Clever Geek Handbook
📜 ⬆️ ⬇️

Ultrasonic Phased Array

An ultrasonic phased array is an ultrasound device that provides electronic dynamic focusing, that is, allows you to change the focus location without moving the array itself, and also create if necessary several tricks at the same time [1] [2] . They are used in medicine , in industrial non - destructive testing systems .

For ultrasound surgery and therapy , two types of lattices are used: extracorporeal ones installed outside the patient’s body, and lattices introduced into the body. The first of them have no size restrictions (hemispherical grids for surgery with a diameter of 30 cm are known), and therefore can be performed two-dimensional. Lattices of the second variety with significant acoustic power should have the smallest possible transverse dimensions (preferably no more than 20-25 mm), and therefore are linear.

Potential areas of clinical application of the lattice are: oncology , destruction of the tissues of the prostate gland (prostate), surgery of uterine fibroids , lithotripsy, stimulation of receptor nerve structures. The prospects of using two-dimensional lattices in cardiology , for the treatment of glaucoma , for neuromodulation of brain structures and exposure to intracerebral tumors through an unopened skull, as well as in plastic surgery and cosmetology are shown [1] [2] .

Content

History

The development of two-dimensional phased arrays for hyperthermia of tumors, and then for surgical purposes, began in the mid-1980s under the supervision of Professor C. Cain from the University of Michigan . The first lattices developed were distinguished by a wide variety of designs. In some of them, geometric focusing was used, in others - electronic. Some were designed to move through the space of a single focus, others - to synthesize a more complex field with some specific configuration, to immediately overlap the required tumor volume. At first, to simplify electronics and reduce its dimensions, the number of channels was minimized [3] [4] . However, in subsequent designs of gratings with plane, spherical, or cylindrical geometry, it was assumed that all elements were used [5] [6] . In particular, the design of a sector-vortex lattice [7] was developed, which made it possible to create an annular focus of various diameters.

In the early 1990s, a lattice design with elements mounted on a part of a spherical surface was proposed [8] . This allows you to combine the electronic focusing method with the geometric one and thereby achieve the highest grating gain. Since then, this design has become the most popular of all available variants of therapeutic two-dimensional lattices.

In 1988, the possibility of creating two or more tricks at the same time with the help of a single lattice was shown for the first time [8] [9] . The possibility of creating a hotbed of destruction or destruction using a specially synthesized set of foci determined a particular interest in the possible use of powerful two-dimensional lattices in surgery and hyperthermia . However, the calculation of the phases and amplitudes of the exciting signals required for this on the elements, the number of which in modern therapeutic gratings can exceed 1000, requires the development of special calculation algorithms. This problem was solved in [9] , in which a method for synthesizing multifocal ultrasonic fields was presented, which allows one to determine the phases and amplitudes of the signals necessary to create a certain field level in a number of “control points” in a given volume. The physical meaning of this method, which is called "pseudo-inverse" [9] , is as follows. M tricks are represented in the form of imaginary sound sources located on a certain plane, and then the total amplitude-phase distribution in the center of the lattice elements is calculated, which is obtained when these sources are turned on simultaneously. If we now apply signals with the indicated amplitude-phase distribution to the lattice elements by changing the phase sign, then we obtain the desired M foci in the indicated plane. In principle, using the "pseudo-inverse" method, you can create a scope of any given size and configuration. When calculating multifocal ultrasonic fields, optimization methods are used that allow you to obtain a given number of foci at the same amplitudes on all elements and thereby maximize the acoustic power of the grating [9] .

The rationale for the use of intracavitary linear phased array for surgical treatment of the prostate was given in theoretical work [10] . The essence of this approach is based on the use of energy emitted by all elements of the lattice to generate one or (less often) several foci electronically moved in three-dimensional space.

In the late 1990s, the ideology of randomizing the arrangement of elements on the surface of the grating began to develop actively, which led to a significant improvement in the quality of the acoustic fields created by the grating [11] [12] .

Linear Grilles

The most famous application of linear phased arrays in medicine is the surgical treatment of diseases of the prostate gland (prostate). The challenge is to destroy the tumor of the prostate gland or, at least, significantly reduce its volume. The lattice is inserted through the rectum (transrectally), and a thin-walled rubber balloon filled with water is used to create acoustic contact between the lattice and tissues. The distance from the wall of the rectum to the desired site of destruction in the prostate is from 2 to 5 cm, and the transverse size of the prostate usually does not exceed 4 cm. Thus, the limits of movement of the focus (or foci) along the tissues of the prostate should correspond to the indicated dimensions. It is known that Sonablate [13] and Ablatherm [14] instruments are used to destroy prostate tissues, the working element of which is a single-element focusing transducer with a fixed focal length.

 
Sonablate Sensor [13]

. This means that if you need to change the depth of exposure, you need to change one emitter to another, having a different focal length, and reconfigure the focusing system. Obviously, phased arrays are much more flexible and promising in this regard, allowing you to electronically move the focus on the prostate tissue, as well as create, if necessary, several tricks. The possibility of using the intracavitary linear phased array of surgical treatment of the prostate was implemented in practice independently by two groups - the American [15] [16] and the English-Russian [17] [18] . In the latter case, the lattice consisted of 70 elements with a width of 1 mm, a length of 15 mm, and a thickness corresponding to an operating frequency of 1 MHz (1.72 mm) [18] .

 
Linear array for surgical treatment of the prostate [18] [1]

. The grating was equipped with a magnetic resonance (MR) antenna, allowing visualization of the site of exposure.

Experimental studies showed [18] that the use of a linear lattice with the indicated parameters allows you to move the focus within at least 30 to 60 mm in the axial direction and ± 20 mm in the direction perpendicular to it, which corresponds to the size of the prostate. In this case, the level of secondary intensity maxima in the focal plane was significantly less than 10% of the maximum intensity in focus and not higher than 10% near the surface of the device.

The designs of other lattices for prostate surgery are described in a number of works [19] [20] [21] [22] and are discussed in detail in books [1] [2] .

Two-dimensional lattices

Regular two-dimensional lattices

Until the early 2000s, most two-dimensional lattices were regular, that is, elements in them were installed on the surface of the lattice in a regular way: in the form of squares, rings or hexagons. The arrangement of the elements in the form of squares, which, as subsequent studies showed, may be recognized as perhaps the most unsuccessful way of arranging the elements, was for many years the most popular of all the methods used [8] [23] [24] [25] [26 ] [27] .

So, in the late 1990s, a lattice was developed, manufactured and tested in vivo in the form of a part of a spherical shell with a radius of curvature of 10 cm and a diameter of 12 cm at a frequency of 1.1 MHz, consisting of 256 elements installed in the form of squares [28] [29] . Unlike earlier designs of spherical two-dimensional lattices [8] , the lattice was made not from separate elements, but from a single piece of a piezocomposite material of 1-3 connections.

Since the beginning of the 2000s, the use of focused ultrasound for exposure to the deep tissues of the human brain through an intact skull has received significant development in order to treat a number of neurological diseases and neuromodulation of central nervous structures. For this, several modifications of focusing systems were developed, made in the form of a hemisphere in which a human head is placed. So, in work [30] , an axisymmetric grating at a frequency of 0.665 MHz in the form of a hemisphere with a radius of curvature of 15 cm and a diameter of 30 cm, consisting of 64 elements of the same size (the area of ​​each of them was ~ 22 cm 2 ) was described and studied.

InSightech (Israel) was founded in 1999. Its goal was to develop technologies based on the use of powerful focused ultrasound under MRI control. Several ultrasonic focusing systems have been created and are commercially available: ExAblate 2000, 3000, 4000 and ExAblate Neuro . They contain 512-1024 elements and have the shape of a hemisphere with a diameter of 30 cm. The frequencies of various modifications are as follows: 220-230 kHz, 650-660 kHz, 1 and 2.3 MHz [2] . The acoustic power is at least 800 watts. Lattices are made axisymmetric. The ExAblate Neuro system is designed to affect the deep structures of the brain through an unopened skull and therefore uses lower frequencies from the specified range.

Randomized 2D Bars

An important task in the development of all phased arrays is to reduce the level of secondary intensity maxima in the field created by it. Their physical nature is substantially related to the presence of discrete elements in the lattice, which is equivalent to placing a single grid or lattice transducer in front of the surface. The occurrence of such maxima can lead to the appearance of a “hot spot” away from the site of exposure and to undesirable overheating and even to destruction of structures outside the specified area of ​​impact. The classic recipe for eliminating side lobes in the radiation pattern is that the distance between the centers of the lattice elements should be equal to or less than λ / 2 [31] , where λ is the wavelength, that is, for example, ≤ 0.5 mm at a frequency 1.5 MHz It is impossible to fulfill this requirement in powerful therapeutic grids, since for its implementation it would be necessary to use an extremely large number of elements and electronic channels. It is known that the level of side lobes in the directional pattern of the lattice can be reduced by decreasing the amplitude on the elements of the lattice from its center to the periphery [31] . However, the role of this effect is not so great as to drastically reduce the acoustic power of the grating for its implementation. In [15] [32] , a method based on the use of linear gratings with unequal distances between the centers of elements was investigated. It turned out that the decrease in the level of secondary intensity maxima expected due to the aperiodicity of the elements of the linear lattice can reach 30-45% compared with lattices with equal distances between the elements. The use of broadband signals for powering lattice elements [33] is also not very efficient and is not yet used in real lattice designs.

One of the first works in which the authors set the task of finding out whether a violation of the regularity of the arrangement of elements improves the quality of the intensity distributions in the field created by the grating was the work of Goss and colleagues [11] . They calculated the field of the lattice with a random arrangement of elements on its surface, but the resulting effect was small. The reason was that the ratio of the diameter of the element to the wavelength λ , chosen by the authors of this work, was too large - 11.2. In other words, the directivity pattern of such an element was very narrow. The influence of the sizes of elements (and, consequently, their directivity) on the ability of gratings to move focus was discussed in [34] . The recommendations of the authors were reduced to the need to reduce the size of elements and simultaneously increase their number if the diameter of the heated volume should reach 1 cm.

A way to improve the quality of acoustic fields created by powerful two-dimensional gratings, based on the use of “thinned out” gratings with elements randomly located on the surface of the grating, was substantiated and studied in detail in [12] [35] . It was concluded that high quality ultrasound intensity distributions can be achieved if two conditions are met: a random arrangement of elements on the surface of a two-dimensional lattice and a fairly wide directional pattern of the element. Estimates showed [12] [35] that the maximum element size at which satisfactory field quality can still be achieved is no more than 5 λ . Naturally, the smaller the wave size of the element, the higher the lattice's ability to move focus in space.

In [12] [35] , a comparison was made of the characteristics of ultrasonic fields created by randomized and regular arrays (in the form of squares, rings, and hexagons) over a wide range of parameter values ​​(frequency, number of elements, diameter of the arrays, etc.). It turned out that the quality of the fields generated by the gratings, estimated as far as possible to move one or several foci, as well as by the amplitude of the secondary intensity maxima resulting from this, was significantly higher for randomized gratings. In the same works, criteria were developed to compare the quality of the fields of various lattices [12] [35] .

A separate series of works was devoted to the study of the ability of lattices to create and move in space a large number of foci (for example, 16 or 25) [35] [36] , [37] , which is especially important for hyperthermia of tumors. Numerical methods for calculating single-focus and multi-focus acoustic fields are described in detail in a number of papers [12] [35] [36] . Recently, an express calculation method has been developed based on the application of an analytical solution in the far field of each element [38] .

The first real designs of randomized gratings were fabricated and experimentally investigated at the University of Paris [39] and at Imperial College, London [40] .

 
A randomized grid for use in surgery [1] [2] [40] . Above - the appearance, below - the location of the elements

. The parameters of these lattices are close to each other and to those proposed in [12] [35] [36] . The randomization of the distribution of elements in a two-dimensional lattice was also used by Philips Healthcare to create a multi-element focusing system for use in the clinic [41] [42] .

Among the various technologies based on the use of focused high-intensity ultrasound in medicine in the 2000s. a new technology has appeared, named by its author prof. Kane histotripsy by analogy with lithotripsy [43] . Histotripsy is realized using extremely intense, short (usually not more than 3-10 periods) ultrasound pulses that allow fractionation of the targeted tissue site using a cloud of cavitation bubbles. Moreover, if the amplitude of the side lobes in the lattice field does not reach the cavitation threshold, then the destruction is carried out only at the main maximum. This is especially valuable when conducting therapy through an unopened skull. In addition, the use of such technology allows avoiding overheating of the bones of the skull when powerful ultrasound passes through them. An ultra-powerful focusing system for transcranial action on brain structures by histotripsy has been described [44] [45] .

In a recent work, a two-dimensional lattice design was proposed, which allows combining randomization in the arrangement of lattice elements with a high packing density, and hence with the maximum possible acoustic lattice power [46] . This is achieved by arranging the elements on the surface of the lattice in the form of spirals.

Promising areas of application of therapeutic grids

Discussion of the results of theoretical and experimental studies, indicating significant potential possibilities of using powerful therapeutic grids in medicine, is the subject of hundreds of articles and several books [1] [2] . Promising areas of clinical use of lattices are: oncology, destruction of the tissues of the prostate gland (prostate), surgery of uterine fibroids, lithotripsy, hyperthermia, stimulation of receptor nerve structures. The possibilities of using two-dimensional lattices in cardiology, for the treatment of glaucoma and exposure to tissues located behind the chest, as well as in plastic surgery and cosmetology are shown [1] [2] .

Phased arrays are successfully used for exposure by focused ultrasound to intracerebral tumors through an unopened skull, as well as for neuromodulation of brain structures. Some of the new features have already been confirmed in preclinical trials, while others are still being studied in laboratories. Hemispherical phased arrays have already been used in neurological clinics for the treatment of neuropathic pain [47] , treatment of essential tremor [48] and Parkinson's disease. Promising results have been obtained on the use of focused ultrasound to destroy an intracerebral tumor - glioblastoma [49] , trigeminal neuralgia [50] , as well as intracerebral hemorrhage [51] and Alzheimer's disease . The possibility of using powerful focused ultrasound to affect the blood- brain barrier of the brain, as well as the ability to strengthen the human immune system to fight cancer, was also shown [1] [2] .

Non-Destructive Testing

See also

  • Phased array antenna
  • Active phased array antenna
  • Ultrasound
  • Ultrasonic cavitation
  • High Intensity Focused Ultrasound in Medicine
  • Singleton Focusing Ultrasound Emitters

Notes

  1. ↑ 1 2 3 4 5 6 7 8 Gavrilov, L. R. Focused high-intensity ultrasound in medicine. - M .: Fazis, 2013. −656 s. - 978-5-7036-0131-2.
  2. ↑ 1 2 3 4 5 6 7 8 Gavrilov LR, Hand JW High-Power Ultrasound Phased Arrays for Medical Applications. - NY: Nova Science Publishers, 2014 .-- 200 p.
  3. ↑ Ocheltree K.V., Benkeser PJ, Frizzell LA, Cain S.A. An ultrasonic phased array applicator for hyperthermia // IEEE Trans. Sonics Ultrasonics. - 1984. - V. 31. - P. 526-31.
  4. ↑ Benkeser PJ, Frizzel LA, Ocheltree KB, Cain CA A tapered phased array ultrasound transducer for hyperthermia treatment. // IEEE Trans. Ultrason Ferroelec Freqency Control. - 1987. - V. 34. - P. 446 −453.
  5. ↑ Ibbini MS, Ebbini ES, Cain C.A. N x N square-element ultrasound phased array applicator: simulated temperature distributions associated with directly synthesized heating patterns // IEEE Trans. Ultrasonics Ferrorelectr. Freq. Control - 1990. - V. 37. - P. 491-500.
  6. ↑ Ebbini ES, Umemura S.-I., Ibbini M., Cain S.A. A cylindrical-section ultrasound phased-array applicator for hyperthermia cancer therapy // IEEE Trans. Ultrasonics Ferroelectr. Freq. Control - 1988. - V. 35, No. 5. -P. 561-572.
  7. ↑ Umemura S., Cain S. A. The sector-vortex phased array: acoustic field synthesis for hyperthermia // IEEE Trans. Ultrasonics Ferroelectr. Freq. Control - 1989. - V. 36, No. 2. - P. 249—257
  8. ↑ 1 2 3 4 Ebbini ES, Cain CA A spherical-section ultrasound phased-array applicator for deep localized hyperthermia // IEEE Trans. Biomed. Eng. - 1991. - V. 38, No. 7. - P. 634-643.
  9. ↑ 1 2 3 4 Ebbini ES, Cain CA. Multiple-focus ultrasound phased array pattern synthesis: Optimal driving signal distributions for hyperthermia // IEEE Trans. Ultrason Ferroelec Freq. Ctrl. - 1989. - V. 36, No. 5. - P. 540-548
  10. ↑ Hand JW, Ebbini E., O'Keefe D., Israel D., Mohammadtaghi S. An ultrasound linear array for use in intracavitary applicators for thermotherapy of prostatic diseases // IEEE 1993 Ultrasonics Symp. Proc. (Piscataway, NJ: IEEE) .- 1993. -P. 1225-1228.
  11. ↑ 1 2 Goss SA, Frizell LA, Kouzmanoff JT, Barich JM, Yang JM Sparse random ultrasound phased array for focal surgery // IEEE Trans. Ultras Ferroelectr. Freq. Ctrl. - 1996. - V. 43, No. 6. - P. 1111-1121.
  12. ↑ 1 2 3 4 5 6 7 Gavrilov L., Hand J. A theoretical assessment of the relative performance of spherical phased arrays for ultrasound surgery // IEEE Trans. Ultrason Ferroelectr. Freq. Control - 2000. - V. 47. - P. 125-138.
  13. ↑ 1 2 Illing, R., Emberton, M. Sonablate®-500: transrectal high-intensity focused ultrasound for the treatment of prostate cancer // Future Drugs, Ltd. - 2006.
  14. ↑ Crouzet, S., Murat, FJ, Pasticier, G., Cassier, P., Chapelon, JY, Gelet, A. High intensity focused ultrasound (HIFU) for prostate cancer: current clinical status, outcomes and future perspectives // Int J Hyperthermia. −2010. - V. 26, No. 8. - P. 796-803.
  15. ↑ 1 2 Hutchinson EB, Buchanan MT, Hynynen K. Design and optimization of an aperiodic ultrasound phased array for intracavitary prostate thermal therapies // Med. Phys. - 1996. - V. 23, No. 5. - R. 767—776.
  16. ↑ Sokka SD, Hynynen KH The feasibility of MRI-guided whole prostate ablation with a linear aperiodic intracavitary ultrasound phased array // Phys. Med. Biol. - 2000. - V. 45. - P. 3373-3383.
  17. ↑ Gavrilov LR, Hand JW, Abel P., Cain CA A method of reducing grating lobes associated with an ultrasound linear phased array intended for transrectal thermotherapy of prostate // IEEE Trans. Ultrason Ferroelectr. Freq. Contr. - 1997. -V. 44, No. 5. - R. 1010-1017.
  18. ↑ 1 2 3 4 Gavrilov L.R., Hand J. Development and experimental study of the intracavitary phased antenna array for ultrasound surgery of the prostate // Acoust. journal - 2000. - T. 46, No. 2. - C. 182—191
  19. ↑ Diederich CJ, Hynynen K., The development of intracavitary ultrasonic applicators for hyperthermia: A design and experimental study // Med. Phys. - 1990. - V. 17. - P. 626-634.
  20. ↑ Smith NB, Buchanan MT, Hynynen K. Transrectal ultrasound applicator for prostate heating monitored using MRI thermometry // Int. Journ. of Radiat. Oncol. Biol. Physics. - 1999. - V. 43, No. 1. - P. 217-225.
  21. ↑ Tan JS, Frizzell LA, Sanghvi NT, Wu JS, Seip R., Kouzmanoff JT Ultrasound phased array for prostate treatment // J. Acoust. Soc. Am. - 2001. - V. 109, No. 6. - P. 3055-3064.
  22. ↑ Curiel L., Chavrier F., Souchon R., Birer A., ​​Chapelon JY 1.5-D High intensity focused ultrasound array for non-invasive prostate cancer surgery // IEEE Trans. Ultrason Ferroelectr. Freq. Control - 2002. - V. 49, No. 2. - P. 231-242.
  23. ↑ Fan X., Hynynen K. A study of various parameters of spherically curved phased arrays for noninvasive ultrasound surgery // Phys. Med. Biol. - 1996. - V. 41, No. 4. - P. 591-608.
  24. ↑ Wan H., VanBaren P., Ebbini ES, Cain CA Ultrasound surgery: comparison of strategies using phased array systems // IEEE Trans. Ultras Ferroelectr. Freq. Ctrl. - 1996. - V. 43, No. 6. - P. 1085-1097.
  25. ↑ McGough RJ, Kessler ML, Ebbini ES, Cain CA Treatment planning for hyperthermia with ultrasound phased arrays // IEEE Trans. Ultras Ferroelec Freq. Ctrl. - 1996. - V. 43, No. 6. - P. 1074-1084.
  26. ↑ Daum DR, Hynynen K. Thermal dose optimization via temporal switching in ultrasound surgery // IEEE Trans. Ultrason Ferroelectr. Freq. Ctrl. - 1998. - V. 45, No. 1. - P. 208-215.
  27. ↑ Saleh KY, Smith NB Two-dimensional ultrasound phased array design for tissue ablation for treatment of benign prostatic hyperplasia / Int. J. Hyperthermia. - 2004. - V. 20, No. 1. - P. 7-31.
  28. ↑ Daum DR, Hynynen K. A 256-element ultrasonic phased array system for the treatment of large volumes of deep seated tissue // IEEE Trans. Ultras Ferroelec Freq. Ctrl. - 1999. - V. 46, No. 5. - P. 1254-1268.
  29. ↑ Daum DR, Smith NB, King R., Hynynen K. In vivo demonstration of non-invasive, thermal surgery of the liver and kidney using an ultrasonic phased array // Ultrasound in Med. and Biol. - 1999. - V. 25, No. 7. - P. 1087-1098.
  30. ↑ Clement GT, Sun J., Giesecke T., Hynynen K. A hemisphere array for non invasive ultrasound surgery and therapy // Phys. Med. Biol. - 2000. -V. 45. - P. 3707-3719.
  31. ↑ 1 2 Skolnik M. Introduction to the technique of radar systems / Per. from English - M.: Mir, 1965. −747 p.
  32. ↑ Hutchinson EB, Hynynen K. Intracavitary ultrasound phased array for noninvasive prostate surgery // IEEE Trans. Ultras Ferroelec Freq. Ctrl. - 1996. - V. 43, No. 6. - R. 1032-1042
  33. ↑ Dupenloup F., Chapelon JY, Cathignol DJ, Sapozhnikov OA Reduction of the grating lobes of annular arrays used in focused ultrasound surgery // IEEE Trans. Ultras Ferroelectr. Freq. Ctrl. - 1996. - V. 43, No. 6. - P. 991—998.
  34. ↑ Frizell LA, Goss SA, Kouzmanoff JT, Yang JM Sparse random ultrasound phased array for focal surgery // 1996 IEEE Ultrasonics Symposium. San Antonio, TX, Nov. 4-6. - 1996. - P. 1319-1323.
  35. ↑ 1 2 3 4 5 6 7 “Gavrilov L. R., Hand J., Yushina I. G.” Two-dimensional phased arrays for use in surgery: scanning with several foci // Acoust. journal - 2000. - T. 46, No. 5. - S. 632-639.
  36. ↑ 1 2 3 Gavrilov L. R. Two-dimensional phased arrays for use in surgery: multifocus generation and scanning // Acoust. journal - 2003. - T. 49, No. 5. - S. 604-612
  37. ↑ Gavrilov L. R. The possibility of creating focal regions of complex configuration as applied to problems of stimulation of receptor structures of a person by focused ultrasound // Acoustic Journal. - 2008. - T. 54, No. 1. - S. 1-12.
  38. ↑ Ilyin S.A., Yuldashev P.V., Khokhlova V.A., Gavrilov L.R., Rosnitsky P.B., Sapozhnikov O.A. Application of the analytical method to assess the quality of acoustic fields with electronic focus shifting of multi-element therapeutic lattices // Acoustic journal. −2015. - T. 61, No. 1. - C. 57-64
  39. ↑ Pernot M., Aubry J.-F., Tanter M., Thomas J.-L., Fink M. High power transcranial beam steering for ultrasonic brain therapy // Phys. Med. Biol. - 2003. - V. 48. - P. 2577-2589.
  40. ↑ 1 2 Hand, JW, Shaw, A., Sadhoo, N., Rajagopal, S., Dickinson, RJ & Gavrilov, LR A random phased array device for delivery of high intensity focused ultrasound // Phys. Med. Biol. - 2009. - V. 54. - P. 5675-5693.
  41. ↑ Yuldashev, PV & Khokhlova, VA Simulation of three-dimensional nonlinear fields of ultrasound therapeutic arrays // Acoustical Physics. - 2011. - V. 57, No. 3. - P. 334—343.
  42. ↑ Kreider, W., Yuldashev, PV, Sapozhnikov, OA, Farr, N., Partanen, A., Bailey, MR & Khokhlova, VA Characterization of a multi-element clinical HIFU system using acoustic holography and nonlinear modeling // IEEE Trans . Ultrason Ferroelec Freq. Contr.-2013. -V. 60, No. 8. - P. 1683-1698.
  43. ↑ Cain C. Histotripsy: Controlled mechanical sub-division of soft tissues by high intensity pulsed ultrasound // 5th International Symposium on Therapeutic Ultrasound, Boston, USA. - 2005 .-- P. 13.
  44. ↑ Kim Y., Hall TL, Xu Z., Cain CA Transcranial histotripsy therapy: a feasibility study. // IEEE Trans. Ultrason Ferroelectr. Freq. Ctrl. - 2014. - V. 61, No. 4. - P. 582-593.
  45. ↑ Lin KW, Kim Y., Maxwell AD, Wang TY, Hall TL, Xu Z., Fowlkes JB, Cain CA Histotripsy beyond the intrinsic cavitation threshold using very short ultrasound pulses: microtripsy.// IEEE Trans Ultrason Ferroelectr Freq Control. - 2014. - V. 61, No. 2. - P. 251-65.
  46. ↑ Gavrilov L.R., Sapozhnikov O.A., Khokhlova V.A. Spiral arrangement of elements of two-dimensional ultrasonic therapeutic gratings as a method for improving the quality of dynamic focusing and increasing intensity in focus // Izvestiya RAS. Ser. physical. −2015. - T. 79, No. 10. - P. 1386-1392.
  47. ↑ Jeanmonod, D., Werner, B., Morel, A., Michels, L., Zadicario, E., Schiff, G. & Martin, E. Transcranial magnetic resonance imaging-guided focused ultrasound: noninvasive central lateral thalamotomy for chronic neuropathic pain // Neurosurg. Focus - 2012. - V. 32, No. 1. - E1.
  48. ↑ Elias, W., J., Huss, D., Voss, T., Loomba, J., Khaled, M., Zadicario, E., Frysinger, R., C., Sperling, SA, Wylie, S. , Monteith, SJ, Druzgalm J., Shahm BB, Harrison, M., Wintermark, M. A pilot study of focused ultrasound thalamotomy for essential tremor // The New England Journal of Medicine. - 2013. - V. 369, No. 7. - P. 640—648.
  49. ↑ McDannold, N., Clement, G., Black, P. Jolesz, F., Hynynen, K. Transcranial MRI-guided focused ultrasound surgery of brain tumors: Initial findings in three patients // Neurosurgery. - 2010. - V. 66, No. 2. - P. 323-332.
  50. ↑ Monteith, S., Medel, R., Kassell, NF, Wintermark, W., Eames M., Snell J., Zadicario, E., Grinfeld J., Sheehan JP, Elias WJ Transcranial magnetic resonance-guided focused ultrasound surgery for trigeminal neuralgia: a cadaveric and laboratory feasibility study // Journal of Neurosurgery. - 2013. - V. 118, No. 2. - P. 319—328.
  51. ↑ Monteith, SJ, Harnof, S., Medel, R., Popp, B., Wintermark, M., Lopes, MB, Kassell, NF, Elias, WJ, Snell, J., Eames, M., Zadicario, E ., Moldovan, K., Sheehan, J. Minimally invasive treatment of intracerebral hemorrhage with magnetic resonance-guided focused ultrasound. Laboratory investigation // J. Neurosurg. - 2013. - V. 118, No. 5. - P. 1035-1045.

Literature

  • Gavrilov LR, Hand JW High-Power Ultrasound Phased Arrays for Medical Applications. - NY: Nova Science Publishers, 2014 .-- 200 p.
  • Skolnik M. Introduction to the technique of radar systems / Per. from English - M.: Mir, 1965. −747 p.
  • Gavrilov, L. R. Focused high-intensity ultrasound in medicine. - M .: Fazis, 2013. −656 s. - 978-5-7036-0131-2.
  • Ebbini ES, Cain CA Multiple-focus ultrasound phased array pattern synthesis: Optimal driving signal distributions for hyperthermia // IEEE Trans. Ultrason Ferroelec Freq. Ctrl. - 1989. - V. 36, No. 5. - P. 540-548.
  • Goss SA, Frizell LA, Kouzmanoff JT, Barich JM, Yang JM Sparse random ultrasound phased array for focal surgery // IEEE Trans. Ultras Ferroelectr. Freq. Ctrl. - 1996. - V. 43, No. 6. - P. 1111-1121.
  • Hutchinson EB, Buchanan MT, Hynynen K. Design and optimization of an aperiodic ultrasound phased array for intracavitary prostate thermal therapies // Med. Phys. - 1996. - V. 23, No. 5. - R. 767—776.
Source - https://ru.wikipedia.org/w/index.php?title=Ultrasonic_phased_grid&oldid=91986533


More articles:

  • Semenikhin, Vladimir Anatolyevich
  • Annexation of Central America by Mexico
  • Ganyo, Denis
  • Changchunsaurus
  • Rural Settlement Tupikskoye
  • Ost + Front
  • City settlement "Drovyaninsky"
  • Sitch Tammy Lynn
  • Olympia (cave, Ishimbay district)
  • Pokrovka (Luga District)

All articles

Clever Geek | 2019