A leadless neurostimulation device including a header unit having at least one primary electrode having a contact surface that defines an external surface on a side of the device, an outer housing that forms a side of the header unit opposite of the contact surface of the primary electrode, and a dielectric mount that receives at least a portion of the primary electrode and at least partially surrounds the primary electrode, the dielectric mount being configured to electrically insulate the primary electrode from the outer housing, the dielectric mount being received and fixed within a recessed portion of the outer housing, and a housing having a secondary electrode positioned on the same side of the leadless neurostimulation device as the primary electrode, the primary electrode and the secondary electrode being configured to transmit an electrical stimulation signal therebetween to provide electrical stimulation therapy to a tibial nerve of a patient.

TECHNICAL FIELD

The present application relates to implantable medical devices, and more specifically to minimally invasive implantable neurostimulation devices.

BACKGROUND

Implantable medical devices may be configured to deliver electrical stimulation therapy or monitor physiological signals. Electrical stimulation of nerve tissue, for example, may provide relief for a variety of disorders thereby improving the quality of life for many patients.

Some implantable medical devices (IMDs) may employ electrical leads that carry electrodes. For example, electrodes may be located at a distal portion of an elongate lead. Other examples of electrical leads may be relatively short, having one or more electrodes located along a body of the lead. Such electrical leads are provided separate from the housing or body of the IMD and coupled to the IMD during implantation to provide stimulation via the electrode at a location separated from the housing of the IMD.

Simulation of different nerve branches and clusters have been explored for treating various ailments. One avenue that has shown promising development has been the stimulation of the tibial nerve for the treatment of certain ailments such as incontinence or over-active bladder.

SUMMARY

Embodiments of the present disclosure are directed to minimally invasive, leadless neurostimulation devices. Leadless devices do not require the use of a separate lead and instead provide a unitary structured device that may be more robust and less invasive than lead-based counterpart devices.

The disclosed devices include a housing containing components therein configured for delivering neurostimulation therapy, and an attached header unit. The header unit includes one or more primary electrodes that form a portion of the exterior and side of the header unit. The one or more primary electrodes are electrically insulated from other portions of the exterior surface of the neurostimulation device. The housing of the neurostimulation device includes a secondary electrode that operates in conjunction with the one or more primary electrodes to provide electrical simulation therapy or neuro sensing capabilities. The secondary electrode is positioned on the same side of the device as the one or more primary electrodes positioned in the header unit.

In an embodiment, the disclosure describes system including a leadless neurostimulation device including a header unit having at least one primary electrode having a contact surface that defines an external surface on a side of the leadless neurostimulation device, an outer housing that forms a side of the header unit opposite of the contact surface of the primary electrode, and a dielectric mount that receives at least a portion of the at least one primary electrode and at least partially surrounds the at least one primary electrode, the dielectric mount being configured to electrically insulate the at least one primary electrode from the outer housing, the dielectric mount being received and fixed within a recessed portion of the outer housing, and a housing having a secondary electrode positioned on the same side of the leadless neurostimulation device as the at least one primary electrode, the at least one primary electrode and the secondary electrode being configured to transmit an electrical stimulation signal therebetween to provide electrical stimulation therapy to a tibial nerve of a patient.

In an embodiment, the disclosure describes a leadless neurostimulation device comprising a header unit comprising at least one primary electrode having a contact surface that defines an external surface on a side of the leadless neurostimulation device, an outer housing that forms a side of the header unit opposite of the contact surface of the primary electrode, and a dielectric mount that receives at least a portion of the at least one primary electrode and at least partially surrounds the at least one primary electrode, the dielectric mount being configured to electrically insulate the at least one primary electrode from the outer housing, the dielectric mount being received and fixed within a recessed portion of the outer housing, wherein the dielectric mount defines a channel between the outer housing and the dielectric mount, the channel configured to receive a medical adhesive therein to fix the outer housing to the dielectric mount, and wherein the primary electrode comprises an interior surface that defines an interlocking structure with the dielectric mount. The leadless neurostimulation device further includes a housing comprising a secondary electrode positioned on the same side of the leadless neurostimulation device as the at least one primary electrode, the at least one primary electrode and the secondary electrode being configured to transmit an electrical stimulation signal therebetween to provide electrical stimulation therapy to a tibial nerve of a patient, and a lead pin configured to pass through the mounting plate and connect to processing circuitry and components contained in the housing configured to transmit the electrical stimulation signal between the one or more primary electrodes or secondary electrodes to provide electrical stimulation therapy to the tibial nerve, wherein the primary electrode is electrically coupled to the lead pin. The leadless neurostimulation device further includes a mounting plate, wherein the housing is coupled to a first side of the mounting plate and the header unit is coupled to a second side of the mounting plate, and wherein the at least one primary electrode and the secondary electrode define a separation distance of about 10 mm to about 20 mm, and wherein the leadless neurostimulation device defines a total volume of about 1.5 cubic centimeters (cc) to about 3.5 cc.

In an embodiment, the disclosure describes a method of manufacturing a leadless neurostimulation device, the method comprising forming a header unit, including a primary electrode having a contact surface that defines an external surface on a side of the leadless neurostimulation device, forming the header unit comprising forming an outer housing as a side of the header unit opposite of the contact surface of the primary electrode, forming a dielectric mount to receive at least a portion of the primary electrode and at least partially surround the at least one primary electrode, the dielectric mount being configured to electrically insulate the at least one primary electrode from the outer housing, and fixing the dielectric mount within a recessed portion of the outer housing. The method of manufacturing further comprising forming a housing, including a secondary electrode positioned on the same side of the leadless neurostimulation device as the primary electrode.

DETAILED DESCRIPTION

Embodiments of leadless neurostimulation devices described herein may be useful for numerous types of neurostimulation therapies, such as for pain control, autonomic nervous system modulation, functional electrical stimulation, tremors, and more. In preferred embodiments, the leadless neurostimulation devices described herein may be useful for stimulating one or more nerves to control symptoms of overactive bladder, urgency frequency, nocturia, painful bladder syndrome, chronic pelvic pain, incontinence, or other pelvic health conditions. These embodiments may also be useful for stimulating one or more peripheral nerves to control pain in one or more areas of the body, such as a foot, ankle, leg, groin, shoulder, arm, wrist, or the back, for example. In one example, embodiments of the disclosed leadless neurostimulation devices may be used to stimulate a tibial nerve of a patient.

FIG.1is schematic view showing an example leadless neurostimulation device10. Leadless neurostimulation device10includes a housing12containing components therein configured for delivering neurostimulation therapy, a header unit14that includes one or more primary electrodes18, and a mounting plate16that couples housing12to header unit14. Header unit14includes at least one primary electrode18that forms part of an exterior surface of header unit14. Housing12includes a secondary electrode20that forms part of an exterior surface of housing12and is positioned on the same side of device10as primary electrode18. In an alternate embodiment not depicted, primary electrode18and secondary electrode20may be arranged on opposite sides of device10.

Primary electrode18and secondary electrode20operate in conjunction with one another to provide stimulation therapy to a target treatment site (e.g., a tibial nerve). Secondary electrode20may also be referred to as a case electrode, can electrode or reference electrode. In an embodiment, primary electrode18may comprise a cathode and secondary electrode20may comprise an anode. In some embodiments, primary and secondary electrodes18and20may be characterized as a bipolar pair or system.

The terms “primary” and “secondary” are used to differentiate two or more electrodes that are configured to transmit an electrical signal therebetween. The terms are not used to imply a hierarchy among the electrodes, positive and negative terminal, a total number of electrodes, or a directionality by which a signal is transmitted between the electrodes.

FIGS.2A-2Cprovide various schematic views of mounting plate16and header unit14and the components contained therein. In particular,FIG.2Ais a schematic view of a partially assembled header unit14coupled to mounting plate16.FIG.2Bis an exploded view that illustrates how the components of header unit14and mounting plate16are assembled.FIG.2Cis a cross sectional view ofFIG.2Aalong line A-A that illustrates portions of header unit14.

Header unit14includes outer housing24, primary electrode18, and dielectric mount26. Outer housing24is coupled to mounting plate16and may define a partially recessed cavity that receives dielectric mount26and primary electrode18. Outer housing24and mounting plate16may be made of metal or metal alloy (e.g., titanium or titanium alloy) to allow for easy coupling there between (e.g., laser welding) as well as allow for the coupling of mounting plate16to housing12. Additionally, or alternatively, outer housing24or mounting plate16may be composed of a ceramic material, or non-conductive plastic material (e.g., polypropylene) including appropriate mechanisms (e.g., metal inserts) for coupling outer housing24to mounting plate16.

In some embodiments, the seam between mounting plate16and outer housing26may form at least a partial hermetic seal. As discussed further below, while portions of mounting plate16and outer housing24define the exterior shape and body of leadless neurostimulation device10, the exterior surface of these components may be coated with a dielectric material to prevent the body of such components from interfering with the electrical pathway of primary electrode18and secondary electrode20as well as contribute to the hermetic seal of device10. In an alternate embodiment not depicted, header unit14may be configured so as to be coupleable directly to housing12, without the need for a separate mounting plate element.

Primary electrode18defines exterior contact surface30configured to be brought into direct contact with tissue of the patient. Contact surface30may also form a portion of a side of header unit14, which is preferably on the same side of device10as secondary electrode20. The exterior perimeter of contact surface30is bordered by dielectric mount26, which also forms a portion of the exterior surface of header unit14and electrically insulates and physically separates primary electrode18from outer housing24and mounting plate16.

Primary electrode18may be of any suitable size and shape to provide electrical stimulation to the tibial nerve through the fascia layer of a patient. In some embodiments, primary electrode18may define a contact surface area of about 15 mm2to about 90 mm2. In preferred embodiments that include only a single primary electrode18, the contact surface area may be greater than about 15 mm2, greater than about 18 mm2, greater than about 20 mm2, less than 35 mm2, less than 30 mm2, and less than 25 mm2. As discussed further in the provisional application Ser. Nos. 63/198,054 filed Sep. 25, 2020, and 63/199,274 filed Dec. 17, 2020, both entitled “MINIMALLY INVASIVE LEADLESS NEUROSTIMULATION DEVICE,” incorporated by reference above, the surface area of primary and secondary electrodes18and20, and separation distance there between may be optimized to provide sufficient penetration and stimulation of the tibial nerve through the fascia layer in a patient's leg.

In some embodiments, the size, shape, and physical separation distance between primary electrode18and secondary electrode20may be configured to produce an impedance of less than 2,000 ohms (e.g., between about 250 ohms and 1,000 ohms). Additionally, or alternatively, primary and secondary electrodes18and20may be arranged in a non-concentric arrangement such that one electrode does not substantially encircle the other.

In some embodiments, contact surface30of primary electrode may be substantially flat (e.g., flat or nearly flat) as shown inFIG.1. Alternatively, primary electrode18may define a curved surface (e.g., a semi-cylindrical shape or other 2D or 3D curved plane) that helps primary electrode18follow the curvatures of the fascia layer of a patient when implanted to provide better contact and focusing of the electrical signal directed to the tibial nerve. The curved surface may extend over the entirety of contact surface30, or only over a portion of the surface. Additionally, or alternatively, the curved curvature may be confined to only contact surface30of primary electrode18, or may extend over other portions of device10such as other parts of header14, mounting plate16, or housing12. By including the curvature over other portions of device10, the device may provide a more ergonomic fit when implanted while also helping to direct the stimulation signal to the tibial nerve.

In some embodiments, contact surface30of primary electrode18may also protrude from the plane defined by housing12. Such a protrusion may help apply additional pressure to the fascia of the patient and help guide the electrical stimulation signal deeper into the tissue of the patient. Primary electrode18may also define one or more interlocking features, carveouts, recesses, or other structures below contact surface30that reduce the overall volume of primary electrode18without interfering with contact surface30. The reduced volume and interlocking features may also help reduce manufacturing costs as well as help fix primary electrode18relative to dielectric mount26. In some embodiments, contact surface30may possess a textured finish such as a laser textured finish. The textured finish may be added to the general shapes described above. For example, contact surface30may be flat or curved with a laser texturing added to contact surface30. In some examples, contact surface30may include a titanium, titanium alloy, or platinum iridium textured surface.

Primary electrode18may be formed using any suitable material capable of delivering electrical stimulation therapy to the patient once implanted and having desirable long-term biological compatibility with the surrounding tissue. Such materials may include, but are not limited to titanium, titanium alloy, platinum iridium, or the like. In preferred embodiments, at least contact surface30is formed of platinum iridium, titanium, titanium alloy, while the body of primary electrode18may be made of the same or different material. For example, the body of primary electrode18may be formed of titanium or titanium alloy with contact surface30formed of platinum iridium. Using platinum iridium may be beneficial in reducing or eliminating the potential for charge buildup on the external surface of device10during operation. Platinum iridium also provides low impedance with the surrounding bodily tissue, has great biological compatibility, and works well as a contact surface for implantable electrodes. However, platinum iridium can be costly or can have diminished compatibility (e.g., metallurgical bonding) with other metals or alloys.

In some embodiments, primary electrode18can be made entirely out of platinum iridium, titanium, or titanium alloy. Titanium or titanium alloy offers significant cost advantages over platinum iridium or other specialty metals. However, titanium-based electrodes have been generally discouraged in implantable devices that administer chronic or long-term stimulation therapy. It is believed that such titanium-based electrodes can develop an oxide surface layer with time. This oxide layer along the surface of the electrode can increase the impedance between the electrode and bodily tissue and lead to charge buildup along the outer surface. As a result, the efficacy of the stimulation therapy can diminish with time when using titanium-based electrodes requiring increased voltage or current to deliver therapeutic stimulation levels.

Due to the relatively large surface area of primary electrode18(e.g., approximately 21 mm2), the phenomenon of diminished efficacy while using a titanium-based electrode has been observed to be negligible or avoided altogether. Thus, titanium-based electrodes may be used for primary electrode18(including contact surface30) without experiencing reduced efficacy in the stimulation therapy over the useful life of device10. In some embodiments, primary electrode18can be made out of commercially pure titanium (e.g., metal comprised of >99% Ti, or Grade 2 titanium). Commercially pure titanium, particularly Grade 2 titanium, offers certain manufacturing advantages including, for example, the ability for primary electrode18to be produced through machine stamping rather than a casting or other costly fabrication process. Titanium and select titanium alloys also have general acceptance as being biologically compatible and suitable for construction of implantable medical devices.

Titanium and titanium alloys also offer good compatibility (e.g., metallurgical bonding) compared to platinum iridium with other metals and alloys. For example, lead pin42, which is discussed further below, is used to couple primary electrode18to the device circuitry contained in housing12. Lead pin42may be constructed of niobium or niobium alloy. Soldering or welding between niobium and platinum iridium has been found to have reduced metallurgical compatibility causing the introduction micro fractures and other indications of poor bonding through the well joint between the niobium and platinum iridium metals. These micro fractures can diminish the reliability and impedance of the device. In contrast, titanium has great compatibility with niobium and can be coupled to lead pin42efficiently through laser welding.

In some embodiments, improved bonding between niobium and platinum iridium through the use of an intermediary or constructing the body of primary electrode18using a different material than platinum iridium. For example, the body of primary electrode18can be made of titanium and surface30can be coated with platinum iridium (e.g. through sputtering or other deposition method) thereby offering the advantages of having contact surface30formed of platinum iridium while also obtaining good bonding capabilities through the use of titanium. Additionally, or alternatively, a titanium sleeve can be introduced between the niobium based lead pin42and platinum iridium body of primary electrode18to obtain a similar effect. The titanium improves the electrical coupling between lead pin42and primary electrode18because titanium can be efficiently welded or friction bonded to both niobium and platinum iridium. The titanium body or sleeve acts as an intermediary between the niobium and platinum iridium to eliminate the presence of micro fractures and other indications of poor bonding thereby improving the conductive transfer and reliability of device10over its lifespan.

Dielectric mount26is configured to conform to at least some of the internal surfaces of primary electrode18to help physically retain and electrically insulate primary electrode18from other portions of header unit14and mounting plate16. In some embodiments, primary electrode18and dielectric mount26define interlocking interior surfaces32that allow primary electrode18to sit within dielectric mount26and help prevent physical separation (e.g., movement of primary electrode18out of device10). For example, primary electrode18may define a retention channel, protuberance, or some other physical structure that forms at least a portion of a perimeter of the interior surface(s) of primary electrode and provides interlocking surface32. Additionally, including the presence of a structure that provides interlocking surface32may help reduce the overall quantity of material used to form primary electrode18which may reduce manufacturing costs as well as help fix primary electrode18relative to dielectric mount26and header14.

Dielectric mount26may be formed of any suitable material that electrically insulates primary electrode18from other portions of header unit14and mounting plate16. In some embodiments, dielectric mount26may be formed of liquid silicone rubber (LSR), silicone, or similar material. For example, LSR, silicone, or other suitable dielectric material may be cast or molded around primary electrode18to produce a secure fit with primary electrode18, prevent physical separation there between, and provide the desired physical and electrical separation from outer housing26and portions of mounting plate16. In some embodiments, dielectric mount26may be formed integrally with outer housing24provided the components are formed of a non-conductive material.

In some embodiments, dielectric mount26may also include one or more recesses or strategically placed gaps, that may receive a medical adhesive to help aid with assembly of header unit14. For example, as shown inFIGS.2A-2C, dielectric mount26may be generally shaped to be received within the recessed area34defined by outer housing24. Along a portion of the adjacent surfaces between dielectric mount26and outer housing24, dielectric mount26may define a channel36configured to receive, after assembly, a suitable adhesive (e.g., non-conductive medical adhesive, epoxy volcanized silicone, or the like) that fixes dielectric mount24and outer housing24together. As best seen inFIGS.1and2C, outer housing may define a filling port38that is in fluid communication with channel36and allows for injection of the adhesive after assembly.

Dielectric mount26may also be shaped to provide a gap40between mounting plate16and primary electrode18. Upon assembly, gap40provides access for coupling the one or more primary electrodes18to the respective lead pins42which are used to electrically connect primary electrode18to the device circuitry contained in housing12. After coupling primary electrode18to lead pin42(e.g., soldering), gap40may be filled with a dielectric material44such as the medical adhesive injected through fill port38, LSR, silicone, or other suitable material.

Outer housing24may form the majority of the body of header unit14. In particular, outer housing24forms the side of header unit14opposite of contact surface30, the perimeter edges (apart from the contact surface provided with mounting plate16), and a portion of the same side of header unit14as contact surface30of primary electrode18. In some embodiments, outer housing24may have a rounded, semi-circular, or D-shaped perimeter edge that provides a relatively smooth surface without any abrupt or sharp edges or lines than may present an irritation to the patient after implantation. In some embodiments, outer housing24is configured to receive and form a partial shell around dielectric mount26. As such, outer housing24may define a concave interior surface (not shown) that receives a portion of dielectric mount26. Dielectric mount26may be secured to outer housing26using a suitable medical adhesive.

Header unit14is coupled to mounting plate16and likewise mounting plate16is coupled to housing12. Housing12includes secondary electrode20. In some embodiments, secondary electrode20may be defined by an area of the body of housing12. For example, housing12may be formed of a metallic material (e.g., titanium) and electrically coupled to the processing circuitry of leadless neurostimulation device10. The outer surface of housing12, including portions of mounting plate16and header unit14, may be coated with a dielectric material apart from the surface area that defines secondary electrode20and primary electrode18. The dielectric material may at least partially encapsulate device10such that the boundary created by the dielectric material defines the area of secondary electrode20, contact surface30, or both.

The dielectric coating may be applied using any suitable technique. In some such examples, the areas defining contact surface30and secondary electrode20may be masked with a suitable material such as tape. Leadless neurostimulation device10may be then coated using vapor deposition, dip coating, spray coating of similar technique with an adherent dielectric material followed by subsequent removal of the mask material to expose the surfaces of contact surface30and secondary electrode20.

Suitable dielectric materials for coating leadless neurostimulation device10may include, but are not limited to, parylene, LSR, or silicone. Additionally, or alternatively, the outer surface of neurostimulation device10or portions thereof, may include a surface treatment such as an anodization treatment to modify portions of the surface to make the surface non-conductive. For example, portions of housing12, outer housing24, or both, if made of metal (e.g., titanium) may be treated through anodization to make select surfaces non-electrically conductive. In such examples, for purposes of this disclosure the exterior surface of the components may still be characterized as being metal (e.g., titanium) although the component has received such surface treatment.

In preferred examples, the outer surface of leadless neurostimulation device10may be formed primarily of parylene. Formation of the desired electrode profiles may utilize dielectric blocking methods (e.g., use of a masking material during manufacture) or dielectric removal methods (e.g., removal via laser or soda blast) without damaging the dielectric coating.

In some embodiments, the dielectric coating may also contribute to creating a hermetic seal around leadless neurostimulation device10. The general configuration of attaching header14and housing12respectively to mounting plate16may also produce a hermetic seal within device10. Coating device10with a dielectric material possessing sealing properties such as parylene, LSR, or silicone may either provide additional robustness to the hermetic seal of device10. Providing leadless neurostimulation device10in a hermetically sealed form may contribute to the device's long-term functionality thereby providing advantages over other non-hermetically sealed devices.

Secondary electrode20may define a contact surface area of about 40 mm2to about 120 mm2. However, devices having larger sized secondary electrodes may increase the minimal current needed to create a therapeutic response. The separation distance between primary electrode18and secondary electrode20may be about 5 mm to about 15 mm.

The processing circuitry and components of neurostimulation device10are contained within housing12. Examples of such processing components may include one or more electronic circuits for delivering electrical stimulation therapy, telemetry hardware, power supply, memory, processor(s). Housing12can also include communication circuitry disposed therein for receiving programming communication from an external programmer, or providing feedback to a programmer or other external device.

In one example, housing12can include an energy source enclosed therein, e.g., a rechargeable or non-rechargeable battery. In another example, leadless neurostimulator10can also be configured to receive energy signals from an external device and transduce the received energy signals into electrical power that is used to recharge a battery of the device, an energy source e.g., a battery, processing circuitry, and other necessary components enclosed therein. In some embodiments, device10can be configured to receive energy signals from an external device and transduce the received energy signals into electrical power that is used to recharge a battery of device10. Additionally, or alternatively device10may include a non-rechargeable primary cell battery.

In some embodiments, housing12of leadless neurostimulation device10, and its various processing components may be substantially similar to the housing portion of the InterStim Micro Neurostimulator available from Medtronic. The InterStim Micro Neurostimulator may be modified to receive header unit14described herein along with modifications to provide secondary electrode20. The total volume of neurostimulation device10may be relatively small as well. In some embodiments device10may have a total volume of about 0.5 cubic centimeters (cc) to about 6 cc, about 1.5 cc to about 3.5 cc, or about 2 cc to about 3 cc.

Referring now to implantation,FIG.3Ais a side view of a patient's leg100showing the leadless neurostimulation device10ofFIG.1implanted andFIG.3Bshows a cross-sectional schematic view of leadless neurostimulation device10implanted in leg100of a patient near the ankle adjacent to the tibial nerve102. The cross section of leg100illustrates tibia104, fibula106, fibularis tertius108, flexor digitorum longus110, flexor hallucis longus112, fibularis brevis114, soleus116, posterior tibial artery118, posterior tibial vein120, skin122, cutaneous fat layer124, and fascia layer126. Device10can be implanted through skin122and cutaneous fat layer124via a small incision101(e.g., about one to three cm) above the tibial nerve on a medial aspect of the patient's ankle. Device10may be positioned adjacent to the region defined by flexor digitorum longus110, flexor hallucis longus112, and soleus116in which tibial nerve102is contained and implanted adjacent and proximal to fascia layer128with primary electrode18and secondary electrode20facing toward tibial nerve102.

In an embodiment, incision101does not cross fascia layer128thereby reducing the risk of complications with the surgical procedure. While incision101is shown approximately horizontal to the length of the tibial nerve, other incisions or implantation techniques could be used according to physician preference. In an embodiment, leadless neurostimulation device10may be implanted such that primary electrode18is oriented inferiorly relative to secondary electrode20.

Optional testing of leadless neurostimulation device10may be performed to determine if device10is been properly positioned in proximity to tibial nerve102to elicit a desired response from an applied electrical stimulation. In an example, device10has controlled by an external programmer to deliver test stimulation, and one or more indicative responses are monitored, such as toe flexion from simulation of the tibial motor neurons controlling the flexor hallucis brevis or flexor digitorum brevis, or a tingling sensation in the heel or sole of the foot excluding the medial arch. If such testing does not elicit appropriate motor or sensory responses, the practitioner may reposition device10and retest.

Once a practitioner has determined device10is properly positioned to provide an appropriate patient response to delivered stimulation therapy, housing12can be secured in place if needed. Such anchoring means may be optional as the natural shape of the region in which device10is implanted, and the shape of device10itself has shown good compatibility with the surrounding tissue thus preventing device10from shifting or rolling after implantation, in some embodiments, leadless neurostimulation device10may further include one or more suture points to help secure device10to fascia102or other parts of leg100. In some embodiments, a suture anchor130may be included at the distal end of housing12, opposite of the end attached to mounting plate16.

An advantage of the devices and methods described herein can be improved patient safety and satisfaction after implant. In contrast to other approaches, leadless neurostimulation device10does not require fascia layer126to be disturbed which may reduce risks affiliated with alternative procedures. Further, as device10is a unitary structure and can be hermetically sealed, the device is more robust than other lead-based stimulation units.

During operation, an electrical stimulation signal may be transmitted between primary electrode18and secondary electrode20through facia layer126. The electrical signal may be used to stimulate tibial nerve102which may be useful in the treatment of overactive bladder (OAB) symptoms of urinary urgency, urinary frequency and/or urge incontinence, or fecal incontinence.

In one or more examples, the described techniques may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media may include non-transitory computer-readable media, which corresponds to a tangible medium such as data storage media (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer). Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Accordingly, the term “processor” as used herein may refer to any of the foregoing structure or any other physical structure suitable for implementation of the described techniques. Also, the techniques could be fully implemented in one or more circuits or logic elements.