transmitted through a solid, liquid or gas medium and capable of being detected by human ear. The medium in which the sound waves travel must have mass and elasticity. Frequency (f) is the number of pressure cycles per unit time; its unit is cycles per second or Hertz (Hz). Sound is made up of different frequency components. The human audible range is 20 Hz to 20,000 Hz. The human ear is not capable of hearing sounds whose frequency is beyond these limits. Infrasound is that sound whose frequency components extend below lower audible frequency limit of 20 Hz. Ultrasound is that sound whose frequency components extends above the upper audible frequency limit of 20,000 Hz. The following sections deal with each ultrasound and infrasound in detail, listing out their practical applications in medicine and other areas. INFRASOUND Infrasound frequencies are too low to be heard by the human ear. Infrasound occurs naturally when ocean waves pound against the shores, during storms and earthquakes, when meteors hit the earth’s atmosphere. Infrasound is not absorbed to the same degree as other higher frequencies, consequently it can travel great distances. Infrasound content was also found to be present in animal sounds like those of the whale, elephant etc. The applications of infrasound have been discussed in the following sub-section. China. Filatov and Alimova. At least two hand-held vibrotherapy devices are currently advertised to the public.25-in. 2001). 1999). 2001). and is said to be "recognized by FDA as a 510k Therapeutic Massager” (CHI Institute. 1999). 1997). The second device is the Nostrafon Infrasound Wave Massager from Novafon. The Chi infrasound device is said to calm race horses by . The Infratronic QGM Quantum device. 70 dB. improving motor-evacuation function of the biliary system (Poddubnaya.Applications of Infra and Ultrasound 2 APPLICATIONS OF INFRASOUND Therapeutic Devices Several studies conducted in Russia and Europe reported that infrasound has therapeutic effects. developed out of scientific research in Beijing. 1998). It operates at 8 to 14 Hz. Such vibrotherapy devices are used for treating horses and athletes (CHI Institute. Levitski and Beloborodova. Infrasound phonophersis of antibacterial drugs in the treatment of patients with bacterial keratitis was as effective as local instillation of the same drugs (Sidorneko. 1974). deep massage using mixed-frequency sound waves ( Nostrafon. Infrasound pneumomassage at 4 Hz (daily 10 minute sessions for 10 days) stabilized the progression of myopia in school children (Sidorenko. Obrubov and Alimova. Vibrotherapy sources used in medicine generate audible as well as infrasound frequencies (Naoun and legras. Thermovibration massage at 10 Hz was a useful adjunct in combined treatment of patients with chronic cholecystitis and opisthorchiasis. is said to focus chi or life energy into patients' bodies and stimulate[s] relaxation and healing. which is said to provide a 2. Applications of Infra and Ultrasound 3 stimulating production of alpha brain waves (Brunker. The treatments can be applied through clothing and casts and the low-frequency waves can be programmed to penetrate surface muscles and internal organs to massage deep tissue. small differences in arrival times of the signal of the signal at the individual array elements are used to calculate the velocity and direction of the signal (Haak and Evers. clear-air turbulences etc radiate infrasound in advance. . Detecting Nuclear Explosions Utilizing the received infrasonic waves radiated from a nuclear explosion. thus by monitoring the infrasound waves. The operating principle is as follows. one can detect some characteristics and rules of the large scale meteorological motions (Nishiyama. and this influence is closely related with the distribution of temperature and wind in the atmosphere. Forecasting Natural Disasters Many disasters such as volcanic eruptions. Bedard and Kirschner. the source can be detected. Monitoring the Activities of the Atmosphere The infrasonic waves will be influenced by atmosphere during its propagation. undated). 2002). when an infrasound signal crosses the array. 2002).The HydroSonic Relaxation System delivers infrasound and other low-frequency sound to the body by water conduction through a heated water mattress. landslides. earthquakes. 2001). we can in a way forecast these disasters. By measuring the propagation properties of infrasonic waves generated by natural sources. The frequencies are generated by a compact disc and amplified (HydroSonic Systems. Typical treatments last about 30 minutes. Jellins and Kossoff. this technique has been limited to objects with relatively simple and repeatable geometry. A-mode visualization of the eye . It can be used in a wide range of clinical conditions and is useful in many parts of the body. Ultrasound is rapidly becoming the imaging method of choice for much of diagnostic medicine. The fundamentals of ultrasound are same as the principles of physical acoustics which apply to sound generally. More information about the application of ultrasound is provided in the following subsection. The main uses of A-mode system have been in the determination of the position of the midline of the brain (Robinson. Due to the difficulty in identifying individual echoes in a complex echo pattern. with the transducer position and orientation which defines the line of sight and the delay of received echoes. 1969) and in the fetal biparietal diameter measurement.000 Hz. The information about the object is obtained by using discrete lines of sight. which are used to determine the range of the echo producing object. 1970) in ophthalmology (Wainstock. APPLICATIONS OF ULTRASOUND Diagnostic Applications in Medicine: Pulse Echo Visualization Ultrasonic pulse echo techniques provide a lot of information about the internal structure of an object.Applications of Infra and Ultrasound ULTRASOUND 4 Ultrasound is defined as a sound whose frequency is too high for the perception of the human ear. There are different modes of operation of pulse echo visualization. The three important modes of operation along with their application areas are given below:A Mode: A-mode display only allows measurements of distances along the line of sight. The lower limit frequency limit for the ultrasound is taken as 20. or accumulation of fluid around the heart. The identity of the lesion can be identified as a fibroid or a malignancy or an early pregnancy. 1970). or through the window provided by the full bladder. The period of gestation or age of the fetus can also be revealed to within a few days during the first 10 weeks of pregnancy. Ultrasonic visualization can provide diagnostic information from a very early stage in pregnancy.Applications of Infra and Ultrasound 5 has shown success in measurement of the physical size of the eye and localizing and diagnosing intraocular lesions. identification of the echo producing structures was achieved by demonstration of an easily recognizable and unique pattern of movement of the structures of interest. 1972). M-Mode: The M-mode technique has received has found wide clinical acceptance in the examination of the heart (Feigenbaum. The heart beats have been seen at the sixth week of gestation. Multiple pregnancy is easily diagnosed. in differential diagnosis of mitral stenosis. 1972).It is also used in investigation of pericardial effusion. The kidneys are readily outlined and are usually examined from the back (King. Fetal abnormalities which require prompt surgical attention ca be diagnosed before the baby is born. The expanding uterus can be examined first through the full bladder and later directly through the abdominal wall. The size and the shape of the . The original applications were in the examination of the mitral valve. The examination of abdominal organs is the second most common application after obstetrics and gynecology. B-Mode: A very wide area of application of the B-mode technique is in obstetrics and gynecology (Garett and Robsinson. The measurement of fetal growth rate allows an accurate assessment of fetal progress to be obtained. A swelling in the lower abdominal area can be examined directly if it is sufficiently large to displace the air containing bowel. In each case. The principal applications of Doppler Effect are in cardiac and peripheral vascular diagnostic specialties. Wiseman. which employ the Doppler effect to assess whether structures (usually blood) are moving towards or away from the probe. The examination of thyroid reveals the presence of enlargement of the thyroid tissue (Jellins.Applications of Infra and Ultrasound 6 kidneys can be determined. Kossoff. 1978). Diagnostic Applications in Medicine: Doppler Techniques Ultrasound based diagnostic imaging technique can be enhanced with Doppler measurements. The second is imaging of flow lumen to show the location and alterations in the anatomy of a vessel. Current qualitative applications involve two aspects of blood flow evaluation. its speed and direction can be determined and visualized. and its relative velocity. 1978). Pulsed Doppler devices are used in both areas with continuous wave devices are predominantly used in peripheral vascular examination. The first is detection and localization of normal versus abnormal blood flow. By calculating the frequency shift of a particular sample volume. the presence of gross structural change such as a tumor or a polycystic disease can be seen and deviations from normal echographic picture can lead to diagnosis of functional abnormalities. The cardiac applications of pulsed Doppler devices are primarily concerned with the detection and evaluation of blood flow disturbances resulting from valve and septal defects (Fry ed. Reeve and Hales. for example a jet of blood flow over a heart valve. The thyroid is a superficial organ and is well suited to ultrasonic visualization.. . Applications of Infra and Ultrasound Therapeutic Applications 7 Ultrasound is useful as a therapeutic agent primarily because of its ability to heat tissues. This is due the ability of ultrasound to elevate temperature. Besides medicine ultrasound is also used in wide variety of industrial applications like mixing. Ultrasound can also be useful for relieving muscle spasms which may be associated with bone. Temperature elevation resulting from ultrasound application can produce an increase in the extensibility of the collagen tissue. cell disruption. Many of the applications of infrasound research are connected to natural disaster and meteorology. Therapeutic procedures such as range of motion exercises and stretch are best applied together with application of therapeutic heat to produce greatest residual elongation with least damage to tissue. from which the whole human race can benefit.. emulsification etc. joint or nerve pathology (Fry ed. CONCLUSION In conclusion. The utility of ultrasound therapy is based on its selective propagation and absorption patterns in the human tissue. 1978). thus it can be used for reducing joint contractures. . Ultrasound is used in this case as it is selectively absorbed by bone and elevates temperature in adjacent contracted tissue. infrasound and ultrasound have many applications not only in the filed of medicine but also other fields. Experimental studies have shown that in humans the pain threshold can be elevated by ultrasonic application to both peripheral nerve and free nerve endings. and Evers. Jellins. L.com/news/567829..Applications of Infra and Ultrasound REFERENCES Back Be Nimble. Ronald J. DVM and certified human neurophysiologist. CHI Newsletter. Ultrasound: Its Applications in Medicine and Biology Part II. (1970). Fry.asp. Available at http://www. Lea and Febiger.com/new/pages/novafon/index.hydrosonic.com/infratronic. undated. CHI Institute. Available at http://backbenimble. Haak. Fry. HydroSonic relaxation table. CHI Institute Infratronic. 2001. Echocardiography. 613-628.htm?cont=1 8 Brunker. M. H. T. Philadelphia. G. I.E. (1978).J.J. (1978). Reeve..com/newsletters/104/104_A. Pg 566-571. D. and Robinson. J. HydroSonic Systems. Seeking the alternative therapy edge: More trainers use acupuncture. Pg 254-255. MSNBC news story. CHI Institute. 1998. Available at http://www. Nostrafon – The infrasound (sub-sonic) wave massager from Novafon.com/hydroson. F. ed. J. Riegel.chinahealthways. In Verification Yearbook. F.. and Biology. Pg 207-221. W. Elsevier Scientific Publishing Company.chinahealthways. Ultrasound in Clinical Obstetrics. Ultrasound in Med. CHI Institute. . Garett. (1978).htm. ed. Kossoff. 2001. 2002.J. Infrasound profiles: An interview with Dr. and Hales. H. Infrasound as a tool for CTBT verification. Elsevier Scientific Publishing Company. (1972).html Feigenbaum. Ultrasound: Its Applications in Medicine and Biology Part I. Wiseman. other treatments on their horses.msnbc. Available at http://www. 2001. Available at http://www.html. Little. 2002. M. J. Vopr. Legras. Ultrasonography in Ophthalmology. 1974. (1970).I. Pg18-20 Wainstock. Oftalmol. Fizioter. Bedard. and Yu. In Journal of Applied Meteorology.A..14 (84): EMBASE record 76039928. Pg 633. A. Clinical assessment of infrasonic phonophoresis efficacy in the treatment of bacterial keratitis. V. and Kirschner.J.L. Naoun. The effect of thermalvibration massage on the function of the hepatobiliary system in patients with chronic cholecystitis and opisthorchiasis. and B.A. ed. Sidorenko. M. . A. Vestn.E. 113(3): MEDLINE record 97381659. D. Kossoff.I. Beloborodova. E.A. Vestn. S. E. (Pg 879-881) Poddubnaya. O. D. Kurortol..I. Filatov. Alimova..Applications of Infra and Ultrasound 9 King. Levitskii. A. MEDLINE record 2000106297. Radiology.. Pg 3-12 Nishiyama.T. 1999. Oftalmol. Boston.F.. and E. Kult. R. 1999.. Ultrasonic’s Pg 93. Tumasian.L. (1969). Experience of clinical use of infrasound pneumomassage in the treatment of progressive myopia in school children. Jellins. 1997. Brown and Company.R. Infrasound and vibrotherapy. Obrubov and A. Strong Winds Over Mountains and Infrasound: Possible Applications fro detecting Regions Related to Aircraft Turbulence Reports. Fiz. Pg 31-32 Sidorenko. G. Electroradiol. Feuill... 115(2): MEDLINE record 1999305635. E. (6): Pg19-21.V. Robinson. (1972).