Patch electrode connectors

Abstract

A neurostimulation system (10) includes an electrode patch (20), including one or more lower adhesive surfaces (24). A ferromagnetic stud (52) of a male fastener (30) of the electrode patch (20) defines a stud base (54) and a raised protrusion (56) that protrudes from an upper stud-base surface (58) of the stud base (54); is coupled in electrical communication with a conductive surface (22) of the electrode patch (20); and is disposed on an upper surface (26) of the electrode patch (20). A housing (50) of a control unit (40) includes a lower shell (60) that defines a socket (62) defining a lower receptacle (64) and an upper receptacle (66), and includes magnetic material, which magnetically attracts the raised protrusion (56) to the upper receptacle (66). The upper receptacle (66) is shaped to receive the raised protrusion (56) so that the stud base (54) is positioned within the lower receptacle (64) and a gap (80) is defined between the raised protrusion (56) and an upper end surface (74) defined by the upper receptacle (66). Other embodiments are also described.

Description

[0001] PATCH ELECTRODE CONNECTORS

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] The present application claims priority from US Provisional Application 63 / 689,955, filed September 3, 2024, which is assigned to the assignee of the present application and incorporated herein by reference.

[0004] FIELD OF THE APPLICATION

[0005] The present invention relates generally to patch electrodes.

[0006] BACKGROUND OF THE APPLICATION

[0007] Electrical nerve stimulation has been used as a possible treatment for acute pain relief, including headaches. Clinical studies have shown that two ranges of pulse frequencies (high frequency and low frequency) are especially effective for pain relief. Neuromodulation is a term used to describe electrical nerve stimulation when it is applied for the purpose of pain relief. Some neuromodulation techniques rely upon invasive, implantable electrical stimulation for pain relief, and others apply non-invasive stimulation via the skin.

[0008] US Patent 6,745,082 to Axelgaard describes a medical electrode including a conductive flexible member having a top side and a bottom side with a non-conductive flexible sheet covering the conductive flexible member top side. A connector in contact with the conductive flexible member bottom side is provided for establishing electrical contact with an external electrical apparatus. A conductive adhesive adhered to the conductive flexible member bottom side provides electrical conduction to a patient's skin.

[0009] US Patent 11,040,190 to Bachinksi et al. describes multilayer electrodes, electrode systems, and stimulation systems. An electrode may include a conductive layer with a unitary tail, a connector disposed on a distal end of the tail, and a nonconductive top layer disposed along a top portion of the conductive layer. An electrode may include a magnetic lead connector socket, or a receptacle formed by a depression in the conductive layer configured to receive a male connector. An electrode system may include a plurality of conductive zones and a plurality of connectors. A stimulation system may include an electronics layer in electrical contact with a conductive layer via a puncture connection, and may provide an iontophoretic treatment followed by a TENS treatment. Other electrodes, systems and methods are also disclosed.

[0010] PCT Publication WO 2023 / 078913 to Hellmold et al. describes a plasma treatment device for the treatment of a skin surface containing living cells with a dielectric barrier plasma, comprising: a housing having a handle part; a treatment head located on the housing; an electrode assembly which is provided on the treatment head and has at least one electrode and a dielectric which completely covers the electrode up to the skin surface to be treated, has a treatment surface and is designed together with the at least one electrode so that the at least one electrode and the skin surface to be treated functioning as a counter electrode interact in order to generate the plasma; and a high-voltage stage which is located in the housing for generating high-voltage signals required to generate the plasma and which is electrically contacted or can be electrically contacted, via a connection assembly comprising at least one high-voltage supply line, by the at least one electrode of the electrode assembly; characterised in that the electrode assembly is movably mounted in the housing, and a drive assembly having at least a motor and a drive train is provided in the housing, which drive train is operatively connected to the electrode assembly for motor- driven motion, while the electrode is electrically contacted or can be electrically contacted, via the connection assembly, by the high-voltage stage in order to generate the dielectric barrier plasma between the electrode and the skin surface acting as a counter electrode.

[0011] SUMMARY OF THE APPLICATION

[0012] In some embodiments of the present invention, a neurostimulation system is provided for application to skin of a subject. The neurostimulation system comprises an electrode patch and a control unit. The electrode patch comprises one or more electrically conductive surfaces; one or more lower adhesive surfaces, which are configured to adhere the electrode patch to the subject's skin; an upper surface, opposite the one or more lower surfaces; and a male fastener. The control unit comprises an electronics module, which comprises electronic circuitry; and a housing, which comprises a lower shell that is shaped so as to define a socket.

[0013] The male fastener of the electrode patch comprises a stud, which comprises a ferromagnetic material, is shaped so as to define a stud base and a raised protrusion that protrudes from an upper stud-base surface of the stud base, is coupled in electrical communication with one of the one or more conductive surfaces, and is disposed on the upper surface of the electrode patch.

[0014] The socket of the lower shell of the housing of the control unit is shaped so as to receive the stud. The socket is shaped so as to define a lower receptacle and an upper receptacle. The socket comprises magnetic material, which is arranged to magnetically attract the raised protrusion to the upper receptacle.

[0015] The upper receptacle:

[0016] • extends upward from a portion of the lower receptacle, such that the lower receptacle defines an upper shoulder surface that surrounds an opening of the upper receptacle and faces at least partially downward; at least a portion of the upper shoulder surface is electrically conductive and in electrical communication with the electronics module,

[0017] • is shaped so as to define an upper end surface, and

[0018] • is shaped to receive the raised protrusion so that the stud base is positioned within the lower receptacle and a gap is defined between the raised protrusion and the upper end surface, such that the upper stud-base surface mechanically and electrically contacts the upper shoulder surface of the lower receptacle.

[0019] Providing the gap helps ensure that the upper stud-base surface mechanically and electrically contacts the upper shoulder surface of the lower receptacle even if the raised protrusion is slightly longer than its nominal dimension, such as because of manufacturing variations within manufacturing tolerances. If the gap were not provided, even a very small manufacturing variation that results in a greater height of an upper end of the raised protrusion from the upper stud-base surface of the stud base than the nominal height, would cause the contact of the upper end of the raised protrusion with the upper end surface of the upper receptacle to prevent the upper stud-base surface from mechanically and electrically contacting the upper shoulder surface of the lower receptacle.

[0020] For some applications, the raised protrusion of the stud is hollow, and the male fastener further comprises an eyelet. The eyelet is shaped so as to define an eyelet base and a post protruding from the eyelet base. The eyelet base is disposed below the upper surface of the electrode patch, and the post passes through and protrudes upward from the upper surface of the electrode patch. The post of the eyelet is permanently secured within the raised hollow protrusion of the stud, thereby permanently securing the eyelet to the stud.

[0021] In another embodiment of the present invention, which optionally may be implemented in combination with the embodiment described above, a neurostimulation system is provided for application to skin of a subject. The neurostimulation system comprises an electrode patch and a control unit. The electrode patch comprises first and second electrically conductive surfaces; one or more lower adhesive surfaces, which are configured to adhere the electrode patch to the subject's skin; an upper surface, opposite the one or more lower surfaces; and first and second male fasteners. The control unit comprises an electronics module, which comprises electronic circuitry; and a housing, which comprises a lower shell that is shaped so as to define first and second sockets.

[0022] The first and the second male fasteners comprise first and seconds studs, respectively, which (i) comprise a ferromagnetic material, (ii) are shaped so as to define first and second stud bases, respectively, and first and second raised protrusions, respectively, that protrude from first and second upper stud-base surfaces of the first and the second stud bases, respectively, (iii) are coupled in electrical communication with the first and the second conductive surfaces, respectively, and (iv) are disposed on the upper surface of the electrode patch; and

[0023] The first and the second sockets (i) are shaped so as to receive the first and the second studs, respectively, (ii) comprise magnetic material, which is arranged to magnetically attract the first and the second raised protrusions to the first and the second sockets, respectively, and (iii) are, at least in part, electrically conductive and in electrical communication with the electronics module.

[0024] The first and the second studs and the first and the second sockets are configured such that:

[0025] • placement of the first and the second studs within the first and the second sockets, respectively, removably couples the electrode patch to the lower shell of the housing of the control unit, and couples the first and the second studs in electrical contact with the first and the second sockets, respectively, and • application of as little as a threshold total force to the first and the second sockets in a direction away from the first and the second studs, respectively, decouples the first and the second studs from the first and the second sockets, respectively.

[0026] Typically, the threshold total force is 3 - 25 N.

[0027] This threshold total force is relatively weak, e.g., substantially less than the total force required to decouple commercially-available snap electrodes, or conventional garment snaps on clothing. This relatively weak threshold total force may facilitate easy removal of the neurostimulation system from the patient, e.g., from the patient's arm, which, when performed by the patient himself or herself, must be done with only the single other hand. In configurations of the neurostimulation system that comprise a band, in order to remove the neurostimulation system from the arm, the patient removes the band. Because the housing of the control unit is coupled to an opening of the band, the housing is removed with the band. Because of the weak threshold total force required to disengage the studs from the sockets, the housing is readily decoupled from the electrode patch, allowing easy removal of the band and control unit while the electrode patch remains adhered to the skin, and is subsequently peeled off the skin after the band and the control unit are put aside. If a stronger threshold total force were required, the patient might find it difficult to pull off the band using just his or her one free hand. The user might instead need to allow the band to dangle and try to peel off the electrode patch while the control unit and the band are still coupled to the electrode patch.

[0028] The neurostimulation systems described herein may be used for applying any type of electrical stimulation to skin of a patient, including neuromodulation treatments for treating pain (e.g., a headache, such as a migraine or post-traumatic headache; fibromyalgia; dysmenorrhea; and / or another form of pain). The neuromodulation treatments may be applied using techniques described in the patents and patent application publications incorporated by reference hereinbelow. Alternatively or additionally, the neurostimulation systems described herein may be used for applying Transcutaneous Electrical Nerve Stimulation (TENS).

[0029] There is therefore provided, in accordance with an application of the present invention, a neurostimulation system for application to skin of a subject, the neurostimulation system including: an electrode patch, which includes (a) one or more electrically conductive surfaces; (b) one or more lower adhesive surfaces, which are configured to adhere the electrode patch to the subject's skin; (c) an upper surface, opposite the one or more lower surfaces; and (d) a male fastener, which includes a stud, which (i) includes a ferromagnetic material, (ii) is shaped so as to define a stud base and a raised protrusion that protrudes from an upper studbase surface of the stud base, (iii) is coupled in electrical communication with one of the one or more conductive surfaces, and (iv) is disposed on the upper surface of the electrode patch; and a control unit, which includes (a) an electronics module, which includes electronic circuitry, and (b) a housing, which includes a lower shell that is shaped so as to define a socket shaped so as to receive the stud, wherein the socket (a) is shaped so as to define a lower receptacle and an upper receptacle, and (b) includes magnetic material, which is arranged to magnetically attract the raised protrusion to the upper receptacle, wherein the upper receptacle:

[0030] (i) extends upward from a portion of the lower receptacle, such that the lower receptacle defines an upper shoulder surface that surrounds an opening of the upper receptacle and faces at least partially downward, wherein at least a portion of the upper shoulder surface is electrically conductive and in electrical communication with the electronics module,

[0031] (ii) is shaped so as to define an upper end surface, and

[0032] (iii) is shaped to receive the raised protrusion so that the stud base is positioned within the lower receptacle and a gap is defined between the raised protrusion and the upper end surface, such that the upper stud-base surface mechanically and electrically contacts the upper shoulder surface of the lower receptacle.

[0033] For some applications: the raised protrusion of the stud is hollow, the male fastener further includes an eyelet, which is shaped so as to define an eyelet base and a post protruding from the eyelet base, wherein the eyelet base is disposed below the upper surface of the electrode patch, and the post passes through and protrudes upward from the upper surface of the electrode patch, and the post of the eyelet is permanently secured within the raised hollow protrusion of the stud, thereby permanently securing the eyelet to the stud.

[0034] For some applications, the portion of the lower receptacle from which the upper receptacle extends upward is a central portion of the lower receptacle.

[0035] For some applications, at least a portion of an internal surface of the upper receptacle is electrically conductive and in electrical communication with the electronics module.

[0036] For some applications, the at least a portion of the internal surface of the upper receptacle that is electrically conductive includes the upper end surface of the upper receptacle.

[0037] For some applications, the upper end surface of the upper receptacle is not electrically conductive.

[0038] For some applications, a depth of the upper shoulder surface of the lower receptacle from an outer surface of the lower shell surrounding the lower receptacle is 1.8 - 2.2 mm.

[0039] For some applications, the lower receptacle is circular and has a greatest diameter of 14 - 15 mm.

[0040] For some applications, a height of an upper end of the raised protrusion from the upper stud-base surface of the stud base equals 96% - 98% of a depth of the upper end surface of the upper receptacle from the upper shoulder surface of the upper receptacle.

[0041] For some applications, the upper stud-base surface of the stud base is disposed at a height of 2.2 - 2.6 mm above the upper surface of the electrode patch surrounding the stud.

[0042] For some applications, the height is 2.3 - 2.5 mm.

[0043] For some applications, a depth of the gap is at least 0.05 mm.

[0044] For some applications, the depth of the gap is no more than 2 cm.

[0045] For some applications, a height of an upper end of the raised protrusion from the upper surface of the electrode patch surrounding the stud is 4.8 - 5.6 mm.

[0046] For some applications, the height of the upper end of the raised protrusion from the upper surface of the electrode patch surrounding the stud is 5.18 - 5.38 mm.

[0047] For some applications, a height of an upper end of the raised protrusion from the upper stud-base surface is 2.6 - 3.0 mm. For some applications, the height of the upper end of the raised protrusion from the upper stud-base surface is 2.78 - 2.98 mm.

[0048] For some applications: the one or more conductive surfaces include first and second conductive surfaces, the male fastener is a first male fastener, the stud is a first stud, the stud base is a first stud base, the raised protrusion is a first raised protrusion, and the upper stud-base surface is a first upper stud-base surface, the first stud is coupled in electrical communication with the first conductive surface, the socket is a first socket, the lower receptacle is a first lower receptacle, and the upper receptacle is a first upper receptacle, the electrode patch further includes a second male fastener, which includes a second stud, which (i) includes a ferromagnetic material, (ii) is shaped so as to define a second stud base and a second raised protrusion that protrudes from a second upper stud-base surface of the second stud base, (iii) is coupled in electrical communication with the second conductive surface, and (iv) is disposed on the upper surface of the electrode patch, the lower shell of the housing is shaped so as to define a second socket shaped so as to receive the second stud, the upper shoulder surface is a first upper shoulder surface, the opening is a first opening, and the upper end surface is a first upper end surface, the gap is a first gap, the second socket (a) is shaped so as to define a second lower receptacle and a second upper receptacle, and (b) includes magnetic material, which is arranged to magnetically attract the second raised protrusion to the second upper receptacle, and the second upper receptacle:

[0049] (i) extends upward from a portion of the second lower receptacle, such that the second lower receptacle defines a second upper shoulder surface that surrounds a second opening of the second upper receptacle and faces at least partially downward, wherein at least a portion of the second upper shoulder surface is electrically conductive and in electrical communication with the electronics module,

[0050] (ii) is shaped so as to define a second upper end surface, and (iii) is shaped to receive the second raised protrusion so that the second stud base is positioned within the second lower receptacle and a second gap is defined between the second raised protrusion and the second upper end surface, such that the second upper stud-base surface mechanically and electrically contacts the second upper shoulder surface of the second lower receptacle.

[0051] For some applications, a distance between respective centroids of the first and the second raised protrusions is 20 - 50 mm.

[0052] For some applications, the distance between the respective centroids of the first and the second raised protrusions is 37.3 - 37.5 mm.

[0053] For some applications: the one or more lower adhesive surfaces include first and second lower adhesive surfaces, the electrode patch includes first and second hydrogel layers, which include the first and the second lower adhesive surfaces, respectively, and a closest distance between the first and the second hydrogel layers is 5 - 20 mm.

[0054] For some applications, the closest distance is 12.7 - 13.3 mm.

[0055] For some applications, the neurostimulation system further includes a band, which is shaped so as to define an opening for receiving the housing of the control unit, and which is configured to secure the housing and the electrode patch to the skin of a limb of the subject.

[0056] There is further provided, in accordance with an application of the present invention, a neurostimulation system for application to skin of a subject, the neurostimulation system including: an electrode patch, which includes (a) first and second electrically conductive surfaces; (b) one or more lower adhesive surfaces, which are configured to adhere the electrode patch to the subject's skin; (c) an upper surface, opposite the one or more lower surfaces; and (d) first and second male fasteners, which include first and seconds studs, respectively, which (i) include a ferromagnetic material, (ii) are shaped so as to define first and second stud bases, respectively, and first and second raised protrusions, respectively, that protrude from first and second upper stud-base surfaces of the first and the second stud bases, respectively, (iii) are coupled in electrical communication with the first and the second conductive surfaces, respectively, and (iv) are disposed on the upper surface of the electrode patch; and a control unit, which includes (a) an electronics module, which includes electronic circuitry, and (b) a housing, which includes a lower shell that is shaped so as to define first and second sockets, which:

[0057] (i) are shaped so as to receive the first and the second studs, respectively,

[0058] (ii) include magnetic material, which is arranged to magnetically attract the first and the second raised protrusions to the first and the second sockets, respectively, and

[0059] (iii) are, at least in part, electrically conductive and in electrical communication with the electronics module, and wherein the first and the second studs and the first and the second sockets are configured such that: placement of the first and the second studs within the first and the second sockets, respectively, removably couples the electrode patch to the lower shell of the housing of the control unit, and couples the first and the second studs in electrical contact with the first and the second sockets, respectively, and application of as little as a threshold total force to the first and the second sockets in a direction away from the first and the second studs, respectively, decouples the first and the second studs from the first and the second sockets, respectively, wherein the threshold total force is 3 - 25 N.

[0060] For some applications, the threshold total force is 5 - 25 N, such as 8 - 15 N.

[0061] For some applications, the threshold total force is greater than the product of 9.81 m / s2 and a mass of the control unit, measured in kg.

[0062] For some applications: the first and the second raised protrusions of the first and the seconds studs are hollow, the first and the second male fasteners further include first and second eyelets, respectively, which are shaped so as to define first and second eyelet bases, respectively, and first and second posts protruding from the first and the second eyelet bases, respectively, the first and the second eyelet base are disposed below the upper surface of the electrode patch, and the first and the second post pass through and protrude upward from the upper surface of the electrode patch, and the first and the second posts of the first and the second eyelets, respectively, are permanently secured within the first and the second raised hollow protrusions of the first and the second studs, respectively, thereby permanently securing the first and the second eyelets to the first and the second studs, respectively.

[0063] For some applications, the placement of the first and the second studs within the first and the second sockets, respectively, removably couples the electrode patch to the lower shell of the housing without deformation of any of the first or the second studs or the first or the second sockets.

[0064] For some applications, the first and the second sockets include (a) first and second lower receptacles, respectively, and (b) first and second upper receptacles, respectively, which:

[0065] (i) extend upward from respective portions of the first and the second lower receptacles, respectively, such that the first and the second lower receptacles define first and second upper shoulder surfaces, respectively, that surround first and second openings of the first and the second upper receptacles, respectively, and face at least partially downward, at least a portion the first upper shoulder surface and at least a portion of the second upper shoulder surface are electrically conductive and in electrical communication with the electronics module, and

[0066] (ii) are shaped to receive the first and the second raised protrusions so that the first and the second stud bases are positioned within the first and the second lower receptacles, respectively, such that the first and the second upper stud-base surfaces mechanically and electrically contact the first and the second upper shoulder surfaces of the first and the second lower receptacles, respectively.

[0067] For some applications, the portions of the first and second lower receptacles from which the first and the second upper receptacles extend upward, respectively, are central portions of the first and the second lower receptacles, respectively.

[0068] For some applications, at least a portion of an internal surface of the first upper receptacle and at least a portion of the second upper receptacle are electrically conductive and in electrical communication with the electronics module. For some applications, a depth of the first upper shoulder surface of the first lower receptacle from an outer surface of the lower shell surrounding the first lower receptacle is 1.8 - 2.2 mm.

[0069] For some applications, the first lower receptacle is circular and has a greatest diameter of 14 - 15 mm.

[0070] For some applications, a height of an upper end of the first raised protrusion from the upper stud-base surface of the first stud base equals 96% - 98% of a depth of the first upper end surface of the first upper receptacle from the first upper shoulder surface of the first upper receptacle.

[0071] For some applications: the magnetic material is arranged to magnetically attract the first and the second raised protrusions to the first and the second upper receptacles, respectively, and the first and the second upper receptacles are:

[0072] (i) shaped so as to define first and second upper end surfaces, respectively, and

[0073] (ii) shaped so as to receive the first and the second raised protrusions, respectively, so that a first gap is defined between the first raised protrusion and the first upper end surface, and a second gap is defined between the second raised protrusion and the second upper end surface.

[0074] For some applications, a depth of each of the first and the second gaps is at least 0.05 mm.

[0075] For some applications, the depth of each of the first and the second gaps is at least 0.1 mm.

[0076] For some applications, the depth of each of the first and the second gaps is no more than 2 cm.

[0077] For some applications, a distance between respective centroids of the first and the second raised protrusions is 20 - 50 mm.

[0078] For some applications, the distance between the respective centroids of the first and the second raised protrusions is 37.3 - 37.5 mm. For some applications, the first upper stud-base surface of the first stud base is disposed at a height of 2.2 - 2.6 5 mm above the upper surface of the electrode patch surrounding the first stud.

[0079] For some applications, the height is 2.3 - 2.5 mm.

[0080] For some applications, a height of an upper end of the first raised protrusion from the upper surface of the electrode patch surrounding the first stud is 4.8 - 5.6 mm.

[0081] For some applications, the height of the upper end of the first raised protrusion from the upper surface of the electrode patch surrounding the stud is 5.18 - 5.38 mm.

[0082] For some applications, a height of an upper end of the first raised protrusion from the first upper stud-base surface is 2.6 - 3.0 mm.

[0083] For some applications, the height of the upper end of the first raised protrusion from the first upper stud-base surface is 2.78 - 2.98 mm.

[0084] For some applications: the one or more lower adhesive surfaces include first and second lower adhesive surfaces, the electrode patch includes first and second hydrogel layers, which include the first and the second lower adhesive surfaces, respectively, and a closest distance between the first and the second hydrogel layers is 5 - 20 mm.

[0085] For some applications, the closest distance is 12.7 - 13.3 mm.

[0086] For some applications, the neurostimulation system further includes a band, which is shaped so as to define an opening for receiving the housing of the control unit, and which is configured to secure the housing and the electrode patch to the skin of a limb of the subject.

[0087] The present invention will be more fully understood from the following detailed description of embodiments thereof, taken together with the drawings, in which:

[0088] BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Fig. l is a schematic illustration of a neurostimulation system for application to skin of a subject, in accordance with an application of the present invention; Figs. 2A-B and 2C are schematic isometric views and a cross-sectional view, taken along line IIC — IIC of Fig. 2B, respectively, of a control unit of the neurostimulation system of Fig. 1, in accordance with an application of the present invention;

[0090] Fig. 3 is another schematic cross-sectional view of the control unit of the neurostimulation system of Fig. 1, taken along line III — III of Fig. 2B, in accordance with an application of the present invention;

[0091] Fig. 4A-C are schematic illustrations of an electrode patch of the neurostimulation system of Fig. 1, in accordance with an application of the present invention;

[0092] Figs. 5A and 5B are schematic cross-sectional illustrations of a portion of the electrode patch of Figs. 4A-C and a portion of the control unit of the neurostimulation system of Fig. 1, in accordance with an application of the present invention;

[0093] Fig. 6 is a schematic exploded view of the electrode patch of Figs. 4A-C, in accordance with an application of the present invention; and

[0094] Figs. 7A-C are schematic illustrations of a method of applying the neurostimulation system of Fig. 1 to skin of a limb of a subject, in accordance with an application of the present invention.

[0095] DETAILED DESCRIPTION OF APPLICATIONS

[0096] Fig. 1 is a schematic illustration of a neurostimulation system 10 for application to skin of a subject, in accordance with an application of the present invention. For some applications, neurostimulation system 10 is configured to apply therapeutic and / or prophylactic neurostimulation by applying electrical pulses to the skin of the subject. For example, neurostimulation system 10 may be configured to treat and / or prevent pain caused by a headache (such as a migraine headache or a post-traumatic headache), fibromyalgia, dysmenorrhea, premenstrual syndrome, menstrual cramps, and / or another cause, optionally using techniques described in one or more the patents and patent application publications incorporated herein by reference.

[0097] Neurostimulation system 10 comprises an electrode patch 20 and a control unit 40.

[0098] Reference is further made to Figs. 2A-B and 2C, which are schematic isometric views and a cross-sectional view, taken along line IIC — IIC of Fig. 2B, respectively, of control unit 40, in accordance with an application of the present invention. Reference is still further made to Fig. 3, which is another schematic cross-sectional view of control unit 40, taken along line III — III of Fig. 2B, in accordance with an application of the present invention.

[0099] Reference is additionally made to Fig. 4A-C, which are schematic illustrations of electrode patch 20, in accordance with an application of the present invention.

[0100] Reference is still additionally made to Figs. 5A and 5B, which are schematic cross- sectional illustrations of a portion of electrode patch 20 and a portion of control unit 40, in accordance with an application of the present invention.

[0101] Reference is also made to Fig. 6, which is a schematic exploded view of electrode patch 20, in accordance with an application of the present invention.

[0102] Electrode patch 20 typically comprises:

[0103] • one or more electrically conductive surfaces 22;

[0104] • one or more lower adhesive surfaces 24, which are configured to adhere electrode patch 20 to the subject's skin; typically, electrode patch 20 comprises one or more hydrogel layers 94, which comprise the one or more lower adhesive surfaces 24 (which are illustrated as opaque in Fig. 4A and transparent in Fig. 4C), respectively;

[0105] • upper surface 26 (which is illustrated as transparent in Fig. 1), opposite the one or more lower adhesive surfaces 24; and

[0106] • a male fastener 30.

[0107] Additional optional details regarding electrode patch 20 are described hereinbelow with reference to Fig. 6.

[0108] Figs. 4A and 4C show a lower side of electrode patch 20. Fig. 4B shows an upper surface 26 of electrode patch 20.

[0109] Control unit 40 comprises (a) an electronics module 42, which comprises electronic circuitry 44, and (b) a housing 50. Typically, electronic circuitry 44 comprises one or more processors and memory, which are configured in hardware and / or software to perform functions necessary to apply stimulation using electrode patch 20.

[0110] For some applications, such as labeled in Fig. 5A, male fastener 30 comprises a stud

[0111] 52, which comprises a ferromagnetic material, such as steel. Stud 52 is shaped so as to define a stud base 54 and a raised protrusion 56 that protrudes from an upper stud-base surface 58 of stud base 54. Stud 52 is coupled in electrical communication with one of the one or more conductive surfaces 22. Stud 52 is disposed on upper surface 26 of electrode patch 20.

[0112] Reference is made to Figs. 1, 2A-C, 3, and 5A-B. For some applications, housing 50 comprises a lower shell 60 that is shaped so as to define a socket 62 shaped so as to receive stud 52. Socket 62 is shaped so as to define a lower receptacle 64 and an upper receptacle 66.

[0113] For some applications, upper receptacle 66:

[0114] • extends upward from a portion of lower receptacle 64 (e.g., a central portion of lower receptacle 64, such as shown), such that lower receptacle 64 defines an upper shoulder surface 70 that surrounds an opening 72 of upper receptacle 66 and faces at least partially downward (labeled in Figs. 3 and 5A-B); at least a portion of upper shoulder surface 70 is electrically conductive and in electrical communication with electronics module 42,

[0115] • is shaped so as to define an upper end surface 74 (labeled in Figs. 3 and 5A-B), and

[0116] • is shaped to receive raised protrusion 56 so that stud base 54 is positioned within lower receptacle 64 and a gap 80 is defined between raised protrusion 56 and upper end surface 74, such that upper stud-base surface 58 mechanically and electrically contacts upper shoulder surface 70 of lower receptacle 64, such as shown in Fig. 5B.

[0117] For some applications, as labeled in Fig. 5B, a depth D4 of gap 80 is at least 0.05 mm, e.g., at least 0.1 mm, and / or no more than 2 cm, e.g., no more than 1 cm, and, optionally, no more than 0.3 mm, such as no more than 0.2 mm.

[0118] Providing gap 80 helps ensure that upper stud-base surface 58 mechanically and electrically contacts upper shoulder surface 70 of lower receptacle 64 even if raised protrusion 56 is slightly longer than its nominal dimension, such as because of manufacturing variations within manufacturing tolerances. If gap 80 were not provided, even a very small manufacturing variation that results in a greater height Hl of an upper end 92 of raised protrusion 56 from upper stud-base surface 58 of stud base 54 than the nominal height, would cause the contact of upper end 92 of raised protrusion 56 with upper end surface 74 of upper receptacle 66 to prevent upper stud-base surface 58 from mechanically and electrically contacting upper shoulder surface 70 of lower receptacle 64.

[0119] For some applications, at least a portion of an internal surface 88 of upper receptacle 66 (labeled in Fig. 5A) is electrically conductive and in electrical communication with electronics module 42. For some of these applications, such as shown, the conductive portion of internal surface 88 includes upper end surface 74; optionally, in these applications, a single piece of metal is shaped so as to define both (a) an entirety of internal surface 88 of upper receptacle 66 (including upper end surface 74), and (b) upper shoulder surface 70 of lower receptacle 64, such as shown.

[0120] Alternatively, for some applications (configuration not shown), upper end surface 74 of upper receptacle 66 is not electrically conductive, and may comprise a piece of non- conductive material separate from the material of lateral portions of internal surface 88 (the lateral portions may be conductive or non-conductive). For example, upper end surface 74 may be defined by a non-conductive element of housing 50.

[0121] As used in the present application, including in the claims and Inventive Concepts, the directions "down" and "up" are to be understood as meaning with respect to the device. Thus, for example, that upper shoulder surface 70 faces at least partially downward should be understood as meaning that the shoulder surface faces at least partially in the same direction as lower shell 60 of housing 50 and in a direction at least partially opposite the direction in which upper surface 26 of electrode patch 20 faces. The directions "down" and "up" should not be understood with respect to the Earth.

[0122] Socket 62 comprises magnetic material 68 (labeled in Figs. 3 and 5A-B), which is arranged to magnetically attract raised protrusion 56 to upper receptacle 66. For example, magnetic material 68 may be disposed:

[0123] • surrounding upper receptacle 66, as shown in the figures, and optionally above upper shoulder surface 70 of lower receptacle 64, also as shown in the figures, and / or

[0124] • above upper end surface 74 of upper receptacle 66 (configuration not shown).

[0125] Reference is made to Figs. 5A-B. For some applications, raised protrusion 56 of stud 52 is hollow. Male fastener 30 further comprises an eyelet 82, which is shaped so as to define an eyelet base 84 and a post 86 protruding from eyelet base 84. Eyelet base 84 is disposed below upper surface 26 of electrode patch 20, and post 86 passes through and protrudes upward from upper surface 26 of electrode patch 20. Post 86 of eyelet 82 is permanently secured within raised hollow protrusion 56 of stud 52, thereby permanently securing eyelet 82 to stud 52. Eyelet 82 may be permanently secured within raised hollow protrusion 56 of stud 52 using techniques known in the snap art.

[0126] Alternatively or additionally, stud 52 may be fixed to upper surface 26 of electrode patch 20 in another way, such as by an adhesive and / or by stitching.

[0127] Reference is made to Fig. 3. For some applications:

[0128] • a depth D 1 of upper shoulder surface 70 of lower receptacle 64 from an outer surface 90 of lower shell 60 surrounding lower receptacle 64 is at least 1.8 mm, no more than 2.2 mm, and / or 1.8 - 2.2 mm, such as 2.0 - 2.2 mm, and / or

[0129] • lower receptacle 64 is circular and has a greatest diameter D2 of at least 14 mm, no more than 15 mm, and / or 14 - 15 mm (in configurations in which the wall of lower receptacle 64 is slanted, such as shown, the greatest diameter is measured at the widest portion of the lower receptacle).

[0130] Reference is made to Figs. 5A-B. For some applications:

[0131] • height Hl of an upper end 92 of raised protrusion 56 from upper stud-base surface 58 of stud base 54 (a) equals at least 96%, no more than 98%, and / or 96% - 98% of a depth D3 of upper end surface 74 of upper receptacle 66 from upper shoulder surface 70 of upper receptacle 66, and / or (b) is at least 2.6 mm, no more than 3.0 mm, and / or 2.6 - 3.0 mm, such as 2.78 - 2.98 mm,

[0132] • upper stud-base surface 58 is disposed at a height H2 of at least 2.2 mm, no more than 2.6 mm, and / or 2.2 - 2.6 mm, such as 2.3 - 2.5 mm above upper surface 26 of electrode patch 20 surrounding stud 52,

[0133] • height H2 is greater than or equal to depth DI, and / or

[0134] • a height H3 of upper end 92 of raised protrusion 56 from upper surface 26 of electrode patch 20 surrounding stud 52 is at least 4.8 mm, no more than 5.6 mm, and / or 4.8 - 5.6 mm, such as 5.18 - 5.38 mm.

[0135] Reference is made to Figs. 1-4C. In some applications of the present invention: • the one or more electrically conductive surfaces 22 comprise first and second electrically conductive surfaces 22A and 22B,

[0136] • male fastener 30 is a first male fastener 30A, stud 52 is a first stud 52, stud base 54 is a first stud base 54, raised protrusion 56 is a first raised protrusion 56, and upper stud-base surface 58 is a first upper stud-base surface 58,

[0137] • first stud 52 is coupled in electrical communication with first conductive surface 22,

[0138] • socket 62 is a first socket 62A, lower receptacle 64 is a first lower receptacle 64, and upper receptacle 66 is a first upper receptacle 66,

[0139] • electrode patch 20 further comprises a second male fastener 30B, which comprises a second stud 52, which (i) comprises a ferromagnetic material, (ii) is shaped so as to define a second stud base 54 and a second raised protrusion 56 that protrudes from a second upper stud-base surface 58 of second stud base 54, (iii) is coupled in electrical communication with second conductive surface 22B, and (iv) is disposed on upper surface 26 of electrode patch 20,

[0140] • lower shell 60 of housing 50 is shaped so as to define a second socket 62B shaped so as to receive second stud 52,

[0141] • upper shoulder surface 70 is a first upper shoulder surface 70, opening 72 is a first opening 72, and upper end surface 74 is a first upper end surface 74,

[0142] • gap 80 is a first gap 80,

[0143] • second socket 62B (a) is shaped so as to define a second lower receptacle 64 and a second upper receptacle 66, and (b) comprises magnetic material 68, which is arranged to magnetically attract second raised protrusion 56 to second upper receptacle 66, and

[0144] • second upper receptacle 66:

[0145] ■ extends upward from a portion of second lower receptacle 64, such that second lower receptacle 64 defines a second upper shoulder surface 70 that surrounds a second opening 72 of second upper receptacle 66 and faces at least partially downward; at least a portion of second upper shoulder surface 70 is electrically conductive and in electrical communication with electronics module 42, ■ is shaped so as to define a second upper end surface 74, and

[0146] ■ is shaped to receive second raised protrusion 56 so that second stud base 54 is positioned within second lower receptacle 64 and a second gap 80 is defined between second raised protrusion 56 and second upper end surface 74, such that second upper stud-base surface 58 mechanically and electrically contacts second upper shoulder surface 70 of second lower receptacle 64.

[0147] In some applications of the present invention, first and second studs 52 and first and second sockets 62A and 62B are configured such that:

[0148] • placement of first and second studs 52 within first and second sockets 62A and 62B, respectively, such as shown for one pair of studs and sockets in Fig. 5B, removably couples electrode patch 20 to lower shell 60 of housing 50 of control unit 40, and couples first and second studs 52 in electrical contact with first and second sockets 62A and 62B, respectively, and

[0149] • application of as little as a threshold total force to first and second sockets 62A and 62B in a direction away from first and second studs 52, respectively, decouples first and second studs 52 from first and second sockets 62A and 62B, respectively.

[0150] Typically, the threshold total force is 3 - 25 N, such as 5 - 25 N, e.g., 8 - 25 N, such as 8 - 15 N.

[0151] Optionally, the threshold total force is greater than the product of the gravitational constant G (9.81 m / s2) and a mass of the control unit, measured in kg, such as at least 1 N, e.g., at least 2 N, greater than the product. This threshold total force may reduce the likelihood of gravity alone causing control unit 40 to inadvertently become decoupled from electrode patch 20 if the control unit is positioned below the electrode patch (with respect to the Earth).

[0152] This threshold total force is relatively weak, e.g., substantially less than the total force required to decouple commercially-available snap electrodes, such as UltraStim® Snap electrodes and UltraStim® Garment electrodes (Axelgaard Manufacturing Co., Ltd. Fallbrook, CA, USA), or conventional garment snaps on clothing. This relatively weak threshold total force may facilitate easy removal of neurostimulation system 10 from the patient, e.g., from the patient's arm, which, when performed by the patient himself or herself, must be done with only the single other hand. In configurations of neurostimulation system 10 that comprise a band 100, as described with reference to Figs. 1 and Figs. 7A-C, in order to remove neurostimulation system 10 from the arm, the patient removes band 100. Because housing 50 of control unit 40 is coupled to opening 102 of band 100, the housing is removed with the band. Because of the weak threshold total force required to disengage the studs from the sockets, the housing is readily decoupled from electrode patch 20, allowing easy removal of the band and control unit while the electrode patch remains adhered to the skin, and is subsequently peeled off the skin after the band and the control unit are put aside. If a stronger threshold total force were required, the patient might find it difficult to pull off the band using just his or her one free hand. The user might instead need to allow the band to dangle and try to peel off the electrode patch while the control unit and the band are still coupled to the electrode patch.

[0153] In addition, providing a relatively weak coupling allows the use of a relatively small amount of magnetic material 68. The use instead of a larger amount of magnetic material 68 would increase the size and weight of control unit 40.

[0154] As mentioned above, the threshold total force must be at least 3 N in order to pull first and second sockets 62 A and 62B away from first and second studs 52, respectively. This minimum force ensures that the relatively weak coupling is strong enough to magnetically guide first and second studs 52 to and into first and second sockets 62A and 62B as the patient moves housing 50 of control unit 40 on upper surface 26 of electrode patch 20 during coupling of the control unit to the patch, as described hereinbelow with reference to Fig. 7B. This minimum force also ensures that the relatively weak coupling is strong enough to hold housing 50 of control unit 40 coupled to electrode patch 20 until band 100 provides much stronger coupling of housing 50 of control unit 40 to electrode patch 20 (and to the patient's limb), as described hereinbelow with reference to Fig. 7C.

[0155] One way to measure the threshold total force that must be applied to first and second sockets 62A and 62B in order to decouple first and second studs 52 from first and second sockets 62A and 62B, respectively, is to strongly adhere the one or more lower adhesive surfaces 24 of electrode patch 20 to a flat surface that is oriented horizontally with respect to the Earth, and to couple first and second studs 52 to first and second sockets 62A and 62B, respectively. A push-pull force gauge is attached to the upper surface of housing 50 of control unit 40 (the surface opposite lower shell 60 of housing 50), and the applied force is gradually increased until first and second sockets 62A and 62B are decoupled from first and second studs 52, respectively.

[0156] The total force applied to first and second sockets 62A and 62B (as opposed to the total force applied to the upper surface of housing 50 of control unit 40) depends on the orientation of housing 50 with respect to the Earth. If housing 50 is oriented such that first and second sockets 62A and 62B face directly downward toward the Earth, and first and second studs 52 of electrode patch 20 face upward, the total (upward) force applied to first and second sockets 62A and 62B equals the force measured by the force gauge less the gravitational constant G (9.81 m / s2) multiplied by the mass of control unit 40, measured in kg. On the other hand, if housing 50 is oriented such that first and second sockets 62A and 62B face directly upward away from the Earth, and first and second studs 52 of electrode patch 20 face downward, the total (downward) force applied to first and second sockets 62A and 62B equals the force measured by the force gauge plus the gravitational constant G multiplied by the mass of control unit 40.

[0157] In an experiment conducted on behalf of the inventors using this force application / measurement technique, three different control units similar to control unit 40 were tested 10 times each in each of the following positions:

[0158] (1) the housings of the control units were oriented such that first and second sockets 62A and 62B faced directly downward toward the Earth, and first and second studs 52 of electrode patch 20 faced upward, and the force was applied to the upper surface of the housing in an upward direction; and

[0159] (2) the housings of the control units were oriented such that first and second sockets 62A and 62B faced directly upward from the Earth, and first and second studs 52 of electrode patch 20 faced downward, and the force was applied to the upper surface of the housing in a downward direction.

[0160] The average force, applied to the upper surface of the housing of the control unit, necessary to decouple first and second sockets 62A and 62B from first and second studs 52, respectively, was 14.0 N in position (1) and 10.8 N in position (2).

[0161] Other ways of measuring the required force will be readily apparent to those skilled in the art who have read the present application. For some applications, the placement of first and second studs 52 within first and second sockets 62A and 62B, respectively, removably couples electrode patch 20 to lower shell 60 of housing 50 without deformation (e.g., without elastic deformation and / or without plastic deformation) of any of first or second studs 52 or first or second sockets 62A and 62B. Alternatively or additionally, the placement of first and second studs 52 within first and second sockets 62A and 62B, respectively, removably couples electrode patch 20 to lower shell 60 of housing 50 without snapping. The inventors have observed that mechanical snaps were difficult for patients to couple to and decouple from electrode patches using just their one free hand.

[0162] In addition, the use of magnetic coupling without mechanical snap coupling (i.e., without deformation of the studs or sockets) provides a separation between the mechanical coupling mechanism and the electrical contact, and thus allows a larger electrical contact surface on studs 52, and more predictable electrical coupling in view of manufacturing variations, than some conventional snap electrode studs that rely on mechanical coupling.

[0163] Reference is made to Fig. 4C. For some applications, the one or more lower adhesive surfaces 24 comprise first and second lower adhesive surfaces 24A and 24B. For some of these applications, electrode patch 20 comprises first and second hydrogel layers 94A and 94B, which comprise first and second lower adhesive surfaces 24A and 24B, respectively.

[0164] Reference is still made to Fig. 4C. For some applications, a distance D5 between respective centroids of first and second raised protrusions 56 is 20 - 50 mm, such as 37.3 - 37.5 mm.

[0165] For some applications, a closest distance D6 between first and second hydrogel layers 94A and 94B is 5 - 20 mm, such as 12.7 - 13.3 mm.

[0166] Reference is again made to Fig. 6. As described above, electrode patch 20 typically comprises one or more hydrogel layers 94, which comprise the one or more lower adhesive surfaces 24. Hydrogel layers 94 are configured (a) to adhere the patch to the patient's skin, and (b) to electrically couple the one or more respective conductive surfaces 22 to the patient's skin. For some applications, portions of patch 20, such as conductive surfaces 22 and / or the hydrogel layer, comprise portions of electrodes manufactured by Axelgaard Manufacturing Co., Ltd. (Fallbrook, CA, USA), such as UltraStim® Snap electrodes (e.g., Part Number SN2020) or UltraStim® Garment electrodes (e.g., Part Number US2020); dual-side gel electrodes manufactured by Top-Rank Health Care Co., Ltd. (Shangyu City, Zhejiang Province, China), such as models AB5050 or AC5050; or dual-side gel electrodes manufactured by Wandy Rubber Industrial Co., Ltd. (New Taipei City, Taiwan).

[0167] For some applications, each of conductive surfaces 22 comprises a printed layer 110 having a pattern of a conductive material printed thereon, as described in further detail hereinbelow. Printed layer 110 comprise a conductive layer (which typically comprises conductive materials, such as, silver, silver / silver chloride, carbon, graphene, nickel, iron, tungsten, bismuth, zinc, PEDOT, and / or blends such as platinized carbon) printed upon a substrate (such as polyester (PET, PEN), polycarbonate (PC), paper, polyimide (PI), and / or polyetherimide (PEI)). Typically, the pattern of conductive material is printed only on the side of the layer in contact with the one or more hydrogel layers 94. For some applications, each of conductive surfaces 22 is shaped as a grid, such as shown in Fig. 6.

[0168] For some applications, conductive surfaces 22 are used for sensing an electrical signal of the subject.

[0169] Optionally, electrode patch 20 comprises a device label 114.

[0170] Typically, prior to electrode patch 20 being applied to the subject's skin, such as described hereinbelow with reference to Figs. 7A-C, electrode patch 20 is supplied to the patient with a removable liner 112 covering the one or more hydrogel layers 94 (shown in Fig. 6). For example, the liner may comprise a polyester film, in order to facilitate removal of the liner from the hydrogel. Optionally, removable liner 112 comprises two sub-layers adhered together, the two sub-layers comprising two respective materials. For example, the sub-layer facing the one or more hydrogel layers 94 may have a smooth and oily feel so that it adheres to the hydrogel but peels off easily when required, and the sub-layer facing in the opposite direction (toward device label 114, if provided) may comprise a foamy material, which provides a pleasant feel for the user, as well as allows the device label, if provided, to better adhere to the layer.

[0171] Optionally, electrode patch 20 comprises one or more internal adhesive layers 116, which couple the one or more hydrogel layers 94 to the one or more conductive surfaces 22, respectively. Typically, electrode patch 20 comprises an electrically insulating layer 118, which ensures that the electrical contact between electrode patch 20 and the skin of the patient is only through the one or more hydrogel layers 94, which have shapes, locations, and surface areas configured to provide effective stimulation and avoid discomfort and possible harm, such as reddening of skin, to the patient. If electrically insulating layer 118 were not provided, the applied current might flow directly to the skin through eyelets 82 and any portions of printed layer 110 not covered by the hydrogel layers 94, in addition to the hydrogel layers 94.

[0172] Reference is again made to Fig. 1, and is further made to Figs. 7A-C, which are schematic illustrations of a method of applying neurostimulation system 10 to skin 96 of a limb 98 of a subject, in accordance with an application of the present invention. For example, limb 98 may be an upper arm, as shown, or a leg (configuration not shown). Alternatively, neurostimulation system 10 may be applied to skin 96 of a part of the patient's body other than a limb.

[0173] For some applications, neurostimulation system 10 further comprises band 100 (e.g., an armband), which is shaped so as to define an opening 102 (labeled in Fig. 1) for receiving housing 50 of control unit 40, and which is configured to secure housing 50 and electrode patch 20 to skin 96 of limb 98.

[0174] In order to apply and secure neurostimulation system 10 to skin 96, the patient typically first adheres electrode patch 20 to skin 96, using the one or more lower adhesive surfaces 24 of the electrode patch, as shown in Fig. 7A.

[0175] The patient may then couple control unit 40 to upper surface 26 of electrode patch 20 by placing one or more (e.g., two) sockets 62 of housing 50 of control unit 40 on one or more (e.g., two) respective male fasteners 30 of electrode patch 20, such as shown in Fig. 7B. The magnetic attraction between the sockets and the studs may magnetically guide first and second studs 52 to and into first and second sockets 62A and 62B as the patient moves housing 50 of control unit 40 on upper surface 26 of electrode patch 20. As described above with reference to Figs. 1-4C, once coupled, so long as the patient does not move limb 98 excessively, the magnetic coupling between the one or more male fasteners and the one or more sockets is typically strong enough to hold control unit 40 in place on electrode patch 20 at least until band 100 is applied, as described immediately below. The patient may then insert housing 50 of control unit 40 into opening 102 of band 100, and secure band 100 to limb 98, such as around limb 98, such as shown in Fig. 7C. Typically, housing 50 mechanically snaps into opening 102 and becomes securely coupled to band 100, as described hereabove with reference to Figs. 1-4C regarding the subsequent removal of the control unit and band.

[0176] Alternatively, the patient may perform the coupling in the following order. The patient may first insert housing 50 of control unit 40 into opening 102 of band 100, then couple control unit 40 to electrode patch 20, and finally secure band 100 to limb 98 (order not shown).

[0177] In an embodiment, techniques and apparatus described in one or more of the following patents and patent applications, which are assigned to the assignee of the present application and incorporated herein by reference, are combined with techniques and apparatus described herein:

[0178] • US Patent 9,895,533 to Harpak et al.

[0179] • US Patent 10,213,602 to Ironi et al.

[0180] • US Patent 10,289,594 to Harpak et al.

[0181] • US Patent 10,926,090 to Ironi et al.

[0182] • US Patent 11,167,135 to Ironi

[0183] • US Patent 11,357,980 to Ironi et al.

[0184] • US Patent Application Publication 2021 / 0052884 to Jashek et al.

[0185] • US Provisional Application 63 / 560,904, filed March 4, 2024

[0186] • US Provisional Application 63 / 689,955, filed September 3, 2024

[0187] • US Application 19 / 069,327, filed March 4, 2025

[0188] It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof that are not in the prior art, which would occur to persons skilled in the art upon reading the foregoing description.

Claims

CLAIMS1. A neurostimulation system for application to skin of a subject, the neurostimulation system comprising: an electrode patch, which comprises (a) one or more electrically conductive surfaces; (b) one or more lower adhesive surfaces, which are configured to adhere the electrode patch to the subject's skin; (c) an upper surface, opposite the one or more lower surfaces; and (d) a male fastener, which comprises a stud, which (i) comprises a ferromagnetic material, (ii) is shaped so as to define a stud base and a raised protrusion that protrudes from an upper stud-base surface of the stud base, (iii) is coupled in electrical communication with one of the one or more conductive surfaces, and (iv) is disposed on the upper surface of the electrode patch; and a control unit, which comprises (a) an electronics module, which comprises electronic circuitry, and (b) a housing, which comprises a lower shell that is shaped so as to define a socket shaped so as to receive the stud, wherein the socket (a) is shaped so as to define a lower receptacle and an upper receptacle, and (b) comprises magnetic material, which is arranged to magnetically attract the raised protrusion to the upper receptacle, wherein the upper receptacle:(i) extends upward from a portion of the lower receptacle, such that the lower receptacle defines an upper shoulder surface that surrounds an opening of the upper receptacle and faces at least partially downward, wherein at least a portion of the upper shoulder surface is electrically conductive and in electrical communication with the electronics module,(ii) is shaped so as to define an upper end surface, and(iii) is shaped to receive the raised protrusion so that the stud base is positioned within the lower receptacle and a gap is defined between the raised protrusion and the upper end surface, such that the upper stud-base surface mechanically and electrically contacts the upper shoulder surface of the lower receptacle.

2. The neurostimulation system according to claim 1, wherein the raised protrusion of the stud is hollow,wherein the male fastener further comprises an eyelet, which is shaped so as to define an eyelet base and a post protruding from the eyelet base, wherein the eyelet base is disposed below the upper surface of the electrode patch, and the post passes through and protrudes upward from the upper surface of the electrode patch, and wherein the post of the eyelet is permanently secured within the raised hollow protrusion of the stud, thereby permanently securing the eyelet to the stud.

3. The neurostimulation system according to claim 1, wherein the portion of the lower receptacle from which the upper receptacle extends upward is a central portion of the lower receptacle.

4. The neurostimulation system according to claim 1, wherein at least a portion of an internal surface of the upper receptacle is electrically conductive and in electrical communication with the electronics module.

5. The neurostimulation system according to claim 4, wherein the at least a portion of the internal surface of the upper receptacle that is electrically conductive includes the upper end surface of the upper receptacle.

6. The neurostimulation system according to claim 1, wherein the upper end surface of the upper receptacle is not electrically conductive.

7. The neurostimulation system according to claim 1, wherein a depth of the upper shoulder surface of the lower receptacle from an outer surface of the lower shell surrounding the lower receptacle is 1.8 - 2.2 mm.

8. The neurostimulation system according to claim 1, wherein the lower receptacle is circular and has a greatest diameter of 14 - 15 mm.

9. The neurostimulation system according to claim 1, wherein a height of an upper end of the raised protrusion from the upper stud-base surface of the stud base equals 96% - 98% of a depth of the upper end surface of the upper receptacle from the upper shoulder surface of the upper receptacle.

10. The neurostimulation system according to claim 1, wherein the upper stud-base surface of the stud base is disposed at a height of 2.2 - 2.6 mm above the upper surface of the electrode patch surrounding the stud.

11. The neurostimulation system according to claim 10, wherein the height is 2.3 - 2.5 mm.

12. The neurostimulation system according to claim 1, wherein a depth of the gap is at least 0.05 mm.

13. The neurostimulation system according to claim 12, wherein the depth of the gap is no more than 2 cm.

14. The neurostimulation system according to claim 1, wherein a height of an upper end of the raised protrusion from the upper surface of the electrode patch surrounding the stud is 4.8 - 5.6 mm.

15. The neurostimulation system according to claim 14, wherein the height of the upper end of the raised protrusion from the upper surface of the electrode patch surrounding the stud is 5.18 - 5.38 mm.

16. The neurostimulation system according to claim 1, wherein a height of an upper end of the raised protrusion from the upper stud-base surface is 2.6 - 3.0 mm.

17. The neurostimulation system according to claim 16, wherein the height of the upper end of the raised protrusion from the upper stud-base surface is 2.78 - 2.98 mm.

18. The neurostimulation system according to any one of claims 1-17, wherein the one or more conductive surfaces comprise first and second conductive surfaces, wherein the male fastener is a first male fastener, wherein the stud is a first stud, wherein the stud base is a first stud base, wherein the raised protrusion is a first raised protrusion, and wherein the upper stud-base surface is a first upper stud-base surface, wherein the first stud is coupled in electrical communication with the first conductive surface, wherein the socket is a first socket, wherein the lower receptacle is a first lower receptacle, and wherein the upper receptacle is a first upper receptacle, wherein the electrode patch further comprises a second male fastener, which comprises a second stud, which (i) comprises a ferromagnetic material, (ii) is shaped so as to define a second stud base and a second raised protrusion that protrudes from a second upper stud-base surface of the second stud base, (iii) is coupled in electrical communicationwith the second conductive surface, and (iv) is disposed on the upper surface of the electrode patch, wherein the lower shell of the housing is shaped so as to define a second socket shaped so as to receive the second stud, wherein the upper shoulder surface is a first upper shoulder surface, wherein the opening is a first opening, and wherein the upper end surface is a first upper end surface, wherein the gap is a first gap, wherein the second socket (a) is shaped so as to define a second lower receptacle and a second upper receptacle, and (b) comprises magnetic material, which is arranged to magnetically attract the second raised protrusion to the second upper receptacle, and wherein the second upper receptacle:(i) extends upward from a portion of the second lower receptacle, such that the second lower receptacle defines a second upper shoulder surface that surrounds a second opening of the second upper receptacle and faces at least partially downward, wherein at least a portion of the second upper shoulder surface is electrically conductive and in electrical communication with the electronics module,(ii) is shaped so as to define a second upper end surface, and(iii) is shaped to receive the second raised protrusion so that the second stud base is positioned within the second lower receptacle and a second gap is defined between the second raised protrusion and the second upper end surface, such that the second upper stud-base surface mechanically and electrically contacts the second upper shoulder surface of the second lower receptacle.

19. The neurostimulation system according to claim 18, wherein a distance between respective centroids of the first and the second raised protrusions is 20 - 50 mm.

20. The neurostimulation system according to claim 19, wherein the distance between the respective centroids of the first and the second raised protrusions is 37.3 - 37.5 mm.

21. The neurostimulation system according to claim 18, wherein the one or more lower adhesive surfaces comprise first and second lower adhesive surfaces, wherein the electrode patch comprises first and second hydrogel layers, which comprise the first and the second lower adhesive surfaces, respectively, andwherein a closest distance between the first and the second hydrogel layers is 5 - 20 mm.

22. The neurostimulation system according to claim 21, wherein the closest distance is 12.7 - 13.3 mm.

23. The neurostimulation system according to any one of claims 1-17, further comprising a band, which is shaped so as to define an opening for receiving the housing of the control unit, and which is configured to secure the housing and the electrode patch to the skin of a limb of the subject.

24. A neurostimulation system for application to skin of a subject, the neurostimulation system comprising: an electrode patch, which comprises (a) first and second electrically conductive surfaces; (b) one or more lower adhesive surfaces, which are configured to adhere the electrode patch to the subject's skin; (c) an upper surface, opposite the one or more lower surfaces; and (d) first and second male fasteners, which comprise first and seconds studs, respectively, which (i) comprise a ferromagnetic material, (ii) are shaped so as to define first and second stud bases, respectively, and first and second raised protrusions, respectively, that protrude from first and second upper stud-base surfaces of the first and the second stud bases, respectively, (iii) are coupled in electrical communication with the first and the second conductive surfaces, respectively, and (iv) are disposed on the upper surface of the electrode patch; and a control unit, which comprises (a) an electronics module, which comprises electronic circuitry, and (b) a housing, which comprises a lower shell that is shaped so as to define first and second sockets, which:(i) are shaped so as to receive the first and the second studs, respectively,(ii) comprise magnetic material, which is arranged to magnetically attract the first and the second raised protrusions to the first and the second sockets, respectively, and(iii) are, at least in part, electrically conductive and in electrical communication with the electronics module, and wherein the first and the second studs and the first and the second sockets are configured such that:placement of the first and the second studs within the first and the second sockets, respectively, removably couples the electrode patch to the lower shell of the housing of the control unit, and couples the first and the second studs in electrical contact with the first and the second sockets, respectively, and application of as little as a threshold total force to the first and the second sockets in a direction away from the first and the second studs, respectively, decouples the first and the second studs from the first and the second sockets, respectively, wherein the threshold total force is 3 - 25 N.

25. The neurostimulation system according to claim 24, wherein the threshold total force is 5 - 25 N.

26. The neurostimulation system according to claim 24, wherein the threshold total force is 8 - 15 N.

27. The neurostimulation system according to claim 24, wherein the threshold total force is greater than the product of 9.81 m / s2 and a mass of the control unit, measured in kg-28. The neurostimulation system according to claim 24, wherein the first and the second raised protrusions of the first and the seconds studs are hollow, wherein the first and the second male fasteners further comprise first and second eyelets, respectively, which are shaped so as to define first and second eyelet bases, respectively, and first and second posts protruding from the first and the second eyelet bases, respectively, wherein the first and the second eyelet base are disposed below the upper surface of the electrode patch, and the first and the second post pass through and protrude upward from the upper surface of the electrode patch, and wherein the first and the second posts of the first and the second eyelets, respectively, are permanently secured within the first and the second raised hollow protrusions of the first and the second studs, respectively, thereby permanently securing the first and the second eyelets to the first and the second studs, respectively.

29. The neurostimulation system according to claim 24, wherein the placement of the first and the second studs within the first and the second sockets, respectively, removablycouples the electrode patch to the lower shell of the housing without deformation of any of the first or the second studs or the first or the second sockets.

30. The neurostimulation system according to any one of claims 24-29, wherein the first and the second sockets comprise (a) first and second lower receptacles, respectively, and (b) first and second upper receptacles, respectively, which:(i) extend upward from respective portions of the first and the second lower receptacles, respectively, such that the first and the second lower receptacles define first and second upper shoulder surfaces, respectively, that surround first and second openings of the first and the second upper receptacles, respectively, and face at least partially downward, wherein at least a portion the first upper shoulder surface and at least a portion of the second upper shoulder surface are electrically conductive and in electrical communication with the electronics module, and(ii) are shaped to receive the first and the second raised protrusions so that the first and the second stud bases are positioned within the first and the second lower receptacles, respectively, such that the first and the second upper stud-base surfaces mechanically and electrically contact the first and the second upper shoulder surfaces of the first and the second lower receptacles, respectively.

31. The neurostimulation system according to claim 30, wherein the portions of the first and second lower receptacles from which the first and the second upper receptacles extend upward, respectively, are central portions of the first and the second lower receptacles, respectively.

32. The neurostimulation system according to claim 30, wherein at least a portion of an internal surface of the first upper receptacle and at least a portion of the second upper receptacle are electrically conductive and in electrical communication with the electronics module.

33. The neurostimulation system according to claim 30, wherein a depth of the first upper shoulder surface of the first lower receptacle from an outer surface of the lower shell surrounding the first lower receptacle is 1.8 - 2.2 mm.

34. The neurostimulation system according to claim 30, wherein the first lower receptacle is circular and has a greatest diameter of 14 - 15 mm.

35. The neurostimulation system according to claim 30, wherein a height of an upper end of the first raised protrusion from the upper stud-base surface of the first stud base equals 96% - 98% of a depth of the first upper end surface of the first upper receptacle from the first upper shoulder surface of the first upper receptacle.

36. The neurostimulation system according to claim 30, wherein the magnetic material is arranged to magnetically attract the first and the second raised protrusions to the first and the second upper receptacles, respectively, and wherein the first and the second upper receptacles are:(i) shaped so as to define first and second upper end surfaces, respectively, and(ii) shaped so as to receive the first and the second raised protrusions, respectively, so that a first gap is defined between the first raised protrusion and the first upper end surface, and a second gap is defined between the second raised protrusion and the second upper end surface.

37. The neurostimulation system according to claim 36, wherein a depth of each of the first and the second gaps is at least 0.05 mm.

38. The neurostimulation system according to claim 37, wherein the depth of each of the first and the second gaps is at least 0.1 mm.

39. The neurostimulation system according to claim 37, wherein the depth of each of the first and the second gaps is no more than 2 cm.

40. The neurostimulation system according to claim 24, wherein a distance between respective centroids of the first and the second raised protrusions is 20 - 50 mm.

41. The neurostimulation system according to claim 40, wherein the distance between the respective centroids of the first and the second raised protrusions is 37.3 - 37.5 mm.

42. The neurostimulation system according to claim 24, wherein the first upper studbase surface of the first stud base is disposed at a height of 2.2 - 2.6 5 mm above the upper surface of the electrode patch surrounding the first stud.

43. The neurostimulation system according to claim 42, wherein the height is 2.3 - 2.5 mm.

44. The neurostimulation system according to claim 24, wherein a height of an upper end of the first raised protrusion from the upper surface of the electrode patch surrounding the first stud is 4.8 - 5.6 mm.

45. The neurostimulation system according to claim 44, wherein the height of the upper end of the first raised protrusion from the upper surface of the electrode patch surrounding the stud is 5.18 - 5.38 mm.

46. The neurostimulation system according to claim 24, wherein a height of an upper end of the first raised protrusion from the first upper stud-base surface is 2.6 - 3.0 mm.

47. The neurostimulation system according to claim 46, wherein the height of the upper end of the first raised protrusion from the first upper stud-base surface is 2.78 - 2.98 mm.

48. The neurostimulation system according to claim 24, wherein the one or more lower adhesive surfaces comprise first and second lower adhesive surfaces, wherein the electrode patch comprises first and second hydrogel layers, which comprise the first and the second lower adhesive surfaces, respectively, and wherein a closest distance between the first and the second hydrogel layers is 5 - 20 mm.

49. The neurostimulation system according to claim 48, wherein the closest distance is 12.7 - 13.3 mm.

50. The neurostimulation system according to claim 24, further comprising a band, which is shaped so as to define an opening for receiving the housing of the control unit, and which is configured to secure the housing and the electrode patch to the skin of a limb of the subject.

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