Wearable ultrasound device

Abstract

A wearable ultrasound device for use with various biomedical applications including musculoskeletal ("MSK") imaging and analysis is disclosed. In at least one embodiment, the device provides 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 located (hereinafter referred to as "target site" for simplicity), an electrophysiology ("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.

Description

[0001] Related Applications

[0002] This application claims priority to and the benefit of U.S. Provisional Application Serial No. 62 / 965,276, filed January 24, 2020. The contents of the above application are incorporated herein by reference.

[0003] BACKGROUND

[0004] The subject matter of this patent application relates generally to ultrasound devices, and more specifically to a wearable ultrasound apparatus configured for use with various biomedical applications.

[0005] Applicant hereby incorporates by reference any and all patents and published patent applications cited in this application or mentioned in the background section of this application.

[0006] By way of background, ultrasound waves are used in many different fields, often as a tool to penetrate a medium to measure its reflective characteristics. In medicine, among other applications, ultrasound imaging devices are commonly used for diagnostic medical imaging of internal organs, muscles, tendons, and other objects located within a patient’s body. Conventional ultrasound imaging devices are capable of providing sophisticated real-time images and are capable of extracting unique features with advanced signal processing techniques. However, they are typically large, fixed, and expensive. Medium-sized imaging devices with limited mobility, such as computer-on-wheels systems, can also achieve roughly similar performance to larger systems. In recent years, hand-held versions of such devices, as well as wearable versions, have also been developed, which provide relatively more mobility. However, to the best of Applicant’s knowledge, none of these known devices are capable of simultaneously acquiring ultrasound imaging, electrophysiology, hemodynamic, and metabolic information of a patient’s internal organs, muscles, tendons, and other soft tissues in biomedical and clinical applications.

[0007] Aspects of the present invention satisfy these needs and provide further related advantages as described in the following outline of sections.

[0008] It should be noted that the above background discussion includes information helpful for understanding the aspects of the present invention. It 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.

[0009] SUMMARY

[0010] Aspects of the present invention teach some benefits with respect to construction and use which result in the exemplary advantages described below.

[0011] The present invention solves the above problems by providing a wearable ultrasound device configured for use with various biomedical applications, including musculoskeletal ("MSK") imaging and analysis. In at least one embodiment, the device provides 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 located (hereinafter referred to for simplicity as "target site"), an electrophysiology ("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.

[0012] 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. BRIEF DESCRIPTION OF DRAWINGS

[0014] The accompanying drawings illustrate aspects of the present invention. In such drawings:

[0015] Figure 1 is a cross-sectional schematic view of an exemplary wearable ultrasound device according to at least one embodiment;

[0016] Figure 2A , Figure 2B and Figure 2C is a schematic view of exemplary piezoelectric sensors and electrodes of an exemplary ultrasound transducer according to at least one embodiment;

[0017] Figure 3 is another schematic view of an exemplary piezoelectric sensor according to at least one embodiment;

[0018] Figure 4 is another schematic view of an exemplary piezoelectric sensor array according to at least one embodiment;

[0019] Figure 4A is a detailed view of the cross-section defined by line 4A of Figure 4 ;

[0020] Figure 5A and Figure 5B are schematic views of exemplary piezoelectric sensor arrays according to at least one embodiment;

[0021] Figure 6 is a schematic view of an exemplary wearable ultrasound device according to at least one embodiment;

[0022] Figure 7 is a schematic view of an exemplary ultrasound transceiver according to at least one embodiment;

[0023] Figure 8 This is a schematic diagram of an exemplary electrophysiological (“EP”) module according to at least one embodiment;

[0024] Figure 9 This is a schematic diagram of an exemplary near-infrared spectroscopy (“NIRS”) module according to at least one embodiment;

[0025] Figure 10 This is a schematic cross-sectional view of another exemplary wearable ultrasound device according to at least one embodiment; and

[0026] Figure 11 This is a schematic cross-sectional view of yet another exemplary wearable ultrasound device according to at least one embodiment.

[0027] The above-described figures illustrate aspects of the invention in at least one exemplary embodiment, which are further defined in detail in the following description. According to one or more embodiments, features, elements, and aspects of the invention denoted by the same reference numerals in different figures represent the same, equivalent, or similar features, elements, or aspects.

[0028] Detailed description

[0029] Turn now Figure 1 This image shows a schematic cross-sectional view of an exemplary embodiment of a wearable ultrasound device 20 configured for use with various biomedical applications, including musculoskeletal (“MSK”) imaging and analysis. In at least one embodiment, the device 20 provides at least one of the following: an ultrasound module 22 configured to acquire at least one ultrasound image of a portion of a user’s body where at least one ultrasound module 22 is located (hereinafter referred to as the “target site” 24 for simplicity); an electrophysiological (“EP”) module 26 configured to detect bioelectrical signals at the target site 24; and a near-infrared spectroscopy (“NIRS”) module 28 configured to monitor the oxygenation status and / or biochemical measurements of the target site 24, each of which is further discussed below. First, it should be noted that... Figure 1 The specific arrangement of the components shown is merely exemplary. Therefore, in other embodiments, as discussed further below, the various components may employ many other arrangements.

[0030] In at least one embodiment, ultrasound module 22 provides at least one ultrasound transducer 30 for superficial scanning in the 7-14 MHz range and deep target scanning in the 2-6 MHz range. However, in further embodiments, at least one ultrasound transducer 30 can operate in any other range now known or hereafter developed, capable of allowing device 20 to substantially perform the functions described herein. Moreover, in at least one embodiment, at least one ultrasound transducer 30 is configured to operate in a pulse-echo configuration, i.e., it is configured to transmit and subsequently receive ultrasound pulses in order to obtain at least one ultrasound image. In at least one embodiment, at least one ultrasound transducer 30 comprises at least one piezoelectric sensor 32. In at least one such embodiment, ultrasound transducer 30 comprises a plurality of piezoelectric sensors 32 configured as at least one array 34, the number of piezoelectric sensors 32 in a given array 34 ranging between 2 and 256. However, in further embodiments, any other number of piezoelectric sensors 32 can be used. In at least one alternative embodiment, as shown for example in FIG. 1, in addition to, or instead of, at least one piezoelectric sensor 32, at least one ultrasound transducer 30 comprises at least one microelectromechanical (“MEM”) sensor 102, such as at least one capacitive micromachined ultrasound transducer (“CMUT”) or piezoelectric micromachined ultrasound transducer (“PMUT”). Both CMUTs and PMUTs are based on the oscillation of a membrane suspended over a cavity formed in a silicon substrate. Figure 10

[0031] ​In at least one embodiment, the at least one ultrasonic transducer 30 is located on at least one elastic substrate 38. In at least one such embodiment, the elastic substrate 38 is composed of a flexible and / or stretchable material. For example, in at least one such embodiment, the material includes at least one of a silicon-based material, rubber, a thermoplastic elastomer, a polymeric material, a foil (such as those mixed with epoxy), and various fabrics. In at least one further embodiment, the elastic substrate 38 is composed of a material that is transparent in nature, flexible, and conformable. Moreover, in at least one embodiment, the material is biocompatible, latex-free, non-toxic, and non-sensitizing. In still other embodiments, the elastic substrate 38 can include any other material (or combination of materials) having flexible and / or rigid-flex properties now known or later developed, 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 of a composite epoxy material (“CEM”), a fiberglass or paper-based class material, providing a solid foundation for a printed circuit board (“PCB”). For example, in at least one such embodiment, the material includes at least one of an epoxy resin (FR4, FR5, FE-3), a PF resin (XPC, FR1, FR2), and a polyester resin. In at least one alternative embodiment, the elastic substrate 38 is positioned and used to perform the functions of any layer of the ultrasonic module 22, the EP module 26, or the NIRS module 28, so long as it is placed in the location of the layer performing the function and its material properties are suitable. In at least one embodiment, the elastic substrate 38 has a thickness of approximately 180 micrometers or less, such that the device 20 has a total thickness of approximately 25 millimeters or less. However, in further embodiments, the elastic substrate 38 can have any other thickness, 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 configured as a flexible film having signal traces embedded within or above the elastic substrate 38, and the at least one piezoelectric sensor 32 is attached to the elastic substrate 38. In at least one alternative embodiment, the at least one piezoelectric sensor 32 and the signal traces are simultaneously screen printed onto the elastic substrate 38, which can provide a number of benefits. 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 can reduce the number of steps involved in the manufacturing process. Moreover, the size, shape, and arrangement of the at least one piezoelectric sensor 32 (relative to the elastic substrate 38) can be freely tailored, depending on the intended use of the device 20 in a given embodiment. In particular, the shape of the at least one piezoelectric sensor 32 can be modified to have rounded corners in order to introduce aperture apodization, thereby improving sidelobe suppression. Other example shapes can include (but are in no way limited to) a ring shape, a hexagon shape, a circle shape, a rectangular shape, etc.Furthermore, in at least one such embodiment, at least one piezoelectric sensor 32 includes a piezoelectric material 40 sandwiched between two or more electrodes 42 (e.g.). Figure 2A , Figure 2B and Figure 2C As shown and discussed further below, assuming that the distance between the electrodes 42 (at least in part based on the thickness of the piezoelectric material 40) defines the excitation frequency between them, it is possible to achieve different distances between the multiple electrodes 42, thereby enabling at least one ultrasonic transducer 30 to operate at multiple frequencies and have improved bandwidth.

[0032] In at least one embodiment, for phased array operation, the distance between the centers of two adjacent piezoelectric sensors 32 of array 34 is less than about 0.5λ, and for linear array operation, this distance is less than about 0.75λ-3λ, where λ = c / f, and λ is the wavelength of an ultrasonic signal with frequency f and longitudinal sound velocity c ≈ 1500 m / s. Some numerical examples of the above limits are given in Table 1 below.

[0033]

[0034] Table 1

[0035] In at least one embodiment, such as Figure 3 As shown, the width W of each piezoelectric sensor 32 is relatively smaller than the spacing P, assuming that small notches K (i.e., separations) are required between the piezoelectric sensors 32 to provide acoustic element isolation for each piezoelectric sensor 32. Furthermore, in at least one embodiment, each piezoelectric sensor 32 has a thickness or height H, which is at least partially dependent on the resonant frequency at which the ultrasonic transducer 30 operates. Several examples of thicknesses for different materials are shown in Table 2 below. Additionally, in at least one embodiment, each piezoelectric sensor 32 has a length L, which is less constrained by design limitations compared to the other two dimensions.

[0036]

[0037] Table 2

[0038] In at least one embodiment, the thickness / height H of a given piezoelectric sensor 32 is a function of the acoustic frequency. In at least one such embodiment, each piezoelectric sensor 32 has a height H of approximately 300 micrometers or less. However, in other embodiments, each piezoelectric sensor 32 may have any other height H, provided that the device 20 is capable of substantially performing the functions described herein.

[0039] In at least one embodiment, the at least one piezoelectric sensor 32 can be made of any suitable material, including but not limited to a flexible piezoelectric coating (film, paste, or paint), a ceramic transducer, or a polymer bulk transducer. Further, in at least one embodiment, the at least one piezoelectric sensor 32 can include quartz, polyvinylidene fluoride, ceramic including PZT and screen printed ceramic, magneto strictive, or composite including molded ceramic and flexure. For example, the piezoelectric material can be selected from the group consisting of polyvinylidene fluoride (PVDF) and its copolymers, lead zirconate titanate Pb(Zr,Ti)03, lead metaniobate Pb(Nb20e), modified lead titanate PbTi3, (Pb,Ca)Ti03, (Pb,Sm)Ti03, barium titanate BaTi03, PMN-PT (l-x)Pb(Mgi / 2,Nbi / 3)03-xPb-Ti03, PZN-PT / BT Pb(ZNi / 2,Nbi / 3)03-xPbTi03-BaTi03, (l-x)Pb(ZNi / 2,Nbi / 3)03-x(yPbTi03-(l-y)PbZr03). In at least one embodiment, the at least one piezoelectric sensor 32 consists 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. Patent No. 10,079,336) provide piezoelectric materials 40 that can be applied to a variety of substrates. Of course, other flexible piezoelectric coatings can be used in at least one embodiment of the present application.

[0040] Additionally, as shown in FIG. 1, in at least one embodiment, the plurality of piezoelectric sensors 32 can be positioned in a stacked arrangement. Another benefit of simultaneously screen printing the at least one piezoelectric sensor 32 and the signal trace onto the elastic substrate 38 is the ability to integrate additional resources, such as the EP module 26 and / or the NIRS module 28, as discussed further below. Thus, as shown in the figures (and as described herein), the size, shape, dimensions, configuration, and number of each of the at least one piezoelectric sensor 32 and the corresponding elastic substrate 38 are merely exemplary. In further embodiments, each of the at least one piezoelectric sensor 32 and the corresponding elastic substrate 38 can take on any other size, shape, dimensions, configuration, and / or number now known or hereafter developed, so long as the device 20 is capable of substantially performing the functions described herein. In still further embodiments, any other technique (or combination of techniques) now known or hereafter developed for positioning the at least one piezoelectric sensor 32 on the elastic substrate 38 can be used instead. Figure 2A Figure 2B Additionally, as shown in FIG. 1, in at least one embodiment, the plurality of piezoelectric sensors 32 can be positioned in a stacked arrangement. Another benefit of simultaneously screen printing the at least one piezoelectric sensor 32 and the signal trace onto the elastic substrate 38 is the ability to integrate additional resources, such as the EP module 26 and / or the NIRS module 28, as discussed further below. Thus, as shown in the figures (and as described herein), the size, shape, dimensions, configuration, and number of each of the at least one piezoelectric sensor 32 and the corresponding elastic substrate 38 are merely exemplary. In further embodiments, each of the at least one piezoelectric sensor 32 and the corresponding elastic substrate 38 can take on any other size, shape, dimensions, configuration, and / or number now known or hereafter developed, so long as the device 20 is capable of substantially performing the functions described herein. In still further embodiments, any other technique (or combination of techniques) now known or hereafter developed for positioning the at least one piezoelectric sensor 32 on the elastic substrate 38 can be used instead. ​

[0041] In at least one additional embodiment, piezoelectric material 40 can be sandwiched between a plurality of electrodes 42 arranged in a row-column configuration to form a quasi- two-dimensional array. An example of such an embodiment is shown in Figure 4 and Figure 4A where electrodes 42 are arranged in a 3x3 matrix and piezoelectric material 40 is located substantially between electrodes 42 in the area where they overlap (as shown in Figure 4A ).

[0042] In at least one embodiment, at least one ultrasound transducer 30 is configured to perform a B-mode scan (or "B-scan") of target site 24. However, in additional embodiments, at least one ultrasound transducer 30 can 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 at least one ultrasound transducer 30 depends on the body part of the user that requires at least one ultrasound image. Moreover, as noted above, in at least one embodiment, at least one ultrasound transducer 30 includes a plurality of piezoelectric sensors 32 configured as at least one array 34. In at least one such embodiment, at least one array 34 can be arranged in a variety of configurations. For example, as shown in the schematic of Figure 5A , two or more linear arrays 34 can be arranged so as to acquire orthogonal cross-sections of target site 24. As another example, as shown in the schematic of Figure 5B , at least one array 34 can be configured as a curve (rather than linear). As yet another example, at least one array 34 can be configured as a convex curve, thereby providing a relatively wide field of view. Moreover, the size of at least one array 34 depends at least in part on the specific context in which device 20 is to be used. As noted above, in at least one embodiment, the number of piezoelectric sensors 32 in a given array 34 ranges between 2 and 256. However, in additional embodiments, any other number of piezoelectric sensors 32 can be used. Thus, the size, shape, dimensions, configuration, and number of at least one array 34 as shown in the drawings (and as described herein) are merely exemplary. In additional embodiments, at least one array 34 can take any other size, shape, dimensions, configuration, and / or number now known or later developed, so long as device 20 is capable of substantially performing the functions described herein.

[0043] In at least one embodiment, in which at least one ultrasound transducer 30 is configured to perform B-mode scanning of a target region and includes a plurality of piezoelectric transducers 32 configured as at least one linear array 34, a subset of adjacent or contiguous piezoelectric transducers 32 are configured to be excited / activated simultaneously at any given time. The signals of each piezoelectric transducer 32 of the subset can be identical or exhibit a particular time delay to provide focusing or beam steering, while different signal amplitudes on each piezoelectric transducer 32 of the subset can be applied to achieve apodization. Multi-line acquisition techniques can be used to improve the frame rate of the resulting at least one ultrasound image. In still other embodiments, multi-line transmission can be utilized to further improve the frame rate, including simultaneously exciting multiple ultrasound beams of the same or different frequencies. Further, in at least one embodiment, harmonic imaging is implemented to improve image resolution.

[0044] In at least one embodiment, as Figure 1As shown, the bottom surface 44 of the at least one piezoelectric sensor 32 provides at least one matching layer 46 configured to provide an acoustic impedance adaptation. When an acoustic wave 36 encounters a boundary between two layers having a relatively large difference in their respective acoustic impedances, the acoustic wave 36 is reflected at the boundary. Thus, in at least one embodiment, multiple matching layers 46 are used such that the acoustic impedance of each matching layer 46 can gradually change to minimize reflections. In at least one such embodiment, the at least one matching layer 46 (or at least the bottom-most one of the at least one matching layer 46) is configured to selectively adhere the at least one ultrasonic transducer 30 to the target site 24 either directly (i.e., adhered to the user’s skin) or indirectly (i.e., adhered to a garment or other material that, in turn, is 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. Generally, it has been found that a higher number of matching layers 46 results in a relatively better adaptation (i.e., less energy is reflected to the at least one ultrasonic transducer 30) and broadband operation, which improves the 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 the respective at least one elastic substrate 38, the at least one elastic substrate 38 itself can be configured to function as a matching layer 46. In at least one embodiment, the at least one matching layer 46 is composed of a flexible and / or stretchable material, similar to the at least one elastic substrate 38. For example, in at least one such embodiment, the material is a silicone adhesive gel. In further embodiments, the material is at least one of a rubber, a silicone, a thermoplastic elastomer, or other polymeric material (e.g., a polyester, a polyethylene terephthalate, a polyethylene naphthalate, a polycarbonate, a polystyrene, a polyacrylic acid, a polyether sulfone, etc.). Moreover, 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-sensitizing. In still other embodiments, the at least one matching layer 46 can include any other suitable material (or combination of materials) now known or later developed that has flexible and / or stretchable properties that can enable the at least one matching layer 46 to substantially perform the functions described herein.

[0045] In at least one embodiment, where at least one matching layer 46 is composed of a polymeric material, the acoustic impedance of the polymeric material can be increased by the addition of one or more fillers. Suitable fillers include, but are not limited to, PZT, tungsten, alumina, quartz glass, tungsten carbide, titanium, glass powder, and the like, with glass powder being preferred. In at least one such embodiment, the size of the filler particles is in the range of about 0.1-50 microns, preferably about 0.5-5 microns. The amount of filler used will be that amount necessary to impart the desired acoustic impedance. Typically, about 2 to about 50 volume percent of filler is used, preferably about 5 to about 30 volume percent. A preferred polymeric material is silicone rubber.

[0046] In at least one embodiment, as Figure 1As shown, the ultrasound module 22 also provides a coupling layer 48 positioned in contact with a bottom surface 50 of at least one matching layer 46 (or a bottom-most one of the at least one matching layer 46) and configured to selectively adhere the ultrasound module 22 (and, in turn, the device 20) to the target site 24 either directly (i.e., to the user’s skin) or indirectly (i.e., to a garment or other material that, in turn, is in contact with the user’s skin). In at least one embodiment, the coupling layer 48 comprises a sonolucent silicone gel or other adhesive material capable of transmitting ultrasound signals between the ultrasound module 22 and the target site 24. “Sonolucent” refers to a gel capable of transmitting ultrasound pulses without introducing significant interference or attenuation, such that an acceptable acoustic response can be obtained from the target site 24. Thus, the material of the coupling layer 48 can be selected according to its ability to provide a solid and gapless contact between the ultrasound module 22 and the adjacent target site 24. The acoustic impedance of the coupling layer 48 should be close to that of the adjacent target site 24 to provide impedance matching. In at least one embodiment, the coupling layer 48 is part of the matching layer 46, and the impedance of the coupling layer 48 is selected according to the design criteria of such matching layer 46. In at least one embodiment, in which the at least one piezoelectric sensor 32 is screen-printed onto the respective at least one elastic substrate 38, the at least one elastic substrate 38 itself can be configured to function as the coupling layer 48. Further, in at least one embodiment, the coupling layer 48 provides a temporary backing configured to be peeled off before the coupling layer 48 is adhered to the target site 24. In at least one embodiment, the coupling layer 48 has a thickness of approximately 100 to 500 micrometers (e.g., 100, 200, 300, 400, 500 micrometers, or some range therebetween). However, in further embodiments, the coupling layer 48 can have any other thickness, so long as the device 20 is capable of substantially performing the functions described herein. Further, in at least one embodiment, in which the at least one coupling layer 48 is configured to be in direct contact with the user’s skin, the at least one coupling layer 48 is biocompatible, latex-free, non-toxic, and non-allergenic. In still other embodiments, the at least one coupling layer 48 can comprise any other suitable material (or combination of materials) now known or later developed that has the above-described properties, capable of allowing the at least one coupling layer 48 to substantially perform the functions described herein.

[0047] In at least one embodiment, as Figure 1As shown, the ultrasonic transducer 30 also provides at least one backing layer 52 positioned in contact with the at least one piezoelectric sensor 32 and opposite the respective side on which energy is intended to be radiated (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 any ultrasonic waves radiated by the at least one piezoelectric sensor 32 that are not directed toward the target site 24, thereby preventing any reverberation and / or resonance that would otherwise reduce the bandwidth of the pulses emitted from the at least one piezoelectric sensor 32. In at least one embodiment, where the at least one piezoelectric sensor 32 is screen printed onto the respective at least one elastic substrate 38, the at least one elastic substrate 38 itself can be configured to function as the backing layer 52. Thus, in at least one embodiment, the at least one backing layer 52 is made of a material that has an acoustic impedance close to that of the at least one piezoelectric sensor 32 and has a relatively high damping 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, most of the waves transmitted back are quickly attenuated and turned into heat, and only a very small portion can bounce back. In at least one embodiment, the at least one backing layer 52 is composed of at least one of tungsten-loaded epoxy, pyrolytic, brass, carbon, etc. In still other embodiments, the at least one backing layer 52 can include any other suitable material (or combination of materials) now known or later developed that is capable of allowing the at least one backing layer 52 to substantially achieve the functionality described herein.

[0048] With continued reference to Figure 1In at least one embodiment, the ultrasonic module 22 also provides a pair of electrically conductive layers 54 positioned to sandwich at least one piezoelectric sensor 32, such that the electrically conductive layers 54 integrate the electrodes 42 of each piezoelectric sensor 32, as well as traces that interconnect them to an electronic system associated with the ultrasonic module 22 (hereinafter referred to as "microelectronic module" 56, as described below). In at least one embodiment, the electrically conductive layers 54 each comprise a thin metal film (e.g., aluminum, copper, gold, molybdenum, iridium, magnesium, silver, lithium fluoride, and alloys thereof) or a non-metallic material. Further, in at least one embodiment, each electrically conductive layer 54 has a thickness of about 200 μιη or less (e.g., about 200, 180, 160, 140, 120, 100, 90, 80, 70, 60, 50, 40, 30 μιη or less). Preferably, each electrically conductive layer 54 has a thickness of less than 10 μιη (e.g., about 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.8, 0.6, 0.4, 0.2 μιη or less or some range therebetween). Further, in at least one embodiment, the electrically conductive layers 54 are flexible. In at least one such embodiment, the electrically conductive layers 54 are composed of a transparent conductive polymer material, such as indium tin oxide (ITO), fluorine-doped tin oxide (FTO), ZnO-Ga2O3, ZnO-Al2O3, SnO2-Sb2O3, and polythiophene. Further, the electrically conductive layers 54 can be composed of silver or copper grids or busbars plated on a transparent substrate, or silver nanowires or nanoparticles deposited on a substrate with a poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) coating. Additional conductive polymer layers can be added to improve conductivity. In at least one embodiment, the electrically conductive layers 54 can be carbon-based, such as carbon nanotubes ("CNTs"), carbon nanowires, or graphene, among others. One preferred electrically conductive layer 54 (electrically conductive and transparent to infrared radiation) comprises graphene. While one or two layers of graphene are preferred, the electrically conductive layers 54 can each comprise approximately 1 to 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 electrically conductive layers 54 can comprise several inner electrically conductive layers 54 separated by insulating material, in order to manage a large number of tracks.

[0049] With continued reference to Figure 1In at least one embodiment, the ultrasonic transducer 30 also provides a pair of encapsulation layers 58 positioned to sandwich the pair of conductive layers 54 (and, in turn, the at least one piezoelectric sensor 32) in between, such that the encapsulation layers 58 are configured to isolate the at least one piezoelectric sensor 32 from the surrounding environment. In at least one embodiment, the encapsulation layers 58 are substantially impermeable to moisture and oxygen. Generally, moisture and oxygen sensitive components of the device 20 should be surrounded by a material with gas permeation properties. The encapsulation layers 58 preferably achieve a low water vapor permeability of 10 -4 g / mi 2 hr or lower, 10 -5 g / mi 2 hr or lower, even more preferably about 10 -6 g / mi 2 hr or lower. In at least one embodiment, the encapsulation layers 58 are constructed of, for example, glass or plastic. In at least one embodiment, the encapsulation layers 58 are constructed of a flexible and / or stretchable material. For example, in at least one such embodiment, the material includes at least one of a silicon-based material, rubber, a thermoplastic elastomer, a polymeric material, a foil (such as those mixed with epoxy), and various fabrics. Ideally, the substrate in direct contact with the organic layers would have excellent barrier capabilities, be able to withstand heat, provide flexibility, have consistent reliability, and be mass producible.

[0050] As described above, in at least one embodiment, device 20 also provides an electrophysiological (“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 the potential generated by muscle fibers (muscle cells). The frequency range of the EMG amplitude is 20 μV–5 μV; however, in other embodiments, other amplitudes may be used instead. The amplitude of the sEMG signal increases when more muscle fibers are recruited to maintain a constant load or to support an increase in load. In at least one embodiment, the sEMG signal reflects muscle activation driven by motor neurons and can be collected non-invasively from the skin surface. As an effective tool, the sEMG sensor can be used for the diagnosis of neuromuscular diseases, the assessment of muscle fatigue, and human-machine interfaces for prosthetic manipulation. In at least one such embodiment, when combining the functionality of various modalities of sEMG sensors with the ultrasound module 22, the device 20 can be used in a wide variety of contexts, including but not limited to: exercise and training; identifying muscle, tendon, and other soft tissue injuries; identifying electromyographic manifestations of fatigue; assessing EMG signal modification in pathology; evaluating motor coordination and treatment effectiveness; identifying neurological disorders; identifying disuse, immobility, and inactivity; and measuring age-related neuromuscular changes. In at least one embodiment, the device 20 is configured to be in close / close contact with the user's skin (to eliminate or at least minimize motion artifacts or displacement of the device 20), substantially on top of the muscle of interest.

[0051] In at least one embodiment, such as Figure 6 As shown, device 20 also provides at least one ultrasonic transceiver 60 that electrically communicates with at least one piezoelectric sensor 32 of ultrasonic module 22. In at least one such embodiment, device 20 provides a relatively larger number of piezoelectric sensors 32 than ultrasonic transceivers 60, such that at least one ultrasonic transceiver 60 electrically communicates with a plurality of piezoelectric sensors 32. In at least one such embodiment, device 20 provides at least one analog bidirectional multiplexer 62 that electrically communicates with at least one ultrasonic transceiver 60 and the corresponding plurality of piezoelectric sensors 32. Figure 6The schematic diagram illustrates an exemplary configuration of multiplexer 62. However, it should be noted that the configuration and number of at least one multiplexer 62 shown in the figures (and as described herein) are merely exemplary. In other embodiments, at least one multiplexer 62 may employ any other configuration (relative to at least one ultrasonic transceiver 60 and the corresponding plurality of piezoelectric sensors 32) and / or number, provided that device 20 is substantially capable of performing the functions described herein. In at least one embodiment, where device 20 provides a plurality of 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 another such embodiment, the number of layers is equal to the quotient of the number of piezoelectric sensors 32 divided by the number of multiplexers 62. In still other embodiments, any other number of layers and any other arrangement of signal traces between said layers may be used, provided that device 20 is substantially capable of performing the functions described herein.

[0052] In at least one embodiment, such as Figure 7 As shown in the simplified schematic diagram, at least one ultrasonic transceiver 60 comprises a pulse generator 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, at least one ultrasonic transceiver 60 is capable of transmitting ultrasonic pulses with several discrete levels to provide amplitude apodization. In other embodiments, at least one ultrasonic transceiver 60 can transmit pulses with any waveform and subsequently perform precise amplitude apodization, which even includes transmitting a finite diffraction beam, such as a zeroth-order Bessel beam.

[0053] Refer again Figure 6In at least one embodiment, the apparatus 20 also provides at least one controller 78 in electrical communication with each of the ultrasound module 22, the EP module 26, and / or the NIRS module 28. Thus, in such embodiments, the controller 78 is configured to interface with and manage each of the ultrasound module 22, the EP module 26, and / or the NIRS module 28, and to process at least one ultrasound image of the target site 24. In at least one such embodiment, the processing can include image reconstruction and / or data compression. In at least one alternative embodiment, one or more of the ultrasound module 22, the EP module 26, and / or the NIRS module 28 provide their own dedicated power source 80. In at least one embodiment, the controller 78 is also in electrical communication with at least one transceiver 82 configured for transmission of at least one ultrasound image and any data associated therewith to select external devices, such as computing and electrical devices in communication with the apparatus 20. In at least one further embodiment, the at least one transceiver 82 is also configured to receive select information from such external devices as well. The at least one transceiver 82 can utilize any now known or later developed wired or wireless based communication protocol (or combination of protocols), including but not limited to Wi-Fi and Bluetooth-LE.

[0054] Further, in at least one embodiment, the controller 78 is in selective communication with at least one data storage device 84 (local or remote) configured for storage of at least one ultrasound image and any data associated therewith. It should be noted that the term “data storage device” is intended to include any type of electronic storage medium (or combination of storage mediums) now known or later developed, such as a local hard drive, RAM, flash memory, secure digital (“SD”) card, external storage device, network or cloud storage device, integrated circuit, etc.

[0055] In at least one further embodiment, where the device 20 includes further modules, such as, for example, the EP module 26 and / or the NIRS module 28, the controller 78 is configured to manage any such further modules. Further, in embodiments where the device 20 provides the EP module 26, the controller can selectively trigger ultrasound image acquisition upon detection of a particular value of a bioelectric signal and / or electrophysiological parameter in the target site 24, which prevents measurements to be taken during irrelevant periods and optimizes the use of energy intended for ultrasound imaging. This functionality also allows for acquisition in specific circumstances or upon detection of specific events. In at least one such embodiment, the controller 78 can optimize the acquisition of ultrasound images of the target site 24 during very fast repetitive movements, i.e., it can optimize the acquisition of ultrasound images of the target site 24 even if the acquisition rate is low, assuming that the ultrasound image acquisition process can be synchronized with the periodic movement, then ultrasound images or their lines can be acquired along several cycles. In still other embodiments, the controller 78 can be configured to selectively control other aspects and / or functions of the device 20, such as, for example, running various components in a “low power mode”. In at least one embodiment, the controller 78 is at least one of a field programmable gate array (“FPGA”), a digital signal processor (“DSP”), a microcontroller, and a microprocessor.

[0056] With continued reference to Figure 6 In at least one embodiment, the device 20 also provides a power source 80. The power source 80 can be any power source now known or later developed capable of providing the necessary power to each of the ultrasound module 22, the EP module 26, and / or the NIRS module 28, including but not limited to one or more batteries (rechargeable or otherwise), an AC adapter, a DC adapter, and the like. In at least one alternative embodiment, one or more of the ultrasound module 22, the EP module 26, and / or the NIRS module 28 provide their own dedicated power source 80.

[0057] In at least one embodiment, as Figure 8 shown, the EP module 26 is configured as a multi-channel, compact, wireless acquisition system, providing 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, for example, a Bluetooth-LE module. In at least one embodiment, the EP module 26 provides a biocompatible printed electrode array to capture bioelectric signals. Further, in at least one embodiment, as Figure 1As shown, the EP module provides at least one electrode array, which includes 32 or fewer electrodes 42 (e.g., about 32, 30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2) and a reference electrode 90. However, in further embodiments, any other number of electrodes 42 can be used. In at least one embodiment, the reference electrode 90 is positioned between two differential electrodes 42 to avoid asymmetry in bioelectric signal recording, and the inter-electrode spacing is increased in the configuration of the electrodes 42. However, a small inter-electrode spacing is preferred because this will reduce the amount of cross-talk signal detected from adjacent active muscles. Thus, as a preferred trade-off, the inter-electrode spacing is set to be about 32 to 8 millimeters (e.g., about 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8 millimeters, or some range therebetween). However, in further embodiments, any other spacing can be utilized so long as the device 20 is capable of performing substantially the functions described herein. Moreover, in at least one embodiment, the electrodes 42 have a thickness of about 100 micrometers or less (e.g., about 100, 90, 80, 70, 60, 50, 40, 30, 20, 10, 5 μιη or less). However, in further embodiments, the electrodes 42 can have any other thickness so long as the device 20 is capable of performing substantially the functions described herein. The EP module 26 can optionally include electrodes 42 of different sizes and shapes, such as rectangular, circular, elliptical, ring, or disc shaped electrodes. In a non-limiting example, the array of electrodes 42 is characterized by a disc shaped conductor and at least one ring shaped conductor concentric to the disc shaped conductor, which are disposed on a substrate so as to capture bioelectric signals and are configured to provide different weights to the voltage of the conductors, thereby producing a plurality of outputs corresponding to different sensitivity-based spatial distributions, configured according to the requirements of capturing the bioelectric potentials to be measured. In at least one embodiment, the EP module 26 also provides a coupling layer 48 positioned in contact with a bottom surface of at least one electrode 42 (or at least the bottom-most one of the at least one array of electrodes 42) and configured to selectively adhere the EP module 26 (and, in turn, the device 20) to the target site 24 either directly (i.e., to the user's skin) or indirectly (i.e., to a garment or other material, which in turn is in contact with the user's skin). In at least one embodiment, the coupling layer 48 includes a gel (e.g., a hydrogel having adhesive properties). The hydrogel can be electrically conductive and capable of transmitting bioelectric signals between the target site 24 and the EP module 26.

[0058] In at least one embodiment, the electrodes 42 and conductive tracks of the EP module 26 are composed of a conductive metal ink / paste, which is made using metal nanoparticles, organometallic compounds, or metal salts as precursors (primarily silver-based) and conductive polymers, because its conductivity is generally lower than that of its metal counterpart, but it has better adhesion and mechanical stability, and generally does not require post-processing steps. Alternatively, dispersions of graphene or CNTs can also be used for printing to produce 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 pastes, stretchable silver conductor pastes, medical-grade conductive Ag / AgCl inks, or poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate), because they offer flexible processing and durable conductivity.

[0059] As described above, in at least one embodiment, the device 20 further provides a near-infrared spectroscopy (“NIRS”) module 28, which is configured for monitoring the oxygenation status and / or biochemical measurements of the target site 24. In at least one such embodiment, as Figure 1 and Figure 9 As shown, 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 blood oxygenation assay).

[0060] Human tissues are relatively transparent to light in the near-infrared range of 650-1000 nanometers. The near-infrared radiation (“NIR”) window, also known as the “optical window,” is the wavelength range with the greatest penetration depth in tissues. In fact, because NIR is minimally absorbed by water and hemoglobin, spectral readings can be easily collected from the body surface; the main absorbers are the blood chromophores of oxyhemoglobin (HbO2) and deoxyhemoglobin (HHb). When near-infrared light emitted by LED 94 passes through tissue, a portion 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 LED 94 and photodetector 92. It is generally considered that for a source-detector distance of 3 cm, approximately 1.5 cm below the skin surface (half the source-detector distance) can be detected through a banana-shaped area. Therefore, considering the specific anatomy of different muscles, the LED-detector distance can be selected within the range of 2-7 cm for muscle activity detection. However, in other embodiments, any other interval can be used, as long as device 20 can substantially perform the functions described herein. Furthermore, HbO2 and HHb have different light absorption characteristics for near-infrared light; muscle contraction alters the amount of near-infrared light scattered back to the skin surface, and this change can be detected by photodetector 92. The relative concentration changes of HbO2 and HHb can be calculated and quantified using a modified Beer-Lambert law.

[0061] Therefore, in at least one embodiment, the combined advantages of the EP module 26 and the NIRS module 28 will help to understand muscle activity from an electrophysiological and metabolic perspective, providing more valuable 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, revealing the mechanisms of muscle fatigue or injury. However, using separate sEMG and NIRS sensor systems results in large size, cumbersome data synchronization, cumbersome signal lines, and limited channels. Therefore, in at least one embodiment, the device 20 with an integrated EP module 26, NIRS module 28, and ultrasound module 22 is essential to meet the requirements of clinical practice.

[0062] In at least one embodiment, one or more of the at least one photodetector 92 can be used to provide a reference signal. For example, the photodetector 92 closest to the near infrared LED 94 can provide a reference intensity against which the intensities measured by the other photodetectors 92 are compared. In this way, control and knowledge of the variation in signal intensity emitted by the near infrared LED 94 can be provided, simplifying the design and operation of the NIRS module 28. In at least one embodiment, the photodetectors 92 can be spaced 10 millimeters between the center of each adjacent photodetector 92 and between the center of a first photodetector 92 of a plurality of additional photodetectors 92 and the near infrared LED 94. In other configurations, a smaller spacing (e.g., a spacing of 8 mm) can be used to allow for a greater number of photodetectors 92 to be included. For example, the photodetectors 92 can 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 can be between 5 mm and 20 mm, less than 5 mm, less than 1 mm, or any distance or range of distances within these ranges. In further embodiments, any other spacing can be utilized so long as the device 20 is able to substantially perform the functions described herein. In at least one embodiment, the photodetectors 92 are electronically arranged and configured to operate in synchronization with the near infrared LED 94. In at least one such embodiment, the photometric front end 100 is used to operate the photodetectors 92 and 94. In at least one embodiment, the near infrared LED 94 can comprise a thin light source, which can include, for example, an OLED or a printable LED (organic or inorganic). In at least one such embodiment, the light source includes a flexible light emitter located between two conductive layers 54 (i.e., electrodes) including an anode and a cathode, where the flexible light emitter emits light in response to an electrical current applied to the anode and the cathode. A typical light source uses a transparent substrate, a transparent anode, a flexible light emitter, and a reflective cathode. Light generated by 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, a plurality of photodetectors 92 are arranged substantially linearly on a path originating from the location of the near infrared LED 94 for measuring the light signal at different locations relative to the near infrared LED 94. In a preferred configuration, at least two photodetectors 92 are used to measure the light signal intensity at at least two different distances from the LED 94 to provide an improved fit of the measured signal as a function of distance to a model used to provide any one or more of oxygenated (+muscle) hemoglobin (O2Hb), deoxygenated hemoglobin (+muscle) (HHb), total hemoglobin (+muscle) (tHb), or muscle oxygen saturation (SmO2) based on the measured intensity.

[0063] 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 common anode for the ultrasonic module 22, EP module 26, and / or NIRS module 28. The anode for the EP module 26 and / or NIRS module 28 includes, for example, a transparent conductive oxide (TCO), such as, but not limited to, indium tin oxide (ITO), zinc oxide (ZnO), etc. In practice, the conductive layer 54 will include a network of tracks connecting these components to their associated electronics. In addition to the conductive layer containing the anode or cathode of the ultrasonic module 22, EP module 26, or NIRS module 28, the conductive layer 54 may also be included to allow proper wiring of all tracks. Furthermore, the conductive layer 54 having a continuous conductive plane can be considered to allow for impedance-controlled traces (e.g., microstrips or striplines) and / or provide electromagnetic shielding. The conductive plane or traces can be considered to collect heat generated by any element of the device 20 and conduct it to at least one heat sink, where such heat can be safely transferred to the surrounding environment.

[0064] In at least one embodiment, one or more electronic systems, such as, but not limited to, an ultrasonic transceiver 60, an analog bidirectional multiplexer 62, a controller 78, a transceiver 82, a power supply 80, a front-end signal conditioning circuit 86, a photometric front-end 100, a wireless communication module 88, a data storage device 84, etc., may be included in at least one microelectronic module 56. Figure 1 Within the device 20, the microelectronic module 56 is positioned to contact the top surface 96 of at least one backing layer 52. In at least one additional embodiment, the microelectronic module 56 is located within a cover 98, which is positioned on top of and in electrical contact with various components of the device 20. In yet another embodiment, the microelectronic module 56 may be located on or relative to other parts of the device 20. For example, in at least one such additional embodiment, such as Figure 11 As shown, the microelectronic module 56 may be located externally to or separate from other components of the device 20, wherein each of at least one ultrasonic module 22, EP module 26, and / or NIRS module 28 is in electrical communication with the microelectronic module 56. These embodiments allow the microelectronic module 56 to be manufactured using conventional and relatively reliable processes, while also increasing the modularity of the device 20. In other such embodiments, each of at least one ultrasonic module 22, EP module 26, and / or NIRS module 28 may be implemented together in a single flexible patch (as discussed further below) or individually, depending at least in part on the technology required for a given use case and the location of the target site 24.

[0065] In at least one embodiment, the cover 98 is made of a transparent or translucent material. However, in further embodiments, the cover 98 can be constructed of an opaque material. The cover 98 can provide comfort to the user, especially when the user is engaged in physical activity. The cover 98 can provide protection for the various components of the device 20, prevent dust and fluids from entering the components, and provide cushioning to protect the device 20 from impact. The cover 98 can additionally improve heat transfer between any components of the device 20 and the ambient environment if the material has a reasonably low thermal resistivity.

[0066] It should be noted that the configuration and arrangement of the various components of the device 20 shown in the figures, including the relative positioning of the components of each of the ultrasound module 22, the EP module 26, and / or the NIRS module 28, is merely exemplary. Thus, in further embodiments, the various components can take any other configuration and arrangement now known or hereafter developed, so long as the device 20 is capable of substantially performing the functions described herein.

[0067] Also as Figure 1As shown, in at least one embodiment, the various components of the device 20 described above are configured as independent, wearable patches that can be adhesively secured to a user's skin (or to a garment that directly contacts a user's skin), or alternatively, secured or otherwise integrated into the fabric of a garment that directly contacts a user's skin. In each such instance, the device 20 is configured as a wearable, flexible solution for providing remote flow monitoring of a target site. Thus, in embodiments where the device 20 is used in the context of MSK ultrasound (which is generally used to generate ultrasound images of the muscles, tendons, ligaments, and joints throughout the body to aid in the diagnosis of sprains, strains, tears, and other soft tissue conditions), the device 20 will allow for real-time data collection in the field of sports medicine and real-time health monitoring, while also being useful for a variety of advanced applications, including human-machine interfaces, advanced prosthetic technology (bionics), e-skin, wearable consumer electronics, and soft robotics, to name a few. Moreover, by incorporating each of the ultrasound module 22, the EP module 26, and the NIRS module 28 in at least one embodiment, the device 20 is capable of functioning as a novel multi-modal "3-in-l" system (or at least a "2-in-l" system where only one of the EP module 26 or the NIRS module 28 is combined with the ultrasound module 22), that simultaneously acquires ultrasound imaging, bioelectric signals, and oxygenation state and / or biochemical measurements in a variety of biomedical and clinical applications, including but not limited to sonomyography ("SMG"), electromyography ("EMG"), electrocardiography ("ECG"), electroencephalography ("EEG"), galvanic skin response ("GSR"), photoplethysmography ("PPG"), arterial blood oxygen saturation ("Sp02"), oxygen (+muscle) hemoglobin, (O2Hb), deoxyhemoglobin (+muscle) (HHb), total hemoglobin (+muscle) (tHb), muscle oxygen saturation (SmO2), muscle activity, emotion, carbon monoxide ("SpCO"), and arterial saturation of blood carbon dioxide ("CO2"), blood pressure ("BP"), 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.

[0068] Aspects of the present specification can also be described as the following embodiments:

[0069] 1. A wearable ultrasound device positionable on a target site of a user's body, comprising: at least one ultrasound module configured to obtain at least one ultrasound image of the target site, the ultrasound module comprising at least one ultrasound transducer, at least one electrically conductive layer, and at least one ultrasound transceiver, the at least one ultrasound transducer located on at least one elastic substrate, comprising at least one sensor, the at least one electrically conductive layer positioned in electrical communication with the at least one sensor, the at least one ultrasound transceiver in electrical communication with the at least one sensor; at least one electrophysiological ("EP") module located on the at least one elastic substrate and configured to detect a bioelectric signal in the target site; at least one controller in electrical communication with each of the ultrasound module and the EP module via the electrically conductive layer, the at least one controller configured to selectively cause the ultrasound module to obtain the at least one ultrasound image of the target site upon detection of the bioelectric signal in the target site via the EP module.

[0070] 2. The wearable ultrasound device of embodiment 1, wherein the at least one sensor is at least one of a piezoelectric sensor or a microelectromechanical ("MEM") sensor.

[0071] 3. The wearable ultrasound device of embodiments 1-2, wherein the at least one sensor is a piezoelectric sensor comprising a piezoelectric material sandwiched between two or more electrodes.

[0072] 4. The wearable ultrasound device of embodiments 1-3, wherein the at least one ultrasound module comprises a pair of electrically conductive layers positioned to substantially sandwich the at least one piezoelectric sensor therebetween.

[0073] 5. The wearable ultrasound device of embodiments 1-4, wherein the at least one ultrasound module further comprises at least one matching layer located on a bottom surface of the at least one sensor and configured to provide acoustic impedance adaptation.

[0074] 6. The wearable ultrasound device of embodiments 1-5, wherein the at least one ultrasound module further comprises at least one encapsulation layer positioned to isolate the at least one electrically conductive layer from the surrounding environment.

[0075] 7. The wearable ultrasound device of embodiments 1-6, wherein the at least one ultrasound module further comprises a pair of encapsulation layers positioned to substantially sandwich the at least one electrically conductive layer therebetween.

[0076] 8. The wearable ultrasound device of embodiments 1-7, wherein the at least one ultrasound transducer is configured to operate in a range of 7-14 MHz for shallow layer scanning and in a range of 2-6 MHz for scanning of deeper target sites.

[0077] 9. The wearable ultrasound device according to embodiments 1-8, wherein the at least one ultrasound transducer is configured to operate in a pulse-echo configuration.

[0078] 10. The wearable ultrasound device according to embodiments 1-9, wherein each of the at least one piezoelectric sensor has a width that is smaller than its pitch.

[0079] 11. The wearable ultrasound device according to embodiments 1-10, wherein the at least one ultrasound transducer comprises a plurality of adjacently arranged sensors configured as at least one array.

[0080] 12. The wearable ultrasound device according to embodiments 1-11, wherein for phased array operation, the distance between the centers of two adjacent piezoelectric sensors of the array is less than about 0.5λ, and for linear array operation, the distance is less than about 0.75λ-3λ, where λ=c / f, λ being the wavelength of the ultrasound signal having a frequency f and a longitudinal acoustic speed c ~ 1500 m / s.

[0081] 13. The wearable ultrasound device according to embodiments 1-12, wherein adjacent piezoelectric sensors of the array are separated by a small cut in order to provide acoustic element isolation for each piezoelectric sensor.

[0082] 14. The wearable ultrasound device according to embodiments 1-13, wherein the at least one ultrasound transducer comprises a plurality of arrays positioned in a side-by-side arrangement.

[0083] 15. The wearable ultrasound device according to embodiments 1-14, wherein the at least one ultrasound transducer comprises a plurality of arrays arranged to collect orthogonal cross sections of a target site.

[0084] 16. The wearable ultrasound device according to embodiments 1-15, wherein the at least one array is configured as a curved element.

[0085] 17. The wearable ultrasound device according to embodiments 1-16, wherein a subset of consecutive sensors is configured to be activated simultaneously as needed.

[0086] 18. The wearable ultrasound device according to embodiments 1-17, wherein a plurality of sensors are sandwiched between a plurality of electrodes arranged in a row-column structure so as to form at least one quasi-two-dimensional array.

[0087] 19. The wearable ultrasound device according to embodiments 1-18, wherein a bottommost one of the at least one matching layers is configured for selectively adhering the corresponding at least one ultrasound transducer to a target site.

[0088] 20. The wearable ultrasound device of embodiments 1-19, wherein the at least one matching layer is comprised of at least one of a silicone adhesive gel, rubber, silicone, thermoplastic elastomer, and polymeric material.

[0089] 21. The wearable ultrasound device of embodiments 1-20, wherein the at least one matching layer is further comprised of a biocompatible, latex-free, non-toxic, and non- allergenic material.

[0090] 22. The wearable ultrasound device of embodiments 1-21, wherein the at least one matching layer is comprised of a polymeric material along with at least one filler, the filler comprising at least one of PZT, tungsten, aluminum oxide, quartz glass, tungsten carbide, titanium, and glass powder, the at least one filler configured to increase the acoustic impedance of the polymeric material.

[0091] 23. The wearable ultrasound device of embodiments 1-22, wherein the ultrasound module further comprises a coupling layer positioned in contact with a bottom surface of a bottommost one of the at least one ultrasound transducer and configured to selectively adhere the ultrasound module to the target site.

[0092] 24. The wearable ultrasound device of embodiments 1-23, wherein the coupling layer is positioned in contact with a bottom surface of a bottommost one of the at least one matching layer.

[0093] 25. The wearable ultrasound device of embodiments 1-24, wherein the coupling layer comprises an acoustic transparent silicone gel or other adhesive material capable of transmitting ultrasound signals between the ultrasound module and the target site.

[0094] 26. The wearable ultrasound device of embodiments 1-25, wherein the coupling layer is further comprised of a biocompatible, latex-free, non-toxic, and non-allergenic material.

[0095] 27. The wearable ultrasound device of embodiments 1-26, wherein the coupling layer has an acoustic impedance that approximates the acoustic impedance of the target site so as to provide impedance matching.

[0096] 28. The wearable ultrasound device of embodiments 1-27, wherein the ultrasound module further comprises at least one backing layer positioned in contact with a side of the at least one sensor that is furthest from the target site, the at least one backing layer configured to absorb any ultrasound waves radiated by the at least one sensor that are not directed toward the target site.

[0097] 29. The wearable ultrasound device of embodiments 1-28, wherein the at least one backing layer has an acoustic impedance that approximates the acoustic impedance of the at least one sensor.

[0098] 30. The wearable ultrasound device of embodiments 1-29, wherein the at least one backing layer is comprised of at least one of tungsten-loaded epoxy, pyrolytic, brass, and carbon.

[0099] 31. The wearable ultrasound device of embodiments 1-30, wherein the at least one conductive layer is comprised of at least one of conductive polymer materials, carbon, graphene, aluminum, copper, gold, molybdenum, iridium, magnesium, silver, lithium fluoride, and alloys thereof.

[0100] 32. The wearable ultrasound device of embodiments 1-31, wherein the at least one encapsulation layer is comprised of at least one of glass and plastic.

[0101] 33. The wearable ultrasound device of embodiments 1-32, wherein the at least one encapsulation layer is substantially impermeable to moisture and oxygen.

[0102] 34. The wearable ultrasound device of embodiments 1-33, wherein the device includes a relatively greater number of sensors than ultrasound transceivers, such that at least one ultrasound transceiver is in electrical communication with a plurality of sensors.

[0103] 35. The wearable ultrasound device of embodiments 1-34, further comprising at least one bi-directional multiplexer in electrical communication with the at least one ultrasound transceiver and the corresponding plurality of sensors.

[0104] 36. The wearable ultrasound device of embodiments 1-35, wherein the EP module includes at least one electrode array and at least one reference electrode.

[0105] 37. The wearable ultrasound device of embodiments 1-36, wherein the at least one ultrasound transceiver includes a pulse generator, a transmit / receive switch (“T / R switch”), a low noise amplifier (“LNA”), a variable gain amplifier (“VGA”), and a low pass filter (“LPF”).

[0106] 38. The wearable ultrasound device of embodiments 1-37, further comprising at least one transceiver in electrical communication with the at least one controller and configured for communication with a selected external device.

[0107] 39. The wearable ultrasound device of embodiments 1-38, wherein the EP module includes at least one electrode, a front-end signal conditioning circuit, a controller, and a communication module.

[0108] 40. The wearable ultrasound device of embodiments 1-39, wherein the at least one flexible substrate is comprised of at least one of silicon-based materials, rubber, thermoplastic elastomers, polymeric materials, foils, and various fabrics.

[0109] 41. The wearable ultrasound device of embodiments 1-40, wherein the at least one elastic substrate is further comprised of a material that is transparent in nature, flexible, and conformable.

[0110] 42. The wearable ultrasound device of embodiments 1-41, wherein the at least one elastic substrate is further comprised of a material that is biocompatible, latex-free, non-toxic, and non-sensitizing.

[0111] 43. The wearable ultrasound device of embodiments 1-42, wherein the at least one elastic substrate has a thickness of no more than about 180 microns, such that the device has a total thickness of no more than about 25 millimeters.

[0112] 44. The wearable ultrasound device of embodiments 1-43, wherein the at least one elastic substrate provides a plurality of signal traces embedded within or above the elastic substrate.

[0113] 45. The wearable ultrasound device of embodiments 1-44, 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 for monitoring oxygenation status and / or biochemical measurements of the target site.

[0114] 46. The wearable ultrasound device of embodiments 1-45, wherein the NIRS module comprises at least one photodetector and at least one near-infrared light-emitting diode (“LED”).

[0115] 47. The wearable ultrasound device of embodiments 1-46, wherein at least one of the at least one controller and the ultrasound transceiver is positioned within the at least one microelectronic module.

[0116] 48. The wearable ultrasound device of embodiments 1-47, 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.

[0117] 49. The wearable ultrasound device of embodiments 1-48, wherein the device is configured as a self-contained wearable patch capable of selectively engaging, directly or indirectly, with the target site.

[0118] 50. A wearable ultrasound device positionable on a target site of a user's body, comprising: at least one ultrasound module configured to obtain at least one ultrasound image of the target site, the ultrasound module comprising at least one ultrasound transducer, a pair of electrically conductive layers, and at least one ultrasound transceiver: the at least one ultrasound transducer positioned on at least one flexible substrate, comprising at least one piezoelectric sensor, each of the at least one piezoelectric sensor comprising a piezoelectric material sandwiched between two or more electrodes, the pair of electrically conductive layers positioned to substantially sandwich the at least one piezoelectric sensor therebetween, the at least one ultrasound transducer in electrical communication with the at least one piezoelectric sensor; at least one electrophysiological ("EP") module positioned on the at least one flexible substrate and configured to detect a bioelectric signal in the target site; at least one controller in electrical communication with each of the ultrasound module and the EP module via the electrically conductive layers, the at least one controller configured to selectively cause the ultrasound module to obtain the at least one ultrasound image of the target site upon detection of the bioelectric signal in the target site via the EP module.

[0119] 51. A wearable ultrasound device positionable on a target site of a user's body, comprising: at least one ultrasound module configured to obtain at least one ultrasound image of the target site, the ultrasound module comprising at least one ultrasound transducer, at least one electrically conductive layer, and at least one ultrasound transceiver, the at least one ultrasound transducer positioned on at least one flexible substrate, comprising at least one sensor, the at least one electrically conductive layer positioned in electrical communication with the at least one sensor, the at least one ultrasound transceiver in electrical communication with the at least one sensor; at least one of an electrophysiological ("EP") module and a near-infrared spectroscopy ("NIRS") module, the EP module positioned on the at least one flexible substrate and configured to detect a bioelectric signal in the target site, the near-infrared spectroscopy ("NIRS") module positioned on the at least one flexible substrate and configured to monitor an oxygenation state and / or a biochemical measurement of the target site; at least one controller in electrical communication with each of the ultrasound module and the at least one of the EP module and the NIRS module via the electrically conductive layer, the at least one controller configured to selectively cause the ultrasound module to obtain the at least one ultrasound image of the target site upon detection of at least one of the bioelectric signal, the oxygenation state, and / or the biochemical measurement in the target site.

[0120] Finally, with regard to the exemplary embodiments of the application shown and described herein, it will be understood that a wearable ultrasound device is disclosed and configured for use with various biomedical applications, including musculoskeletal (“MSK”) imaging and analysis. Because the principles of the application can be implemented in a variety of configurations other than those shown and described, it should be understood that the application is not limited to the exemplary embodiments in any way, but is generally directed to a wearable ultrasound device and can take a variety of forms to achieve the same without departing from the spirit and scope of the application. It will further be understood by those skilled in the art that the application is not limited to the specific geometric shapes and materials of construction disclosed, but can instead require other functionally equivalent structures or materials now known or later developed which do not depart from the spirit and scope of the application.

[0121] Certain embodiments of the application are described herein, including the best mode known to the inventors of carrying out the application. Of course, alterations and modifications will occur to others upon reading the preceding description. It is the intent of the inventors to encompass all such alterations and modifications as fall within the scope of the application. Accordingly, the application includes all modifications and equivalents that can fall within the scope of the subject matter recited in the appended claims. Additionally, any combination of the above-described embodiments in all possible variations thereof is encompassed by the application unless otherwise indicated herein or otherwise obvious to one of ordinary skill in the art.

[0122] Groupings of alternative embodiments, elements or steps are not to be construed as limitations. Each member of the group can be present individually or in any combination with other members of the group. One or more members of a group can be included in or deleted from a group for reasons of convenience and / or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus falling within the scope of the appended claims.

[0123] Unless otherwise stated, all figures indicating features, items, quantities, parameters, characteristics, terms, etc., used in this specification and claims should be understood to be modified in all cases by the term "about." As used herein, the term "about" means that such a limited feature, item, quantity, parameter, characteristic, or term includes a range of plus or minus ten percent above and below the value of said feature, item, quantity, parameter, characteristic, or term. Therefore, unless indicated to the contrary, the numerical parameters set forth in the specification and appended claims are approximate values ​​that may vary. At least not in an attempt to limit the application of the doctrine of equivalence to the scope of the claims, each numerical indication should be interpreted at least according to the number of significant figures reported and by applying ordinary rounding techniques. Although the numerical ranges and values ​​that present a broad scope of the invention are approximate, the numerical ranges and values ​​set forth in the specific examples are reported as precisely as possible. However, any numerical range or value inherently includes some error that must be caused by the standard deviation found in their respective test measurements. References to numerical ranges of values ​​herein are intended merely as a method of abbreviating the individual reference to each separate value falling within that range. Unless otherwise stated herein, each individual value of a numerical range is incorporated herein as if it were listed separately. Similarly, as used herein, unless otherwise indicated, the term "substantially" is a degree term intended to indicate an approximate value of such defined feature, item, quantity, parameter, characteristic, or term, including a range that can be understood and interpreted by one of ordinary skill in the art.

[0124] When referring to embodiments or aspects of embodiments, the use of the terms "may" or "can" also carries the alternative meaning of "cannot" or "cannot." Therefore, if this specification discloses an embodiment or aspect of an embodiment that may or can be included as part of the subject matter of the invention, then a negative limitation or exclusionary proviso is also explicit, meaning that an embodiment or aspect of an embodiment may not or cannot be included as part of the subject matter of the invention. Similarly, the use of the term "optionally" when referring to embodiments or aspects of embodiments means that such an embodiment or aspect of an embodiment may or may not be included as part of the subject matter of the invention. Whether such a negative limitation or exclusionary proviso applies will depend on whether it is set forth in the claimed subject matter.

[0125] The use of the terms "a" and "an" and "the" and similar referents in the context of describing the application (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, the sequence of ordering elements identified by ordinal indicators, such as "first," "second," "third," etc. are used to differentiate elements and do not, unless otherwise specifically stated, indicate or imply a required or limited order or sequence of these elements, nor do they indicate a specific position or order of these elements, unless otherwise specifically stated. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. Any and all examples or exemplary language (e.g., "such as") provided herein are intended to better illuminate the application, and do not, unless otherwise indicated herein, limit its scope, unless otherwise indicated herein. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the application.

[0126] When used in the claims, the open-ended transitional phrase "comprising," along with the like open-ended transitional phrases such as "comprising," "including" and "having," alone or in conjunction with other transitions, are intended to allow for the inclusion of any element, limitation, step, or feature, whether expressly stated or not, except in no way limits the scope of the claims. The specific embodiments disclosed herein can be further limited by the terms "consisting of" or "consisting essentially of" in place of "comprising" or as a modification thereto, further limiting the scope of the claims. When used in the claims, the closed-ended transitional phrases "consisting of" and "consisting essentially of" do not include any element, limitation, step, or feature not expressly recited in the claim. The closed-ended transitional phrase "consisting essentially of" limits the scope of a claim to the elements, limitations, steps, and / or features expressly stated in the claim and to those that do not materially affect the basic and novel characteristic(s) of the claimed subject matter. Thus, the meaning of the open-ended transitional phrase "comprising" is defined herein as including all stated elements, limitations, steps, and / or features and any optional, additional unspecified elements, limitations, steps, and / or features. The meaning of the closed-ended transitional phrase "consisting of" is defined herein as including only those elements, limitations, steps, and / or features expressly recited in the claim and the meaning of the closed-ended transitional phrase "consisting essentially of" is defined herein as including only those elements, limitations, steps, and / or features expressly recited in the claim and those that do not materially affect the basic and novel characteristic(s) of the claimed subject matter. Thus, as a limitation on claims in which the transitional phrase, "comprising" (along with the like open-ended transitional phrases such as "including," "containing," and "having") is used, within its meaning, includes the claimed subject matter (in this case the use of the closed-ended transitional phrase "consisting of" or "consisting essentially of") specifies the claimed subject matter. Thus, embodiments described herein or claimed using the phrase "comprising" are expressly and inherently described, enabled and supported herein by the phrases "consisting essentially of" and "consisting of."

[0127] Any claim intended to be treated under 35 U.S.C. § 112(f) will start with "means for" but the use of the term "means" in any other context is not intended to invoke 35 U.S.C. § 112(f) treatment. Accordingly, Applicant reserves the right to pursue additional claims in this application or continuation applications after filing that are directed to apparatuses "for" performing the functions of the claimed subject matter.

[0128] It should be understood that the order of execution of the logical code, programs, modules, processes, methods, and individual elements of each method is merely exemplary. They can be executed in any order or in parallel, depending on the implementation, unless otherwise specified in the disclosure. Furthermore, the logical code does not involve or be limited to any particular programming language, and can include one or more modules executed on one or more processors in a distributed, non-distributed, or multi-processing environment. In addition, various illustrative logical blocks, modules, methods, and algorithmic processes and sequences described in conjunction with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, various illustrative components, blocks, modules, and process actions have been described above in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the particular application and design constraints of the overall system. For each particular application, the described functions can be implemented differently, but such implementation decisions should not be interpreted as causing a departure from the scope of the document.

[0129] The phrase "non-transitory" as used in this document, except in the context of a computer-readable medium, does not necessarily mean "lasting forever." The phrase "non-transitory" as used in this document, except in the context of a computer-readable medium, means "not transitory" or "not ephemeral." The phrase "non-transitory computer-readable medium" as used in this document, unless otherwise indicated, includes any and all computer-readable media, the only exception being a transitory, propagating signal. By way of example, and without limitation, this includes non-transitory computer-readable media such as register memory, processor cache, and random access memory ("RAM").

[0130] The above-described methods can be used in the manufacture of integrated circuit chips. The resulting integrated circuit chips can be distributed by the fabricant as raw chips, i.e., as single chips having a plurality of unpackaged chips, in bare die, or in a packaged form. In the latter case, the chips are mounted in single-chip packages (e.g., a plastic carrier, with leads that are affixed to a motherboard or other higher level carrier) or multiple-chip packages (e.g., a ceramic carrier that has one or more of a mold or a flip chip interconnects). In any 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) an end product. The end product can be any product that includes integrated circuit chips, ranging from toys and other low-end applications to advanced computer products having a display, a keyboard or other input device, and a central processor.

[0131] All patents, patent publications, or other publications referenced and identified in this specification are individually and expressly incorporated herein by reference in their entirety for the purpose of describing and disclosing, inter alia, the compositions and methodologies described in such publications that might be used in connection with the present application. These publications are provided solely for their disclosure prior to the filing date of the present application. Nothing in this regard should be construed as a limitation on the scope or coverage of this application unless otherwise explicitly recited in the claims. All statements as to the date or representation as to the contents of these documents is based on the information available to me and does not constitute any admission as to the correctness of the dates or contents of these documents.

[0132] While aspects of the present application have been described with reference to at least one example embodiment, it will be evident to those skilled in the art that various modifications can be made within the scope of the application. Accordingly, the present application is not limited to the described embodiments, but rather is intended to embrace all within the scope of the appended claims, and the specification is to be construed as illustrative only and not limiting of the present application.

Claims

1. A wearable ultrasound device capable of being positioned on a target part of a user's body, comprising: At least one ultrasound module configured to acquire at least one ultrasound image of the target site, the ultrasound module comprising: At least one ultrasonic transducer located on at least one elastic substrate, the at least one ultrasonic transducer including at least one sensor; At least one conductive layer positioned to electrically communicate with the at least one sensor; and At least one ultrasonic transceiver that is in electrical communication with the at least one sensor; At least one electrophysiological (EP) module is located on the at least one elastic substrate and is configured to detect bioelectrical signals at the target site; A near-infrared spectroscopy (NIRS) module, located on the at least one elastic substrate, is configured for detecting muscle activity at the target site; and At least one controller is electrically in communication with each of the ultrasound module, the EP module, and the NIRS module via the conductive layer. The at least one controller is configured to selectively enable the ultrasound module to acquire at least one ultrasound image of the target site when a bioelectrical signal in the target site is detected via the EP module.

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

3. The wearable ultrasound device according to claim 2, wherein, The at least one sensor is a piezoelectric sensor comprising a piezoelectric material sandwiched between two or more electrodes.

4. The wearable ultrasound device according to claim 1, wherein, The at least one ultrasound module further includes at least one matching layer located on the bottom surface of the at least one sensor and configured to provide acoustic impedance matching.

5. The wearable ultrasound device according to claim 1, wherein, The ultrasonic module further includes at least one backing layer positioned to contact the top surface of the at least one sensor furthest from the target site, the at least one backing layer being configured to absorb any ultrasonic waves radiated by the at least one sensor that are not directed toward the target site.

6. The wearable ultrasound device according to claim 1, wherein, The at least one ultrasound module further includes at least one encapsulation layer, which is positioned to isolate the at least one conductive layer from the surrounding environment.

7. The wearable ultrasound device of claim 1 further includes a coupling layer positioned to contact the bottom surface of the bottommost of the at least one ultrasound transducer and configured to selectively adhere the device to the target site.

8. The wearable ultrasound device according to claim 7, wherein, The acoustic impedance of the coupling layer is approximately the same as that of the target location, thereby providing impedance matching.

9. The wearable ultrasound device according to claim 1, wherein, The at least one ultrasonic transducer includes a plurality of adjacently arranged sensors configured as at least one array.

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

11. The wearable ultrasound device according to claim 9, wherein, The at least one ultrasonic transducer includes multiple arrays arranged to acquire orthogonal cross-sections of the target region.

12. The wearable ultrasound device according to claim 9, wherein, The at least one array is configured as a bending element.

13. The wearable ultrasound device according to claim 9, wherein, A subset of continuous sensors is configured to be activated simultaneously as needed.

14. The wearable ultrasound device according to claim 9, wherein, Multiple sensors are sandwiched between multiple electrodes arranged in a row-column structure to form at least one quasi-two-dimensional array.

15. The wearable ultrasound device according to claim 1, wherein, The device includes a relatively larger number of sensors than an ultrasonic transceiver, such that the at least one ultrasonic transceiver is in electrical communication with the multiple sensors.

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

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

18. The wearable ultrasound device of claim 1, wherein the NIRS module is configured to monitor the oxygenation status and / or biochemical measurements of the target site.

19. A wearable ultrasound device capable of being positioned on a target part of a user's body, comprising: At least one ultrasound module configured to acquire at least one ultrasound image of the target site, the ultrasound module comprising: At least one ultrasonic transducer located 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 between the pair of conductive layers; and At least one ultrasonic transceiver that is in electrical communication with the at least one piezoelectric sensor; At least one electrophysiological (EP) module is located on the at least one elastic substrate and is configured to detect bioelectrical signals at the target site; A near-infrared spectroscopy (NIRS) module, located on the at least one elastic substrate, is configured for detecting muscle activity at the target site; and At least one controller is electrically in communication with each of the ultrasound module, the EP module, and the NIRS module via the conductive layer. The at least one controller is configured to selectively enable the ultrasound module to acquire at least one ultrasound image of the target site when a bioelectrical signal in the target site is detected via the EP module.

20. A wearable ultrasound device capable of being positioned on a target part of a user's body, comprising: At least one ultrasound module configured to acquire at least one ultrasound image of the target site, the ultrasound module comprising: At least one ultrasonic transducer located on at least one elastic substrate, the at least one ultrasonic transducer including at least one sensor; At least one conductive layer positioned to electrically communicate with the at least one sensor; and At least one ultrasonic transceiver that is in electrical communication with the at least one sensor; An electrophysiological (EP) module, positioned on the at least one elastic substrate and configured to detect bioelectrical signals at the target site, A near-infrared spectroscopy NIRS module, positioned on the at least one elastic substrate and configured for detecting muscle activity at the target site; and At least one controller, which is electrically in communication with each of the ultrasound module, the EP module and the NIRS module via the conductive layer, is configured to selectively enable the ultrasound module to acquire at least one ultrasound image of the target site when at least one of a bioelectrical signal, oxygenation status and / or biochemical measurement is detected in the target site.

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