Wearable ultrasound apparatus

Abstract

To disclose a wearable ultrasound apparatus for use in connection with various biomedical applications, including musculoskeletal ("MSK") imaging and analysis.SOLUTION: A wearable ultrasound apparatus includes at least one of an ultrasound module configured for obtaining at least one ultrasound image of a portion of a user's body on which the at least one ultrasound module is positioned (hereinafter referred to as the "target site" for simplicity purposes), an electrophysiological ("EP") module configured for detecting bioelectric signals of the target site, and a near-infrared spectroscopy ("NIRS") module configured for monitoring oxygenation status and / or biochemical measurements of the target site.SELECTED DRAWING: None

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and is entitled to the benefit of the filing date of U.S. Provisional Patent Application No. 62 / 965,276, filed January 24, 2020, the contents of which are incorporated herein by reference.

[0002] The subject matter of this patent application relates generally to ultrasound devices, and more particularly to wearable ultrasound devices configured for use in connection with various biomedical applications.

[0003] The applicant(s) hereby incorporate by reference any and all patents and published patent applications cited or referenced herein. [Background technology]

[0004] By way of background, ultrasound is utilized in many different fields, typically as a tool for penetrating a medium and measuring its reflection signature. In the field of medicine, ultrasound imaging devices are commonly used for medical imaging of internal organs, muscles, tendons, and other objects positioned within a patient's body, among other applications. Conventional ultrasound imaging devices can generate precise live images and enable the extraction of characteristic features using advanced signal processing techniques. However, conventional ultrasound imaging devices are generally large, stationary, and expensive. Moderately sized imaging devices with limited mobility, such as computer-on-wheels systems, are also available with performance similar to that of larger systems. Wearable versions of such devices, as well as handheld versions, have also been developed in recent years, offering relatively greater mobility. However, to the applicant's knowledge, none of these known devices are capable of simultaneously acquiring ultrasound images, electrophysiological, hemodynamic, and metabolic information of a patient's internal organs, muscles, tendons, and other soft tissues in biomedical and clinical applications.

[0005] Aspects of the present invention fulfill these needs and provide further related advantages as described in the summary below.

[0006] It should be noted that the above background art description includes information that may be useful in understanding aspects of the present invention. The background art description is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art. Summary of the Invention

[0007] Aspects of the present invention teach particular advantages in construction and use that result in exemplary benefits described below.

[0008] The present invention solves the above-described problems by providing a wearable ultrasound device configured for use in connection with various biomedical applications, including musculoskeletal ("MSK") imaging and analysis. In at least one embodiment, the device comprises at least one of an ultrasound module configured to acquire at least one ultrasound image of a portion of a user's body in which the at least one ultrasound module is positioned (hereinafter referred to as a "target site" for simplicity), an electrophysiology ("EP") module configured to detect bioelectrical signals of the target site, and a near-infrared spectroscopy ("NIRS") module configured to monitor oxygenation status and / or biochemical measurements of the target site.

[0009] Other features and advantages of aspects of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of aspects of the invention.

[0010] The accompanying drawings illustrate aspects of the present invention. [Brief explanation of the drawings]

[0011] [Figure 1]FIG. 1 is a cross-sectional view of an exemplary wearable ultrasound device according to at least one embodiment. [Figure 2A] 1 is a diagram of an exemplary piezoelectric sensor and electrodes of an exemplary ultrasound transducer according to at least one embodiment. [Figure 2B] 1 is a diagram of an exemplary piezoelectric sensor and electrodes of an exemplary ultrasound transducer according to at least one embodiment. [Figure 2C] 1 is a diagram of an exemplary piezoelectric sensor and electrodes of an exemplary ultrasound transducer according to at least one embodiment. [Figure 3] FIG. 2 is another diagram of an exemplary piezoelectric sensor according to at least one embodiment. [Figure 4] FIG. 2 is another diagram of an exemplary piezoelectric sensor array according to at least one embodiment. [Figure 4A] FIG. 4 is a detailed view of the cross section defined by line 4A in FIG. [Figure 5A] FIG. 1 is a diagram of an exemplary piezoelectric sensor array according to at least one embodiment. [Figure 5B] FIG. 1 is a diagram of an exemplary piezoelectric sensor array according to at least one embodiment. [Figure 6] FIG. 1 is a schematic diagram of an exemplary wearable ultrasound device according to at least one embodiment. [Figure 7] FIG. 1 is a schematic diagram of an exemplary wearable ultrasonic transmitter / receiver according to at least one embodiment. [Figure 8] FIG. 1 is a schematic diagram of an exemplary electrophysiology (“EP”) module, according to at least one embodiment. [Figure 9] FIG. 1 is a schematic diagram of an exemplary near-infrared spectroscopy (“NIRS”) module according to at least one embodiment. [Figure 10] FIG. 1 is a cross-sectional view of another exemplary wearable ultrasound device according to at least one embodiment. [Figure 11] FIG. 10 is a cross-sectional view of yet another exemplary wearable ultrasound device according to at least one embodiment.

[0012] The above-mentioned drawings illustrate aspects of the present invention in at least one of the exemplary embodiments defined in more detail in the following description. Features, elements, and aspects of the present invention designated with the same numerals in different drawings are intended to represent the same, equivalent, or similar features, elements, or aspects according to one or more embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0013] Referring now to FIG. 1 , a cross-sectional view of one exemplary embodiment of a wearable ultrasound device 20 configured for use in connection with various biomedical applications, including musculoskeletal ("MSK") imaging and analysis, is shown. In at least one embodiment, the device 20 comprises at least one of an ultrasound module 22 configured to acquire at least one ultrasound image of a portion of a user's body in which the at least one ultrasound module 22 is positioned (hereinafter referred to as a "target site" 24 for simplicity), an electrophysiology ("EP") module 26 configured to detect bioelectrical signals at the target site 24, and a near-infrared spectroscopy ("NIRS") module 28 configured to monitor oxygenation status and / or biochemical measurements at the target site 24. It should initially be noted that the particular arrangement of components shown in FIG. 1 is merely exemplary. Accordingly, in further embodiments, the various components may assume many other arrangements, as further described below.

[0014] In at least one embodiment, the ultrasound module 22 includes at least one ultrasound transducer 30 intended to operate in the 7-14 MHz range for surface scanning and the 2-6 MHz range for deeper targets. However, in further embodiments, the at least one ultrasound transducer 30 may operate in any other range, known or later developed, that enables the device 20 to substantially perform the functions described herein. Furthermore, in at least one embodiment, the at least one ultrasound transducer 30 is configured to operate in a pulse-echo configuration, i.e., to emit and subsequently receive ultrasound pulses to acquire at least one ultrasound image. In at least one embodiment, the at least one ultrasound transducer 30 includes at least one piezoelectric sensor 32. In at least one such embodiment, the ultrasound transducer 30 includes a plurality of piezoelectric sensors 32 arranged as at least one array 34, with the number of piezoelectric sensors 32 in a given array 34 ranging from 2 to 256. However, in further embodiments, any other quantity of piezoelectric sensors 32 may be utilized. 10, the at least one ultrasonic transducer 30 includes at least one microelectromechanical ("MEM") sensor 102, such as, for example, at least one capacitive micromachined ultrasonic transducer ("CMUT") or piezoelectric micromachined ultrasonic transducer ("PMUT"), in addition to or instead of the at least one piezoelectric sensor 32. Both CMUTs and PMUTs are based on the vibration of a membrane suspended over a cavity formed in a silicon substrate.

[0015] In at least one embodiment, the at least one ultrasound transducer 30 is positioned on at least one elastic substrate 38. In at least one such embodiment, the elastic substrate 38 is made of a flexible and / or stretchable material. For example, in at least one such embodiment, the material is made of at least one of a silicone-based material, rubber, a thermoplastic elastomer, a polymeric material, foil (such as mixed with an epoxy), and various fabrics. In at least one further embodiment, the elastic substrate 38 is made of a transparent, flexible, and inherently conformable material. Furthermore, in at least one embodiment, the material is biocompatible, latex-free, non-toxic, and non-allergenic. In yet another embodiment, the elastic substrate 38 may comprise any other material (or combination of materials) known or later developed that has flexible and / or rigid-flexible properties, so long as the device 20 is capable of substantially performing the functions described herein. In at least one embodiment, the elastic substrate 38 is made from a composite epoxy material ("CEM"), fiberglass, or paper-based class material that forms a solid foundation for a printed circuit board ("PCB"). For example, in at least one such embodiment, the material is composed of at least one of epoxy resin (FR4, FR5, FE-3), PF resin (XPC, FR1, FR2), and polyester resin. In at least one alternative, the elastic substrate 38 is positioned and used to perform the function of any of the layers of the ultrasound module 22, EP module 26, or NIRS module 28, provided that the elastic substrate 38 is located at the layer where the function is to be performed and its material properties are appropriate. In at least one embodiment, the elastic substrate 38 has a thickness of about 180 micrometers or less, such that the device 20 has a total thickness of about 25 millimeters or less. However, in further embodiments, the elastic substrate 38 can have any other thickness as long as the device 20 can substantially perform the functions described herein.In at least one embodiment, the elastic substrate 38 is configured as a flexible film having signal traces embedded therein or thereon, and the at least one piezoelectric sensor 32 is attached to the elastic substrate 38. In at least one alternative, the at least one piezoelectric sensor 32 and the signal traces are simultaneously screen-printed onto the elastic substrate 38, which may provide numerous advantages. For example, in at least one such embodiment, simultaneously screen-printing the at least one piezoelectric sensor 32 and the signal traces onto the elastic substrate 38 may reduce the number of steps involved in the manufacturing process. Furthermore, the size, shape, and placement of the at least one piezoelectric sensor 32 (relative to the elastic substrate 38) may be freely customized depending on the intended use of the device 20 in a given embodiment. Specifically, the shape of the at least one piezoelectric sensor 32 may be modified to have rounded corners to introduce aperture apodization, thereby improving sidelobe suppression. Further exemplary shapes may include (but are by no means limited to) a ring, a hexagon, a circle, a rectangle, etc. Furthermore, in at least one such embodiment where at least one piezoelectric sensor 32 includes a piezoelectric material 40 sandwiched between two or more electrodes 42 (as shown in Figures 2A, 2B, and 2C and described further below), given that the distance between the electrodes 42 (based at least in part on the thickness of the piezoelectric material 40) defines the excitation frequency therebetween, the multiple electrodes 42 may be implemented with varying distances therebetween to enable the at least one ultrasonic transducer 30 to operate at multiple frequencies and with improved bandwidth.

[0016] In at least one embodiment, the distance between the centers of two adjacent piezoelectric sensors 32 in the array 34 is less than about 0.5λ for phased array operation and between about 0.75λ and 3λ for linear array operation, where λ = c / f, where λ is the wavelength of an ultrasonic signal having a frequency f and a longitudinal wave sound speed c ≈ 1500 m / s. Some numerical examples of the above limits are shown in Table 1 below. [Table 1]

[0017] In at least one embodiment, as shown in FIG. 3 , each of the piezoelectric sensors 32 has a width W that is relatively smaller than the pitch P, given the small kerf K (i.e., separation) required between the piezoelectric sensors 32 to separate the acoustic elements of each of the piezoelectric sensors 32. Further, in at least one embodiment, each of the piezoelectric sensors 32 has a thickness or height H that depends at least in part on the resonant frequency at which the ultrasonic transducer 30 operates. Some example thicknesses for different materials are shown in Table 2 below. Further, in at least one embodiment, each of the piezoelectric sensors 32 has a length L that is less limited by design constraints compared to the other two dimensions. [Table 2]

[0018] In at least one embodiment, the thickness / height H of a given piezoelectric sensor 32 is a function of the frequency of the acoustic wave. In at least one such embodiment, each of the piezoelectric sensors 32 has a height H of about 300 micrometers or less. However, in further embodiments, each of the piezoelectric sensors 32 may have any other height H so long as the device 20 is able to substantially perform the functions described herein.

[0019] In at least one embodiment, the at least one piezoelectric sensor 32 may be made from any suitable material, including, but not limited to, a flexible piezoelectric coating (film, paste, or paint), a ceramic transducer, or a polymer block transducer. Additionally, in at least one embodiment, the at least one piezoelectric sensor 32 may be made from quartz, polyvinylidene fluoride, ceramics including PZT and screen-printed ceramics, magnetostrictive materials, or composites including molded ceramics and benders. For example, the piezoelectric material may be selected from the group consisting of polyvinylidene fluoride (PVDF) and its copolymers, lead zirconate titanate Pb(Zr,Ti)O, lead metaniobate Pb(NbO), modified lead titanate PbTi, (Pb,Ca)TiO, (Pb,Sm)TiO, barium titanate BaTiO, PMN-PT(lx)Pb(Mg,Nb)O, Pb-TiO, PZN-PT / BTPb(ZN,Nb)O, PbTiO-BaTiO, (lx)Pb(ZN,Nb)O(yPbTiO-(ly)PbZrO). In at least one embodiment, at least one piezoelectric sensor 32 is comprised of a flexible piezoelectric coating (film, paste, or paint), such as PVDF or its copolymers. Those skilled in the art will appreciate that recent developments in flexible piezoelectric coatings (e.g., U.S. Pat. No. 1,007,336) provide for piezoelectric materials 40 that can be applied onto a variety of substrates. Of course, other flexible piezoelectric coatings may be utilized in at least one embodiment of the present invention.

[0020] Also, as shown in FIG. 2A , in at least one embodiment, multiple layers of piezoelectric material 40 can be stacked on top of each other with electrodes 42 positioned therebetween. In at least one further embodiment, multiple piezoelectric sensors 32 can be positioned side-by-side, as shown in FIG. 2B . Another advantage of simultaneously screen-printing at least one piezoelectric sensor 32 and signal traces onto a resilient substrate 38 is the ability to integrate additional resources, such as an EP module 26 and / or a NIRS module 28, as described further below. Accordingly, the size, shape, dimensions, configuration, and quantity of each of the at least one piezoelectric sensor 32 and corresponding resilient substrate 38 as shown in the drawings (and described herein) are merely exemplary. In further embodiments, each of the at least one piezoelectric sensor 32 and corresponding resilient substrate 38 can have any other size, shape, dimension, configuration, and / or quantity, now known or later developed, so long as the device 20 is capable of substantially performing the functions described herein. In yet other embodiments, any other known or later developed technique (or combination of techniques) for positioning at least one piezoelectric sensor 32 on elastic substrate 38 may be substituted.

[0021] In at least one further embodiment, the piezoelectric material 40 may be sandwiched between a plurality of electrodes 42 arranged in a matrix configuration to form a quasi-two-dimensional array. An example of such an embodiment is shown in Figures 4 and 4A, where the electrodes 42 are arranged in a 3x3 matrix and the piezoelectric material 40 is positioned substantially between the electrodes 42 in the areas where the electrodes 42 overlap (as shown in Figure 4A).

[0022] In at least one embodiment, the at least one ultrasound transducer 30 is configured to perform a B-mode scan (or "B-scan") of the target region 24. However, in further embodiments, the at least one ultrasound transducer 30 may be configured to perform other types of scans, now known or later developed, including, but not limited to, A-mode (or "amplitude mode"), C-mode, M-mode (or "motion mode"), Doppler mode, pulse inversion mode, harmonic mode, etc. The positioning of the at least one ultrasound transducer 30 depends on the part of the user's body for which at least one ultrasound image is desired. Further, as described above, in at least one embodiment, the at least one ultrasound transducer 30 includes multiple piezoelectric sensors 32 arranged as at least one array 34. In at least one such embodiment, the at least one array 34 may be arranged in various configurations. For example, as shown in FIG. 5A, two or more linear arrays 34 may be arranged to obtain orthogonal cross-sections of the target region 24. As another example, as shown in FIG. 5B, the at least one array 34 may be configured as a curved (rather than linear) surface. As yet another example, the at least one array 34 may be configured as a convex curved surface, thereby providing a relatively wide field of view. Furthermore, the size of the at least one array 34 will depend, at least in part, on the particular context in which the device 20 is used. As noted above, the number of piezoelectric sensors 32 in a given array 34, in at least one embodiment, ranges from 2 to 256. However, in further embodiments, any other number of piezoelectric sensors 32 may be utilized. Accordingly, the size, shape, dimensions, configuration, and quantity of the at least one array 34 as shown in the drawings (and described herein) are merely exemplary. In further embodiments, the at least one array 34 may have any other size, shape, dimensions, configuration, and / or quantity, now known or later developed, so long as the device 20 is capable of substantially performing the functions described herein.

[0023] In at least one embodiment where at least one ultrasound transducer 30 is configured to perform a B-mode scan of a target region and includes multiple piezoelectric sensors 32 configured as at least one linear array 34, a subset of adjacent or consecutive piezoelectric sensors 32 are configured to be excited / activated simultaneously at any given time. The signals of each piezoelectric sensor 32 of the subset may be identical or may exhibit a specific time delay to achieve focusing or beam steering, while different signal amplitudes on each piezoelectric sensor 32 of the subset may be applied to achieve apodization. Multiline acquisition techniques may be used to improve the frame rate of the resulting at least one ultrasound image. In yet another embodiment, multiline transmission, including simultaneous excitation of multiple ultrasound beams, either at the same frequency or at different frequencies, may be utilized to further improve the frame rate. Additionally, in at least one embodiment, harmonic imaging is implemented to improve image resolution.

[0024] In at least one embodiment, as shown in FIG. 1 , the bottom surface 44 of the at least one piezoelectric sensor 32 includes at least one matching layer 46 configured to adapt the acoustic impedance. When sound waves 36 strike an interface between two layers with a relatively large variation in acoustic impedance, the sound waves 36 are reflected at the interface. Therefore, in at least one embodiment, multiple matching layers 46 are used, allowing the acoustic impedance of each matching layer 46 to be gradually varied to minimize reflection. In at least one such embodiment, the at least one matching layer 46 (or at least the bottommost matching layer of the at least one matching layer 46) is configured to selectively attach the at least one ultrasound transducer 30 to the target site 24, either directly (i.e., attached to the user's skin) or indirectly (i.e., attached to clothing or other material in contact with the user's skin). In at least one embodiment, the number of matching layers 46 depends (at least in part) on the characteristics of the at least one piezoelectric sensor 32. In general, it has been found that a greater number of matching layers 46 results in relatively better accommodation (i.e., less energy reflected back to the at least one ultrasound transducer 30) and broader bandwidth, which in turn improves axial resolution of the at least one ultrasound image. In at least one embodiment in which the at least one piezoelectric sensor 32 is screen-printed onto a corresponding at least one elastic substrate 38, the at least one elastic substrate 38 itself may be configured to function as the matching layer 46. In at least one embodiment, the at least one matching layer 46, like the at least one elastic substrate 38, is made of a flexible and / or stretchable material. For example, in at least one embodiment, the material is a silicone adhesive gel. In further embodiments, the material is at least one of rubber, silicone, thermoplastic elastomer, or other polymeric material such as polyester, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polystyrene, polyacrylic, polyethersulfone, and the like.Additionally, in at least one embodiment in which the at least one matching layer 46 is configured to be in direct contact with the user's skin, the at least one matching layer 46 is biocompatible, latex-free, non-toxic, and non-allergenic. In yet other embodiments, the at least one matching layer 46 may comprise any other suitable flexible and / or stretchable material (or combination of materials), known or later developed, that enables the at least one matching layer 46 to substantially perform the functions described herein.

[0025] In at least one embodiment in which at least one matching layer 46 is comprised of a polymeric material, the acoustic impedance of the polymeric material can be increased by incorporating one or more fillers. Suitable fillers include, but are not limited to, PZT, tungsten, alumina, silica glass, tungsten carbide, titanium, and glass powder, with glass powder being preferred. In at least one such embodiment, the filler size ranges from about 0.1 to 50 microns, preferably about 0.5 to 5 microns. The amount of filler used is that amount necessary to provide the desired acoustic impedance. Typically, about 2% to about 50% by volume of filler is used, and preferably about 5% to about 30% by volume of filler is used. A preferred polymeric material is silicone rubber.

[0026] In at least one such embodiment, as shown in FIG. 1 , the ultrasonic module 22 further comprises a bonding layer 48 positioned in contact with the bottom surface 50 of the at least one matching layer 46 (or at least the lowest matching layer of the at least one matching layer 46) and configured to selectively attach the ultrasonic module 22 (and thus the device 20) to the target site 24, either directly (i.e., attached to the user's skin) or indirectly (i.e., attached to clothing or other material that contacts the user's skin). In at least one embodiment, the bonding layer 48 comprises a sonolucent silicone gel or other adhesive material capable of transmitting ultrasonic signals between the ultrasonic module 22 and the target site 24. "Sonolucent" means that the gel is capable of transmitting ultrasonic pulses without introducing significant interference or attenuation, resulting in an acceptable acoustic response from the target site 24. Thus, the material of the bonding layer 48 may be selected for its ability to create a strong, void-free contact between the ultrasonic module 22 and the adjacent target site 24. The acoustic impedance of the bonding layer 48 must be close to that of the adjacent target site 24 for impedance matching. In at least one embodiment, the bonding layer 48 is part of the matching layer 46, and its impedance is selected according to the design guidelines of such a matching layer 46. In at least one embodiment in which the at least one piezoelectric sensor 32 is screen-printed onto a corresponding at least one elastic substrate 38, the at least one elastic substrate 38 itself may be configured to function as the bonding layer 48. Additionally, in at least one embodiment, the bonding layer 48 includes a temporary backing configured to be peeled off before the bonding layer 48 is attached to the target site 24. In at least one embodiment, the bonding layer 48 has a thickness of approximately 100 to 500 micrometers (e.g., 100 micrometers, 200 micrometers, 300 micrometers, 400 micrometers, 500 micrometers, or some range therebetween). However, in further embodiments, the bonding layer 48 may have any other thickness so long as the device 20 is able to substantially perform the functions described herein.Additionally, in at least one embodiment in which the at least one bonding layer 48 is configured to be in direct contact with the user's skin, the at least one bonding layer 48 is biocompatible, latex-free, non-toxic, and non-allergenic. In yet other embodiments, the at least one bonding layer 48 may comprise any other suitable material (or combination of materials) having the above-described properties, whether known or later developed, that enables the at least one bonding layer 48 to substantially perform the functions described herein.

[0027] 1 , the ultrasonic transducer 30 further includes at least one backing layer 52 positioned in contact with the at least one piezoelectric sensor 32 on a side opposite the corresponding side from which energy is intended to be emitted (i.e., where the target site 24 is located), such that the at least one piezoelectric sensor 32 is substantially sandwiched between the at least one backing layer 52 and the target site 24. The at least one backing layer 52 is configured to absorb ultrasonic waves emitted by the at least one piezoelectric sensor 32 that are not directed toward the target site 24, thus preventing echoes and / or resonances that would otherwise reduce the bandwidth of the emitted pulse from the at least one piezoelectric sensor 32. In at least one embodiment in which the at least one piezoelectric sensor 32 is screen-printed on a corresponding at least one elastic substrate 38, the at least one elastic substrate 38 itself may be configured to function as the backing layer 52. Thus, in at least one embodiment, the at least one backing layer 52 is made from a material having an acoustic impedance close to that of the at least one piezoelectric sensor 32 and a relatively high attenuation coefficient. In such an embodiment, because the acoustic impedance of the at least one backing layer 52 is similar to that of the at least one piezoelectric sensor 32 and because of the absorption of the material of the at least one backing layer 52, a majority of the backward-transmitted waves may rapidly decay into heat, with only a small portion bouncing back. In at least one embodiment, the at least one backing layer 52 is composed of at least one of tungsten-doped epoxy, pyrolysis material, brass, carbon, and the like. In yet another embodiment, the at least one backing layer 52 may include any other suitable material (or combination of materials), now known or later developed, that enables the at least one backing layer 52 to substantially perform the functions described herein.

[0028] 1 , in at least one embodiment, the ultrasonic module 22 further includes a pair of conductive layers 54 positioned to substantially sandwich the at least one piezoelectric sensor 32, such that the conductive layers 54 integrate the electrodes 42 of each piezoelectric sensor 32 as well as traces interconnecting them to an electronic system associated with the ultrasonic module 22 (referred to as a “microelectronics module” 56, as described further below). In at least one embodiment, the conductive layers 54 each include a thin metallic film, such as aluminum, copper, gold, molybdenum, iridium, magnesium, silver, lithium fluoride, and alloys thereof, or a non-metallic material. Furthermore, in at least one embodiment, the thickness of each conductive layer 54 is typically about 200 μm or less (e.g., about 200 μm, 180 μm, 160 μm, 140 μm, 120 μm, 100 μm, 90 μm, 80 μm, 70 μm, 60 μm, 50 μm, 40 μm, 30 μm, or less). Preferably, the thickness of each conductive layer 54 is less than 10 μm (e.g., about 10 μm, 9 μm, 8 μm, 7 μm, 6 μm, 5 μm, 4 μm, 3 μm, 2 μm, 1 μm, 0.8 μm, 0.6 μm, 0.4 μm, 0.2 μm or less, or some range therebetween). Furthermore, in at least one embodiment, the conductive layers 54 are flexible. In at least one such embodiment, the conductive layers 54 are composed of a transparent conductive polymer material, such as indium tin oxide (ITO), fluorine-doped tin oxide (FTO), ZnO—GaO, ZnO—AlO, SnO—SbO, and polythiophene. Additionally, the conductive layer 54 may consist of a silver or copper grid or busbar plated on a transparent substrate, or silver nanowires or nanoparticles deposited on a substrate having a poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) coating. Additional conductive polymer layers may be added to improve conductivity. In at least one embodiment, the conductive layer 54 may be carbon-based, such as carbon nanotubes ("CNTs"), carbon nanowires, or graphene. One preferred conductive layer 54 (which is conductive and infrared transparent) comprises graphene.Although one or two layers of graphene are preferred, each of the conductive layers 54 may comprise between about 1 and 20 layers of graphene (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 layers, or some range therebetween). In at least one embodiment, the conductive layers 54 may include several internal conductive layers 54 separated by insulating material to manage multiple tracks.

[0029] Continuing to refer to FIG. 1 , in at least one embodiment, the ultrasonic transducer 30 further includes a pair of sealing layers 58 positioned to substantially sandwich the pair of conductive layers 54 (and thus the at least one piezoelectric sensor 32), such that the sealing layers 58 are configured to isolate the at least one piezoelectric sensor 32 from the ambient environment. In at least one embodiment, the sealing layer 58 is substantially impermeable to moisture and oxygen. Generally, moisture- and oxygen-sensitive components of the device 20 should be encapsulated by a material having gas-permeable properties. The sealing layer 58 is preferably 10 -4 g / ni 2 / day or less, 10 -5 g / m 2 / day or less, and even more preferably about 10 -6 g / ni 2 The organic layer 58 achieves a low water vapor transmission rate of 1000 kJ / day or less. In at least one embodiment, the sealing layer 58 is composed of, for example, glass or plastic. In at least one embodiment, the sealing layer 58 is composed of a flexible and / or stretchable material. For example, in at least one such embodiment, the material is composed of at least one of a silicone-based material, rubber, a thermoplastic elastomer, a polymeric material, a foil (such as one mixed with an epoxy), and various fabrics. Ideally, the substrate in direct contact with the organic layer has excellent barrier properties that withstand heat, exhibits flexibility, has sustainable reliability, and is capable of being mass-produced.

[0030] As described above, in at least one embodiment, device 20 further includes an electrophysiology ("EP") module 26 configured to detect bioelectrical signals at target site 24. In at least one such embodiment, at least one EP module 26 is configured as a surface electromyography ("sEMG") sensor to detect electrical potentials generated by muscle fibers (myocytes). The frequency range of EMG amplitude is 20 μV to 5 μV, although other amplitudes may be substituted in further embodiments. The amplitude of the sEMG signal increases as more muscle fibers are recruited to maintain a constant load or to support an increase in load. In at least one embodiment, sEMG signals reflect muscle activation driven by motor neurons and can be collected noninvasively from the skin surface. As an effective tool, sEMG sensors can be used in diagnosing neuromuscular disorders, assessing muscle fatigue, and human-machine interfaces for prosthetic operation. In at least one such embodiment, combining the various modalities of the sEMG sensor with the functionality of the ultrasound module 22, device 20 may be used in a variety of contexts, including, but not limited to, exercise and training, identifying muscle, tendon, and other soft tissue injuries, identifying myoelectric manifestations of fatigue, assessing EMG signal variations in medical conditions, evaluating motor coordination and treatment effectiveness, identifying neurological disorders, identifying disuse, immobility, and lack of exercise, and measuring neuromuscular changes with age. In at least one embodiment, device 20 is configured to firmly / closely engage the user's skin (so as to eliminate or at least minimize movement artifacts or displacement of device 20) substantially over the muscle of interest.

[0031] In at least one embodiment, as shown in FIG. 6 , the device 20 further includes at least one ultrasonic transceiver 60 in electrical communication with the at least one piezoelectric sensor 32 of the ultrasonic module 22. In at least one such embodiment, the device 20 includes a relatively greater number of piezoelectric sensors 32 than ultrasonic transceivers 60, such that the at least one ultrasonic transceiver 60 is in electrical communication with the plurality of piezoelectric sensors 32. In at least one such embodiment, the device 20 includes at least one analog bidirectional multiplexer 62 in electrical communication with the at least one ultrasonic transceiver 60 and the corresponding plurality of piezoelectric sensors 32. An exemplary configuration of the multiplexer 62 is shown in the schematic diagram of FIG. 6 . However, it should be noted that the configuration and quantity of the at least one multiplexer 62 as shown in the drawings (and as described herein) are merely exemplary. In further embodiments, the at least one multiplexer 62 may take any other known or later-developed configuration (relative to the at least one ultrasonic transceiver 60 and corresponding plurality of piezoelectric sensors 32) and / or quantity, so long as the device 20 is capable of substantially performing the functions described herein. In at least one embodiment in which the device 20 includes multiple multiplexers 62, the multiplexers 62 are arranged in a multi-layer configuration, with the signal traces between each layer varying depending on the number of multiplexers 62 and piezoelectric sensors 32. For example, in at least one such embodiment, the number of layers is equal to the number of multiplexers 62, while in at least one further such embodiment, the number of layers is equal to the number of piezoelectric sensors 32 divided by the number of multiplexers 62. In yet other embodiments, any other number of layers and any other arrangement of signal traces between the layers may be substituted, so long as the device 20 is capable of substantially performing the functions described herein.

[0032] In at least one embodiment, as shown in the simplified diagram of FIG. 7 , the at least one ultrasonic transceiver 60 itself comprises a pulser 64, a transmit / receive switch (“T / R switch”) 66, a low-noise amplifier (“LNA”) 68, a variable gain amplifier (“VGA”) 70, a low-pass filter (“LPF”) 72, and an analog-to-digital converter (“ADC”) 74. More specifically, in at least one such embodiment, the at least one ultrasonic transceiver 60 can emit ultrasonic pulses having several discrete levels to perform amplitude apodization. In yet another embodiment, the at least one ultrasonic transceiver 60 can emit pulses having an arbitrary waveform and then perform precise amplitude apodization, further including emitting a limited diffraction beam, such as a zero-order Bessel beam.

[0033] Referring again to FIG. 6 , in at least one embodiment, device 20 further comprises at least one controller 78 in electrical communication with each of ultrasound module 22, EP module 26, and / or NIRS module 28. Accordingly, in such an embodiment, controller 78 is configured to interface with and manage each of ultrasound module 22, EP module 26, and / or NIRS module 28 and process at least one ultrasound image of target region 24. In at least one such embodiment, processing may include image reconstruction and / or data compression. In at least one alternative embodiment, one or more of ultrasound module 22, EP module 26, and / or NIRS module 28 include their own dedicated power source 80. In at least one embodiment, controller 78 is further in electrical communication with at least one transceiver 82 configured to transmit at least one ultrasound image and any data associated therewith to select external devices, such as computing devices and electrical devices, with which device 20 communicates. In at least one further embodiment, at least one transceiver 82 is further configured to receive selection information from such external devices as well. The at least one transceiver 82 may utilize any known or later developed wired or wireless-based communication protocol (or combination of protocols), including but not limited to Wi-Fi and Bluetooth-LE.

[0034] Additionally, in at least one embodiment, the controller 78 selectively communicates (locally or remotely) with at least one data storage device 84 configured to store at least one ultrasound image and any data associated therewith. Note that the term "data storage device" is intended to include any type of electronic storage medium (or combination of storage media) now known or later developed, such as a local hard drive, RAM, flash memory, secure digital ("SD") cards, external storage, network or cloud storage, integrated circuits, etc.

[0035] In at least one further embodiment in which device 20 incorporates additional modules (e.g., EP module 26 and / or NIRS module 28), controller 78 is configured to manage any such additional modules. Furthermore, in embodiments in which device 20 includes EP module 26, the controller can selectively trigger ultrasound image acquisition upon detection of specific values ​​of bioelectric signals and / or electrophysiological parameters at target site 24, thereby preventing measurements during irrelevant periods and optimizing energy use for ultrasound imaging. Such functionality also enables acquisition at specific instances or when specific events are detected. In at least one such embodiment, controller 78 can synchronize the ultrasound image capture process with the cyclical motion, optimizing acquisition of ultrasound images of target site 24 during very fast, repetitive motion, even at slow acquisition rates, given that ultrasound images or lines thereof can be acquired along several cycles. In yet another embodiment, controller 78 can be configured to selectively control other aspects and / or functions of device 20, such as operating various components in a “low power mode.” In at least one embodiment, controller 78 is at least one of a field programmable gate array ("FPGA"), a digital signal processor ("DSP"), a microcontroller, and a microprocessor.

[0036] 6 , in at least one embodiment, device 20 further includes a power supply 80. Power supply 80 may be any known or later developed power source capable of supplying the necessary power to each of ultrasound module 22, EP module 26, and / or NIRS module 28, including, but not limited to, one or more batteries (rechargeable or otherwise), an AC adapter, a DC adapter, etc. In at least one alternative, one or more of ultrasound module 22, EP module 26, and / or NIRS module 28 include their own dedicated power supply 80.

[0037] In at least one embodiment, as shown in FIG. 8 , the EP module 26 is configured as a multi-channel miniature wireless acquisition system including at least one electrode 42, a front-end signal conditioning circuit 86, a power source 80, a controller 78, and a wireless communication module 88, such as a Bluetooth-LE module. In at least one embodiment, the EP module 26 includes a biocompatible printed electrode array for capturing bioelectrical signals. Additionally, in at least one embodiment, as shown in FIG. 1 , the EP module includes at least one electrode array including 32 or fewer (e.g., about 32, 30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2) electrodes 42 along with a reference electrode 90. However, in further embodiments, any other number of electrodes 42 may be utilized. In at least one embodiment, the reference electrode 90 is positioned between the two differential electrodes 42 to avoid asymmetries in the bioelectrical signal recording, and the electrode spacing is increased by this electrode 42 configuration. However, small electrode spacing is preferred because it reduces the amount of crosstalk signal detected from adjacent active muscles. Therefore, the electrode spacing is set to approximately 32-8 millimeters (e.g., approximately 32 mm, 31 mm, 30 mm, 29 mm, 28 mm, 27 mm, 26 mm, 25 mm, 24 mm, 23 mm, 22 mm, 21 mm, 20 mm, 19 mm, 18 mm, 17 mm, 16 mm, 15 mm, 14 mm, 13 mm, 12 mm, 11 mm, 10 mm, 9 mm, 8 mm, or some range therebetween) as a preferred compromise. However, in further embodiments, any other spacing may be utilized as long as the device 20 is able to substantially perform the functions described herein. Additionally, in at least one embodiment, electrode 42 has a thickness of about 100 micrometers or less (e.g., about 100 μm, 90 μm, 80 μm, 70 μm, 60 μm, 50 μm, 40 μm, 30 μm, 20 μm, 10 μm, 5 μm or less). However, in further embodiments, electrode 42 can have any other thickness so long as device 20 is capable of substantially performing the functions described herein.The EP module 26 may optionally include electrodes 42 having different sizes and shapes, such as rectangular, circular, oval, ring, or disk-shaped electrodes. In a non-limiting example, the electrode 42 array is arranged on a substrate to capture bioelectric signals and features a disk-shaped conductor and at least one ring conductor concentric with the disk-shaped conductor, configured to differentially weight the conductor's voltages to generate multiple outputs corresponding to different sensitivity-based spatial distributions configured according to the requirements for capturing the measured biopotentials. In at least one embodiment, the EP module 26 further includes a bonding layer 48 positioned in contact with the bottom surface of at least one electrode 42 (or the bottommost electrode of at least one electrode 42 array) and configured to selectively attach the EP module 26 (and thus the device 20) to the target site 24 either directly (i.e., attached to the user's skin) or indirectly (i.e., attached to clothing or other material in contact with the user's skin). In at least one embodiment, the bonding layer 48 includes a gel (e.g., a hydrogel with adhesive properties). The hydrogel may be electrically conductive and capable of transmitting bioelectrical signals between the target site 24 and the EP module 26 .

[0038] In at least one embodiment, the electrodes 42 and conductive tracks of the EP module 26 are made of conductive metal inks / pastes produced by using metal nanoparticles, metal-organic complexes, or metal salts (mostly silver-based) as precursors, conductive polymers, because although their conductivity is typically lower than their metallic counterparts, their adhesion and mechanical stability are better, and they usually do not require post-processing steps. Alternatively, graphene or CNT dispersions can be used for printing to fabricate the conductive electrodes 42 and / or tracks (conductor patterns). In at least one such embodiment, for example, the electrodes 42 and conductive tracks of the EP module 26 comprise silver polymer paste, stretchable silver conductor paste, medical-grade conductive Ag / AgCl ink, or poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) for reasons of flexible processing and permanent conductivity.

[0039] As mentioned above, in at least one embodiment, device 20 further comprises a near-infrared spectroscopy (“NIRS”) module 28 configured to monitor oxygenation status and / or biochemical measurements of target site 24. In at least one such embodiment, as shown in FIGS. 1 and 9 , at least one NIRS module 28 includes at least one photodetector 92 supported by a substrate and at least one near-infrared light emitting diode (“LED”) 94 for muscle oxygenation measurement (muscle oximetry).

[0040] Human tissue is relatively transparent to light in the near-infrared range of 650 nm to 1000 nm. The near-infrared ("NIR") window, also known as the "optical window," is the range of wavelengths with the greatest penetration depth into tissue. Indeed, because NIR is minimally absorbed by water and hemoglobin, spectral readings can be easily collected from the body surface, with the primary absorbers being the blood chromophores of oxygenated hemoglobin (HbO2) and deoxygenated hemoglobin (HHb). As the near-infrared light emitted by the LED 94 passes through tissue, some of the light is reflected and absorbed, while the remaining light is scattered and can be measured by at least one photodetector 92. The depth of the detected NIRS signal can be controlled by the distance between the LED 94 and the photodetector 92. It is generally accepted that for a source-to-detector distance of 3 cm, approximately 1.5 cm below the skin surface (half the source-to-detector distance) can be detected through the banana-shaped region. Therefore, taking into account the specific anatomical structures of different muscles, the LED-detector distance may be selected in the range of 2 to 7 cm for muscle activity detection. However, in further embodiments, any other spacing may be utilized as long as device 20 can substantially perform the functions described herein. Furthermore, HbO2 and HHb have different optical absorption characteristics for near-infrared light. When a muscle contracts, the amount of near-infrared light scattered back to the skin surface changes, and this change can be detected by photodetector 92. By using the modified Beer-Lambert law, the relative concentration changes of HbO2 and HHb can be calculated and quantified.

[0041] Therefore, combining the benefits of the EP module 26 and the NIRS module 28, in at least one embodiment, facilitates understanding muscle activity from electrophysiological and metabolic perspectives, providing more useful information for human health and physiological performance. For example, NIRS combined with an sEMG sensor has been used to obtain more reliable information for assessing metabolic and neuromuscular activity, which can suggest mechanisms of muscle fatigue or injury. However, the adoption of separate sEMG and NIRS sensor systems has resulted in large size, cumbersome data synchronization, unwieldy signal lines, and limited channels. Therefore, in at least one embodiment, a device 20 with an integrated EP module 26 and NIRS module 28 alongside the ultrasound module 22 is crucial to meeting clinical practice requirements.

[0042] In at least one embodiment, one or more of the at least one photodetector 92 may serve to provide a reference signal. For example, the photodetector 92 closest to the near-infrared LED 94 may provide a reference intensity relative to the intensities measured by the other photodetectors 92. In this manner, control and knowledge of variations in the intensity of the signal emitted by the near-infrared LED 94 is provided, simplifying the design and operation of the NIRS module 28. In at least one embodiment, the photodetectors 92 may be spaced 10 millimeters apart between the centers of each adjacent photodetector 92 and between the center of the first photodetector 92 of the plurality of additional photodetectors 92 and the near-infrared LED 94. In other configurations, it may be possible to include a larger number of photodetectors 92 using smaller spacing, such as 8 mm spacing. For example, the photodetectors 92 may be spaced 8 mm, 16 mm, 24 mm, and 32 mm from the near-infrared LED 94, respectively. In some configurations, the spacing between adjacent photodetectors 92 may be 5 mm to 20 mm, less than 5 mm, less than 1 mm, or any distance or range of distances within such ranges. In further embodiments, any other interval may be utilized so long as the device 20 is capable of substantially performing the functions described herein. In at least one embodiment, the photodetector 92 is electronically arranged and configured to operate synchronously with the near-infrared LED 94. In at least one such embodiment, a photometric front end 100 is utilized to operate the photodetector 92 and the LED 94. In at least one such embodiment, the near-infrared LED 94 may comprise a thin light source, which may be comprised of, for example, an OLED or a printable LED (organic or inorganic). In at least one such embodiment, the light source comprises a flexible light emitter positioned between two conductive layers 54 (i.e., electrodes) comprising an anode and a cathode, the flexible light emitter emitting light in response to a current applied to the anode and cathode. One typical light source uses a transparent substrate, a transparent anode, a flexible light emitter, and a reflective cathode. Light generated from the flexible light emitter is emitted through the transparent anode and the transparent substrate. This is commonly referred to as a bottom-emitting light source.By way of example, in at least one such embodiment, multiple photodetectors 92 are arranged in a substantially linear fashion on a path beginning at the location of the near-infrared LED 94 for measuring the optical signal at various locations from the near-infrared LED 94. In a preferred configuration, at least two photodetectors 92 are used to measure the intensity of the optical signal for at least two different distances from the LED 94, and based on the measured intensities, improve the fitting of the measured signal as a function of distance to a model used to provide any one or more of oxy(+myo)hemoglobin, (OHb), deoxyhemo(+myo)globin (HHb), total hemo(+myo)globin (tHb), or muscle oxygen saturation (SmO2).

[0043] In at least one embodiment, the conductive layer 54 may include a shared electrode such that the same conductive layer 54 serves as a common cathode or a common anode for the ultrasound module 22, the EP module 26, and / or the NIRS module 28. The anode of the EP module 26 and / or the NIRS module 28 may include a transparent conductive oxide (TCO), such as, but not limited to, indium tin oxide (ITO), zinc oxide (ZnO), or the like. In practice, the conductive layer 54 includes a network of tracks connecting these components to their associated electronic systems. The inclusion of the conductive layer 54 in addition to the conductive layer including the anode or cathode of the ultrasound module 22, the EP module 26, or the NIRS module 28 may enable proper routing of all tracks. Furthermore, the conductive layer 54 having a continuous conductive surface may enable the implementation of impedance-controlled traces (such as microstrip or stripline) and / or may be considered to shield electromagnetic waves. The conductive surfaces or traces may be thought of as collecting heat generated by any element of device 20 and conducting it to at least one heat sink where such heat may be safely transferred to the surrounding environment.

[0044] In at least one embodiment, one or more of the electronic systems (such as, but not limited to, ultrasonic transceiver 60, analog bidirectional multiplexer 62, controller 78, transceiver 82, power supply 80, front-end signal conditioning circuitry 86, photometric front-end 100, wireless communication module 88, data storage device 84, etc.) may be housed within at least one microelectronic module 56 ( FIG. 1 ) positioned in contact with a top surface 96 of at least one backing layer 52. In at least one further embodiment, microelectronic module 56 is positioned within a cover 98 positioned on top of and in electrical contact with the various components of device 20. In yet another embodiment, microelectronic module 56 may be positioned elsewhere on or relative to device 20. 11 , the microelectronics module 56 may be positioned external to or separate from the other components of the device 20, with each of the at least one ultrasound module 22, EP module 26, and / or NIRS module 28 in electrical communication with the microelectronics module 56. Such an embodiment allows for the fabrication of the microelectronics module 56 through conventional, relatively reliable processes, while increasing the modularity of the device 20. In yet another such embodiment, each of the at least one ultrasound module 22, EP module 26, and / or NIRS module 28 may be implemented together within a single flexible patch (as described further below) or separately, depending at least in part on the technology required for a given use case and the location of the target site 24.

[0045] In at least one embodiment, the cover 98 is constructed of a transparent or translucent material. However, in further embodiments, the cover 98 may be constructed of an opaque material. The cover 98 may provide comfort to the user, particularly when the user is physically active. The cover 98 may protect the various components of the device 20, keep the components free of dirt and fluids, and provide a cushion to protect the device 20 from impacts. The cover 98 may further improve heat transfer between any component of the device 20 and the surrounding environment if the material has a significantly lower heat resistance.

[0046] It should be noted that the configuration and arrangement of the various components of device 20 as shown in the drawings (including the relative positioning of each component of ultrasound module 22, EP module 26, and / or NIRS module 28) is merely exemplary. Thus, in further embodiments, the various components may have any other configuration and arrangement, now known or later developed, so long as device 20 is capable of substantially performing the functions described herein.

[0047] Also, as shown in FIG. 1 , in at least one embodiment, the various components of device 20 described above are configured as a self-contained, wearable patch, i.e., adhesively secured to a user's skin (or to clothing in direct contact with the user's skin), secured to the fabric of clothing in direct contact with the user's skin, or otherwise incorporated. In each such example, device 20 is configured as a wearable, flexible solution for providing remote, ambulatory monitoring of a target site. Thus, in embodiments in which device 20 is utilized in conjunction with MSK ultrasound (typically used to generate ultrasound images of muscles, tendons, ligaments, and joints throughout the body, helping to diagnose sprains, strains, tears, and other soft tissue conditions), device 20 enables real-time data collection in sports medicine and real-time healthcare monitoring domains, while also being useful in many advanced applications, including human-machine interfaces, advanced prosthetic technology (bionics), electronic skin, wearable consumer electronics, and soft robotics, to name a few.Additionally, by incorporating each of the ultrasound module 22, EP module 26, and NIRS module 28 in at least one embodiment, the device 20 is capable of measuring blood oxygen saturation ("SpO2"), oxyhemoglobin (OHb), deoxyhemoglobin (OHb), total hemoglobin (tHb), muscle oxygen saturation (SmO2), muscle activity, emotion, arterial blood saturation of carbon monoxide ("SmO2"), and other blood oxygen saturation ("SmO2") in a variety of biomedical and clinical applications. The NIRS module 28 may function as a novel multimodal "3-in-1" system (or at least a "2-in-1" system, where only one of the EP module 26 or the NIRS module 28 is integrated with the ultrasound module 22) that simultaneously acquires ultrasound images, bioelectrical signals, and oxygenation status and / or biochemical measurements, including, but not limited to, respiration such as respiratory rate ("RF") and / or respiratory volume ("RV"), heart rate ("HR") and / or heart rate variability ("HRV"), pulse, bioimpedance, and temperature such as skin temperature ("ST") and / or core body temperature.

[0048] Aspects of the present specification can be further described as the following embodiments.

[0049] (1) A wearable ultrasound device positionable over a target region of a user's body, the wearable ultrasound device including: at least one ultrasound module configured to acquire at least one ultrasound image of the target region, the ultrasound module including at least one ultrasound transducer positioned on at least one elastic substrate and including at least one sensor, at least one conductive layer positioned in electrical communication with the at least one sensor, and at least one ultrasound transceiver in electrical communication with the at least one sensor; at least one electrophysiology ("EP") module positioned on the at least one elastic substrate and configured to detect bioelectric signals of the target region; and at least one controller in electrical communication with each of the ultrasound module and the EP module via the conductive layer, the at least one controller configured to selectively cause the ultrasound module to acquire at least one ultrasound image of the target region upon detecting bioelectric signals at the target region via the EP module.

[0050] (2) The wearable ultrasound device of embodiment 1, wherein at least one sensor is at least one of a piezoelectric sensor or a microelectromechanical ("MEM") sensor.

[0051] (3) The wearable ultrasound device according to any one of the first to second embodiments, wherein at least one sensor is a piezoelectric sensor including a piezoelectric material sandwiched between two or more electrodes.

[0052] (4) A wearable ultrasonic device according to any one of embodiments 1 to 3, wherein at least one ultrasonic module includes a pair of conductive layers positioned to substantially sandwich at least one piezoelectric sensor.

[0053] (5) The wearable ultrasonic device of any one of claims 1 to 4, wherein the at least one ultrasonic module further includes at least one matching layer positioned on the bottom surface of the at least one sensor and configured to adapt the acoustic impedance.

[0054] (6) A wearable ultrasonic device as described in any one of claims 1 to 5, wherein at least one ultrasonic module further includes at least one sealing layer positioned to isolate the at least one conductive layer from the surrounding environment.

[0055] (7) A wearable ultrasonic device according to any one of the first to sixth embodiments, wherein at least one ultrasonic module further comprises a pair of sealing layers positioned to substantially sandwich at least one conductive layer.

[0056] (8) A wearable ultrasound device as described in any one of embodiments 1 to 7, wherein at least one ultrasound transducer is configured to operate in the range of 7 to 14 MHz for surface scanning and in the range of 2 to 6 MHz for deeper targets.

[0057] (9) A wearable ultrasound device according to any one of embodiments 1 to 8, wherein at least one ultrasound transducer is configured to operate in a pulse-echo configuration.

[0058] (10) The wearable ultrasonic device according to any one of the first to ninth embodiments, wherein each of the at least one piezoelectric sensor has a width that is relatively smaller than the pitch.

[0059] (11) A wearable ultrasound device according to any one of embodiments 1 to 10, wherein at least one ultrasound transducer includes a plurality of adjacently arranged sensors configured as at least one array.

[0060] (12) The wearable ultrasonic device of any one of embodiments 1 to 11, wherein the distance between the centers of two adjacent piezoelectric sensors of the array is less than about 0.5λ for phased array operation and between about 0.75λ and 3λ for linear array operation, where λ = c / f, and λ is the wavelength of an ultrasonic signal having a frequency f and a longitudinal wave sound speed c ≈ 1500 m / s.

[0061] (13) The wearable ultrasound device of any one of embodiments 1 to 12, wherein adjacent piezoelectric sensors of the array are separated by small kerfs to provide separation between the acoustic elements of each of the piezoelectric sensors.

[0062] (14) A wearable ultrasound device according to any one of embodiments 1 to 13, wherein at least one ultrasound transducer includes multiple arrays positioned side-by-side.

[0063] (15) A wearable ultrasound device as described in any one of embodiments 1 to 14, wherein at least one ultrasound transducer includes multiple arrays arranged to obtain orthogonal cross sections of the target area.

[0064] (16) The wearable ultrasound device according to any one of the first to fifteenth embodiments, wherein the at least one array is configured as a curved surface.

[0065] (17) A wearable ultrasound device as described in any one of embodiments 1 to 16, wherein a subset of consecutive sensors are configured to be activated simultaneously on demand.

[0066] (18) A wearable ultrasound device as described in any one of embodiments 1 to 17, wherein the plurality of sensors are sandwiched between a plurality of electrodes arranged in a matrix configuration to form at least one quasi-two-dimensional array.

[0067] (19) A wearable ultrasound device as described in any one of embodiments 1 to 18, wherein the bottommost matching layer of at least one matching layer is configured to selectively attach the corresponding at least one ultrasound transducer to the target site.

[0068] (20) A wearable ultrasound device as described in any one of embodiments 1 to 19, wherein at least one matching layer is composed of at least one of a silicone adhesive gel, rubber, silicone, a thermoplastic elastomer, and a polymer material.

[0069] (21) The wearable ultrasound device of any one of embodiments 1 to 20, wherein at least one matching layer is further comprised of a material that is biocompatible, latex-free, non-toxic, and non-allergenic.

[0070] (22) A wearable ultrasonic device as described in any one of embodiments 1 to 21, wherein at least one matching layer is composed of a polymer material together with at least one filler including at least one of PZT, tungsten, alumina, silica glass, tungsten carbide, titanium, and glass powder, and the at least one filler is configured to increase the acoustic impedance of the polymer material.

[0071] (23) A wearable ultrasound device as described in any one of embodiments 1 to 22, wherein the ultrasound module further includes a bonding layer positioned in contact with the bottom surface of the lowest ultrasound transducer of the at least one ultrasound transducer and configured to selectively attach the ultrasound module to the target site.

[0072] (24) A wearable ultrasonic device according to any one of embodiments 1 to 23, wherein the bonding layer is positioned in contact with the bottom surface of the lowest matching layer of at least one matching layer.

[0073] (25) The wearable ultrasound device of any one of embodiments 1 to 24, wherein the bonding layer comprises a sonolucent silicone gel or other adhesive material capable of transmitting ultrasound signals between the ultrasound module and the target site.

[0074] (26) The wearable ultrasound device of any one of embodiments 1 to 25, wherein the bonding layer is further comprised of a material that is biocompatible, latex-free, non-toxic, and non-allergenic.

[0075] (27) A wearable ultrasonic device according to any one of the first to twenty-sixth embodiments, wherein the coupling layer has an acoustic impedance close to the acoustic impedance of the target site for impedance matching.

[0076] (28) A wearable ultrasound device as described in embodiments 1 to 27, wherein the ultrasound module further includes at least one backing layer positioned in contact with a side of the at least one sensor farthest from the target site, the at least one backing layer configured to absorb ultrasound emitted by the at least one sensor that is not directed toward the target site.

[0077] (29) The wearable ultrasonic device according to any one of the first to twenty-eighth embodiments, wherein at least one backing layer has an acoustic impedance close to an acoustic impedance of at least one sensor.

[0078] (30) A wearable ultrasound device according to any one of embodiments 1 to 29, wherein at least one backing layer is made of at least one of tungsten-doped epoxy, pyrolytic material, brass, and carbon.

[0079] (31) The wearable ultrasound device according to any one of embodiments 1 to 30, wherein at least one conductive layer is made of at least one of a conductive polymer material, carbon, graphene, aluminum, copper, gold, molybdenum, iridium, magnesium, silver, lithium fluoride, and alloys thereof.

[0080] (32) The wearable ultrasound device according to any one of embodiments 1 to 31, wherein at least one sealing layer is made of at least one of glass and plastic.

[0081] (33) The wearable ultrasound device according to any one of embodiments 1 to 32, wherein at least one sealing layer is substantially impermeable to moisture and oxygen.

[0082] (34) A wearable ultrasound device as described in any one of embodiments 1 to 33, including a relatively greater number of sensors than ultrasonic transmitters and receivers, such that at least one ultrasonic transmitter and receiver is in electrical communication with multiple sensors.

[0083] (35) A wearable ultrasound device as described in any one of embodiments 1 to 34, further comprising at least one bidirectional multiplexer in electrical communication with at least one ultrasound transmitter / receiver and a corresponding plurality of sensors.

[0084] (36) A wearable ultrasound device as described in any one of embodiments 1 to 35, wherein the EP module includes at least one electrode array and at least one reference electrode.

[0085] (37) A wearable ultrasound device as described in embodiments 1 to 36, wherein at least one ultrasound transmitter / receiver includes a pulser, a transmit / receive switch ("T / R switch"), a low noise amplifier ("LNA"), a variable gain amplifier ("VGA"), and a low pass filter ("LPF").

[0086] (38) A wearable ultrasound device as described in embodiments 1 to 37, further comprising at least one transceiver configured to electrically communicate with at least one controller and to communicate with a selected external device.

[0087] (39) A wearable ultrasonic device as described in any one of embodiments 1 to 38, wherein the EP module includes at least one electrode, a front-end signal conditioning circuit, a controller, and a communication module.

[0088] (40) A wearable ultrasound device as described in embodiments 1 to 39, wherein at least one elastic substrate is composed of at least one of a silicone-based material, rubber, a thermoplastic elastomer, a polymer material, a foil, and various fabrics.

[0089] (41) A wearable ultrasound device according to any one of embodiments 1 to 40, wherein at least one elastic substrate is further comprised of a transparent, flexible, and inherently conformable material.

[0090] (42) A wearable ultrasound device as described in any one of embodiments 1 to 41, wherein at least one elastic substrate is further comprised of a material that is biocompatible, latex-free, non-toxic, and non-allergenic.

[0091] (43) A wearable ultrasound device as described in any one of embodiments 1 to 42, wherein at least one elastic substrate has a thickness of about 180 micrometers or less, such that the device has a total thickness of about 25 millimeters or less.

[0092] (44) A wearable ultrasound device as described in any one of embodiments 1 to 43, wherein at least one elastic substrate comprises a plurality of signal traces embedded within or on the elastic substrate.

[0093] (45) A wearable ultrasound device as described in any one of embodiments 1 to 44, further comprising a near-infrared spectroscopy (“NIRS”) module positioned on the at least one elastic substrate, in electrical communication with the at least one controller, and configured to monitor oxygenation status and / or biochemical measurements of the target site.

[0094] (46) A wearable ultrasound device as described in any one of embodiments 1 to 45, wherein the NIRS module includes at least one photodetector and at least one near-infrared light-emitting diode ("LED").

[0095] (47) A wearable ultrasound device as described in any one of embodiments 1 to 46, wherein at least one of the at least one controller and the ultrasonic transmitter / receiver is positioned within at least one microelectronic module.

[0096] (48) A wearable ultrasound device as described in any one of embodiments 1 to 47, further comprising a cover configured to protect each of the ultrasound module, the EP module, the NIRS module, and the at least one microelectronic module.

[0097] (49) A wearable ultrasound device as described in any one of embodiments 1 to 48, configured as a self-contained wearable patch that can selectively engage a target site directly or indirectly.

[0098] (50) A wearable ultrasound device positionable over a target site on a user's body, the wearable ultrasound device comprising: at least one ultrasound module configured to acquire at least one ultrasound image of the target site, the ultrasound module including: at least one ultrasound transducer positioned on at least one elastic substrate and including at least one piezoelectric sensor, each including a piezoelectric material sandwiched between two or more electrodes; a pair of conductive layers positioned to substantially sandwich the at least one piezoelectric sensor; and at least one ultrasound transceiver in electrical communication with the at least one piezoelectric sensor; at least one electrophysiology (“EP”) module positioned on the at least one elastic substrate and configured to detect bioelectric signals at the target site; and at least one controller in electrical communication with each of the ultrasound module and the EP module via the conductive layers, the at least one controller configured to selectively cause the ultrasound module to acquire at least one ultrasound image of the target site upon detecting bioelectric signals at the target site via the EP module.

[0099] (51) A wearable ultrasound device positionable over a target site on a user's body, the wearable ultrasound device including: at least one ultrasound module configured to acquire at least one ultrasound image of the target site, the ultrasound module including at least one ultrasound transducer positioned on at least one elastic substrate and including at least one sensor, at least one conductive layer positioned in electrical communication with the at least one sensor, and at least one ultrasound transceiver in electrical communication with the at least one sensor; at least one electrophysiology (“EP”) module positioned on the at least one elastic substrate and configured to detect bioelectric signals of the target site; a near-infrared spectroscopy (“NIRS”) module positioned on the at least one elastic substrate and configured to monitor oxygenation status and / or biochemical measurements of the target site; and at least one controller in electrical communication with each of the ultrasound module and at least one of the EP module and the NIRS module via the conductive layer, the at least one controller configured to selectively cause the ultrasound module to acquire at least one ultrasound image of the target site upon detecting at least one of the bioelectrical signals, oxygenation status and / or biochemical measurements of the target site.

[0100] Finally, with respect to the exemplary embodiments of the present invention shown and described herein, it will be understood that a wearable ultrasound device is disclosed and configured for use in connection with various biomedical applications, including musculoskeletal ("MSK") imaging and analysis. Because the principles of the present invention can be embodied in many configurations other than those shown and described, it will be understood that the present invention is in no way limited to the exemplary embodiments, but is directed generally to wearable ultrasound devices, which can take many forms to do so without departing from the spirit and scope of the present invention. Those skilled in the art will understand that the present invention is not limited to the particular shapes and materials of structures disclosed, but instead can include other functionally equivalent structures or materials, now known or later developed, without departing from the spirit and scope of the present invention.

[0101] Certain embodiments of the present invention are described herein, including the best mode known to the inventor(s) for carrying out the invention. Of course, variations on these described embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor(s) expect those of ordinary skill in the art to adopt such variations as appropriate, and the inventor(s) intend the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Furthermore, this invention includes any combination of the above-described embodiments in all possible variations thereof unless otherwise indicated herein or clearly contradicted by context.

[0102] Groupings of alternative embodiments, elements, or steps of the invention should not be construed as limiting. Each group element may be referred to and claimed individually or in any combination with other group elements disclosed herein. It is anticipated that one or more elements of a group may be included in, or deleted from, a group for reasons of convenience and / or patentability. When any such inclusion or deletion occurs, the specification includes the group as modified and is thus deemed to fulfill the specification of all Markush groups used in the appended claims.

[0103] Unless otherwise indicated, all numbers expressing features, items, quantities, parameters, characteristics, terms, etc. used in the specification and claims should be understood to be modified in all instances by the term "about." As used herein, the term "about" means that the feature, item, quantity, parameter, characteristic, or term so qualified encompasses a range of plus or minus 10 percent of the value of the stated feature, item, quantity, parameter, characteristic, or term. Thus, unless otherwise indicated, the numerical parameters set forth in this specification and the appended claims are approximations that may vary. At the very least, and without intending to limit the application of the doctrine of equivalents to the scope of the claims, each numerical designation should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and values ​​setting forth the broad scope of the invention are approximations, the numerical ranges and values ​​set forth in the specific examples are reported as precisely as possible. However, any numerical range or value inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. The recitation of numerical ranges of values ​​herein is merely intended to serve as a shorthand method of individually referring to each individual numerical value falling within that range. Unless otherwise indicated herein, each value of a numerical range is incorporated herein as if it were individually recited herein. Similarly, as used herein, unless otherwise indicated, the term "substantially" is a degree term intended to indicate the approximation of the characteristic, item, amount, parameter, property, or term so defined, encompassing the range that can be understood and interpreted by one of ordinary skill in the art.

[0104] The use of the term "may" or "can" with respect to an embodiment or an aspect of an embodiment also carries the alternative meaning of "may not" or "cannot." Thus, where the specification discloses that an embodiment or an aspect of an embodiment may or may not be included as part of the inventive subject matter, a negative limitation or exclusionary condition is also expressly expressed, meaning that the embodiment or aspect of an embodiment may or may not be included as part of the inventive subject matter. Similarly, the use of the term "optionally" with respect to an embodiment or an aspect of an embodiment means that such embodiment or aspect of such embodiment may or may not be included as part of the inventive subject matter. Whether such a negative limitation or exclusionary condition applies depends on whether the negative limitation or exclusionary condition is recited in the claimed subject matter.

[0105] As used in the context of describing the present invention (particularly in the context of the claims below), the terms "a," "an," "the," and similar references should be construed to encompass both the singular and the plural unless otherwise indicated herein or clearly contradicted by context. Furthermore, ordinal markers such as "first," "second," and "third" of identified elements are used to distinguish elements and do not indicate or imply a required or limited number of such elements, nor do they indicate a particular location or order of such elements, unless otherwise specified. All methods described herein may be performed in any suitable order unless otherwise indicated herein or clearly contradicted by context. The use of any and all examples or exemplary language (e.g., "such as") provided herein is intended merely to further clarify the invention and does not otherwise limit the scope of the claimed invention. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[0106] When used in the claims, whether as filed or added per amendment, the open-ended transitional term "comprising" (along with equivalent open-ended transitional phrases such as "including," "containing," and "having") includes all of the explicitly recited elements, limitations, steps, and / or features, either alone or in combination with unrecited subject matter, and the specified elements, limitations, and / or features are essential, but other unspecified elements, limitations, and / or features may be added to still form a claim's scope. Specific embodiments disclosed herein may be further limited in the claims using the closed-ended transitional phrases "consisting of" or "consisting essentially of" in place of or as a modification of "comprising." When used in a claim, whether as filed or added per amendment, the closed transitional phrase "consisting of" excludes any element, limitation, step, or feature not expressly recited in the claim. The closed transitional phrase "consisting essentially of" limits the scope of the claim to the elements, limitations, steps, and / or features that are expressly recited and any other elements, limitations, steps, and / or features that do not materially affect the basic and novel characteristic(s) of the claimed subject matter. Accordingly, the meaning of the open-ended transitional phrase "comprising" is defined to include all specifically recited elements, limitations, steps, and / or features, as well as optional additional unspecified ones.The meaning of the closed transitional phrase "consisting of" is defined to include only those elements, limitations, steps, and / or features specifically recited in the claim, while the meaning of the closed transitional phrase "consisting essentially of" is defined to include only those elements, limitations, steps, and / or features specifically recited in the claim and those elements, limitations, steps, and / or features that do not materially affect the basic and novel characteristic(s) of the claimed subject matter. Thus, the open-ended transitional phrase "comprising" (and its equivalent open-ended transitional phrases) takes its extreme meaning to include the claimed subject matter identified by the open-ended transitional phrase "consisting of" or "consisting essentially of." Thus, embodiments described or claimed herein using the phrase "comprising" are expressly or inherently expressly described, enabled, and supported herein relative to the phrases "consisting essentially of" and "consisting of."

[0107] Any claim intended to be treated under 35 U.S.C. 112(f) will begin with the words "means for," but use of the word "for" in any other context is not intended to invoke treatment under 35 U.S.C. 112(f). Accordingly, applicants reserve the right to pursue additional claims after filing this application, either in this application or in any continuing application.

[0108] It should be understood that the order in which the logic code, programs, modules, processes, methods, and respective elements of each method are executed is merely an example. Depending on the implementation, they may be executed in any order or in parallel, unless otherwise indicated in this disclosure. Furthermore, the logic code is not related to or limited to any particular programming language and may include one or more modules executing on one or more processors in a distributed, non-distributed, or multiprocessing environment. Furthermore, the various illustrative logic blocks, modules, methods, and algorithmic processes and sequences described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, and process operations have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the particular application and design constraints imposed on the overall system. The described functionality may be implemented in various ways for each particular application, and such implementation decisions should not be interpreted as causing a departure from the scope of this document.

[0109] The phrase "non-transitory" has its ordinary meaning, and in addition, as used in this document, means "permanent or long-lived." The phrase "non-transitory computer-readable medium" has its ordinary meaning, and in addition, includes any and all computer-readable media, with the sole exception of transitory propagating signals. This includes, by way of example and not limitation, non-transitory computer-readable media such as register memory, processor cache, and random access memory ("RAM").

[0110] The above-described methods can be used to manufacture integrated circuit chips. The resulting integrated circuit chips can be distributed by manufacturers in raw wafer form (i.e., as a single wafer containing multiple unpackaged chips), as bare dies, or in packaged form. In the latter case, the chips are mounted in a single-chip package (such as a plastic carrier with leads secured to a motherboard or other higher-level carrier) or a multi-chip package (such as a ceramic carrier with either surface interconnects or embedded interconnects, or both). In either case, the chips are then integrated with other chips, discrete circuit elements, and / or other signal processing devices as part of either (a) an intermediate product such as a motherboard, or (b) a final product. The final product can be any product containing integrated circuit chips, ranging from toys and other low-end applications to advanced computer products with displays, keyboards or other input devices, and central processors.

[0111] All patents, patent publications, and other publications referenced and identified herein are individually and expressly incorporated herein by reference in their entirety, for example, to describe and disclose the compositions and methodologies described therein that may be used in connection with the present invention. These publications are provided solely for their disclosure prior to the filing date of this application. Nothing in this regard should be construed as an admission that the inventors are not entitled to antedate such disclosure by virtue of prior invention or for any other reason. All statements as to the date or representation as to the contents of these documents are based on the information available to the applicant and are not admissions as to the accuracy of the dates or contents of these documents.

[0112] While aspects of the present invention have been described with reference to at least one exemplary embodiment, it should be clearly understood by those skilled in the art that the invention is not limited thereto. Rather, the scope of the present invention should be construed only in conjunction with the appended claims, and it is now made clear that the inventor(s) believe that the claimed subject matter is their invention.

Claims

1. a wearable ultrasound device positionable at a target location on a user's body; at least one ultrasound module configured to acquire at least one ultrasound image of the target region; at least one ultrasonic transducer positioned on at least one elastic substrate, the at least one ultrasonic transducer including at least one sensor; at least one conductive layer positioned in electrical communication with the at least one sensor; and at least one ultrasonic transceiver in electrical communication with the at least one sensor; an ultrasonic module including: at least one electrophysiology ("EP") module positioned on the at least one elastic substrate and configured to detect bioelectrical signals at the target site; at least one controller in electrical communication with each of the ultrasound module and the EP module via the conductive layer, the at least one controller configured to selectively cause the ultrasound module to acquire at least one ultrasound image of the target region upon detecting a bioelectrical signal at the target region via the EP module; 1. A wearable ultrasound device comprising:

2. The wearable ultrasound device of claim 1 , wherein the at least one sensor is at least one of a piezoelectric sensor or a microelectromechanical ("MEM") sensor.

3. The wearable ultrasound device of claim 2 , wherein the at least one sensor is a piezoelectric sensor that includes a piezoelectric material sandwiched between two or more electrodes.

4. 10. The wearable ultrasound device of claim 1, wherein the at least one ultrasound module further comprises at least one matching layer positioned on a bottom surface of the at least one sensor and configured to adapt an acoustic impedance.

5. 10. The wearable ultrasound device of claim 1, wherein the ultrasound module further includes at least one backing layer positioned in contact with a top surface of the at least one sensor furthest from the target site, the at least one backing layer configured to absorb ultrasound emitted by the at least one sensor that is not directed toward the target site.

6. 10. The wearable ultrasound device of claim 1, wherein the at least one ultrasound module further comprises at least one sealing layer positioned to isolate the at least one conductive layer from the surrounding environment.

7. 10. The wearable ultrasound device of claim 1, further comprising a bonding layer positioned in contact with a bottom surface of a lowest ultrasound transducer of the at least one ultrasound transducer and configured to selectively adhere the device to the target site.

8. The wearable ultrasound device of claim 7 , wherein the coupling layer has an acoustic impedance close to that of the target site for impedance matching.

9. The wearable ultrasound device of claim 1 , wherein the at least one ultrasound transducer includes a plurality of adjacently arranged sensors configured in at least one array.

10. 10. The wearable ultrasound device of claim 9, wherein the at least one ultrasound transducer comprises multiple arrays positioned side-by-side.

11. 10. The wearable ultrasound device of claim 9, wherein the at least one ultrasound transducer includes multiple arrays arranged to obtain orthogonal cross sections of the target area.

12. The wearable ultrasound device of claim 9 , wherein the at least one array is configured as a curved surface.

13. 10. The wearable ultrasound device of claim 9, wherein a subset of consecutive sensors are configured to be simultaneously activated on demand.

14. 10. The wearable ultrasound device of claim 9, wherein the plurality of sensors are sandwiched between a plurality of electrodes arranged in a matrix configuration to form at least one quasi-two-dimensional array.

15. The wearable ultrasound device of claim 1 , including a relatively greater number of sensors than ultrasonic transceivers, such that the at least one ultrasonic transceiver is in electrical communication with a plurality of sensors.

16. 16. The wearable ultrasound device of claim 15, further comprising at least one bidirectional multiplexer in electrical communication with the at least one ultrasound transceiver and corresponding plurality of sensors.

17. 10. The wearable ultrasound device of claim 1, wherein the EP module includes at least one electrode array in electrical communication with the at least one signal conditioning circuit and configured to detect bioelectrical signals at the target site.

18. 10. The wearable ultrasound device of claim 1, further comprising a near-infrared spectroscopy ("NIRS") module positioned on the at least one elastic substrate, in electrical communication with the at least one controller, and configured to monitor oxygenation status and / or biochemical measurements of the target site.

19. a wearable ultrasound device positionable at a target location on a user's body; at least one ultrasound module configured to acquire at least one ultrasound image of the target region; at least one ultrasonic transducer disposed on at least one elastic substrate, the at least one ultrasonic transducer including at least one piezoelectric sensor, each of the at least one piezoelectric sensor including a piezoelectric material sandwiched between two or more electrodes; a pair of conductive layers positioned to substantially sandwich the at least one piezoelectric sensor; and at least one ultrasonic transmitter / receiver in electrical communication with the at least one piezoelectric sensor; an ultrasonic module including: at least one electrophysiology ("EP") module positioned on the at least one elastic substrate and configured to detect bioelectrical signals at the target site; at least one controller in electrical communication with each of the ultrasound module and the EP module via the conductive layer, the at least one controller configured to selectively cause the ultrasound module to acquire at least one ultrasound image of the target region upon detecting a bioelectrical signal at the target region via the EP module; a wearable ultrasound device.

20. a wearable ultrasound device positionable at a target location on a user's body; at least one ultrasound module configured to acquire at least one ultrasound image of the target region; at least one ultrasonic transducer positioned on at least one elastic substrate, the at least one ultrasonic transducer including at least one sensor; at least one conductive layer positioned in electrical communication with the at least one sensor; and at least one ultrasonic transceiver in electrical communication with the at least one sensor; an ultrasonic module including: an electrophysiology ("EP") module positioned on the at least one elastic substrate and configured to detect bioelectrical signals at the target site; and a near-infrared spectroscopy ("NIRS") module positioned on the at least one elastic substrate and configured to monitor oxygenation status and / or biochemical measurements at the target site. at least one controller in electrical communication with each of the ultrasound module and at least one of the EP module and the NIRS module via the conductive layer, the at least one controller configured to selectively cause the ultrasound module to acquire at least one ultrasound image of the target site upon detecting at least one of a bioelectrical signal, an oxygenation status, and / or a biochemical measurement at the target site; 1. A wearable ultrasound device comprising:

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