Ultrasonic Transducer Assembly

Abstract

The ultrasound transducer assembly is connectable to an ultrasound system and includes one or more ultrasound transducer elements supported by a cap. The ultrasound transducer elements are operable to direct ultrasound energy toward and / or receive echo ultrasound energy from brain tissue of a subject when the ultrasound transducer assembly is worn on the subject's head. Some embodiments include a fillable jacket coupled to an inner surface of the cap and in acoustic contact with the one or more transducer elements.

Description

[Technical field]

[0001] The present invention relates generally to ultrasound transducers, and more particularly to an ultrasound transducer assembly connectable to an ultrasound system for delivering ultrasound energy to and / or receiving echo ultrasound energy from a subject's brain tissue. [Background technology]

[0002] Ultrasound is often used medically to detect abnormal masses (e.g., tumors) and / or changes in the appearance of organs and tissues. In an ultrasound examination, an ultrasound transducer sends out high frequency sound waves and detects echo waves reflected by organs, tissues, etc. Ultrasound can be delivered to brain tissue for both therapeutic and diagnostic purposes.

[0003] To establish good acoustic coupling between the ultrasound transducer elements and the patient's tissue, a good acoustic coupling medium must be located between the ultrasound transducer elements and the tissue to provide an efficient path for ultrasound propagation. Therefore, medical practitioners commonly perform ultrasound examinations by manually pressing an ultrasound probe against the patient's skin.

[0004] The brain is contained within a rigid skull that has a curved surface. The contours of the skull or head are usually irregular and non-linear. The shape and size of the skull can also vary from subject to subject.

[0005] In some cases, it is desirable to use multiple ultrasound transducer elements to deliver ultrasound waves to the subject's brain. For example, it may be desirable to use multiple transducers to increase the signal-to-noise ratio and / or to provide efficient coverage of the target area. In such cases, multiple ultrasound transducer elements may be provided as part of an ultrasound transducer assembly.

[0006] Designing an ultrasound transducer assembly for delivering ultrasound energy to the brain is made difficult by the presence of the skull. The physical and acoustic properties of the skull present challenges to coupling ultrasound energy in and out of the brain. Some ultrasound transducer assemblies (such as those used for diagnostic imaging) are not designed to fit the complex contours of the skull or head, leaving gaps that can result in poor acoustic coupling between the transducer elements and brain tissue. Other ultrasound transducer assemblies are not adaptable to a variety of patients or require long set-up times. Summary of the Invention [Problem to be solved by the invention]

[0007] There remains a need for an ultrasound transducer assembly that can accommodate the different sizes and shapes of different patient heads. There also remains a need for an ultrasound transducer assembly that provides good acoustic coupling between the ultrasound transducer and the subject's brain. [Means for solving the problem]

[0008] The foregoing examples of the related art and limitations associated therewith are intended to be illustrative, not exhaustive. Other limitations of the related art will become apparent to those of ordinary skill in the art upon reading this specification and studying the drawings.

[0009] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools, and methods that are meant to be exemplary and illustrative rather than limiting in scope. In various embodiments, one or more of the above-described problems are reduced or eliminated, while other embodiments are directed to other improvements.

[0010] The present invention has several aspects, including but not limited to the following: An ultrasound transducer assembly useful for delivering ultrasound energy to the brain; an ultrasound transducer assembly having a fillable jacket for acoustic coupling with a subject's head; Fillable jackets for ultrasonic transducer assemblies, an ultrasonic transducer assembly including a positionable transducer; and Related methods.

[0011] One aspect of the invention relates to an ultrasonic transducer assembly connectable to an ultrasonic system. The assembly comprises a mechanical substructure having an outer surface and an inner surface. The inner surface is shaped to define a cavity therein. The mechanical substructure supports one or more ultrasonic transducer elements. Each of the ultrasonic transducer elements is operable to direct ultrasonic energy toward the cavity and / or receive echo ultrasonic energy. The assembly also comprises a fillable jacket coupled to the inner surface of the mechanical substructure and in acoustic contact with the one or more transducer elements. The fillable jacket lines the inner surface of the mechanical substructure. The fillable jacket comprises a deformable receptacle for maintaining a volume of acoustic transmission fluid within a deformable chamber of the receptacle, a port in fluid communication with the deformable chamber, and a valve for controlling fluid flow through the port, thereby controlling the volume of acoustic transmission fluid within the deformable chamber.

[0012] In some embodiments, the fillable jacket is acoustically coupled to the mechanical sub-structure, hi some embodiments, a layer of acoustic coupling gel is located between the fillable jacket and the mechanical sub-structure.

[0013] The deformable receptacle may be made of a material selected from the group consisting of polyurethane, latex, and silicone. The acoustic transmission fluid may be selected from the group consisting of degassed water, mineral oil, and gel.

[0014] In some embodiments, the ultrasonic transducer assembly includes a second port in fluid communication with the deformable chamber and a second valve for controlling fluid flow through the second port. The first port may be placed in fluid communication with an output of the hydraulic system through the first valve to receive the acoustic transmission fluid into the deformable chamber. The second port may be placed in fluid communication with an input of the hydraulic system through the second valve to return the acoustic transmission fluid from the deformable chamber to the hydraulic system. The hydraulic system may include electronics configured to continuously pump the acoustic transmission fluid into the deformable chamber through the first port and continuously withdraw the acoustic transmission fluid from the deformable chamber through the second port. In some embodiments, the first and second valves include respective electronic sensors configured to detect a rate of fluid flow through the respective valves.

[0015] In some embodiments, the ultrasonic transducer assembly includes an air bubble detector for detecting an air bubble in the acoustic transmission fluid. The air bubble detector may include at least one of the ultrasonic transducer elements (i.e., an ultrasonic transducer element configured to deliver a pulse of ultrasonic energy). The hydraulic system may be configured to pump the acoustic transmission fluid into the deformable chamber through a first port and withdraw the acoustic transmission fluid from the deformable chamber through a second port in response to detecting an air bubble in the acoustic transmission fluid. The hydraulic system may be configured to pump the acoustic transmission fluid into the deformable chamber at a faster rate than it withdraws the acoustic transmission fluid from the detectable chamber.

[0016] In some embodiments, the fillable jacket comprises an O-ring extending around a periphery of the deformable receptacle. The fillable jacket may be mechanically coupled to the mechanical sub-structure by inserting an edge portion of the fillable jacket and the O-ring into the channel.

[0017] In some embodiments, the O-ring comprises a segment or strip of conductive material that makes electrical contact with a corresponding conductive portion of the channel when the O-ring is inserted into the channel. The segment of conductive material may extend partially around the circumference of the deformable receptacle. The conductive portion of the O-ring may be adapted to carry a signal to and / or from a sensor on the fillable jacket.

[0018] In some embodiments, the O-ring further comprises a conductive pad in electrical contact with the segment of conductive material. The conductive pad may extend, for example, in a poloidal direction around a portion of the O-ring. Electrical conductors may be provided, for example, by printing, on the exterior surface of the deformable receptacle. The conductive pads of the O-ring may contact corresponding electrical conductors of the fillable jacket when the O-ring mechanically couples the fillable jacket to the substructure. In some embodiments, the O-ring comprises first and second conductive pads in electrical contact with corresponding first and second segments of conductive material and corresponding first and second electrical conductors supported on the surface of the deformable receptacle. The electrical conductors may be located on the interior exterior surface of the deformable receptacle. The electrical conductors may be electrically connected to a sensor (e.g., a temperature sensor).

[0019] In some embodiments, the ultrasonic transducer assembly further comprises one or more baffles located within the deformable chamber. The baffles may be made of a material that has essentially the same acoustic impedance as that of the acoustic transmission fluid. The baffles may have a thickness less than the wavelength of sound in the acoustic transmission fluid. For example, the baffles have a thickness in the range of 0.5 mm to 1.5 mm. The baffles may comprise perforations located between the baffles and an outer surface of the deformable receptacle.

[0020] In some embodiments, the fillable jacket comprises a temperature sensor. The temperature sensor may be configured to measure a temperature of the acoustic transmission fluid in the deformable chamber and / or a temperature of the skin of a subject wearing the ultrasound transducer assembly. In some embodiments, the fillable jacket is removably coupled to the mechanical substructure. In some embodiments, the fillable jacket is made of a disposable material. In some embodiments, the fillable jacket further comprises one or more of an electroencephalography sensor, a motion sensor, and an accelerometer.

[0021] In some embodiments, the mechanical substructure comprises a retention mechanism for securing the mechanical substructure and the fillable jacket coupled thereto against the subject's head. In some embodiments, the mechanical substructure comprises a rigid frame. In some embodiments, the frame comprises a locking hinge mechanism that allows the frame to be pushed toward the subject's head to secure the frame snugly against the subject's head.

[0022] Another aspect of the invention relates to a fillable jacket attachable to an inner surface of a cap supporting one or more ultrasonic transducer elements. The fillable jacket comprises a deformable receptacle. The deformable receptacle holds a volume of acoustic transmission fluid within the deformable chamber. The fillable jacket includes at least one port in fluid communication with the interior of the deformable chamber. A valve may be provided to control fluid flow through the port and thereby control the volume of acoustic transmission fluid within the deformable chamber. The deformable jacket may be held in place within the cap by an O-ring. In some embodiments, one or more of the valve and the O-ring are part of the fillable jacket.

[0023] In some embodiments, the fillable jacket comprises a sensor supported on or coupled to the deformable receptacle, and may include a temperature sensor configured to measure a temperature of the acoustic transmission fluid in the deformable chamber and / or a temperature of the skin of a subject wearing a cap to which the fillable jacket is attached.

[0024] In some embodiments, the fillable jacket comprises one or more electrical conductors. The electrical conductors may be printed, for example, on the exterior surface of the deformable receptacle. The electrical conductors may be designed to electrically connect with conductive pads on the O-ring and / or in the cap when the fillable jacket is attached to the cap by the O-ring. For example, the electrical conductors on the fillable jacket may contact corresponding conductive pads located on the O-ring. The O-ring may further comprise electrical conductors that connect the conductive pads to a segment of conductive material that extends circumferentially around a portion of the O-ring. The segment of conductive material may provide an electrical connection with a conductor on the cap. In some embodiments, the conductive pads are shaped to extend poloidally around a portion of the O-ring. In some embodiments, the deformable receptacle is made of a disposable material. In some embodiments, the deformable receptacle is made of a material having an elastic modulus in the range of 0.5 MPa to 10 MPa.

[0025] Another aspect of the invention relates to an ultrasonic transducer assembly having one or more housings supported by a cap made of a rigid material. Each of the one or more housings includes an ultrasonic transducer element operable to deliver ultrasonic energy, a spring coupled to the ultrasonic transducer element, and a pivotal support coupled to the ultrasonic transducer element. The spring exerts a reaction force directed to urge the ultrasonic transducer element away from the housing along a first axis when the ultrasonic transducer element is moved toward the housing. The pivotal support facilitates rotational movement of the ultrasonic transducer element about a second axis.

[0026] In some embodiments, the pivotal support comprises a gimbal arrangement for facilitating rotational movement of the ultrasonic transducer element about a second axis and a third axis. The first axis, the second axis, and the third axis may be mutually orthogonal. The gimbal arrangement may comprise a first ring coupled to the housing via a first main axis of rotation and a second ring coupled to the first ring via a second main axis of rotation.

[0027] In some embodiments, each of the one or more housings further comprises a first rotary encoder configured to measure a first rotational angle relative to a second axis and a second rotary encoder configured to measure a second rotational angle relative to a third axis. In some embodiments, each of the one or more housings further comprises a linear encoder configured to measure a displacement of the transducer element along the first axis.

[0028] Another aspect of the invention relates to an ultrasonic transducer assembly comprising one or more housings coupled to a cap made of a flexible material, each of the one or more housings comprising an ultrasonic transducer element operable to deliver ultrasonic energy, a localizer attached to the ultrasonic transducer element, and a localization sensor configured to detect a position and orientation of the localizer to determine a corresponding location and orientation of the ultrasonic transducer element.

[0029] In some embodiments, the localizer comprises a reflective surface and the localization sensor comprises an infrared emitter, an infrared receiver, and a camera. In some embodiments, the localization sensor further comprises a light source for providing controlled illumination. In some embodiments, the localizer comprises a circular shaped reflective surface. In some embodiments, the cap is made of silicone. In some embodiments, the housing is attached to the cap via adhesive. In other embodiments, the housing is coupled to a corresponding grommet attached to the cap. The housing may be coupled to its corresponding grommet by a screw.

[0030] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the figures and by study of the following detailed description. Exemplary embodiments are illustrated in the numbered figures of the drawings. It is intended that the embodiments and figures disclosed herein be considered illustrative and not restrictive. [Brief description of the drawings]

[0031] [Figure 1] 1 is a schematic diagram of an ultrasonic transducer assembly in accordance with an exemplary embodiment of the present invention. [Figure 1A] FIG. 2 illustrates the ultrasonic transducer assembly of FIG. 1 connected to an ultrasonic system and a hydraulic system. [Figure 1B]2 is a perspective view of an ultrasonic transducer assembly of the type shown in FIG. 1; [Figure 1C] 2 is an exploded perspective view of a section of the ultrasonic transducer assembly of FIG. 1; [Figure 1D] 2 is a schematic diagram of a baffle that may be provided as part of the ultrasonic transducer assembly of FIG. 1. [Figure 1E] 2 is a flow chart illustrating a method for assembling and mounting the ultrasound transducer assembly of FIG. 1 on a subject's head. [Diagram 2] 4 is a schematic diagram of an ultrasonic transducer assembly according to another exemplary embodiment of the present invention. [Figure 2A] 3 is a front cross-sectional view of a transducer element of the ultrasonic transducer assembly of FIG. 2. [Figure 2B] FIG. 2B is a top cross-sectional view of the transducer element of FIG. 2A. [Diagram 3] 4 is a schematic diagram of an ultrasonic transducer assembly according to another exemplary embodiment of the present invention. [Figure 3A] FIG. 2 illustrates a transducer element of an ultrasonic transducer assembly. [Figure 3B] FIG. 3B illustrates an exemplary localization sensor for determining the position and orientation of the transducer elements of FIG. 3A. [Figure 3C] 3C illustrates an example image taken by the camera of the localization sensor of FIG. 3B. [Figure 3D] 3C illustrates another exemplary image taken by the camera of the localization sensor of FIG. 3B. [Figure 3E] 3C illustrates another exemplary image taken by the camera of the localization sensor of FIG. 3B. [Figure 4A] FIG. 1 illustrates a subarray comprising multiple transducer elements. [Figure 4B] FIG. 4B illustrates an ultrasonic transducer assembly comprising a subarray of the type shown in FIG. 4A. [Figure 5A] 1A-1C illustrate exemplary techniques for achieving acoustic coupling between transducer elements and a subject's head. [Figure 5B]FIG. 2 is another diagram illustrating an exemplary technique for achieving acoustic coupling between the transducer elements and the subject's head. [Figure 5C] FIG. 2 is another diagram illustrating an exemplary technique for achieving acoustic coupling between the transducer elements and the subject's head. [Figure 6] FIG. 1 illustrates an exemplary technique for measuring head orientation in relation to a comfort ultrasound assembly. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Throughout the following description, detailed descriptions are set forth to provide a more complete understanding to those skilled in the art. However, well-known elements may not be shown or described in detail in order to avoid unnecessarily obscuring the present disclosure. Accordingly, the description and drawings are to be regarded in an illustrative sense and not in a restrictive sense.

[0033] One aspect of the present invention relates to an ultrasound transducer assembly that can be applied to deliver ultrasound energy to brain tissue and is adaptable to various subjects (i.e., can accommodate various subjects having various head shapes and sizes). Such an assembly can be worn on the heads of various subjects to deliver ultrasound energy to and / or receive echo ultrasound energy from the brain tissue of the subject. Because head shapes and sizes can vary from subject to subject, the ultrasound transducer assemblies described herein include features that help achieve good coupling of ultrasound energy between the transducer elements of the ultrasound transducer assembly and the brain tissue of the subject.

[0034] First Exemplary Embodiment FIG 1 illustrates an ultrasound transducer assembly 10 according to an exemplary embodiment. The assembly 10 is mounted on the head 2 of a subject 3. The ultrasound transducer assembly 10 may be connected to an ultrasound system 5 and / or a hydraulic system 6, as shown in FIG 1A. The ultrasound system 5 may be, for example, of the type described in PCT Publication WO 2018 / 026738, entitled "ULTRASOUND GUIDED OPENING OF BLOOD-BRAIN BARRIER," which is incorporated herein in its entirety for all purposes.

[0035] The ultrasound transducer assembly 10 comprises a mechanical substructure 12 that supports one or more transducer elements 20. For example, the mechanical substructure 12 may support approximately 256 to 1024 transducer elements 20. When the ultrasound transducer assembly 10 is mounted on the head 2 of the subject 3, the transducer elements 20 may be operated independently or collectively to deliver ultrasound energy to brain tissue of the subject 3 and / or to receive echo ultrasound energy. That is, some transducer elements 20 may be operated to deliver but not receive ultrasound energy, and some other transducer elements 20 may be operated to receive but not deliver ultrasound energy. Some other transducer elements 20 may be operated to both deliver and receive ultrasound energy. These various modes of operation of the transducer elements 20 may be applied to enable any of therapy, imaging, or monitoring, as well as combinations of two or more of these.

[0036] The transducer elements 20 may be operated to transmit or receive ultrasonic energy having various frequencies and / or frequency ranges. For example, some transducer elements 20 may be operated to deliver low frequency ultrasonic energy (e.g., about 200 kHz to 400 kHz). As another example, some transducer elements 20 may be operated to deliver and receive low frequency ultrasonic energy. As another example, some transducer elements 20 may be operated to deliver and receive high frequency ultrasonic energy (e.g., 2 MH or higher). As another example, some transducer elements 20 may be operated to receive both low and high frequency ultrasonic energy.

[0037] In some embodiments, the ultrasonic transducer assembly 10 is connected to an ultrasonic system 5 and receives signals from the ultrasonic system 5 to operate the transducer elements 20 .

[0038] In some embodiments, each of the transducer elements 20 is supported by the mechanical substructure 12 or contained within its own separate housing, as depicted in FIG.

[0039] The mechanical sub-structure 12 has an inner surface 12A and an outer surface 12B. The inner surface 12A is shaped to define a cavity 16 for receiving the head 2 of the subject 3 (see FIG. 1B). Although not required, the mechanical sub-structure 12 will typically have the overall configuration of a cap or helmet. Thus, for brevity, the mechanical sub-structure 12 may be described or referred to herein as a cap or helmet.

[0040] The mechanical substructure 12 is made of a rigid material and / or is coupled to a rigid frame 14. The frame 14 may be integrally formed with the mechanical substructure 12 or may be removably coupled to the mechanical substructure 12 (e.g., by a snap-fit ​​mechanism, hinge, etc.). The frame 14 may include a locking hinge mechanism that helps secure the mechanical substructure 12 to the head 2 of the subject 3. For example, the frame 14 may include a locking hinge mechanism that allows the frame 14 to be pushed toward the head 2 and locked into place to secure the frame 14 snugly against the face of the subject 3. When locked into place, the frame 14 exerts pressure on a facial bone area of ​​the subject 3 (e.g., the area below the temples) to restrict movement of the ultrasound transducer assembly 10 relative to the head 2.

[0041] In some embodiments, frame 14 includes padding 14A coupled to a section of an interior surface of frame 14 (see FIG. 1B). Padding 14A can provide greater comfort to subject 3 when frame 14 is pressed against subject 3's face.

[0042] Fillable jacket The ultrasound transducer assembly 10 includes a fillable jacket 30 coupled to the inner surface 12A of the mechanical sub-structure 12. When the ultrasound transducer assembly 10 is mounted on the head 2, the jacket 30 is located within the cavity 16 between the mechanical sub-structure 12 and the head 2. The jacket 30 may be molded with an outer surface shaped to fit over the inner surface 12A of the mechanical sub-structure 12 and an inner surface shaped to receive the subject's head 2.

[0043] The jacket 30 is acoustically coupled to the transducer elements 20. In some embodiments, the jacket 30 is in direct physical contact with the transducer elements 20. The jacket 30 includes one or more chambers that can contain an acoustic transmission fluid 8. The acoustic transmission fluid 8 can provide a good acoustic coupling medium between the transducer elements 20 and the head 2 (e.g., by eliminating or reducing an air gap between the transducer elements 20 and the head 2). Examples of suitable acoustic transmission fluids 8 include, but are not limited to, water, mineral oil, and gel. The following properties of the acoustic transmission fluid 8 can be similar to those of the tissue of the head 2: attenuation coefficient, reflection coefficient, transmission coefficient, and / or acoustic impedance.

[0044] When filled with the acoustic transmission fluid 8, the jacket 30 expands to contact and apply pressure to the head 2. This may provide good acoustic contact between the transducer elements 20 and the head 2, as well as further reduce movement of the ultrasonic transducer assembly 10 relative to the head 2. The ultrasonic transducer assembly 10 may be fitted to various sizes of heads 2 by filling the fillable jacket 30 with an appropriate amount of acoustic transmission fluid 8.

[0045] In some embodiments, the jacket 30 can be expanded (i.e., filled with the acoustic transmission fluid 8) until it conforms to the shape and / or contour of the head 2. This facilitates good coupling of ultrasonic energy between the transducer elements 20 of the ultrasonic transducer assembly 10 and the brain tissue of the subject 3. In some cases, it may be particularly desirable to establish comfort and good acoustic coupling between the transducer elements 20 and the cranium of the head 2. This allows ultrasonic energy to reach and propagate within the four lobes (frontal, parietal, temporal, and occipital lobes), the cerebellum, and the brain stem. Thus, the jacket 30 can be shaped or otherwise designed to provide good comfort between the transducer elements 20 and the cranium of the head 2 when the jacket 30 is filled with the acoustic transmission fluid 8.

[0046] In the exemplary embodiment shown in FIG. 1, the jacket 30 comprises a deformable receptacle 32 that defines a deformable chamber 32C therein. The deformable receptacle 32 has an outer surface 32A facing towards the mechanical substructure 12 and an inner surface 32B facing away from the mechanical substructure 12 (i.e., facing towards the cavity 16). The deformable receptacle 32 may be made of a material or combination of materials, such as polyurethane, latex, silicone, etc., that seals the chamber 32C against loss of fluid 8 and has good acoustic transmission properties. The material that constitutes at least the inner surface 32B of the receptacle 32 may be elastic so that the receptacle 32 can expand or contract to accommodate different sizes of heads without forming a large amount of wrinkles.

[0047] The jacket 30 may include several regions 50A, 50B, 50C, 50D, 50E as shown in FIG. 1. The material properties (e.g., thickness, hardness, elasticity, etc.) of certain portions of the deformable receptacle 32 may vary among the various regions 50. For example, the inner surface 32B of the deformable receptacle 32 may be thinner in region 50C compared to region 50A or region 50E. For example, the inner surface 32B may have a material thickness in the range of about 1-2 mm in thickness in region 50C and about 3-4 mm in regions 50A, 50E. As another example, the elasticity of the various regions 50 of the jacket 30 may range from 0.5 MPa to 10 MPa, including any value therebetween.

[0048] The deformable chamber 32C may be filled with a volume of an acoustically transmitting fluid 8 (eg, water, mineral oil, gel, etc.). In some embodiments, the deformable chamber 32C is pre-filled with a desired volume of acoustic transmission fluid 8. That is, the deformable chamber 32C may be filled with acoustic transmission fluid 8 before the jacket 30 is mechanically coupled to the mechanical substructure 12 and / or before the assembly 10 is placed on the head 2 of the subject 3. In such an embodiment, the jacket 30 may include a system for adjusting the amount of acoustic transmission fluid 8 contained within a portion of the jacket 30 between the mechanical substructure 12 and the head 2 such that the ultrasound transducer assembly 10 fits onto the subject's head 2. Such a system may include a port 40 that allows the acoustic transmission fluid 8 to escape from the deformable chamber 32C when the ultrasound transducer assembly 10 is placed over the person's head 2. In a simple embodiment, the port 40 is connected to a one-way valve in fluid communication with the deformable chamber 32C. The one-way valve allows the acoustic transmission fluid 8 to exit the deformable chamber 32C. For example, the deformable chamber 32C may be pre-filled with an excess amount of acoustic transmission fluid 8, which may be drawn from the deformable chamber 32C through a one-way valve when the ultrasonic transducer assembly 10 is fitted onto the subject's head 2 (i.e., the excess amount of acoustic transmission fluid 8 may be drawn from the deformable chamber 32C by a force exerted by the head 2).

[0049] In another exemplary embodiment, an accumulator is connected to a port that allows the acoustic transmission fluid 8 to escape from the deformable chamber 32C. The accumulator may receive the acoustic transmission fluid displaced from the deformable chamber 32C and exert a gentle pressure on the displaced acoustic transmission fluid 8, thereby keeping the fillable jacket expanded into contact with the head 2. The acoustic transmission fluid 8 may flow back and forth between the accumulator and the deformable chamber 32C when the ultrasonic transducer assembly 10 is fitted to the head 2.

[0050] In other embodiments, the deformable chamber 32C is left empty or only partially filled before the jacket 30 is mechanically coupled to the mechanical substructure 12 and / or before the assembly 10 is placed on the head 2 of the subject 3. In such embodiments, the deformable chamber 32C may be filled with more acoustic transmission fluid 8 (e.g., by pumping fluid 8 through one or more ports 40 as described in more detail below) after the assembly 10 is placed on the head 2 of the subject 3. For example, the deformable chamber 32C may be filled with more acoustic transmission fluid 8 and expanded until the deformable receptacle 32 conforms to the shape and / or contour of the head 2 of the subject 3.

[0051] In some embodiments, the hydraulic system 6 is connected to the ultrasonic transducer assembly 10 and is operable to pump the acoustic transmission fluid 8 into the deformable chamber 32C and / or to withdraw the acoustic transmission fluid 8 from the deformable chamber 32C. The hydraulic system 6 may include an active hydraulic system (e.g., an electrically operated or manually operated system) and / or non-active components. In some embodiments, the hydraulic system 6 includes a collection bag (e.g., for receiving excess fluid 8 drained from the deformable chamber 32C) and, optionally, a reservoir bag (e.g., for providing additional fluid 8 to the deformable chamber 32C). In some embodiments, the hydraulic system 6 includes active devices such as pumps, computers, controllers, and / or the like.

[0052] The outer surface 32A of the deformable receptacle 32 is acoustically connected to the transducer element 20. For ease of explanation, two elements (e.g., the transducer element 20 and the head 2) are "acoustically coupled" if about 80% or more of the ultrasonic power is transferred from the first element to the second element.

[0053] The outer surface 32A of the deformable receptacle 32 may be acoustically coupled to the mechanical substructure 12 (in particular to the transducer 20) through a layer of acoustic coupling gel 33 (e.g., Aquasonic™ gel, Bolx™ gel, etc.) located between the outer surface 32A and the inner surface 12A of the mechanical substructure 12.

[0054] The jacket 30 may be mechanically coupled to the mechanical substructure 12 through a variety of different mechanisms. For example, the jacket 30 may be integrally formed with the mechanical substructure 12. As another example, the outer surface 32A of the deformable receptacle 32 may be adhered to the inner surface 12A of the mechanical substructure 12 using an adhesive.

[0055] In the exemplary embodiment shown in FIG. 1, the jacket 30 comprises an O-ring 34 that may be pressed or otherwise inserted into the circumferentially extending channel 15 of the mechanical substructure 12. By inserting the O-ring 34 into the channel 15, the jacket 30 is mechanically coupled to the mechanical substructure 12 (see, for example, FIG. 1C). Advantageously, the O-ring 34 may fit snugly within the channel 15 to provide a seal that keeps the acoustic coupling gel 33 between the inner surface 12A of the mechanical substructure 12 and the outer surface 32A of the deformable receptacle 32. That is, the O-ring 34 may fit snugly within the channel 15 to prevent the acoustic coupling gel 33 from leaking out. In some embodiments, the O-ring 34 is integral with the fillable jacket 30 (see, for example, FIG. 1C). In some embodiments, the O-ring 34 is a separate part that keeps the edge of the fillable jacket 30 within the channel 15.

[0056] In some embodiments, the jacket 30 is removable from the mechanical substructure 12. For example, the jacket 30 may be removed from the mechanical structure 12 by pulling the O-ring 34 out of the channel 15. In these embodiments, the jacket 30 and its components may be made of disposable materials. Different jackets 30 may be used for different subjects. In some embodiments, a set of different jackets 30 may be provided, in which the different jackets 30 have different volumes, such as more volume to accommodate smaller heads or less volume to accommodate larger heads.

[0057] The jacket 30 may include a locking mechanism for securing the jacket 30 against the head 2 of the subject 3. For example, the jacket 30 may include an elastic band 35 extending around the inner surface 32B of the deformable receptacle 32 as shown in FIG. 1. The elastic band 35 may be formed with or fused to the deformable receptacle 32. Advantageously, the elastic band 35 may be secured around the head 2 of the subject 3 to prevent leakage of acoustic coupling gel 33 applied between the head 2 and the inner surface 32B of the deformable receptacle 32.

[0058] Although not required, the jacket 30 typically includes one or more ports 40 (i.e., openings) in fluid communication with the deformable chamber 32C. The ports 40 may be physically supported by the mechanical substructure 12. For example, the ports 40 may protrude through openings located on the mechanical substructure 12 as shown in FIG. 1. Advantageously, the ports 40 allow the acoustic transmission fluid 8 to be pumped into and / or withdrawn from the deformable chamber 32C to control the volume of the deformable receptacle 32.

[0059] The hydraulic system 6 may be connected to the port 40 and may be operated to pump the acoustic transmission fluid 8 into the deformable chamber 32C and / or withdraw the acoustic transmission fluid 8 from the deformable chamber 32C. In the exemplary embodiment shown in FIG. 1A, the jacket 30 comprises an inlet port 40A connectable to the hydraulic system 6 for receiving the acoustic transmission fluid 8 and an outlet port 40B connected to the hydraulic system 6 for withdrawing the acoustic transmission fluid 8 from the deformable chamber 32C. The port 40 may be in fluid communication with the hydraulic system 6 through one or more flexible tubes or the like.

[0060] The port 40 may include or otherwise be in fluid communication with one or more valves 42. The valves 42 may be switched between an OPEN position that allows fluid flow therethrough and a CLOSED position that prevents fluid flow therethrough. In the exemplary embodiment shown in FIG. 1A, the inlet valve 42A may be switched to its OPEN position and the outlet valve 42B may be switched to its CLOSED position to allow the hydraulic system 6 to pump the acoustic transmission fluid 8 into the deformable chamber 32C. That is, the outlet valve 42B may be switched to its CLOSED position after flow is established between the inlet valve 42A and the outlet valve 42B to fill the deformable chamber 32C with the acoustic transmission fluid 8.

[0061] Similarly, the inlet valve 42A may be switched to its closed position and the outlet valve 42B may be switched to its open position to enable the hydraulic system 6 to draw the acoustic transmission fluid 8 from the deformable chamber 32C.

[0062] In some embodiments, the valve 42 is an electrically operated control valve and / or includes suitable electronics for receiving electronic signals to control the valve 42. In these embodiments, the valve 42 may be electrically connected to a control system provided as part of the hydraulic system 6 and / or an external control system (not shown) for receiving electronic signals to control the valve 42. The valve 42 may be electrically connected to the hydraulic system 6 and / or another control system via an electrical cable or the like.

[0063] The valve 42 may be operated to control the pressure inside the deformable receptacle 32. For example, the valve 42 may be operated to provide good acoustic coupling between the transducer elements 20 and tissue inside the head 2 and to maintain a level of pressure inside the deformable chamber 32C that is comfortable for the subject 3. In some embodiments, the pressure inside the deformable receptacle 32 is maintained at 1 to 3 atmospheres.

[0064] To determine whether the deformable chamber 32C has expanded sufficiently to fill the space between the head 2 and the inner surface 12A of the transducer assembly 10, one or more transducer elements 20 may be operated to deliver and receive a pulse of ultrasonic energy. If the transducer element 20 detects a strong reflection immediately upon issuance of the pulse, this represents the presence of an air gap between the inner surface 12A and the deformable receptacle 32. In such a case, the valve 42 may be operated to increase the pressure inside the deformable receptacle 32 until the intensity of the immediate reflection is reduced. The ultrasonic system 5 may be connected to the transducer assembly 10 to coordinate the pulse-echo integration with the increase in pressure inside the deformable receptacle 32. For example, the pressure inside the deformable receptacle 32 may be incrementally increased in steps, with a pulse-echo measurement being taken at each step. In some embodiments, the ultrasonic system 5 is configured to set a maximum pressure value to prevent the pressure inside the deformable receptacle 32 from exceeding that maximum pressure value.

[0065] The jacket 30 optionally includes one or more baffles 36 located within the deformable chamber 32C. Advantageously, the baffles 36 can provide a more even distribution of the volume of the acoustic transmission fluid 8 within the deformable chamber 32C by preventing the acoustic transmission fluid 8 from flowing freely in certain areas. For example, the baffles 36 can be positioned to reduce pooling of the acoustic transmission fluid 8 (e.g., due to gravity) at the bottom of the deformable chamber 32C when the subject 3 wears the ultrasound transducer assembly 10. Such pooling can undesirably cause air pockets to form at the top of the deformable chamber 32C.

[0066] In some embodiments, the baffle 36 includes one or more features that help prevent pooling. For example, the baffle 36 may be constructed to limit separation of the inner surface 32B from the outer surface 32A. The baffle 36 may be made of a low elasticity or non-elastic material and may be physically bonded to the outer surface 32A and the inner surface 32B via an adhesive. When the chamber 32C becomes full, the baffle 36 may apply a force that prevents the outer surface 32A and the inner surface 32B from separating beyond a certain distance to prevent the deformable chamber 32C from over-inflating.

[0067] The baffle 36 may be made of a material that has an acoustic impedance that is the same as or nearly matches the acoustic impedance of the acoustic transmission fluid 8 so that it is acoustically transparent, or nearly so. For example, the baffle 36 may be made of silicone, which has an acoustic impedance of about 1.54 MRayl, and the acoustic transmission fluid 8 may be water, which has an acoustic impedance of about 1.48 MRayl.

[0068] Preferably, the thickness of the baffle 36 is significantly less than the wavelength of the ultrasound waves emitted by the transducer elements 20 into the acoustic transmission fluid 8. For example, the baffle 36 may have a thickness of about 1 mm or less, where the transducer elements 20 are configured to deliver ultrasound waves having frequencies up to about 220 KHz, and the acoustic transmission fluid 8 is water or another fluid in which the speed of sound is close to the speed of sound in water.

[0069] In some embodiments, the baffle 36 is constructed to extend between the outer surface 32A and the inner surface 32B. The baffle 36 may be constructed to leave perforations 37 (e.g., gaps between the baffle 36 and the outer surface 32B) as shown in FIG. 1D. The perforations 37 allow some flow of the acoustic transmission fluid 8 to pass through the baffle 36. The perforations 37 may reduce the likelihood of air bubbles forming at the junction of the baffle 36 and the deformable receptacle 32.

[0070] Supplementary Features of the First Exemplary Embodiment The ultrasonic transducer assembly 10 optionally includes one or more sensors 44 (e.g., electronic hydraulic sensors, flow sensors, temperature sensors, etc.) configured to measure flow and / or pressure characteristics of the acoustic transmission fluid 8. The sensors 44 may be located between the port 40 and the hydraulic system 6 as depicted in FIG. 1A. The sensors 44 may be electrically connected to a control system provided as part of the hydraulic system 6 and / or an external control system (not shown). The control system may control the sensors 44, provide power to the sensors 44, read output signals of the sensors 44, process the sensor values, etc.

[0071] The control system may be connected to or may be part of the hydraulic system 6 and / or the ultrasonic system 5. For example, the hydraulic system 6 may include a control system and may be connected to the ultrasonic system 5 via a system interface 7 as shown in FIG. 1A.

[0072] FIG. 1A illustrates one exemplary manner of electrically connecting an ultrasonic transducer assembly 10 to an ultrasonic system 5. As shown in FIG. 1A, the ultrasonic transducer assembly 10 includes a cable housing layer 60 that houses wires connected to the transducer elements 20, and optionally wires connecting to the sensors 44, 46 as described in more detail elsewhere herein. The wires may be bundled or individually routed through the cable housing layer 60 to a connector 62. The electrical connection between the transducer elements 20 and the ultrasonic system 5 may be made through a removable cable connector that mates with the connector 62. The cable housing layer 60 may include mechanical structures such as posts (not shown) to provide mechanical support to the cable housing layer 60. These posts may extend from the mechanical substructure 12 to the top of the cable housing layer 60. In some embodiments, a flex circuit is used to connect the connector 62 to the transducer elements 20.

[0073] Some embodiments apply one or more of a variety of methods to control the flow of acoustic transmission fluid 8 into and out of the deformable chamber 32C when the transducer elements 20 are operated to deliver ultrasonic energy to the head 2 of the subject 3. The ultrasonic system 5, hydraulic system 6, and ultrasonic transducer assembly 10 may be operated, for example, in the following non-limiting manner.

[0074] The hydraulic system 6 may include electronics that receive signals from the valves 42, sensors 44, and / or external control systems and communicate corresponding signals to the ultrasonic system 5 (e.g., via the system interface 7) to start and stop ultrasonic transmission, modulate the timing of certain aspects of the ultrasonic transmission (e.g., the timing between transmitted pulses), etc.

[0075] · The hydraulic system 6 may be manually or automatically controlled to modulate the flow of fluid 8 to and from the jacket 30 and / or the pressure within the deformable chamber 32C.

[0076] The hydraulic system 6 may pump the acoustic transmission fluid 8 into the deformable chamber 32C and stop pumping when the sensor 44 detects a threshold pressure corresponding to the head 2 being restrained by the jacket 30.

[0077] The hydraulic system 6 may continuously flow an acoustic transmission fluid 8 (e.g., degassed water) through the deformable chamber 32C. This may reduce the possibility of air bubbles accumulating inside the jacket 30. Circulating the fluid 8 may help cool the transducer elements 20. In some embodiments, the hydraulic system 6 continuously delivers the fluid 8 into the deformable chamber 32C and regulates the pressure in the chamber 32C by one or more of modulating the rate of flow of the fluid 8 entering the chamber 32C and adjusting a valve connected to regulate the flow of the fluid 8 exiting the deformable chamber 32C.

[0078] The ultrasonic transducer assembly 10 may also optionally include one or more temperature sensors 46. The temperature sensors 46 may include, for example, a thermistor, a thermocouple, or other suitable temperature sensor. The temperature sensors 46 may be positioned and configured to measure the temperature of the acoustic transmission fluid 8, for example, at one or more of the following:

[0079] Near Head 2 Location near transducer element 20 Outlet port of chamber 32C Inlet port of chamber 32C Upper part of chamber 32C In some embodiments, the fillable jacket 30 includes one or more temperature sensors 46. The temperature sensor 46 may be located outside the inner surface 32B of the deformable receptacle 32 (i.e., between the deformable receptacle 32 and the head 2). When the ultrasonic transducer assembly 10 is connected to the ultrasonic system 5, the temperature sensor 46 may transmit a sensor reading to the ultrasonic system 5. This allows the ultrasonic system 5 to control the transducer elements 20 (e.g., stop ultrasonic energy transmission) based on the measurement of the temperature sensor 46. For example, the transducer elements 20 may be controlled to deliver ultrasonic energy until the temperature sensor 46 measures a threshold temperature. In some embodiments, the temperature sensor 46 is oriented to estimate the skin temperature of the subject 3. In such an embodiment, the threshold temperature may be set to a value between, for example, 40° C. and 43° C. to prevent discomfort to the subject 3.

[0080] In some embodiments, the temperature sensor 46 is configured to measure the temperature of the acoustic transmission fluid 8. In these embodiments, the temperature measured by the temperature sensor 46 may be communicated to the hydraulic system 6 (e.g., through the ultrasonic system 5 and the system interface 7). The hydraulic system 6 may be configured to control the flow rate and / or temperature of the acoustic transmission fluid 8 entering the jacket 30 based on the temperature measurement.

[0081] In some embodiments, the hydraulic system 6 includes a temperature control system operable to regulate the temperature of the fluid 8 being delivered to the jacket 30. The temperature control system may include a heater and / or a cooler. In some embodiments, the temperature of the acoustic transmission fluid 8 is maintained within a range of approximately 35° C. to 40° C.

[0082] In some embodiments, some or all of the temperature sensors 46 are interconnected to other systems (e.g., ultrasonic system 5, hydraulic system 6, etc.) by electrical conductors 47 supported on the inner surface 32B of the deformable receptacle 32. For example, the electrical conductors may be formed by printing using a conductive ink. The electrical conductors 47 may be printed or otherwise provided on the outside of the inner surface 32B of the deformable receptacle 32 (see FIG. 1C ). The electrical conductors 47 may provide electrical connection of the sensors (e.g., temperature sensor 46) of the fillable jacket 30 to an external system (e.g., ultrasonic system 5).

[0083] For example, electrical conductors 47 may carry signals to electrical conductors supported on the mechanical substructure 12 to enable temperature sensor 46 to receive and / or transmit signals from ultrasound system 5. For example, electrical conductors 47 may carry electrical current to and from sensor 46. The electrical current may power temperature sensor 46 (and / or other sensors) and / or carry data in analog and / or digital form to ultrasound system 5 (or another system external to jacket 30).

[0084] In some embodiments, the ultrasonic system 5 is configured to modulate the ultrasonic transmission firing sequence and / or control other operations of the ultrasonic system 5 based on data received from the temperature sensor 46. For example, if the temperature sensor 46 detects a temperature value above a threshold, the transmission of ultrasonic energy may be interrupted until the temperature sensor 46 detects a lower (pre-set) temperature value.

[0085] In the exemplary embodiment shown in Figure 1C, the electrical conductors 47A, 47B are electrically connected to the metal strips 34A, 34B via conductive pads 48 located on the O-ring 34. The conductive pads 48 may be shaped to extend in a poloidal direction around a portion of the O-ring 34. Typically, at least a portion of the conductive pads 48 are oriented to face toward the deformable receptacle 32 (i.e., to face radially) as shown in Figure 1C.

[0086] The O-ring 34 may include first and second conductive pads 48 electrically connected to corresponding first and second conductors 47A, 47B. In the exemplary embodiment shown in FIG. 1C, the first conductor 47A is electrically connected to the first conductive (e.g., metal) strip 34A through the first conductive pad 48, and the second conductor 47B is electrically connected to the second conductive strip 34B through a second conductive pad (not shown).

[0087] The first strip 34A and the second strip 34B are electrically isolated from each other. The first strip 34A may, for example, carry a signal current to and / or from the sensor 46. The second strip 34B may, for example, be connected to an electrical ground.

[0088] Like the O-ring 34, the strips 34A, 34B may extend circumferentially around the deformable receptacle 32. When the O-ring 34 is inserted into the channel 15 of the mechanical substructure 12, the strips 34A, 34B of the O-ring 34 contact corresponding conductive strips 15A, 15B located within the channel 15. The strips 15A, 15B may extend circumferentially around the channel 15.

[0089] In embodiments in which the fillable jacket 30 includes multiple sensors (e.g., several temperature sensors 46), the strips 34A, 34B of the O-ring 34 and the strips 15A, 15B located within the channel 15 may be intermittent (i.e., they may be divided into sections, with each section being electrically insulated from one another of the sections).

[0090] The ultrasonic transducer assembly 10 may include a wide range of variations and / or supplemental features that may be applied, where appropriate, to all of the embodiments of the ultrasonic transducer assembly 10 described above and may include, but are not limited to, the following: The inner surface 32B of the deformable receptacle 32 (i.e. the surface of the jacket 30 that is adjacent to the head 2 of the subject 3 when the ultrasound transducer assembly 10 is placed on the head 2 of the subject 3) may be coated with a layer of acoustic coupling material such as gel 33. That is, a layer of acoustic coupling gel 33 may be applied between the inner surface 32B of the deformable receptacle 32 and the head 2 of the subject 3.

[0091] · The ultrasonic transducer assembly 10 may include an air bubble detector (e.g., transducer element 20 configured to detect air bubbles) to detect the presence of air bubbles in the jacket 30. The hydraulic system 6 and / or the ultrasonic transducer assembly 10 may be configured to remove any detected air bubbles from the jacket 30 (e.g., by emptying and refilling the deformable chamber 32C and / or by increasing the flow rate of the acoustic transmission fluid 8 entering the deformable chamber 32C, etc.).

[0092] The ultrasound transducer assembly 10 may include other sensors, including, but not limited to, EEG sensors, motion sensors, and accelerometers. Such sensors may be used, for example, to modulate the ultrasound energy delivered by the ultrasound transducer assembly 10.

[0093] 1E is a flow chart illustrating an exemplary method 1000 for assembling and mounting an ultrasound transducer assembly 10 on a head 2 of a subject 3. In step 1100, acoustic coupling gel 33 is applied to the head 2. In step 1200, acoustic coupling gel 33 is applied to an inner surface 12A of the mechanical substructure 12. Step 1200 may occur before, after, or simultaneously with step 1100.

[0094] In step 1300, the jacket 30 is mechanically coupled to the mechanical sub-structure 12. For example, step 1300 may comprise inserting the O-ring 34 of the jacket 30 into the channel 15 of the mechanical sub-structure 12. Step 1300 may comprise mechanically coupling the jacket 30 to the mechanical sub-structure 12 in a manner that causes the valve 42 to protrude from and pass through the mechanical sub-structure 12. Step 1300 may be performed before, during, or after step 1200.

[0095] After mechanically coupling the jacket 30 to the mechanical sub-structure 12, the ultrasound transducer assembly 10 is mounted on the head 2 of the subject 3 in step 1400. Step 1400 may comprise pressing the frame 14 against the face of the subject 3 to fix the ultrasound transducer assembly 10 in place. In step 1500, the hydraulic system 6 is connected to the ultrasound transducer assembly 10 (i.e., through port 40) and pumps the acoustic transmission fluid 8 into the jacket 30. When the jacket 30 is filled with the acoustic transmission fluid 8, the jacket 30 expands until it conforms to the shape of the head 2. This helps to achieve good acoustic coupling between the transducer elements 20 and the head 2 and helps to reduce the relative motion of the mechanical sub-structure 12 and the head 2.

[0096] Second Exemplary Embodiment Another aspect of the invention relates to an ultrasound transducer assembly that includes transducer elements that may assume various positions and / or orientations based on the shape and size of a subject's head. Because the positions and / or orientations of such transducer elements may vary from subject to subject, it is desirable to measure or at least estimate these positions and / or orientations of the transducer elements to reduce errors in beamforming. Beamforming errors can cause problems such as undesirable acoustic beam patterns and inaccurate focus.

[0097] In some embodiments, the ultrasound transducer assembly is configured to measure or estimate the position of the transducer elements, the orientation of the transducer elements, the position of the head and / or the orientation of the head. The ultrasound transducer assembly may communicate these measurements or estimates to the ultrasound system. Advantageously, the ultrasound system may calculate ultrasound parameters (e.g., the set of transducer elements to be excited, the timing of the excitation of the transducer elements, the amplitude of the excitation of each transducer element, the phase delay, etc.) based on the measurements made by the ultrasound transducer assembly.

[0098] For example, the ultrasound system (e.g., ultrasound system 5) may turn off transducer elements 20 that are not properly oriented (e.g., too oblique) to deliver ultrasound energy to a target area in a meaningful way. This may occur because the radiation pattern of the transducer elements 20 is not uniformly spherical. As an example, a circular planar transducer element 20 emits a radiation pattern that approximates a jinc function (sometimes called a "sombrero function"). For target points (i.e., points in the tissue of the subject 3) located at a certain angle from the transducer element 20, the amount of ultrasound energy delivered to these points is less than the amount of ultrasound energy delivered to target points located immediately in front of the transducer element 20. The ultrasound system 5 may be configured to calculate an expected amount of ultrasound energy to be delivered to a particular point based on the location and / or orientation of the transducer element 20, the pre-established radiation pattern of the transducer element 20, the dimensions of the transducer element 20, etc. If the calculated expected amount is too little, the transducer element 20 may be turned off in some cases.

[0099] In another example, the positions and orientations of the transducer elements 20 may be processed by the ultrasound system to calculate the acoustic path length between a particular transducer element 20 and a target region. The acoustic path length may be calculated, for example, by creating a model of the head 2 (including various layers of head tissue, such as the skull, brain tissue, etc.) and calculating the propagation path between the transducer elements 20 and the target region. After the path length is calculated, the ultrasound system may cause the transducer elements 20 to deliver ultrasonic energy at a particular phase to focus the ultrasonic energy at the target region.

[0100] 2 illustrates diagrammatically an ultrasound transducer assembly 10A according to a second exemplary embodiment. The transducer assembly 10A is mounted on the head 2 of a subject 3. The ultrasound transducer assembly 10A comprises a rigid mechanical substructure 12 that supports one or more transducer element housings 120. The ultrasound transducer assembly 10A optionally includes the jacket 30 described above, although this is not typically required.

[0101] 2, the rigid mechanical sub-structure 12 comprises a rigid frame 14. The frame 14 may include an elastic band 35 that extends circumferentially around the head 2 of the subject 3 to maintain the acoustic coupling gel 33 on the head 2. The band 35 may be fused to or mechanically coupled to a bottom rim of the mechanical sub-structure 12 as shown in FIG.

[0102] Transducer Element Housing 2A illustrates a schematic cross-section of an exemplary transducer element housing 120. The transducer element housing 120 comprises a housing base 121 and a housing body 122. The housing base 121 is mechanically coupled to the mechanical substructure 12. The housing body 122 houses a spring-suspended shaft 125 (e.g., a shaft 125 suspended by a spring 124) that is coupled to the transducer element 20 at a first end 125A and to one or more pivotal supports 130 at a second end 125B. The shaft 125 optionally includes a lid 126 located at the second end 125B to prevent the pivotal supports 130 and / or the transducer element 20 from separating from the transducer element housing 120.

[0103] As depicted in FIG. 2A , the transducer elements 20 typically protrude inwardly through a gap 121A in the housing base 121. When the subject 3 wears the ultrasound transducer assembly 10A, the head 2 contacts the transducer elements 20. In some cases, the head 2 may push the transducer elements 20 radially outward on the axis 101 toward the mechanical substructure 12. As the transducer elements 20 are pushed toward the mechanical substructure 12, the springs 124 exert a restoring force on the transducer elements 20 along the radial axis 101 toward the head 2. The position of the transducer elements 20 along the axis 101 may shift based on the shape and / or size of the head 2.

[0104] The support 130 may allow the shaft 125 and the transducer elements 20 coupled thereto to rotate about one or more axes. In the exemplary embodiment shown in FIG. 2A, the pivoting support 130 comprises a gimbal arrangement that allows the transducer elements 20 to assume an orientation (e.g., pitch and yaw) that matches the shape of the head 2. The gimbal arrangement includes a first ring 130A (i.e., outer ring) coupled to the transducer element housing 120 via a first main rotating shaft 132A and a second ring 130B (i.e., inner ring) coupled to the first ring 130A via a second main rotating shaft 132B (see FIG. 2B). The first main rotating shaft 132A allows the first ring 130A to pivot along the axis B-B'. The second main rotating shaft 132B allows the second ring 130B to pivot along the axis C-C'.

[0105] The shaft 125 is coupled to the second ring 130B. The shaft 125 may be coupled to the second ring 130B via two or more shaft ball bearings 123. For example, the second ring 130B may include pockets cut into its body to receive the ball bearings 123. The ball bearings 123 contact the shaft 125 and provide a rolling surface for the shaft 125 to move up and down along the axis 101, for example, when the head 2 presses against the transducer element 20.

[0106] In some embodiments, the transducer element housing 120 includes one or more linear and / or rotary encoders. The encoder values ​​may be read by an electronic device such as a microprocessor. The signals from the encoders may be carried, for example, by wires that are routed through channels in the transducer element housing 120 and / or through channels in the mechanical substructure 12.

[0107] In the exemplary embodiment shown in FIG. 2B, the transducer element housing 120 includes a first rotary encoder 134A for measuring the orientation of the first ring 130A (i.e., the angle relative to axis B-B'), a second rotary encoder 134B for measuring the orientation of the second ring 130B (i.e., the angle relative to axis C-C'), and a linear encoder 134C for measuring the position of the shaft 125 along the axis 101 (i.e., the displacement relative to an initial position).

[0108] 2A , the linear encoder 134C may be located proximate to the shaft 125. The linear encoder 134C may include a magnet or a magnetic sensor, and the shaft 125 may include a magnetic strip or other suitable markings that enable the linear encoder 134C to measure the displacement of the shaft 125 (along the axis 101) from an initial position.

[0109] Advantageously, the linear and / or rotary encoders described herein may be configured to measure a reference position, such as a "zero" state of the position and / or orientation of each transducer element 20. Before placing the ultrasonic transducer assembly 10A on the head 2, all of the transducer elements 20 are biased inward (i.e., biased away from the mechanical substructure 12) because the springs 124 have no restoring force. The zero state may be used to determine a new position and / or orientation of each transducer element 20 after mounting the ultrasonic transducer assembly 10A on the head 2. When the ultrasonic transducer assembly 10A is mounted on the head 2, each transducer element 20 assumes a position and orientation that corresponds to the position and orientation of the head 2 at the contact point. The linear and / or rotary encoders described herein may measure the position and / or orientation of the transducer elements 20 and communicate the measurements to an ultrasound system (e.g., ultrasound system 5).

[0110] The transducer elements 20 and linear and / or rotary encoders described herein may be powered via wires connected to a power output that is connectable to an ultrasound system. The wires may be located within the cable housing layer 60 described above in connection with the ultrasound transducer assembly 10. The cable housing layer 60 may include a power output for connecting to the ultrasound system (e.g., through a detachable cable or connector).

[0111] Third Exemplary Embodiment 3 illustrates a schematic representation of an ultrasound transducer assembly 10B according to a third exemplary embodiment mounted on the head 2 of a subject 3. The ultrasound transducer assembly 10B comprises a non-rigid (e.g., malleable) substrate 12B that supports one or more transducer element housings 120B. The malleable substrate 12B may be flexible and / or stretchable. The malleable substrate 12B may be made of one or more materials, such as, but not limited to, silicone, Lycra®, and elastic rubber.

[0112] Each transducer element housing 120B houses a transducer element 20. The transducer element housing 120B may be mechanically coupled to the compliant substrate 12B via a variety of possible mechanisms. For example, the transducer element housing 120B may be glued or adhered to the compliant substrate 12B. As another example, the compliant substrate 12B may include a grommet 200, and the transducer element housing 120B may be coupled to the grommet 200. These coupling mechanisms and the compliant substrate 12B allow each transducer element 20 to assume a position and orientation that matches the position and orientation at the contact point of the transducer element 20 with the head 2.

[0113] 3A shows an example transducer element housing 120B coupled to a compliant substrate 12B through a grommet 200. The grommet 200 may include threads for receiving corresponding threads on the transducer element housing 120B.

[0114] The transducer element housing 120B may include an electrical connection mechanism 210 that allows electrical connections to be routed from the compliant substrate 12B to the transducer elements 20. In the exemplary embodiment shown in FIG. 3A, the electrical connection mechanism 210 includes a service loop that allows the transducer elements 20 to position and orient their contact points with the head 2. The compliant substrate 12B may also include a compliant channel 220 that allows electrical wires to be routed. The electrical wires may be routed to a compliant substrate cable connector 260. The cable connector 260 may be in a location that does not obstruct the optical path between the localizer 230 of the transducer elements 20 and the localization sensor 250, as described in more detail below. A cable may be connected between the cable connector 260 and the ultrasound system 5 to connect the ultrasound transducer assembly 10B to the ultrasound system 5.

[0115] In some embodiments, the transducer elements 20 are mechanically coupled to the localizer 230. The localizer 230 may include a disk with a reflective surface, a disk with a distinctive pattern, an object with a reflective surface, etc. The localizer 230 may be provided as part of the transducer element housing 120B. The localizer 230 may be configured to indicate a position and / or orientation of the transducer elements 20 relative to a localization sensor 250 provided, for example, on a localization base 245 (see FIG. 3). Measuring the position and / or orientation of the transducer elements 20 can help increase the accuracy of beam shaping, as described in more detail elsewhere herein. The localization sensor 250 may be, for example, an optical (e.g., camera-based) localization sensor, a magnetic localization sensor, etc.

[0116] 3B illustrates a schematic of the localization base 245, the localization sensor 250, and a section of the localizer 230. As depicted in FIG. 3B, the localization sensor 250 may include an infrared (IR) emitter 252, an infrared receiver 254, and a camera 255. The localization sensor 250 may optionally include a light source (not shown) for providing controlled illumination. In operation, the IR emitter 252 may be configured to direct light toward the localizer 230, and the IR receiver 254 may be configured to receive light reflected from the localizer 230. The position of the localizer 230 may be determined, for example, by calculating the time of flight of light traveling between the IR emitter 252 and the IR receiver 254.

[0117] The orientation of the transducer elements 20 may be measured by the camera 255 as illustrated in Figures 3C, 3D, and 3E. For example, the camera 255 may capture an image of the surface of the localizer 230 and send the image to a computing device (not shown) for analysis. If the surface of the localizer 230 is circular and perpendicular to the camera axis of the camera 255, the image will show a circular disk as shown in Figure 3C. If the reflective surface of the localizer 230 is angled in pitch and / or yaw, the image will show an ellipsoid. For example, if the surface of the localizer 230 is rotated around the E-E' axis of Figure 3C, the image taken by the camera 255 may show an ellipsoid of the type shown in Figure 3D. As another example, if the surface of the localizer 230 is rotated around the F-F' axis of Figure 3C, the image taken by the camera 255 may show an ellipsoid of the type shown in Figure 3E. The computing device may calculate or estimate the orientation of the transducer elements 20 based on the pictures taken by the camera 255.

[0118] In some embodiments, multiple localization sensors 250 may be mounted on the localization base 245 to measure the position and / or orientation of some or all of the transducer elements 20 of the ultrasonic transducer assembly 10B. In some embodiments, the localization sensors 250 are mounted on a mechanical scanning platform that oscillates about an axis. The scanning platform may include an encoder that measures the orientation and / or location of the localization sensors 250. This allows fewer localization sensors 250 to be used.

[0119] The positioning sensor 250 may include the IR sensors and cameras described above, and / or other types of sensors. For example, the positioning sensor 250 may also include electromagnetic and / or radio frequency sensors to detect the position and / or orientation of the transducer elements 20.

[0120] Additional Features of All Exemplary Embodiments An ultrasonic transducer assembly described herein (e.g., ultrasonic transducer assemblies 10, 10A, 10B) may include transducer elements 20 grouped into one or more subarrays 21. FIG. 4A illustrates a first subarray 21A and a second subarray 21B. The group of transducer elements 20 forming the subarray 21 may share a common substrate or mechanical substructure. That is, the subarray 21 may be a self-contained unit with electronics, such as transmission drive electronics, integrated into the structure of the subarray 21 to drive the transducer elements 20. Each transducer element 20 in the subarray 21 may be optimized differently and / or perform different functions. For example, some transducer elements 20 in the subarray 21 may be optimized to transmit low-frequency ultrasonic energy, while other transducer elements 20 in the subarray 21 may be optimized to only receive echo ultrasonic energy.

[0121] Advantageously, the subarray 21 can reduce the number of cables and / or wiring complexity required to electrically connect the ultrasonic machine 5 to the transducer elements 20. For example, a single cable from the ultrasonic system 5 may drive two or more transducer elements 20 in the subarray 21 through integrated electronics contained within the subarray 21. The integrated electronics can receive an input signal from the ultrasonic system 5 and generate one or more control signals that control the transducer elements 20 in the subarray 21.

[0122] The type of electronics may depend on the type of transducer elements 20 included in the subarray 21. For example, if the subarray 21 includes only low-frequency transducer elements 20, the electronics may include an ultrasonic transfer driver circuit for each transducer element 20, digital electronics for sequencing the operation of the transducer elements 20 through the transfer driver circuit, and digital electronics for receiving and sending information to and from the ultrasound system. In this case, only a few DC power lines and a few digital signal lines are required between the ultrasound system and the subarray 21 including multiple elements. If the subarray 21 includes transducer elements 20 that perform multiple functions (e.g., some deliver low-frequency ultrasonic energy and others receive echo ultrasonic energy), the integrated electronics may include low-noise amplifiers (one for each transducer element 20 operating in a receive mode) and / or other additional circuitry.

[0123] In some embodiments, the number of localizers 230 in the subarray 21 is less than the number of transducer elements 20. For example, the subarray 21A may include three transducer elements 20 but only one localizer 230. In the subarray 21A, each transducer element 20 has the same orientation but different position. Because the position of each transducer element 20 in the subarray 21A relative to each other is fixed and therefore known, the position and orientation of all three transducer elements 20 in the subarray 21A can be calculated based on the position and orientation values ​​measured from the localizer 230.

[0124] 4B shows an exemplary embodiment of an ultrasonic transducer assembly 10 having three subarrays 21A, 21B, 21C. The ultrasonic transducer assemblies described herein may include any suitable number of subarrays 21.

[0125] Additional aspects of the invention relate to techniques for achieving acoustic coupling between the transducer elements 20 and the head 2. FIG. 5A illustrates a subject 3 having hair 4. A layer of acoustic coupling gel may be applied to the hair 4 (or to the scalp if the subject 3 does not have hair), as shown in FIG. 5B. After applying the acoustic coupling gel to the head 2, a head cover 9 may be placed over the head 2, as shown in FIG. 5C. The head cover 9 may be made of an elastic material and may include a tight elastic band 35 at its bottom edge, as shown in FIG. 5C. The elastic properties of the head cover 9 allow the cover 9 to accommodate a variety of head sizes and shapes. The tight elastic band at the bottom edge prevents or reduces the penetration of gel to the outside of the cover 9. The head cover 9 may also include one or more perforations 9A, as shown in FIG. 5C. The perforations 9A allow air to escape when the cover 9 is fitted over the head 2. The perforations 9A may be used to apply gel to the head 2 in places where air may be present. The head cover 9 may be made of various materials such as silicone, nylon, etc. The head cover 9 may be a single-use product (e.g., made of a disposable material).

[0126] Another additional aspect of the present invention relates to an imaging array that can be used in connection with an ultrasound transducer assembly described herein to measure the relative position of the head relative to the ultrasound transducer assembly. In some cases, it is desirable to measure or estimate the position of the head 2 relative to the ultrasound transducer assembly 10. To measure or estimate the position of the head 2 relative to the ultrasound transducer assembly 10, at least some of the transducer elements 20 may be positioned adjacent to a thin portion (i.e., an acoustic window) of the skull of the subject 3. Ultrasound images of the anatomy of the subject 3 (e.g., the cerebral arterial circle) are obtained using such transducer elements 20. The resulting images may then be aligned or registered with images of the subject 3 previously obtained by another modality, such as magnetic resonance imaging (MRI). Since MRI can produce high-resolution diagnostic quality images of the brain, areas of the brain that require treatment, for example, by opening the blood-brain barrier, can be determined or selected by a qualified person using these images.

[0127] Because the relative location of the area requiring treatment is known with respect to the anatomy being imaged by ultrasound, this information can be relayed back to the ultrasound system 5. This information can be used to calculate a set of low frequency treatment elements of the transducer assembly that can be activated so that treatment is delivered to the desired location.

[0128] FIG. 6 illustrates an exemplary method of measuring the orientation of the head 2 relative to the ultrasound transducer assembly 10. As depicted in FIG. 6, some transducer elements 20 (i.e., the black ones) are positioned adjacent to a thin area of ​​the skull of the subject 3 and are optimally positioned to image the anatomy inside the skull. The other transducer elements 20 (i.e., the white ones) are low-frequency therapy elements. Using the techniques described herein, the relative position and orientation of each transducer element 20 is calculated. In particular, the relative position and orientation of the therapy transducer elements 20 are calculated with respect to the imaging elements. Since the position of the anatomy that needs to receive the therapy is known through ultrasound and MRI registration, a calculation can be performed to determine which set of therapy elements needs to be activated.

[0129] Interpretation of Terms Unless otherwise clearly required by context, throughout this description and claims: "Comprise", "comprising", and the like, are to be construed in their inclusive sense, i.e., "including but not limited to", as opposed to their exclusive or exhaustive sense.

[0130] "Connected," "coupled," "attached" or any variation thereof means any direct or indirect connection or coupling between two or more elements. The coupling, connection, or attachment between the elements can be physical, logical, or a combination thereof.

[0131] The words "herein," "above," "below," and words of similar import, when used to describe this specification, shall refer to this specification as a whole and not to any particular portions of this specification.

[0132] "Or" in a reference to a list of two or more items covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list.

[0133] The singular forms "a", "an" and "the" include any appropriate plural references. Words indicating directions, such as "longitudinal," "transverse," "horizontal," "upward," "downward," "forward," "rearward," "inward," "outward," "longitudinal," "transverse," "left," "right," "front," "rear," "top," "bottom," "lower," "upper," "lower," and the like, used in this description and in any accompanying claims (if any) are dependent on the specific orientation of the device as described and illustrated. The subject matter described herein may assume a variety of alternative orientations. Thus, these directional terms should not be rigidly defined or narrowly interpreted.

[0134] Implementations of the present invention may be implemented using specially designed hardware, configurable hardware, programmable data processors configured by provision of software (which may optionally comprise "firmware") capable of running on a data processor, special purpose computers or data processors that are specifically programmed, configured, or constructed to perform one or more steps in the methods detailed herein, and / or combinations of two or more of these. Examples of specially designed hardware are logic circuits, application specific integrated circuits ("ASICs"), large scale integrated circuits ("LSIs"), very large scale integrated circuits ("VLSIs"), etc. Examples of configurable hardware are one or more programmable logic devices, such as programmable array logic ("PALs"), programmable logic arrays ("PLAs"), and field programmable gate arrays ("FPGAs"). Examples of programmable data processors are microprocessors, digital signal processors ("DSPs"), embedded processors, graphics processors, mathematical co-processors, general purpose computers, server computers, cloud computers, mainframe computers, computer workstations, etc. For example, one or more data processors in a control circuit for a control system of an apparatus described herein (which may include, e.g., ultrasonic system 5 and / or hydraulic system 6) may implement the methods described herein by executing software instructions in program memory accessible to the processor and / or by processing data via logic configured in a configurable device such as a logic circuit or FPGA.

[0135] Processing may be centralized or distributed. When processing is distributed, information, including software and / or data, may remain central or may be distributed. Such information may be exchanged between different functional units via a communications network, such as a Local Area Network (LAN), a Wide Area Network (WAN), or the Internet, wired or wireless data links, electromagnetic signals, or other data communications channels.

[0136] Although processes or blocks are presented in a given order, alternative examples may perform routines having steps or use systems having blocks in different orders, and some processes or blocks may be removed, moved, added, sub-divided, combined, and / or modified to provide alternative solutions or sub-combinations. Each of these processes or blocks may be implemented in a variety of different ways. Also, while processes or blocks are at times shown as being performed in series, these processes or blocks may instead be performed in parallel, or may be performed at different times.

[0137] Where a component (e.g., a jacket, valve, sensor, assembly, substructure, substrate, etc.) is referenced above, unless otherwise indicated, a reference to that component (including a reference to a "means") should be construed to include, as an equivalent of that component, any component that performs the function of the described component (i.e., is functionally equivalent), including components that are not structurally equivalent to the disclosed structures that perform that function in the illustrated exemplary implementations of the invention.

[0138] Specific examples of systems, methods, and devices have been described herein for illustrative purposes. These are examples only. The techniques provided herein can be applied to systems other than the exemplary systems described above. Many changes, modifications, additions, omissions, and substitutions are possible in the practice of the invention. The invention includes variations in the described implementations that will be apparent to those skilled in the art, including variations obtained by replacing features, elements, and / or acts with equivalent features, elements, and / or acts, mixing and matching features, elements, and / or acts from different implementations, combining features, elements, and / or acts from implementations described herein with features, elements, and / or acts of other technologies, and / or omitting combinations of features, elements, and / or acts from the described implementations.

[0139] Various features are described herein as being present in "some embodiments." Such features are not required and may not be present in all embodiments. An embodiment of the invention may not include such features, or may include any one or any combination of two or more thereof. All possible combinations of such features are contemplated by the present disclosure even if such features are shown in different figures and / or described in different sections or paragraphs. This is limited only to the extent that one of such particular features is incompatible with other of such features, in the sense that it would be impossible for a person of ordinary skill in the art to construct a practical embodiment combining the incompatible features. As a result, a description that "some embodiments" possess feature A and "some embodiments" possess feature B should be interpreted as an explicit indication that the inventors also contemplate embodiments combining features A and B (unless the description states otherwise or features A and B are fundamentally incompatible).

[0140] Accordingly, it is intended that the claims introduced hereafter be interpreted to include all such modifications, permutations, additions, omissions, and subcombinations that may reasonably be inferred. The claims should not be limited by the preferred implementations set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole. The technical ideas contained in the present disclosure are described below. (Appendix 1) 1. An ultrasound transducer assembly connectable to an ultrasound system, the assembly comprising: a mechanical substructure having an outer surface and an inner surface, the inner surface being shaped to define a cavity therein; one or more ultrasonic transducer elements supported by the mechanical substructure; a fillable jacket bonded to the inner surface of the mechanical substructure and in acoustic contact with the one or more transducer elements, the fillable jacket lining the inner surface of the mechanical substructure; a deformable receptacle for holding a volume of acoustic transmission fluid within a deformable chamber of said receptacle; a port in fluid communication with the deformable chamber; and a valve for controlling fluid flow through the port, thereby controlling the volume of the acoustic transmission fluid within the deformable chamber. and a fillable jacket comprising: (Appendix 2) 2. The ultrasonic transducer assembly of claim 1, wherein the fillable jacket is acoustically coupled to the mechanical substructure. (Appendix 3) 3. The ultrasonic transducer assembly of claim 2, further comprising a first layer of acoustic coupling gel positioned between the fillable jacket and the mechanical substructure. (Appendix 4) 4. The ultrasonic transducer assembly of claim 1, wherein the deformable receptacle is made of a material selected from the group consisting of polyurethane, latex, and silicone. (Appendix 5) 5. The ultrasonic transducer assembly of claim 1, wherein the acoustic transmission fluid is selected from the group consisting of degassed water, mineral oil, and gel. (Appendix 6) 6. The ultrasonic transducer assembly of any one of claims 1 to 5, further comprising a second port in fluid communication with the deformable chamber and a second valve for controlling fluid flow through the second port. (Appendix 7) 7. The ultrasonic transducer assembly of claim 6, wherein the first port is fluidly connected to an output of a hydraulic system through the first valve for receiving the acoustic transmission fluid into the deformable chamber, and the second port is fluidly connected to an input of the hydraulic system through the second valve for returning the acoustic transmission fluid from the deformable chamber to the hydraulic system. (Appendix 8) 8. The ultrasonic transducer assembly of claim 7, wherein the hydraulic system comprises electronics configured to continuously pump the acoustic transmission fluid into the deformable chamber through the first port and continuously draw the acoustic transmission fluid from the deformable chamber through the second port. (Appendix 9) 9. The ultrasonic transducer assembly of claim 7 or 8, wherein the first and second valves include respective electronic sensors configured to detect a rate of fluid flow through the respective valves. (Appendix 10) 10. The ultrasonic transducer assembly of claim 7, further comprising an air bubble detector for detecting air bubbles in the acoustic transmission fluid. (Appendix 11) 11. The ultrasonic transducer assembly of claim 10, wherein the air bubble detector comprises at least one of the one or more ultrasonic transducer elements configured to deliver a pulse of ultrasonic energy. (Appendix 12) 12. The ultrasonic transducer assembly of claim 10 or 11, wherein the hydraulic system is configured to pump the acoustic transmission fluid into the deformable chamber through the first port and draw the acoustic transmission fluid from the deformable chamber through the second port in response to detection of an air bubble in the acoustic transmission fluid. (Appendix 13) 13. The ultrasonic transducer assembly of claim 12, wherein the hydraulic system is configured to pump the acoustic transmission fluid into the deformable chamber at a rate faster than the rate at which the acoustic transmission fluid is withdrawn from the deformable chamber. (Appendix 14) 14. The ultrasonic transducer assembly of any one of claims 1 to 13, wherein the fillable jacket further comprises an O-ring extending around a periphery of the deformable receptacle, and the fillable jacket is mechanically coupled to the mechanical substructure by inserting an edge portion of the fillable jacket including the O-ring into a channel of the mechanical substructure. (Appendix 15) 15. The ultrasonic transducer assembly of claim 14, wherein the O-ring comprises a segment of conductive material that makes electrical contact with a corresponding conductive portion of the channel when the O-ring is inserted into the channel. (Appendix 16) 16. The ultrasonic transducer assembly of claim 15, wherein the segment of conductive material extends partially around the O-ring. (Appendix 17) The O-ring is 17. The ultrasonic transducer assembly of claim 15 or claim 16, further comprising a conductive pad in electrical contact with the segment of conductive material and a conductor on the exterior surface of the deformable receptacle. (Appendix 18) 18. The ultrasonic transducer assembly of claim 17, wherein the conductive pad extends in a poloidal direction around a portion of the O-ring. (Appendix 19) The O-ring is a first conductive pad in electrical contact with a first one of the segments of conductive material and a first conductor printed on the exterior surface of the deformable receptacle; 19. The ultrasonic transducer assembly of claim 17 or 18, comprising a second conductive pad electrically insulated from the first conductive pad and in electrical contact with a second of the segments of conductive material and a second conductor printed on the exterior surface of the deformable receptacle. (Appendix 20) 20. The ultrasonic transducer assembly of any one of claims 17 to 19, wherein the conductor is located on an inner exterior surface of the deformable receptacle. (Appendix 21) 21. The ultrasonic transducer assembly of claim 17, wherein the conductor is electrically connected to a sensor. (Appendix 22) 22. The ultrasonic transducer assembly of claim 21, wherein the sensor comprises a temperature sensor configured to measure a temperature of an acoustically transmitting fluid in the deformable chamber. (Appendix 23) 22. The ultrasonic transducer assembly of claim 21, wherein the sensor comprises a temperature sensor configured to measure a temperature of the skin of a subject wearing the ultrasonic transducer assembly. (Appendix 24) 24. The ultrasonic transducer assembly of any one of claims 1 to 23, further comprising one or more baffles positioned within the deformable chamber. (Appendix 25) 25. The ultrasonic transducer assembly of claim 24, wherein the baffle is made of a material having essentially the same acoustic impedance as that of the acoustic transmission fluid. (Appendix 26) 26. The ultrasonic transducer assembly of claim 24 or 25, wherein the baffle has a thickness that is less than a wavelength of sound in the acoustically transmitting fluid. (Appendix 27) 27. The ultrasonic transducer assembly of claim 26, wherein the baffle has a thickness in the range of 0.5 mm to 1.5 mm. (Appendix 28) 28. The ultrasonic transducer assembly of any one of claims 24 to 27, wherein the baffle comprises a perforation located between the baffle and an outer surface of the deformable receptacle. (Appendix 29) 29. The ultrasonic transducer assembly of any one of claims 1 to 28, wherein the fillable jacket further comprises one or more of an electroencephalography sensor, a motion sensor, and an accelerometer. (Appendix 30) 30. The ultrasonic transducer assembly of any one of claims 1 to 29, wherein the mechanical substructure comprises a retention mechanism for securing the mechanical substructure and a fillable jacket coupled to the mechanical substructure to a subject's head. (Appendix 31) 31. The ultrasonic transducer assembly of any one of claims 1 to 30, wherein the fillable jacket is removably coupled to the mechanical sub-structure. (Appendix 32) 32. The ultrasonic transducer assembly of claim 31, wherein the fillable jacket is made of a disposable material. (Appendix 33) 33. The ultrasonic transducer assembly of any one of claims 1 to 32, wherein the mechanical sub-structure includes a rigid frame. (Appendix 34) 34. The ultrasound transducer assembly of claim 33, wherein the frame includes a locking hinge mechanism that enables the frame to be pushed toward the subject's head to secure the frame snugly against the subject's head. (Appendix 35) 35. The ultrasonic transducer assembly of any one of claims 1 to 34, wherein the deformable receptacle is made of a material having an elastic modulus in the range of 0.5 MPa to 10 MPa. (Appendix 36) a fillable jacket attachable to an inner surface of a cap supporting one or more ultrasonic transducer elements, a deformable receptacle for holding a volume of acoustic transmission fluid within a deformable chamber of the deformable receptacle; a port in fluid communication with the deformable chamber; and an O-ring extending around a periphery of the deformable receptacle. (Appendix 37) 37. The fillable jacket of claim 36, further comprising a sensor on the deformable receptacle. (Appendix 38) 38. The fillable jacket of claim 37, wherein the sensor comprises a temperature sensor configured to measure a temperature of the acoustic transmission fluid in the deformable chamber. (Appendix 39) 39. The fillable jacket of claim 37 or 38, wherein the sensor comprises a temperature sensor configured to measure a temperature of the subject's skin. (Appendix 40) an electrical conductor printed on an exterior surface of the deformable receptacle, the electrical conductor being electrically connected to the sensor; a conductive pad located on the O-ring and electrically connected to the electrical conductor; 40. The fillable jacket of any one of claims 37-39, further comprising a segment of conductive material extending circumferentially around a portion of the O-ring and electrically connected to the conductive pad. (Appendix 41) 41. The fillable jacket of claim 40, wherein the conductive pad is molded to extend poloidally around a portion of the O-ring. (Appendix 42) 42. The fillable jacket of any one of clauses 36 to 41, wherein the deformable receptacle is made of a disposable material. (Appendix 43) 43. The fillable jacket of any one of claims 36 to 42, wherein the deformable receptacle is made of a material having an elastic modulus in the range of 0.5 MPa to 10 MPa. (Appendix 44) 1. An ultrasound transducer assembly connectable to an ultrasound system, the assembly comprising: a cap made of a rigid material; One or more housings supported by the cap, each of the one or more housings comprising: an ultrasonic transducer element; a spring coupled to the ultrasonic transducer element for exerting a reaction force directed to urge the ultrasonic transducer element away from the housing along a first axis when the ultrasonic transducer element is moved toward the housing; and a housing comprising a pivotal support coupled to the ultrasonic transducer element to facilitate rotational movement of the ultrasonic transducer element about a second axis. (Appendix 45) 45. The ultrasonic transducer assembly of claim 44, wherein the pivotal support comprises a gimbal arrangement for facilitating rotational movement of the ultrasonic transducer element about the second axis and about a third axis. (Appendix 46) 46. ​​The ultrasonic transducer assembly of claim 45, wherein the first axis, the second axis, and the third axis are mutually orthogonal. (Appendix 47) 47. The ultrasonic transducer assembly of claim 45 or 46, wherein the gimbal arrangement comprises a first ring coupled to the housing via a first main axis of rotation and a second ring coupled to the first ring via a second main axis of rotation. (Appendix 48) 48. The ultrasonic transducer assembly of any one of claims 45 to 47, wherein each of the one or more housings further comprises a first rotary encoder configured to measure a first rotational angle relative to the second axis and a second rotary encoder configured to measure a second rotational angle relative to the third axis. (Appendix 49) 49. The ultrasonic transducer assembly of any one of claims 44 to 48, wherein each of the one or more housings further comprises a linear encoder configured to measure displacement of the transducer element along the first axis. (Appendix 50) 1. An ultrasound transducer assembly connectable to an ultrasound system, the assembly comprising: a cap made of a flexible material; one or more housings coupled to the cap, each of the one or more housings comprising: an ultrasonic transducer element; a housing including a localizer attached to the transducer element; a localization sensor configured to detect a position and orientation of the localizer to determine a corresponding location and orientation of the ultrasonic transducer elements. (Appendix 51) 51. The ultrasonic transducer assembly of claim 50, wherein the localizer comprises a reflective surface and the localization sensor comprises an infrared emitter, an infrared receiver, and a camera. (Appendix 52) 52. The ultrasonic transducer assembly of claim 51, wherein the localization sensor further comprises a light source for providing controlled illumination. (Appendix 53) 53. The ultrasonic transducer assembly of any one of claims 50 to 52, wherein the localizer comprises a circular shaped reflective surface. (Appendix 54) 54. The ultrasonic transducer assembly of any one of claims 50 to 53, wherein the flexible material comprises silicone. (Appendix 55) 55. The ultrasonic transducer assembly of any one of claims 50 to 54, wherein the one or more housings are attached to the cap via an adhesive. (Appendix 56) 56. The ultrasonic transducer assembly of any one of claims 50 to 55, wherein each of the one or more housings is coupled to a corresponding one of a plurality of grommets attached to the cap. (Appendix 57) 57. The ultrasonic transducer assembly of claim 56, wherein the housing is coupled to the corresponding grommet by a screw thread. (Appendix 58) A device having any new and inventive feature, combination of features, or sub-combination of features described in this application. (Appendix 59) A method having any novel and inventive step, act, combination of steps and / or acts, or sub-combination of steps and / or acts described herein.

Claims

1. 1. An ultrasonic transducer assembly connectable to an ultrasonic system, the ultrasonic transducer assembly comprising: a mechanical substructure having an inner surface shaped to define a cavity for receiving the subject's head; one or more ultrasonic transducer elements supported by the mechanical substructure; a fillable jacket removably coupleable to the inner surface of the mechanical substructure in acoustic contact with the one or more ultrasonic transducer elements; a deformable receptacle for receiving an acoustic transmission fluid within the chamber such that when the acoustic transmission fluid is introduced into the chamber of the deformable receptacle, the deformable receptacle deforms to line the inner surface and conform to the shape of the subject's head; a fillable jacket comprising: An ultrasonic transducer assembly comprising:

2. The ultrasonic transducer assembly of claim 1 , wherein the fillable jacket is acoustically coupled to the mechanical substructure.

3. The ultrasonic transducer assembly of claim 2 , further comprising a first layer of acoustic coupling gel located between the fillable jacket and the mechanical substructure.

4. The fillable jacket comprises: a port in fluid communication with the chamber; 4. The ultrasonic transducer assembly of claim 1, further comprising: a valve for controlling fluid flow through the port, thereby controlling the volume of the acoustic transmission fluid in the chamber.

5. 5. The ultrasonic transducer assembly of claim 1, further comprising an air bubble detector for detecting air bubbles in the acoustic transmission fluid.

6. The ultrasonic transducer assembly of claim 5 , wherein the air bubble detector comprises at least one of the one or more ultrasonic transducer elements configured to deliver a pulse of ultrasonic energy.

7. 7. The ultrasonic transducer assembly of claim 1, wherein the fillable jacket further comprises an O-ring extending around a periphery of the deformable receptacle, and the fillable jacket is mechanically coupled to the mechanical substructure by inserting an edge portion of the fillable jacket including the O-ring into a channel of the mechanical substructure, thereby forming a seal between the fillable jacket and the mechanical substructure.

8. An ultrasonic transducer assembly as described in claim 7, wherein the O-ring comprises a segment of conductive material that makes electrical contact with a corresponding conductive portion of the channel when the O-ring is inserted into the channel, thereby providing a conductive path between one or more temperature sensors located within the cavity and one or both of an ultrasonic system and a hydraulic system located outside the cavity.

9. The ultrasonic transducer assembly of claim 1 , further comprising one or more baffles located within the chamber.

10. 10. The ultrasound transducer assembly of claim 1, wherein the fillable jacket further comprises one or more of an electroencephalography sensor, a motion sensor, and an accelerometer.

11. 11. The ultrasound transducer assembly of claim 1, wherein the mechanical substructure comprises a retention mechanism for securing the mechanical substructure and a fillable jacket coupled to the mechanical substructure to the subject's head.

12. An ultrasonic transducer assembly as described in any one of claims 1 to 11, wherein the fillable jacket is made of a disposable material.

13. 13. The ultrasonic transducer assembly of claim 1, wherein the mechanical sub-structure comprises a rigid frame.

14. 14. An ultrasonic transducer assembly according to any one of claims 1 to 13, wherein the deformable receptacle is made of a material having an elastic modulus in the range of 0.5 MPa to 10 MPa.

15. A fillable jacket removably coupleable to an inner surface of a cap, the inner surface of the cap being shaped to define a cavity for receiving a subject's head, the cap supporting one or more ultrasound transducer elements, the fillable jacket comprising: a deformable receptacle capable of holding a volume of acoustic transmission fluid within a chamber of the deformable receptacle and capable of deforming to conform to the shape of the subject's head in response to pressure exerted between the cap and the subject's head received within the cavity; a port extending through the cap in fluid communication with the chamber for directing acoustic transmission fluid into the chamber, withdrawing acoustic transmission fluid from the chamber, or both; an O-ring extending around a periphery of the deformable receptacle and removably coupleable to the cap to provide a seal between the fillable jacket and the cap.

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