Ultrasound radiating device

Abstract

An ultrasound radiator is disclosed comprising at least one ultrasound element configured for generating / transmitting acoustic waves in response to electrical excitation, a rigid support structure having a rear bottom surface coupled to a bottom surface of the at least one ultrasound element for propagation of the acoustic waves from the at least one ultrasound active element through a front surface of the rigid support structure, and at least one fluid channel formed in at least one peripheral portion of the rigid support structure for drawing heat therefrom by a cooling media streamed therealong.

Description

[0001] ULTRASOUND RADIATING DEVICE

[0002] TECHNOLOGICAL FIELD

[0003] The disclosure generally relates to ultrasound devices and systems and more specifically to ultrasound transducer configurations useful for cosmetic / aesthetic body contouring procedures.

[0004] BACKGROUND

[0005] Ultrasound (US) transducers convert electrical energy into mechanical (acoustic) energy based on the piezoelectric effect, and are used for a wide variety of medical applications including medical and cosmetic / aesthetic procedures, such as body contouring. Body contouring is a cosmetic procedure that is used to improve the shape and appearance of the body. It can be used to remove fat deposits, tighten skin, and reduce wrinkles. For example, in certain body contouring procedures ultrasound energy is externally applied to a body part of a living subject to non-invasively heat subdermal and / or subcutaneous tissue, e.g., fat deposits. In such procedures high-frequency (e.g., typically up to 3 MHz) sound waves travel through the skin and are absorbed in the underlying tissue, thereby converting the ultrasound energy into heat energy therein.

[0006] Particularly, the ultrasonic waves absorbed in the underlying tissue cause vibrations of the fat cells and subsequent rapid heating thereof, resulting in formation of pressure inside the fat cells that rupture them and release their contents. The contents of the ruptured fat cells are then egressed out of the body of the treated subject through the lymphatic system and by urine. Cavitation bubbles formed by the ultrasound waved in body liquids can help to break down the fatty acids released from the ruptured fat cells, thereby facilitating elimination thereof from the body of the treated subject.

[0007] A conventional ultrasonic transducer 1 is shown in Fig. 1. This conventional ultrasonic transducer 1 comprises a piezoelectric element la (also referred to herein as ultrasonic / active element) electrically connectable to a signal power source (not shown). The piezoelectric member la is typically made up of a PZT ceramic (e.g., lead zirconate titanate), a piezo-polymer composite or piezoelectric polymer. The piezoelectric member la can be shaped in a form of a plate (a single element transducer) having parallel opposite surfaces extending perpendicular to the propagation direction of the ultrasonic waves thereby generated.

[0008] The parallel opposite surfaces of the piezoelectric member la comprise electrodes situated thereon e.g., a positive electrode Ip in the back (upper) surface of the piezoelectric element la, and a ground electrode 1g on the front (lower) surface of the piezoelectric element la. The piezoelectric member la physically deforms in response to applied electrical signals at an ultrasonic driving frequency, and produces ultrasonic vibrations / acoustic waves transmitted towards the target tissue, with a wavelength of vibrations that corresponds to the thickness of the piezoelectric member la. For example, in a typical medical application, ultrasonic vibrations are emitted from the transducer into a coupling (e.g., liquid or gel) medium, and are transmitted through this coupling medium into the target tissue.

[0009] The piezoelectric member la is typically coupled to one or more anterior matching layers Im, which serves as an interface between the piezoelectric member la and the target tissue. The one or more matching layers Im are configured to maximize transmission of the ultrasound waves from the piezoelectric member la into the tissues by minimizing reflections that typically occur due to the acoustic impedance differences between the piezoelectric member la and the tissue. The interfacing to the tissue can be achieved by multiple layers of material with acoustic impedances that gradually change between the acoustic impedance of soft tissue to the acoustic impedance of the material of the piezoelectric member la or of a carrier member thereof.

[0010] Some ultrasound transducers employ a solid backing / damping element Id having acoustic impedance that is higher than the acoustic impedance of the material of the active element la. The interface between the backing / damping element Id and the active element la serves as a backing interface configured to facilitate reflection of ultrasound waves emitted from the posterior face of the active element la and reinforce the ultrasound wave emitted from its anterior face. For example, a transducer 1 utilizing a polymeric piezoelectric active element la may include a solid backing element Id formed from a metal or ceramic material, which serves as a backing interface that directs the acoustic waves reaching it towards the anterior surface of the piezoelectric member.

[0011] Since the high frequency acoustic energy generated in body contouring applications is induced into subdermal / subcutaneous target tissue by acoustic longitudinal waves, the heat thereby induced may cause undesired overheating of the underlying tissue, that may cause bums and ischemic skin injuries.

[0012] US Patent Publication No. 2011 / 282211 discloses an ultrasound probe having a forced cooling system for circulating a liquid through a probe cable. The ultrasound probe comprises of a handle unit including a plurality of ultrasound transducers, a flexible cable connected to the handle unit and a connector unit coupled to the cable. The cable includes a plurality of electric signal lines and a cooling liquid circulation flow channel. The circulation flow channel is comprised of an outward path for transmitting the cooling liquid from the connector unit to the handle unit, and a return path for transmitting the cooling liquid from the handle unit to the connector unit. At least either one of the outward path or the return path is comprised of a plurality of thin tubes.

[0013] US Patent Publication No. 2015 / 045670 discloses a matrix array probe including a transducer array and integrated circuitry coupled to the transducer elements dissipates heat generated by the array and integrated circuitry through the cover of the transducer probe. A pump in the probe connector pumps fluid through a closed loop system including inbound and outbound fluid conduits in the cable. The fluid conduits in the cable are separated by the cable electrical conductors for the probe. The heat transfer in the probe is done by a heat exchanger in the probe spaceframe or transducer stack backing block and may use a Peltier device. Additional cooling may be provided by metal to metal contact with a chiller in the ultrasound system.

[0014] US Patent Publication No. 2021 / 108866 discloses ultrasound devices and systems in which cooling of an active acoustic element of an ultrasound transducer is achieved via an electrically conductive member that extends beyond a proximal side of the active acoustic element to contact a heat exchanger. The electrically conductive member delivers electrical driving signals to the active acoustic element while conducting heat to the heat exchanger. A region of the proximal surface of the active acoustic element that is free from contact with the electrically conductive member may also absent from contact with a liquid or a solid, thereby facilitating reflection of ultrasound energy. The heat exchanger may include an electrically insulating fluid that contacts the electrically conductive member to remove the heat conducted through the electrically conductive member. The active acoustic element may be a multilayer lateral mode element, and the electrically conductive member may form an electrode of the lateral mode element. GENERAL DESCRIPTION

[0015] There is a need in the art for improved ultrasound transducing apparatuses and systems, and instrumentations for enabling safe and effective heating of subdermal and / or subcutaneous tissues, by accurate and precise delivery / application of ultrasound energy to a desired under-skin tissue regions of a treated subject, while significantly reducing and possibly preventing the risk of skin burns / injuries.

[0016] The present disclosure provides ultrasound waves generating and directing device configurations (referred to herein as US-radiators or ultrasound transducers), for aesthetic body contouring procedures, such as non-invasive heating of subdermal / subcutaneous tissues (e.g., adipose tissue and / or cellulite). The US-radiators disclosed herein enable selective application of ultrasound energy, for example unfocused ultrasonic waves, towards a target tissue to thereby heat a given underlying tissue volume thereof and cause controlled localized hyperthermia of the target tissue to promote cellular break- down / decomposition thereof, so as to achieve the desired aesthetic effect, while preventing overheating and possible damaging of adjacent tissue(s). To this end, US- radiators disclosed herein emulate focusing properties of a lens to provide “focused” heating effect of the selected sub-dermal target tissue.

[0017] In some embodiments the US-radiators hereof are configured to generate a temperature profile / gradient via acoustic energy inside the underlying tissue along and aligned with an interaction region between the US radiator and the skin of the treated subject, for forming a spherical region inside the underlying tissue with maximal temperature at the center of the spherical portion, and gradually decreasing temperature towards the peripheries thereof. In some embodiments, the US-radiator delivers acoustic energy to one or more subdermal tissue layers for heating a given area / volume of sub- dermal tissue to a sufficient temperature level to facilitate fat cell breakdown, while cooling the external surface of the skin for preventing skin burn injuries.

[0018] In embodiments hereof the US-radiator includes an ultrasound active element configured to direct the acoustic waves thereby produced in a direction perpendicular to a plane of the active element, towards a tissue of a body portion of a treated subject. Such an active element can comprise two surface electrodes electrically connected to a piezoelectric material (e.g., PZT transducer) disposed therebetween. In some embodiments, the ultrasound element is coupled to a rigid support structure, such as a metal plate, adapted for supporting passage of the acoustic waves therethrough for emission of the acoustic waves via its anterior surface, which may be in contact with or disposed adjacent to a body portion of the treated subject. The terms “active element” and “US active element “ are used interchangeably throughout this disclosure to refer to (e.g., piezoelectric) elements which physically deforms in response to an applied electrical driving signal at an ultrasonic driving frequency, and generates ultrasonic vibrations.

[0019] Optionally, but in some embodiments preferably, the US-radiators disclosed herein comprise one or more fluid channels passing along peripheries of the support structure e.g., passing through and / or extending along the support structure in parallel to its anterior / posterior surface ( / '.<?., perpendicular to propagation direction of the acoustic waves). The fluid channels are adapted for passage / flow of cooling media therethrough. As such, the fluid channel(s) facilitates cooling of the support structure and heatsinking the upper layers of the underlying tissue, as it is being heated due to propagation of the acoustic waves therethrough.

[0020] For example, the fluid channels can pass along peripheries of the support structure to create a temperature gradient along the support structure with a maximal temperature in the underlying tissue located under the middle / center of the support structure, and gradually decreasing temperature in the upper layers of the underlying tissue located under and towards the peripheries of the support structure. This way, in operation, the support structure can be in thermal communication with a tissue of a body portion to operate as heatsink. Namely, the US-radiator can draw heat from the upper layers of the underlaying tissue to thereby create an internal volumetric (e.g., spherical) region inside the treated tissue with maximal temperature in the center of the spherical region and gradually decreasing temperature towards peripheries thereof.

[0021] In possible embodiments, the US active element is enclosed within a cover element being sealingly coupled to the support structure. The cover element defines a confined space between it and the support structure, in which the US active element is situated. The confined space may be filled with gas, fluid, or other material with a high acoustic impedance (with respect to that of the support structure) for providing acoustic damping / backing .

[0022] In some applications the support structure of the US radiator is configured to provide a US radiator module connectable to support structure of one or more other US radiators. This way, a modular US applicator can be constructed by connecting two or more of the US radiator modules to form an array of US radiators having desired geometrical dimensions. Optionally, but in some embodiments preferably, the US radiator modules are configured to establish fluid communication between at least one of their fluid channels, to thereby form a common fluid channel by at least two US radiators of the US applicator thereby formed.

[0023] In some embodiments the support structures of at least some of the US radiator modules are configured with mating portions configured for improved engagement and connectivity between the US radiator modules. Optionally, but in some embodiments preferably, one or more of the mating portions of the support structures comprise fluid channel portions configured to establish fluid communication with fluid channel portions of mating portions of other US radiators, and thereby form one or more common fluid channels of the US applicator. In possible embodiments the mating portions of the support structures are configured with complimentary properties for obtaining unified and leveled US applicator structures.

[0024] In one aspect there is provided an ultrasound radiator comprising at least one ultrasound element (e.g., comprising a piezoelectrical material) configured for generating and / or transmitting acoustic waves in response to electrical excitation thereof, a rigid support structure having a bottom / rear surface coupled to a front surface of the at least one ultrasound element for propagation of the acoustic waves from the at least one ultrasound active element through a front surface of the rigid support structure. The ultrasound radiator further comprises in some embodiments at least one fluid channel e.g., formed in at least one peripheral portion of the rigid support structure, for drawing heat therefrom by a cooling media streamed therealong. In possible embodiments the support structure material comprises at least one of Aluminum and / or Ceramic.

[0025] The fluid channels of the rigid structure can be configured to induce a temperature gradient within an underlying subdermal tissue. The temperature gradient can have a maximal value under the center of the support structure, and gradually decreasing temperature values under peripheries of the rigid support structure. The rigid support structure can be configured to define at least one side wall projecting upwardly therefrom. The side wall can be configured to improve heatsink of the support structure. The ultrasound radiator can comprise an electrical connector coupled to the support structure.

[0026] The ultrasound comprises in some embodiments a cover element coupled to (e.g., rear surfacejthe rigid support structure for enclosing the at least one ultrasound element. The cover element can be configured to define a (e.g., sealed) compartment filled with a backing (e.g., gaseous) material configured to anteriorly reflect acoustic waves directed thereto. Optionally, the backing material is air.

[0027] In possible embodiments the rigid support structure is configured with complementary mating portions having a partial flow channel. The ultrasound radiator can be configured to generate ultrasonic waves in frequencies in the range 6 to 11 MHz, and / or with intensities in the range of 0.5 to 10 W / cm2. In possible applications the ultrasound radiator is configured to generate ultrasonic waves in frequencies in the range of 7 to 9 MHz, optionally in the range of 8 to 9 MHz.

[0028] In another aspect there is provided a modular ultrasound applicator comprising a plurality of ultrasound radiators, each configured according to any one of embodiments disclosed herein and arranged such that it's at least one fluid channel is in fluid communication with a fluid channel of at least another one of the plurality of ultrasound radiators. The modular ultrasound applicator can further comprise at least one fluid inlet port configured for streaming cooling media into a fluid channel of at least one of the ultrasound radiators. The modular ultrasound applicator can further comprise at least one fluid outlet port configured to allow egress of the cooling media out of the modular ultrasound applicator therethrough.

[0029] Optionally, but in some embodiments preferably, the modular ultrasound applicator is configured to define a fluid flow path along one or more peripheral sides thereof. The modular ultrasound applicator can further comprise a fluid communicating unit configured to fluidly communicate between fluid channels of at least two of the ultrasound radiators. In possible embodiments the fluid communicating unit is configured to form a U-shaped fluid flow path between the fluid inlet port and the fluid outlet port e.g., such that at least some, or all, of the ultrasound elements of the ultrasound radiators are enclosed within the U-shaped fluid flow path of the modular ultrasound applicator.

[0030] The plurality of ultrasound radiators can be configured to form a two-dimensional array comprising one or more columns of the ultrasound radiators arranged to form by their at least one fluid channel at least one fluid flow path therealong. In some embodiments the ultrasound radiators comprise complementary mating portions e.g., configured such that each one of the complementary mating portions having a partial flow channel. The ultrasound radiators of at least two of the one or more columns can be arranged to form a further fluid flow path by the partial flow channel of their complementary mating portions. The modular ultrasound applicator can be configured such that each ultrasound radiator in one of the columns of ultrasound radiators is fluidly coupled to a locally adjacent ultrasound radiator of another one of the column of ultrasound radiators. The partial fluid channel of each ultrasound radiator in the one of the columns can be connected in fluid communication with a partial fluid channel of a locally adjacent ultrasound radiator of at least another one of the columns of ultrasound radiators. The modular US applicator comprises in some embodiments first and second columns of the ultrasound radiators configured to define three fluid flow paths by their fluid channels.

[0031] In another aspect there is provide a method of fabricating an ultrasound radiator, the method comprising attaching at least one ultrasound element to a support structure, the support structure configured to transmit acoustic waves generated by the at least one ultrasound element therethrough into underlying tissue, and forming along at least one peripheral portion of the support structure at least one fluid channel configured for streaming a cooling media therethrough for drawing heat from the support structure. The method comprises in some embodiments forming the support structure with a (e.g., longitudinal) indentation defining a thickness of a tissue interfacing portion readily for propagation of acoustic waves therethrough, and two side walls confining the (e.g., longitudinal) indentation for heatsinking the support structure.

[0032] The method of claim can comprise forming the at least one fluid channel in one of the side walls, or in both of the two side walls, of the support structure. In a variant the method comprising using in the (e.g., longitudinal) indentation a gaseous substance as a backing component of the ultrasound radiator. The method can further comprise forming in one or more sides of the support structure mating portions configured for connecting the mating portion of the support structure to a mating portion of a support structure of at least one other ultrasound radiator.

[0033] The method comprises in possible embodiments configuring the at least one fluid channel to pass along the mating portion of the support structure for establishing fluid communication with a fluid channel passing along the mating portion of the support structure of the at least one other ultrasound radiator. Optionally, the method comprising coupling an electrical connector to the support structure and electrically connecting between the electrical connector and the at least one ultrasound element.

[0034] In another aspect there is provided a method of constructing an ultrasound applicator. The method comprising connecting two or more ultrasound radiators one to the other, each of the two or more ultrasound radiators configured according to any one of the embodiments disclosed herein, so as to form an array of the two or more of ultrasound radiators and establish fluid communication between fluid channels of support structures of at least two of the two or more of ultrasound radiators, to thereby form a fluid flow path in the ultrasound applicator for streaming cooling media therethrough.

[0035] The method optionally comprising determining a number of the ultrasound radiators used to construct the array such that a dimension of the array satisfies a geometrical dimension requirement of the ultrasound applicator e.g., allowing application of the US wave energy to define surface area of the tissue. The method comprises in some embodiments forming at least two fluid flow paths at peripheries of the ultrasound applicator by the fluid channels of support structures of the ultrasound radiators. In some embodiments the method comprising connecting to the array of ultrasound radiators a communicating unit configured to fluidly communicate between the at least two fluid flow paths of the support structures of the ultrasound radiators.

[0036] BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0038] Fig. 1 exemplifies a conventional ultrasound transducer;

[0039] Figs. 2A and 2B schematically illustrate a US radiator according to some possible embodiments, wherein Fig. 2A exemplifies a general configuration and operational principles of the US radiator, and Fig. 2B exemplifies heat distribution achieved by the US radiator utilizing cooling media;

[0040] Figs. 3A and 3B schematically illustrate US radiator implementations according to possible embodiments, wherein Fig. 3A exemplifies a US radiator having a rectangular radiating surface, and Fig. 3B exemplifies a US radiator having an L-shaped radiating surface;

[0041] Fig. 4 schematically illustrates a modular US applicator according to some possible embodiments constructed from a plurality of US radiators of Fig. 3B;

[0042] Fig. 5 schematically illustrates a US system according to some possible embodiments; and Figs. 6A to 6C show a modular US applicator implementation according to possible embodiments comprising six US radiators, wherein Fig. 6A shows a top view of the modular US applicator, Fig. 6B shows a bottom view of the modular US applicator, and Fig. 6C shows a thermal profile obtained utilizing the modular US applicator; and

[0043] Fig. 7 is a flowchart exemplifying construction of a US applicator, and application of a US session therewith, according to possible embodiments.

[0044] DETAILED DESCRIPTION OF EMBODIMENTS

[0045] The subject matter disclosed herein generally pertains to body contouring techniques and instrumentations, configured to apply US stimulations to subdermal tissue structures to facilitate localized heating thereof. One or more specific and / or alternative embodiments of the present disclosure will be described below with reference to the drawings, which are to be considered in all aspects as illustrative only and not restrictive in any manner. It shall be apparent to one skilled in the art that these embodiments may be practiced without such specific details. In an effort to provide a concise description of these embodiments, not all features or details of an actual implementation are described at length in the specification. Elements illustrated in the drawings are not necessarily to scale, or in correct proportional relationships, which are not critical. Emphasis instead being placed upon clearly illustrating the principles of the invention such that persons skilled in the art will be able to make the instrumentations and carry out related procedures therewith, once they understand the principles of the subject matter disclosed herein.

[0046] The body contouring techniques and instrumentations disclosed herein are configured to apply US wave energy to underlying tissue, which is usable for cosmetic / aesthetic procedures. A specially designed US radiator is disclosed, configured to apply periodic or intermittent US stimulations for inducing localized heating to a selected underlying tissue volume. The heated underlying tissue volume may comprise fat deposits, and the US radiator can be configured to restrict the heating thereby applied to a specific predefined area and / or volume of the underlying tissue for breaking- down / decomposing, removing and / or flattening of the fat deposits, and to prevent undesired overheating of adjacent tissues.

[0047] This disclosure may be provided in other specific forms and embodiments without departing from the essential characteristics described herein. For an overview of several example features, process stages, and principles of the invention, the US radiators / applicators and usage procedure examples thereof, illustrated schematically and diagrammatically in the figures, are intended for body contouring procedures. These applicators / systems and their usage procedures are shown as one example implementation that demonstrates a number of features, processes, and principles used to break, remove and / or flatten, fat from under-skin tissue structures, but they are also useful for other applications and can be made in different variations. Therefore, this description will proceed with reference to the shown examples, but with the understanding that the applicators / systems, and related techniques, recited in the claims below, can be also implemented in myriad other ways, once the principles are understood from the descriptions, explanations, and drawings herein. All such variations, as well as any other modifications apparent to one of ordinary skill in the art and useful in US applications, may be suitably employed, and are intended to fall within the scope of this disclosure.

[0048] Reference is made to Figs. 2A and 2B schematically illustrating an ultrasound (US) radiator 10 according to some possible embodiments. The US-radiator 10 is shown in operational state on a body part 14 of a treated subject, wherein it is in contact with the skin 14s for application of US wave energy thereto. The US-radiator 10 is provided with a rigid support structure (e.g., a metal plate) 10s mechanically coupled to at least one US active element / member lOt. Optionally, but in some embodiments preferably, the rigid support structure 10s is made of Aluminum.

[0049] The US active element lOt includes one or more piezo-electric active material(s), such as PZT (Lead Zirconate Titanate), or any other piezo-electric material, and / or any other material capable of generating acoustic energy waves. The support structure 10s can generally be of any geometrical configuration. For example, the support structure 10s can be configured with a substantially rectangular US emitting surface 10s", or with a substantially “L”-shaped US emitting surface (10s'" in Fig. 3B). However, other geometrical configurations of the support structure 10s can be alternatively employed, such as triangular- shaped structures and / or other polygon shape structures.

[0050] The US active element lOt has an anterior surface lOt” coupled to a posterior surface 10s’ of the support structure 10s, and an opposite posterior surface 10t’. The US active element lOt is configured to generate ultrasonic vibrations (acoustic waves) in response to an electrical driving signal applied thereto, and to emit the acoustic waves via its anterior surface lOt" in a direction D substantially perpendicular thereto, towards a target sub-dermal tissue, generally at 12. The rigid support structure 10s is adapted for allowing propagation of acoustic waves therethrough into the tissue 12 from its anterior surface 10s”.

[0051] Optionally, but in some embodiments preferably, the US-radiator 10 includes a cover element / casing 10c coupled to the posterior surface 10s' of the rigid support structure 10s, and configured to enclose the US active element lOt therein, so as to form a (e.g., sealed) compartment 10m for the US active element lOt e.g., to prevent condensation of humidity on the US active element lOt and / or penetration of moisture and / or of the coupling medium (e.g., oil / gel) usable in US procedures for coupling between the support structure 10s and the skin 14s of the treated subject.

[0052] Optionally, but in some embodiments preferably, the (e.g., sealed) compartment 10m, with the US active element lOt mounted in it, is filled with a substance lOq having high acoustic impedance (e.g., air or other fluid / gaseous medium) with respect to acoustic impedance of the material of the US active element lOt. Consequently, in operation, this acoustic impedance difference reflects posteriorly propagating acoustic wave energy generated by the US-radiator 10 to redirect the acoustic wave energy anteriorly from the posterior surface 10t’ of the support structure 10s in a direction D towards the target tissue 12.

[0053] In some embodiments the support structure 10s includes at least one fluid channel formed therein and configured for streaming a cooling media therethrough, thereby improving heatsink capabilities of the support structure 10s. In this non-limiting example two such fluid channels are shown, namely, a first and a second fluid channel, lOf and lOe respectively, located in proximity to edges / peripheries of the support structure 10s. In this embodiment the US active element lOt is located above an operative region lOr of the support structure 10s located between the fluid channels lOf and lOe, so as to prevent distortions to the ultrasound waves R propagating therethrough, that can occur due to the fluid channel 10f,10e and / or the cooling media streamed therethrough.

[0054] In operation, the first and second fluid channels lOf and lOe create a temperature profile / gradient along axis LI of the support structure 10s and an interface / interaction region thereof with the skin of the treated tissue. In some embodiments, such a temperature profile has a maximum value in the tissue 12 located under the center of the support structure 10s e.g., at the center of the operative region lOr, and gradually decreasing temperature values towards regions of the tissue 12 located under peripheries of the support structure 10s e.g., at the edges of the operative region lOr. More specifically, the temperature profile of the temperature gradient increases in the direction D from the support structure 10s towards the axis L2 at a certain depth (e.g., about 1 to 15 mm, optionally about 1 to 25 mm, or about 1 to 30 mm, from the skin surface) inside the tissue 12 and gradually decreases downwardly from the axis L2.

[0055] Fig. 2B demonstrates the cooling effect obtained when cooling media C is streamed through the fluid channels lOf and lOe. This cooling effect in conjunction with spatial attenuation of the acoustic waves R (loss of mechanical energy) at the peripheries of the beam, as it propagates away from the wave source (US -radiator 10) in the direction D, forms a hot volumetric (e.g., spherical) region 12' at a certain depth at L2. The depth W of the hot volumetric region 12' can be controlled as function of the frequency of the US waves propagating inside the target tissue 14. A temperature gradient of the hot volumetric region 12' is characterized by a maximal value at a center of the hot volumetric region 12' (e.g., about 42 to 55 °C), which gradually decreases towards the peripheries thereof (z.e., towards regular body temperatures) to the regular tissue / body temperature. Fig. 2B also graphically illustrates the temperature profile 12p along the hot volumetric region 12', namely the temperature T as a function of position X along the axis L2 of the hot volumetric portion 12.

[0056] The actual shape and size of the hot volumetric region 12' are a function of the size of the US active element lOt and / or the frequency and / or the amplitude of the ultrasound waves R applied to the target tissue 12 z.e., the frequency and / or the amplitude of the electrical signal driving the US-radiator 10. The traversal radius r of the hot volumetric region 12' can be controlled to some extent by the temperature and / or flow rate of the cooling media C streamed through the fluid channels lOf and lOe. In possible embodiments the dimensions of the hot volumetric region 12' are controllably adjusted by setting suitable frequency and / or amplitude of the ultrasound waves R (z.e., of the electrical driving signal), and / or adjusting temperature and / or flow rate of the cooling media C.

[0057] With reference to Fig. 3A, in some embodiments, the US-radiator 10' includes two (e.g., vertical) side walls lOw projecting upwardly from the support structure 10s. The two (e.g., vertical) side walls lOw define a (e.g., longitudinal) channel lOv confined therebetween and passing along a length of the support structure 10s, and configured to improve heatsinking properties of the support structure 10s. The US active element lOt is attached in this embodiment inside the (e.g., longitudinal) channel lOv to the support structure 10s. In this non-limiting example the fluid channels lOf and lOe are formed inside the (e.g., vertical) side walls lOw, thereby allowing use of a relatively thin support structure 10s e.g., having thickness T of its bottom part of about 0.1 to 0.5 cm and having relatively thick side walls lOw e.g., having a width Y of about 0.5 to 1.0 cm and height H of about 1.0 to 5.0 cm.

[0058] The (e.g., longitudinal) channel lOv thus defines therealong a tissue interfacing portion lOi of the support structure 10s, having a reduced thickness T through which the acoustic waves generated by the US active element lOt readily propagate into the underlying tissue. The two side walls lOw can be configured to heatsink the support structure 10s, with or without the fluid channels lOf and lOe.

[0059] The US active element lOt may be electrically coupled to an external electric signal power source (13 in Fig. 5) configured for generation of the US waves R e.g., by voltage pulse trains of defined frequency and amplitude. For example, as shown in Fig. 3A, the US active element lOt may be electrically connected by wires lOr, e.g., to an electric connector 10c, which may be mounted to a support wall lOp projecting upwardly from one of vertical side walls lOw. Optionally, the wires lOr are electrically connected to an electric connector 10c laterally (outwardly) projecting from the support wall lOp.

[0060] Optionally, but in some embodiments preferably, the (e.g., longitudinal) channel lOv, with the US active element lOt mounted in it, is filled with a backing substance having high acoustic impedance (e.g., air or other fluid / gaseous media), to thereby guarantee that the US waves generated by the US active element lOt towards its posterior surface 10t’ are thereby reflected to directionally propagate anteriorly via the anterior face lOt" of the US active element lOt, and via the anterior face 10s" of the support structure 10s, into the target tissue.

[0061] As shown in Fig. 3B, in some embodiments, at least one of the vertical side walls 10w' of the US applicator 10" extends along a partial length of the rigid support structure 10s, thereby defining a recess S such that a segment / portion 10g of the respective fluid channel passes through the partial vertical side wall 10w', while the other fluid channel lOe fully passes through the other vertical side wall lOw of the support structure 10s on an opposite side thereof.

[0062] Optionally, but in some embodiments preferably, the partial vertical side wall 10w' and the recess S are configured to define complementary mating portions of the support structures of US applicators 10" for facilitating connection of such US applicators 10" usable for construction of modular US applicators. The partial fluid channel 10g formed in the partial vertical side wall 10w' of such US applicator modules 10" can be configured to establish fluid communication with the partial fluid channel 10g of at least another US applicator modules 10", to thereby form at least one mutual fluid channel.

[0063] The US applicators 10, 10', 10" of embodiments hereof are configured in some embodiments to generate unfocused ultrasonic waves in frequencies in the range of 6 to 11 MHz, optionally in the range of 5 to 10 MHz. In possible embodiment the US applicators 10, 10', 10" are configured to generate unfocused ultrasonic waves with intensities in the range of 0.5 to 10 W / cm2, optionally in the range of 1 to 5 W / cm2.

[0064] Reference is made to Fig. 4 schematically illustrating a modular US applicator 100 according to some possible embodiments. The modular US applicator 100 is configured to define a fluid flow path 30n between a fluid inlet port 30i configured for receiving cooling media (e.g., water streamed from a cooling media source) and a fluid outlet port 30u configured for enabling egress of the cooling media therethrough. In some embodiments such a fluid flow path 30n defines a substantially “U”-shaped flow path, as demonstrated in Fig. 4.

[0065] In some embodiments, the modular US applicator 100 includes a two-dimensional array / matrix 30 of the US radiator modules (e.g., 10", shown in Fig. 3B). The array 30 is formed by a first column / sub-array 30a and a second column 30b of US-radiators, denoted respectively 10a and 10b. The US-radiators 10a, 10b of each column are arranged in a cascade such that their first fluid channels lOf are respectively aligned for fluid communication with one another, to thereby form a first peripheral fluid channel 30p, and a second peripheral fluid channel 30p’ of the modular US stimulation system 100. The first peripheral fluid channel 30p is fluidly coupled to the inlet fluid port 30i for receiving the cooling media therethrough and the second peripheral fluid channel 30p’ is fluidly coupled to the outlet fluid port 30u for egressing the cooling media therethrough out of the modular US applicator 100.

[0066] As shown in Fig. 4, the first and second US-radiators 10a and 10b of the respective columns 30a and 30b are shaped and arranged to enable fluid communication with one another. In possible embodiments, each two locally adjacent (z.e., in each row) US-radiators 10a and 10b are assembled in a complementary configuration to from a rectangular structure, configured such that their respective fluid channels 10g and 10g’ are connected for fluid communication with one another. In some embodiments, the partial vertical side wall 10w' of each of the US-radiator modules 10a and 10b is at least partially received within the indentation S of the other locally adjacent US-radiator module. Consequently, the fluid channels 10g and 10g’ of all the US-radiator modules 10a and 10b in the array 30 are respectively aligned between them for fluid communication with one another, to thereby form together an intermediate channel 30e. In some embodiments, the modular US applicator 100 is provided with an auxiliary fluid inlet / outlet port 30x coupled to the intermediate channel 30e and configured to enable egress / ingress of the cooling media thereto / therefrom.

[0067] Optionally, but in some embodiment preferably, the modular US applicator 100 further includes a fluid communicating unit 30c configured to fluidly communicate between the peripheral fluid channels 30p and 30p', for flow of cooling media therethrough. Optionally, the fluid communicating unit 30c is further configured to fluidly communicate between the peripheral fluid channels 30p,30p' and the intermediate channel 30e. For example, the fluid communicating unit 30c can have a connecting fluid channel 30h extending therealong and fluidly couplable to the peripheral channels 30p,30p', and possibly also to the intermediate channel 30e connectable to the fluid channels lOf and optionally 10g, 10g'. This way, the peripheral fluid channels 30p,30p' and the fluid communicating unit 30c form together one or more of the substantially “U”- shaped flow paths 30n between the fluid inlet and fluid outlet ports, 30i and 30u.

[0068] Fig. 4 exemplifies introducing the cooling media into the peripheral fluid channel 30p via the intermediate channel 30e, for passage via the connecting fluid channel 30h of the fluid communicating unit 30c into the peripheral fluid channel 30p' and / or the intermediate channel 30e, and discharge via the outlet fluid port 30u and / or the auxiliary fluid inlet / outlet port 30x. In some embodiments, the modular US applicator 100 can be configured to utilize the intermediate channel 30e to define different fluid flow paths therein.

[0069] For example, the cooling media may be introduced into the modular US applicator 100 via the inlet fluid port 30i for passage through the peripheral fluid channel 30p, and also via the auxiliary fluid inlet / outlet port 30x for passage through the intermediate fluid channel 30e the connecting fluid channel 30h, and therefrom into the peripheral fluid channel 30p' for discharge through the outlet fluid port 30u. Alternatively, the cooling media may be introduced into the the modular US applicator 100 via the auxiliary fluid inlet / outlet port 30x for passage through the intermediate fluid channel 30e and therefrom into the peripheral fluid channels 30p and 30p', and discharge through the outlet fluid port 30u and / or the inlet fluid port 30i.

[0070] In some embodiments, the intermediate channel 30e is associated with a valve 30v configured to be switchable between an open state, in which the intermediate channel 30e is open to enable flow of at least a portion of the cooling media therethrough, and a closed state in which the intermediate channel 30e is closed and the cooling media flows in the fluid communicating unit 30c towards the peripheral fluid channel 30p’ in the “U”-shaped flow line 30n. The valve 30v can be configured to assume intermediate states for controllably regulating the flow of the cooling media.

[0071] Reference is made to Fig. 5 schematically illustrating a US stimulation system 500 utilizing the modular US applicator 100, according to some possible embodiments. Each of the US radiator modules 10a and 10b can be operatively coupled to a signal generator 13 configured to periodically or intermittently generate electric-current stimulation signals applied to the respective US active element / member (lOt), thereby activating it to vibrate and emit acoustic waves (R). One or more sensor elements 18 can be used in (or external to) the modular US applicator 100, for generation of measurement data / signals 18d indicative of one or more skin and / or under-skin measures or conditions (e.g., temperature, thicknesses and / or depths of under-skin tissue structures) at the treated body part.

[0072] Optionally, but in some embodiments preferably, as shown in Fig. 5, the US stimulation system 500 is in fluid communication with a fluid cooling unit 16 , and / or fluid reservoir 16r, for streaming the cooling media into the modular US applicator 100 via at least one of the fluid inlet port 30i, fluid outlet port 30u, and / or the fluid inlet / outlet port 30x. The fluid cooling unit 16 can be configured and operable for regulating temperature of the cooling media at least partially based on the measurement data / signals 18d generated by the one or more sensor elements 18.

[0073] Optionally, but in some embodiments preferably, the system 500 includes a control unit 15 having an input / output (I / O) module 15i configured to communicate control / operational data / signals 13d, 16d, and the measurement data / signals 18d, for operation of the signal generator 13 and / or the fluid cooling unit 16. The control unit 15 generally comprises one or more processors 15c and memories 15m, which can be configured to select one or more of the US -radiator modules 10a and 10b for application of the electric stimulation by the signal generator 13 thereto, and / or adjust and / or regulate the US stimulations generated thereby, at least partially based on the measurement data / signals 18d generated by the one or more sensor elements 18.

[0074] For example, in possible embodiments the control unit 15 comprises an electric stimulation module 15e configured and operable to generate the control data / signals used for operating one or more of the US radiator modules 10a and 10b. The electric stimulation module 15e can further be configured for manipulating the temporal and / or spatial parameters of the acoustic waves e.g., including inter alia, the frequency, drive amplitude, and timing of the driving electrical signals 13s supplied to the US radiator modules 10a and 10b by the signal generator 13. Additional modules can be used in the control unit 15 for processing and analyzing the measurement data / signals 18d from the one or more sensors 18, and based thereon determine operational parameters for use by the signal generator 13 in generation / adju sting of the control data / signals 13d.

[0075] Optionally, but in some embodiments preferably, the US stimulation system 500 utilizes one or more tissue imaging units (e.g., US imagers) 19 either in the modular applicator (or external thereto) 100, for visualizing underlying tissue structures and generating imagery measurement data / signals 19d indicative thereof. The control unit 15 in embodiments hereof can be configured to control and / or regulate the stimulations applied by the US radiator modules 10a, 10b, at least partially based on the imagery measurement data / signals 19d from the one or more tissue imaging units 19 and / or the measurement data / signals 18d from the one or more sensor elements 18. The control unit 15 can be configured to select one or more of the US-radiator modules 10a, 10b for periodic or intermittent application of the US-stimulation by the modular US applicator 100, by controlling the signal generator 13 to apply the periodic or intermittent electriccurrent stimulations.

[0076] Optionally, but in some embodiments preferably, the control unit 15 further includes an analysis module 15a configure to receive and process the measurement data / signals 18d generated by the one or more sensor elements 18 and / or the imagery measurement data / signals 19d generated by the one or more tissue imaging units 19. The processed data from the analysis module 15a can be displayed in a display device (e.g., LCD, VGA, LED or touch screen) 15y, with or without the measurement data / signals 18d from the one or more sensor elements 18 and / or the imagery measurement data / signals 19d from the one or more tissue imaging units 19. The control unit 15 can be configures for determining, based on the analysis carried out by analysis module 15a, and / or the measurement data / signals 18d from the one or more sensor elements 18, and / or the imagery measurement data / signals 19d from the one or more tissue imaging units 19, operational parameters of the control data / signals 13d for use by the signal generator 13 in generation of the stimulation signals.

[0077] For example, in some embodiments the one or more sensor elements 18 include a temperature sensor configured to measure the temperature of the cooling media C inside the modular US applicator 100 and / or at its fluid outlet port 30u. The control unit 15 can be accordingly configured with a temperature control module 15t configured to receive and process the measurement data / signals 18d from the one or more sensor elements 18, and based thereon generate control signals 16d instructing the fluid cooling unit 16 to adjust at least one of the temperature and / or the flowrate of the cooling media C, so as to guarantee that the target tissue is not overheated.

[0078] Figs 6A and 6B show top and bottom views of an implementation of the modular US applicator 100 having six (6) US radiator modules 10" arranged in two columns with three (3) US radiator modules 10" in each column. Fig. 6C depicts heat distribution achieved using the modular US applicator 100. This heat distribution was measured / pictured using a thermal camera (19) immediately after applying a US treatment / session. As seen, maximal heat is obtained in the tissue regions located under the centers of the support structures (10s) of the US-radiators (10"), and the tissue regions located under the cooling media flow path 30p,30p' (30n) are substantially cooler, thereby achieving spherical heat distributions (12'), such as demonstrated in Fig. 2B.

[0079] Fig. 7 is a flowchart exemplifying application of a US session 70 according to possible embodiments. The process may start in determining a structure of the modular US applicator (si) usable to achieve one or more heat distribution profiles suitable for the desired US session 70 e.g., determining number of rows and / or columns of the array (30) of US radiator modules. The determined desired modular applicator structure can be then used to determine a suitable cooling media flow path (s2 e.g., 30n) usable for adjusting and shaping the one or more desired heat distribution profiles. The modular US applicator (100) can be then constructed (s4) by connecting a number of the US radiator modules to achieve the desired modular US applicator's structure (30) and flow path (30c).

[0080] Once the desired US applicator's structure (30) and cooling media flow path (30n) are obtained, the US applicator (100) can be connected (s5) to a suitable stimulator (13) and cooling media source (16). Optionally, the US applicator's construction steps (si to s3) further include connecting (s4) one or more fluid communicating units (30c) to the array (30), if so needed, for obtaining the required cooling media flow path (30n). Thereafter, one or more US stimulation cycles can be applied (s6) by controlled activation of the stimulator unit and concurrently streaming the cooling media through the cooling media flow path (30n).

[0081] If more US stimulation cycles are required (s7) one or more further US stimulation cycles can be applied (s6), optionally using a heating profile shaping sequence (s8 to slO). Otherwise, if there is no need for more US stimulation cycles, the US session can be stopped (sll).

[0082] For example, a heat distribution profile (60) can be measured (s8) using one or more sensors (18,19). The heat distribution profile (60) can be then processed and analyzed to determine (s9) if the desired heat distribution profile is achieved. If there is no need to shape the heat distribution profile achieved, the application of the US stimulation cycles (s7) can be then repeated one or more times. Otherwise, if there is a need to shape the heat distribution profile achieved, operational parameters of the stimulator and / or of the cooling media source can be adjusted (slO) before applying any further US cycles e.g., frequency and / or amplitude of the US driving signals supplied to the US radiators, and / or temperature and / or flowrate of the cooling media streamed through the US applicator.

[0083] Relative terms such as "lower," "upper," "horizontal," "vertical," "above," "below," "up," "down," "top" and "bottom", as well as derivatives thereof (e.g., "horizontally," "downwardly," "upwardly," etc.), and similar adjectives in relation to orientation of the described elements / components refer to the manner in which the illustrations are positioned on the paper, not as any limitation to the orientations in which these elements / components can be used in actual applications. It should also be understood that throughout this disclosure, where a process or method is shown or described, the steps / acts of the method may be performed in any order and / or simultaneously, and / or with other steps / acts not-illustrated / described herein, unless it is clear from the context that one step depends on another being performed first. In possible embodiments not all of the illustrated / described steps / acts are required to carry out the method.

[0084] As described hereinabove and shown in the associated figures, the present invention provides stimulation applicators and systems for body contouring, and related methods. While particular embodiments of the invention have been described, it will be understood, however, that the invention is not limited thereto, since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. As will be appreciated by the skilled person, the invention can be carried out in a great variety of ways, employing more than one technique from those described above, all without exceeding the scope of the claims.

Claims

CLAIMS:

1. An ultrasound radiator comprising: at least one ultrasound element configured for generating acoustic waves in response to electrical excitation thereof; a rigid support structure having a bottom surface coupled to a bottom surface of the at least one ultrasound element for propagation of the acoustic waves from the at least one ultrasound element through a front surface of said rigid support structure; and at least one fluid channel formed in at least one peripheral portion of said rigid support structure for drawing heat therefrom by a cooling media streamed therealong.

2. The ultrasound radiator of claim 1, wherein the at least one ultrasound element comprises a piezoelectrical material.

3. The ultrasound radiator of claims 1 or 2, wherein the support structure material comprises at least one of Aluminum and Ceramic.

4. The ultrasound radiator of any one of the preceding claims, wherein the fluid channels of the rigid structure are configured to induce a temperature gradient within a subdermal tissue, said temperature gradient has a maximal value under the center of the support structure and gradually decreasing temperature values under peripheries of the rigid support structure.

5. The ultrasound radiator of any one of the preceding claims, wherein the rigid support structure defines at least one side wall projecting upwardly therefrom configured to improve heatsink thereof.

6. The ultrasound radiator of any one of the preceding claims, comprising a cover element coupled to the rigid support structure for enclosing the at least one ultrasound element.

7. The ultrasound radiator of claim 6, wherein the cover element defines a compartment filled with a backing material configured to anteriorly reflect acoustic waves directed thereto.

8. The ultrasound radiator of claim 7, wherein the backing material is air.

9. The ultrasound radiator of any one of the preceding claims, wherein the rigid support structure configured with complementary mating portions having a partial flow channel.

10. The ultrasound radiator of any one of the preceding claims configured to generate ultrasonic waves in frequencies in the range 6 to 11 MHz.

11. The ultrasound radiator of any one of claims 1 to 9 configured to generate ultrasonic waves in frequencies in the range 8-9 MHz.

12. The ultrasound radiator of any one of the preceding claims configured to generate ultrasonic waves with intensities in the range of 0.5 to 10 W / cm2.

13. A modular ultrasound applicator comprising a plurality of ultrasound radiators, each configured according to any one of claims 1 to 12 and arranged such that its at least one fluid channel is in fluid communication with a fluid channel of at least another one of said plurality of ultrasound radiators.

14. The modular ultrasound applicator of claim 13 further comprising at least one of the following: at least one fluid inlet configured for streaming cooling media into a fluid channel of at least one of the ultrasound radiators; and / or at least one fluid outlet port configured to allow egress of the cooling media out of the modular ultrasound applicator therethrough.

15. The modular ultrasound applicator of claims 13 or 14, configured to define a fluid flow path along peripheral sides thereof.

16. The modular ultrasound applicator of any one of claims 13 to 15, further comprising at least one fluid communicating unit configured to fluidly communicate between fluid channels of at least two of the ultrasound radiators.

17. The modular ultrasound applicator of claim 16, wherein the at least one fluid communicating unit is configured to form a U-shaped fluid flow path between the fluid inlet port and the fluid outlet port.

18. The modular ultrasound applicator of any of claims 13 to 17, wherein the plurality of ultrasound radiators are configured to form a two-dimensional array comprising one or more columns of the ultrasound radiators arranged to form by their at least one fluid channel at least one fluid flow path therealong.

19. The modular ultrasound applicator of claim 18, wherein the ultrasound radiators comprise complementary mating portions, each of said complementary mating portions having a partial flow channel, and wherein the ultrasound radiators of at least two of the one or more columns are arranged to form a further fluid flow path by the partial flow channel of their complementary mating portions.

20. The modular ultrasound applicator of claim 18 or 19, wherein each ultrasound radiator in a first column is fluidly coupled to a locally adjacent ultrasound radiator of a second column, wherein a second fluid channel of each ultrasound radiator in the firstcolumn is in fluid communication with a second fluid channel of a locally adjacent ultrasound radiator of the second column.

21. The modular ultrasound applicator of any one of claims 18 to 20, comprising first and second columns of the ultrasound radiators configured to define three fluid flow paths by their fluid channels.

22. A method of fabricating an ultrasound radiator, the method comprising: attaching at least one ultrasound element to a support structure, said support structure configured to transmit acoustic waves generated by said at least one ultrasound element therethrough into underlying tissue; and forming along at least one peripheral portion of said support structure at least one fluid channel configured for streaming a cooling media therethrough for drawing heat from said support structure.

23. The method of claim 22 comprising forming the support structure with an indentation defining a thickness of a tissue interfacing portion for propagation of acoustic waves therethrough, and two side walls confining said indentation for heatsinking said support structure.

24. The method of claim 23 comprising forming the at least one fluid channel in one or both of the side walls.

25. The method of claims 23 or 24 comprising using in the indentation a gaseous substance as a backing component of the ultrasound radiator.

26. The method of any one of claims 22 to 25 comprising forming in one or more sides of the support structure mating portions configured for connecting the mating portion of said support structure to a mating portion of a support structure of at least one other ultrasound radiator.

27. The method of claim 26 comprising configuring the at least one fluid channel to pass along the mating portion of the support structure for establishing fluid communication with a fluid channel passing along the mating portion of the support structure of the at least one other ultrasound radiator.

28. The method of any one of claims 22 to 27 comprising coupling an electrical connector to the support structure and electrically connecting between said electrical connector and said at least one ultrasound element.

29. A method of constructing an ultrasound applicator, the method comprising connecting two or more ultrasound radiators one to the other, each of said two or more ultrasound radiators configured according to any one of claims 1 to 12, so as to form anarray of said two or more of ultrasound radiators and establish fluid communication between fluid channels of at least two of said two or more of ultrasound radiators to thereby form a fluid flow path in said ultrasound applicator for streaming cooling media therethrough.

30. The method of claim 29 comprising determining a number of the ultrasound radiators used to construct the array such that a dimension of said array satisfies a geometrical dimension requirement of said ultrasound applicator.

31. The method of claims 29 or 30 comprising forming at least two fluid flow paths at peripheries of the ultrasound applicator by the fluid channels of the ultrasound radiators.

32. The method of claim 31 comprising connecting to the array of ultrasound radiators a communicating unit configured to fluidly communicate between the at least two fluid flow paths.

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