Method of controlling electrical energy in an electrical stimulation device with two or more stimulation energy supplies and stimulation device

Abstract

Conventional devices can deliver some level of charge into biological tissue - measures are taken to maintain zero charge residual at the stimulation site for regulatory and safety concerns. Often physically large capacitors are required, making miniaturization more difficult and increasing cost due to one capacitor per electrode. A method of controlling electrical energy provided by a tissue stimulation device (100) to one or more stimulation electrodes (200) included in the device (100), the device comprising: a first stimulation electrode (200); a pulse energy controller (500, 510) for delivering electrical energy as one or more electrical stimulation pulses to the first stimulation electrode (200); the pulse energy controller (500, 510) further comprising two or more stimulation energy supplies each supplying electrical energy as a first pulse (526, 527, 528, 529, 530, 531) to the first stimulation electrode (200) substantially simultaneously; and each individually supplying electrical energy as a second pulse (526*, 527*, 528*, 529*, 530*, 531*) to the first stimulation electrode (200). By considering each energy supply as an energy building block that can be selected as needed, a simpler, more accurate and less expensive stimulation control can be provided.

Description

[0001] field

[0002] This disclosure relates to a method for controlling electrical energy in an electrical stimulation device to provide electrical stimulation, and to a stimulation device. Specifically, this disclosure relates to a method for controlling the electrical energy supplied by the stimulation device to one or more stimulation electrodes included in the device.

[0003] background

[0004] Electrical stimulation systems can be used to deliver electrical stimulation therapy to patients to treat a variety of symptoms or conditions, such as headaches, lower back pain, and incontinence. The system may include one or more devices and is at least partially implantable.

[0005] In many electrical stimulation applications, it is desirable for stimulation devices, which typically include therapeutic leads (which consist of stimulating electrodes and interconnects), to deliver electrical stimulation as safely as possible. Conventional devices can deliver a certain amount of charge into biological tissue—but to meet regulatory and safety concerns, measures are taken to maintain substantially zero charge residue at the stimulation site.

[0006] The most common solution is to connect a DC blocking capacitor in series with each stimulating electrode. This reduces the risk of continuous current (DC) flow through the electrode—essentially blocking the continuous current component entirely, or reducing it to a negligible level. Blocking capacitors typically require physically large capacitors, making miniaturization more difficult and increasing cost due to the need for a capacitor per electrode.

[0007] US Patent Application US 2018 / 0110992 A1 describes the use of electrodes to generate a multiphase field at a neuromodulation site. A first polarity charge is injected into a target region, and a second polarity charge opposite to the first polarity charge is injected into a portion of the neuromodulation site other than the target region to substantially neutralize the injected first polarity charge while retaining at least a portion of the first polarity charge at the target region.

[0008] European application EP 2540340 A1 describes an electrostimulation device including a medical apparatus. The medical apparatus includes: a housing component having at least one conductive region; a plurality of conductors configured to be electrically coupled to a distal electrode array; and a stimulation circuit having a plurality of controllable stimulation channels. A first subset of the stimulation channels is electrically coupled to a conductor. A second subset of the stimulation channels is electrically coupled to the conductive region of the housing component. The stimulation circuit is operable to simultaneously create a first stimulation path in the electrode array and a second stimulation path extending from the electrode array to the housing component.

[0009] US Patent Application US 2019 / 0001139 A1 describes a medical device for a patient, comprising: an implantable system having a first implantable device having at least one implantable functional element configured to deliver stimulation energy to a patient's tissue; and an implantable controller configured to provide a stimulation waveform to the at least one implantable functional element, the stimulation waveform including one or more stimulation parameters. The device is configured to randomly change at least one of the one or more stimulation parameters. The stimulation parameters may also be randomly varied.

[0010] US Patent Application US 2009 / 0062883 A1 describes a spinal cord stimulation (SCS) system that includes multiple electrodes and multiple independently programmable stimulation channels within an implantable pulse generator (IPG). These channels can provide concurrent but unique stimulation fields, allowing for the implementation of virtual electrodes. A real-time clock can provide an automated schedule for daily stimulation. A two-way telemetry link notifies the patient or clinician of the system's status, including the charging status of the IPG battery.

[0011] One object of the present invention is to provide an improved stimulation device that provides a high degree of charge balance with a simplified control method, which can be implemented with less complex hardware. In particular, in some cases, less complex hardware may be easier to miniaturize.

[0012] Overview

[0013] According to a first aspect of this disclosure, a method is provided for controlling electrical energy supplied by a tissue stimulation device to one or more stimulation electrodes included in the device, the device comprising: a first stimulation electrode configured to transmit energy as one or more stimulation pulses to human or animal tissue during use; a pulse energy controller configured and arranged to transmit electrical energy as one or more electrical stimulation pulses to the first stimulation electrode during use; the pulse energy controller further comprising two or more stimulation energy supply units, wherein the method further comprises: supplying electrical energy from each of the two or more stimulation energy supply units substantially simultaneously to the first stimulation electrode as a first pulse; and supplying electrical energy from each of the two or more stimulation energy supply units individually to the first stimulation electrode as a second pulse.

[0014] By treating each energy supply unit as an energy building block that can be selected as needed, simpler stimulation control can be provided. Using power supplies in this way reduces the requirements for them to be highly accurate and highly stable. The charge they supply does not even need to be precisely predetermined and / or controlled. The minimum requirement is that they remain relatively constant over at least one pulse cycle. By requiring fewer functions, the size and cost of the supply unit design can be reduced. The pulse energy controller can be configured and arranged to select the instance of the energy block to be applied, which electrode in the electrodes to be applied, the energy applied, and the polarity.

[0015] A higher degree of reproducibility can be provided by using the same supply unit for different pulses. This can be advantageous in applications where tissue dose needs to be monitored over multiple treatment cycles—in conventional systems, measurements of actual current and / or voltage are likely preferred. However, for more repeatable pulses, limiting monitoring to the supply unit in use and the number of times each supply unit is used may suffice.

[0016] According to another aspect of this disclosure, a method is provided in which two or more energy supply units are configured and arranged to provide electrical energy in such a way as: a predetermined and / or controlled voltage, a predetermined and / or controlled current, a predetermined and / or controlled energy, a predetermined and / or controlled charge, a predetermined and / or controlled power, or any combination thereof.

[0017] Any convenient type of electrical control can be used, such as voltage, current, energy, power, charge, dosage control, and any combination thereof.

[0018] According to another aspect of this disclosure, a method is provided in which the first pulse and the second pulse have substantially different polarities. Additionally or alternatively, a method may be provided in which each of two or more energy supplies is configured and arranged to provide pulses as anode energy pulses and / or cathode energy pulses.

[0019] For charge balance, the pulses should have opposite polarities. Traditionally, tissue stimulation uses a cathodic pulse for stimulation and an anodic pulse (with opposite polarities) for charge neutralization (also known as charge balancing). By using two or more supply units, the energy output of each supply unit can be configured and arranged to be substantially constant—if the same supply unit is used for two pulses, and they are, for example, a cathodic pulse and an anodic pulse, then the anodic and cathodic charges are substantially equal.

[0020] Essentially, the same amount of energy can be applied in each pulse because the same energy building block is applied as a sub-pulse, at least a portion, as an anode pulse, and the same energy building block (but with substantially opposite polarity) is applied as a sub-pulse, at least a portion, as a cathode pulse. Each sub-pulse has a predetermined and / or controlled amplitude and duration provided by a separate power supply. The applied energy is inherently balanced, requiring no more complex and expensive hardware and / or software. If the energy supply is configured and arranged to provide a certain level of charge, the applied charge is inherently balanced, requiring no more complex and expensive hardware and / or software.

[0021] Compared to known solutions, a high degree of balance is achieved through a hardware configuration that uses relatively simple polarity switching for each simplified supply unit.

[0022] According to another aspect of this disclosure, a method is provided in which each of two or more stimulation energy supply units is configured and arranged to supply electrical energy substantially simultaneously as a first pulse. Additionally or alternatively, a method is provided in which each of two or more stimulation energy supply units is configured and arranged to supply electrical energy substantially continuously as a second pulse.

[0023] Generally, a method is provided in which each of two or more energy supplies is configured and arranged to provide electrical energy in such a way that it is substantially simultaneous, at least partially simultaneous, substantially continuous, at least partially continuous, has a predetermined and / or controlled time interval between pulses, or any combination of these. The ability to switch the supplies at different times provides a high degree of control. By using the supplies in overlapping or separate time intervals, the combined output voltage, current, power, energy, or dose can also be predetermined and / or controlled. This allows for the use of waveforms of different shapes, such as ramps.

[0024] By applying the first pulse substantially simultaneously and substantially discontinuously (or substantially continuously), the average amplitude of the second pulse is less than the average amplitude of the first pulse. The ratio between the average amplitudes of the second and first pulses can be predetermined and / or controlled by determining the instance and polarity of each energy supply unit. When the first and second pulses are applied substantially simultaneously to the cathode and substantially dissimilarly to the anode, the average amplitude of the anode pulse can be substantially less than the average amplitude of the cathode pulse. This lower amplitude reduces the risk of reduced therapeutic efficacy, for example, due to electrode corrosion and / or nerve fatigue.

[0025] According to another aspect of this disclosure, a method is provided in which two or more energy supply units are configured and arranged to provide a first pulse and a second pulse, the average amplitude ratio of the first pulse and the second pulse being less than or equal to 1:2.

[0026] By reducing the amplitude of the balancing pulse to less than half that of the stimulation pulse, the risk of reduced therapeutic efficacy is significantly reduced. By applying the cathode pulses substantially simultaneously and the anodic pulses substantially asynchronously, the amplitude of the anodic pulse can be approximately half that of the cathode pulse. When using four or more supply units, the amplitude of the anodic pulse may be approximately one-quarter that of the cathode pulse, thereby increasing the likelihood of maintaining therapeutic efficacy.

[0027] According to another aspect of this disclosure, a method is provided in which two or more energy supply units are configured and arranged to provide a first pulse and a second pulse, the average amplitude ratio of the first pulse and the second pulse being determined at least in part by the number of energy supply units that can be operated substantially simultaneously.

[0028] In some cases, the number of power supplies provides a direct way to indicate an approximate ratio of the average amplitude between the stimulus pulse and the balance pulse. For example, two supplies can provide a ratio of approximately two. Three supplies can provide a ratio of approximately three. Four supplies can provide a ratio of approximately four.

[0029] According to another aspect of this disclosure, a method is provided in which each of two or more energy supply units is configured and arranged to individually supply electrical energy to a first stimulating electrode as a third pulse. Additionally or alternatively, a method is provided in which two or more energy supply units are configured and arranged to provide second and third pulses having a polarity substantially different from the first pulse. Additionally or alternatively, a method is provided in which two or more energy supply units are configured and arranged to: provide second and third pulses having a predetermined and / or controlled time interval therebetween; and provide the first pulse during the time interval.

[0030] Additional pulses can be provided, or one of the pulses can be divided into one or more sub-pulses. By using two or more supply units according to the invention, the energy distribution between the sub-pulses can be predetermined and / or controlled to a greater extent. For example, a balanced pulse can be divided into two sub-pulses or pulse portions—one pulse portion can be provided before the stimulation pulse, and the other pulse portion can be provided after the stimulation pulse. In other words, two balanced pulse portions with a predetermined and / or controlled time interval between them are provided. Similarly, a stimulation pulse can be divided into two sub-pulses or pulse portions.

[0031] According to another aspect of this disclosure, a method is provided in which each of two or more energy supply units is configured and arranged to provide energy pulses of substantially opposite polarities, such that the net charge transferred is substantially zero.

[0032] According to another aspect of this disclosure, a method is provided in which the apparatus further includes one or more DC blocking capacitors, the one or more DC blocking capacitors being electrically connected in series with one or more loop electrodes.

[0033] According to another aspect of this disclosure, a method is provided in which the device is further configured and arranged to electrically short-circuit one or more stimulation electrodes with one or more loop electrodes after one or more pulses are delivered.

[0034] According to another aspect, a stimulation device is provided that can be operated according to any of the methods disclosed herein. The stimulation device includes: an elongated implantable distal end comprising a flexible substrate having a plurality of polymer layers and one or more interconnecting layers, the substrate further comprising: a first stimulation electrode configured to deliver energy as one or more stimulation pulses to human or animal tissue in use; the stimulation device further comprising: one or more loop electrodes configured to provide corresponding electrical returns to the first stimulation electrode in use; and a proximal end comprising a pulse energy controller configured and arranged to deliver electrical energy as one or more electrical stimulation pulses to the first stimulation electrode via one or more interconnecting layers during use; wherein the pulse energy controller further comprises two or more stimulation energy supply portions configured and arranged to: supply electrical energy to the first stimulation electrode substantially simultaneously from each of the two or more stimulation energy supply portions as a first pulse; and supply electrical energy to the first stimulation electrode individually from each of the two or more stimulation energy supply portions as a second pulse.

[0035] According to another aspect, a stimulation device is provided in which a substrate included in an elongated implantable distal end has a maximum thickness of approximately 0.25 mm.

[0036] According to another aspect, a stimulation device is provided, in which one or more loop electrodes are included in a distal end, arranged close to a first stimulation electrode, included in a proximal end, arranged close to a pulse energy controller, or any combination thereof. Brief description of the attached diagram

[0038] Some features and advantages of embodiments of the present invention, as well as ways of implementing these features and advantages, will become more apparent upon consideration of the following detailed description of the invention in conjunction with the accompanying drawings, which illustrate preferred and exemplary embodiments and are not necessarily drawn to scale, wherein:

[0039] Figure 1A , Figure 1B and Figure 1C An example of a stimulating device that can be implanted at a distal end is depicted;

[0040] Figure 2A and Figure 2B Two embodiments of a pulse energy controller suitable for supplying electrical energy to electrodes are schematically depicted;

[0041] Figure 3A and Figure 3B An example of a biphase, cathode-leading pulse is depicted;

[0042] Figure 4A and Figure 4B Another example of a biphase, cathode leader pulse is depicted;

[0043] Figure 5 and Figure 6 Examples of nerves that can be stimulated to treat headaches are described;

[0044] Figure 7 Examples of nerves that can be stimulated for other treatments are depicted;

[0045] Figure 8 Another example of a biphasic cathode leader pulse is depicted; and

[0046] Figure 9 An alternative scheme in which the balancing pulse is divided into two pulse parts is described.

[0047] Detailed description

[0048] In the following detailed description, numerous non-limiting specific details are set forth to aid in understanding this disclosure.

[0049] Typically, the stimulation device described herein may include a stimulation energy source and an implantable end, which includes one or more stimulation electrodes. "Implantable end" means that at least this portion of the stimulation system is configured and arranged for implantation. Optionally, one or more of the remaining portions of the stimulation system may also be configured and arranged for implantation.

[0050] Figure 1A , Figure 1B and Figure 1C A longitudinal cross-section of a first embodiment of the implantable distal end of the stimulation device 100 is depicted, including:

[0051] - An elongated substrate 300 is disposed along a longitudinal axis 700, the elongated substrate having a first surface 310 and a second surface 320 disposed along substantially parallel transverse planes. As depicted, the first surface 310 lies in a plane including the longitudinal axis 700 and the first transverse axis 720, which is substantially perpendicular to the longitudinal axis 700. As depicted, the plane of the first surface 310 is substantially perpendicular to the plane of the cross-sectional view (substantially perpendicular to the surface of the page). The substrate 300 has a thickness or range along a second transverse axis 750, which is substantially perpendicular to the longitudinal axis 700 and the first transverse axis 720, and as depicted, the second transverse axis 750 lies in the plane of the drawing (along the surface of the page). The first surface 310 is depicted as the upper surface and the second surface 320 is depicted as the lower surface.

[0052] To clarify the different perspectives, nominal directions are assigned to the axes:

[0053] - The vertical axis 700 extends from the proximal end on the left (not shown) to the distal end depicted on the right side of the page;

[0054] - As depicted, the first horizontal axis 720 extends into the page; and

[0055] - As depicted, the second horizontal axis 750 extends from the bottom to the top.

[0056] For example, the elongated substrate 300 may include an elastomer distal end composed of silicone rubber or another biocompatible durable polymer, such as siloxane polymers, polydimethylsiloxane, polyurethane, polyether polyurethane, polyether polyurethane urea, polyester polyurethane, polyamide, polycarbonate, polyester, polypropylene, polyethylene, polystyrene, polyvinyl chloride, polytetrafluoroethylene, polysulfone, cellulose acetate, polymethyl methacrylate, and polyvinyl acetate. Suitable examples of polymers (including LCP liquid crystal polymers) are described in "Polymers for Neural Implants" by Hassler, Boretius, and Stieglitz in Journal of Polymer Science: Part B Polymer Physics, 2011, 49, 18-33 (DOI 10.1002 / polb.22169). In particular, Table 1 is included here by reference, which describes the properties of polyimide (UBE U-Varnish-S), parylene C (PCS parylene C), PDMS (NuSil MED-1000), SU-8 (MicroChem SU-8 2000 and 3000 series), and LCP (Vectra MT1300).

[0057] Flexible substrates 300 are also preferred because they very closely follow the contours of the anatomical features below. Very thin substrates 300 have the added advantage of increased flexibility.

[0058] Preferably, the flexible substrate 300 comprises LCP, parylene, and / or polyimide. LCP is a chemically and biologically stable thermoplastic polymer that allows the sealed sensor module to have a small size and low moisture permeation.

[0059] Advantageously, LCP can be thermoformed to allow for complex shapes. Very thin and very flat portions of LCP can be provided. Fine-tuning of the shape can also be achieved using a suitable laser. For example, an LCP substrate 300 with a thickness ranging from 50 micrometers (µm) to 720 micrometers (µm), preferably from 100 micrometers (µm) to 300 micrometers (µm), can be used. For example, values ​​of 150 µm, 100 µm, 50 µm, or 25 µm can be provided. Similarly, for example, LCP can be used to provide a substrate width ranging from 2 mm to 20 mm (ranging from 2 mm to 20 mm).

[0060] At room temperature, thin LCP films have mechanical properties similar to steel. This is important because the implantable substrate 300 must be strong enough to be implanted, strong enough to be removed (explanted), and strong enough to follow any movement of the anatomical features and / or structures to which it is implanted.

[0061] LCP is a polymer material with minimal permeability to gases and water. LCP can self-bond, thus achieving a multilayer structure with a homogeneous composition.

[0062] Compared to LCP, polyimide is a thermosetting polymer that requires an adhesive to construct a multilayer substrate. Polyimide is a thermosetting polymer material with high temperature resistance and flexural strength.

[0063] For example, LCP can be used to provide a substrate with multiple layers (not depicted), in other words, several layers with a thickness of 25 μm. Electrical interconnect layers can also be provided using metallization from technologies in the PCB (printed circuit board) industry, such as metallization using biocompatible metals like gold, silver, or platinum. Electroplating can also be used. These electrical interconnect layers can be used to supply electrical power to any electrode.

[0064] Preferably, a low aspect ratio is used for elongated substrates to reduce the likelihood of implantation problems, for example, the ratio of height (thickness or range along the second horizontal axis 750) to width (range along the first horizontal axis 720) is greater than 10, such as 0.3 mm high and 10 mm wide.

[0065] Although described as a substrate 300 with a basic rectangular cross-section, substrates (and wires) with other cross-sections (such as squares, trapezoids) can be used. The cross-sectional shape and / or size can also vary along the longitudinal axis 700. Alternatively, a substrate with a generally circular cross-section (including circular, flat circular, racetrack-shaped, oval, and elliptical) can be used, which can also be described as tubular or cylindrical.

[0066] Figure 1A The distal end of the device 100 depicted in the image also includes:

[0067] - A stimulating electrode 200, contained within a second surface 320, is configured (after implantation) to deliver energy to human or animal tissue during use. In this example, it is electrical energy. The stimulating electrode 200 has a longitudinal extent along a longitudinal axis 700 and a transverse extent along a first transverse axis 720, which is substantially perpendicular to the longitudinal axis 700 and substantially parallel to the second surface 320.

[0068] "Enclosed in the second surface" means that the stimulation electrode 200 is relatively thin and attached to the second surface 320. The electrode 200 may also be embedded in the second surface 320.

[0069] Typically, one or more stimulating electrodes 200 may be provided. The number, size, and / or spacing of the stimulating electrodes 200 disposed distally can be selected and optimized according to the treatment. For example, if more than one electrode 200 is provided, each electrode 200 can provide an individual stimulation effect, and similar stimulation effects or selections can be achieved by one or two electrodes 200 proximate to the tissue to be affected. Electrodes 200 may include conductive materials such as gold, silver, platinum, iridium, and / or platinum / iridium alloys and / or oxides.

[0070] Figure 1B A stimulation electrode 200 extending along the longitudinal axis 700° is depicted. Although in Figure 1A and Figure 1B An oval cross-section is suggested, but any shape can be used, such as square, rectangular, triangular, polygonal, circular, elliptical, oval, and circular. Long, thin electrodes (or strip electrodes) can also be used.

[0071] Figure 1A The distal end of the device 100 also includes:

[0072] Optionally, one or more loop (or ground) electrodes 400 are configured to provide a corresponding electrical loop for one or more stimulation electrodes 200 during use. In other words, the electrical loop 400 closes the circuit. Any suitable configuration and arrangement can be provided. Additionally or alternatively, one or more loop (ground) electrodes can be configured as follows:

[0073] - Proximity to one or more electrodes 200 at the distal end of the device 100;

[0074] - The electrical energy source is located near the near end of the device (not depicted, see below);

[0075] - is contained in the first surface 310;

[0076] - is contained in the second surface 320;

[0077] Any combination of the above items.

[0078] In some descriptions of conventional stimulation devices, the loop electrode may be referred to as the anode. Traditionally, this is provided via the housing of the IPG (Implantable Pulse Generator). The stimulation electrode may similarly be referred to as the cathode.

[0079] One or more loop electrodes 400 may include conductive materials such as gold, silver, platinum, iridium and / or platinum / iridium alloys and / or oxides.

[0080] Suitable distal ends (or leads) for implantation may include, for example, 12 stimulating electrodes, each 15 cm in length. The stimulating electrodes may have dimensions on the order of 6 mm to 8 mm along the longitudinal axis 700 and 3 mm to 5 mm along the first transverse axis 720, thus approximately 18 to 40 mm². 2 If a 4mm wide strip (ranging along the first horizontal axis 720) is provided as the loop electrode, then a length of 4.5mm to 10mm (ranging along the vertical axis 700) is also provided, ranging from 18 to 40 square millimeters (mm²). 2 () the tissue contact area.

[0081] Figure 1A The distal end of the device 100 also includes:

[0082] - One or more electrical interconnects 250 may also be provided, which are configured to provide electrical power to the electrode 200. They may be contained in the first surface 310, the second surface 320, the substrate between the surfaces 310 and 320, and any combination thereof.

[0083] Alternatively, the substrate 300 may be multilayered, including one or more electrical interconnect layers to provide electrical power to the electrode 200. In use, the electrical interconnects are connected to a power source (not depicted). If an LCP multilayer is used, the thickness (the range of the substrate 300 along the second transverse axis 750 or the vertical distance between the first surface 310 and the second surface 320) is typically about 150 μm in the portion without the electrode 200 or interconnects, 250 μm in the portion with the electrode 200, and 180 μm in the portion with the electrical interconnects 250. If a multilayer is used, an electrical interconnect layer of, for example, 25 μm can be used.

[0084] Figure 1B Depicting Figure 1A The image depicts a view of the implantable distal second surface 320 of the device 100. In other words, the second surface 320 is depicted in the plane of the page, positioned along the vertical axis 700 (from bottom to top) and along the first horizontal axis 720 (from left to right). The second horizontal axis 750 extends into the page. This is a view facing the animal or human tissue being stimulated (in use). The first surface 310 is not shown. Figure 1B It is depicted in the middle, but located at a higher position along the second horizontal axis 750 (enter the page), and is also substantially parallel to the plane of the accompanying drawing.

[0085] The substrate 300 extends between two ranges along the first transverse axis 720 (taking into account the width of the distal end of the stimulation device 100).

[0086] The distal end of the device 100 can be implanted by first creating a tunnel and / or using an implantation tool.

[0087] One or more loop electrodes 400 in Figure 1A and Figure 1C It was depicted in the text, but not in the text. Figure 1B It is depicted in the middle.

[0088] After the distal end of the device 100 is implanted, the energy source can be configured and arranged to provide electrical energy to the stimulation electrode 200 in use with respect to the electrical circuit applied to one or more loop electrodes 400.

[0089] The electrical energy source can, for example, be located near the stimulation device 100:

[0090] - An energy source (such as a pulse generator (not depicted, see below)) is directly connected to one or more energy sources of interconnect 250; and / or

[0091] - One or more energy receivers (not depicted, see below) (such as one or more conductors) are directly connected to one or more interconnects 250. One or more conductors (such as coils having one or more windings) are configured to wirelessly receive energy from an energy source such as a wireless pulse generator (not depicted, see below).

[0092] Figure 2A A suitable electrical energy source is schematically depicted. For controlled stimulation, the electrical energy source preferably comprises a first embodiment of a pulse energy controller 500, which is configured and arranged to provide stimulation energy as one or more electrical pulses through one or more electrodes 200. This changes the potential and / or current applied to one or more electrodes 200. The pulse energy controller 500 can be connected to one or more electrodes 200 via one or more interconnects 250.

[0093] One or more loop (or ground) electrodes 400 are typically provided, configured, and arranged to provide corresponding electrical loops for one or more stimulation electrodes 200 that receive stimulation energy from the pulse energy controller 500 during use. In other words, electrical loop 450 is a closed circuit.

[0094] Any suitable configuration and arrangement can be provided, such as that shown in Figure 1, which is contained within the first surface 310 near one or more stimulation electrodes 200. Alternatively, one or more loop (ground) electrodes 400 may be contained within the first surface 310. Alternatively, one or more loop (ground) electrodes may be provided near the pulse energy controller 500.

[0095] The pulse energy controller 500 may, for example, include a suitably configured and programmed processor to control one or more parameters of the stimulus energy pulse, such as intensity, duration, waveform shape, frequency, and repetition rate, using one or more software or firmware methods. Alternatively or additionally, a hardware-based solution, such as a state machine implemented in an ASIC (Application-Specific Integrated Circuit), may be used.

[0096] It can operate in standalone mode, or it can communicate periodically with an external controller, or some combination thereof.

[0097] For example, the therapeutic pulses provided to electrode 200 for stimulation can be 100 microseconds to 1 millisecond wide and repeated at 40 to 1000 Hz. For pain treatment using peripheral nerve stimulation (PNS), suitable pulse parameters could be: an average amplitude of 0-10 volts, particularly 0.5-4.0 volts, a current of 0-10 mA, a pulse width of 90-200 microseconds, and a repetition frequency of 50-400 Hz.

[0098] A suitable pulse energy controller 500 may also include:

[0099] - A power supply unit configured and arranged to provide stimulation energy suitable for tissue stimulation to one or more electrodes 200. The energy may be provided to the paired electrodes 200 as a differential potential and / or current. Additionally or alternatively, one or more of the electrodes 200 may be configured as loop (or ground) electrodes. Alternatively or alternatively, one or more loop electrodes 400 may be used as described above.

[0100] - Logic control, configured and arranged to control the delivery of stimulus energy to one or more electrodes 200, 400. For example, it may include one or more controllers connected to one or more clock generators.

[0101] - Optionally, one or more monitors are configured and arranged to monitor one or more parameters related to the operation of the pulse energy controller 500, such as one or more current, voltage, energy, power, charge, and dose.

[0102] In conventional devices, one or more capacitors are provided between the pulse energy controller 500 and one or more stimulation electrodes 200 to block a certain degree of continuous current (or unwanted DC component). One of the insights upon which this invention is based is that the blocking capacitors in the interconnects 250 of one or more electrodes 200 can be omitted and functionally replaced by one or more DC blocking capacitors 425 electrically connected in series with one or more loop electrodes 400. Since the number of loop electrodes 400 is typically much smaller than the number of stimulation electrodes 200, this results in an overall reduction in the number of required DC blocking capacitors 425. More advantageously, a single loop electrode 400 can be used in some configurations, thus allowing the use of a single DC blocking capacitor 425. The capacitors 425 should be appropriately sized and configured to handle the energy returned from the corresponding one or more stimulation electrodes 200.

[0103] Assumption:

[0104] - At typical stimulation frequencies (50-60 Hz), the tissue impedance is approximately 1 kΩ.

[0105] - The charge used for stimulation is approximately 2 μC (microcoulombs).

[0106] The supply voltage of device 100 is limited to no more than 13V DC.

[0107] - Murata PICS3HV technology for DC blocking capacitor 425, with a maximum density of 90 nF / mm².

[0108] The capacitor value is approximately:

[0109] -300nF, with a stimulation current of 4mA and an area of ​​5.3mm². 2 ,

[0110] -400nF, with a stimulation current of 7mA and an area of ​​6.8mm². 2 ,

[0111] -1uF, where the stimulation current is 10mA and the area is 16mm². 2 .

[0112] Therefore, reducing the number of required DC blocking capacitors may be advantageous when reducing the size of device 100. Most preferably, a design that eliminates the need for DC blocking capacitors provides a suitable candidate for further miniaturization. This reduction in critical components can also lower the cost of device 100.

[0113] Figure 2B A second embodiment 510 of a pulse energy controller is depicted, which is suitable for supplying electrical energy to the electrodes 200, 400 depicted in FIG1. ​​The second embodiment 510 and... Figure 2A The first embodiment 500 is identical as depicted. However, the second embodiment 510 is configured and arranged to operate without a DC blocking capacitor connected in series with the loop electrode 400.

[0114] The second embodiment 510 is also configured and arranged to provide at least partially charged balancing pulses, and in particular biphase charge balancing pulses. In the context of this disclosure, a charge balancing pulse should be understood as a pulse configured and arranged to provide charge balancing.

[0115] The basic principles are described in Merrilla, Bikson, and Jefferys' article "Electrical stimulation of excitable tissue: design of efficacious and safe protocols" in Journal of Neuroscience Methods 141(2005)171-198 (doi:10.1016 / j.jneumeth.2004.10.020). Figure 3 by Merrilla et al. depicts common pulse types and parameters, including biphasic charge balance.

[0116] This is publicly available. Figure 3A The basic parameters of this pulse are described:

[0117] The pulses 525 and 550 depicted represent the current supplied to the stimulation electrode 200 during a specific time period. It may be advantageous for the pulse energy controller 510 to be configured and arranged to directly control the current supplied to the stimulation electrode 200. However, any convenient type of control may be used, such as voltage, energy, power, charge, dose control, and any combination thereof.

[0118] - Currents i525 and i550 are indicated by the vertical range of the pulse. Durations t525 and t550 are indicated by the horizontal range of the pulse.

[0119] - Two pulses, 525 and 550, are separated by a time interval tINT.

[0120] At t0, the current i is essentially zero.

[0121] At t1, the current supplied to electrode 200 is driven as a negative current i525 for a duration of t525, also known as the cathode pulse 525. In this example, this is the leader pulse 525, which is configured and arranged as a stimulation pulse. During t525, a charge Q1 is injected to stimulate the tissue.

[0122] At t2, i.e., at t1+t525, the current i of the first cathode pulse 525 becomes essentially zero and remains essentially zero during the pulse interval (tINT). Increasing tINT may improve the effectiveness of the stimulation.

[0123] At t3, i.e., at t2+tINT, the current supplied to electrode 200 is driven as a positive current i550 for a duration of t550, also known as the anode pulse 550. In this example, this is the balancing or reversing pulse 550. Therefore, during t550, an opposite charge Q2 is injected, configured, and arranged to at least partially balance Q1. Most preferably, the device 100 is configured and arranged such that Q2 is substantially equal to Q1.

[0124] At t4, that is, at t3+t550, the current i of the first anode pulse 550 becomes substantially zero and remains substantially zero until the end of the depicted time period t1'.

[0125] At t1', the current is driven negative for the next cathode pulse. The period t4 to t1' can be used for neutralization by short-circuiting one or more stimulation electrodes 200 to one or more loop electrodes 400 after providing one or more pulses 525, 550. This is preferably performed before the start of the next pulse cycle.

[0126] For physiological reasons, the lead pulse 525 is typically cathode; however, those skilled in the art will recognize that the pulse energy controller 510 can be configured and arranged to provide an anode lead pulse.

[0127] therefore, Figure 3A The pulses in this context can be described as biphasic, cathode leader pulses used for electrode stimulation. For pain treatment using peripheral nerve stimulation (PNS), suitable pulse parameters could be:

[0128] The peak current i525 of the first cathode pulse is basically the same as the peak current i550 of the first anode pulse. It is approximately 4mA.

[0129] The duration of the first cathode pulse, t525, is essentially the same as the duration of the first anode pulse, t550. It is approximately 250 μs (microseconds).

[0130] - The time or interval tINT between the trailing edge of the first cathode pulse 525 and the leading edge of the anode pulse 550 is approximately 10-100 μs (microseconds).

[0131] - The time or repetition rate (tl to t1') between the leading edge of the first cathode pulse 525 and the leading edge of the subsequent cathode pulse is approximately 50-400 Hz.

[0132] As described by Merrilla et al., net charge injection is preferably substantially zero to reduce the risk of tissue damage and reduced therapeutic efficacy. Not wishing to be bound by theory, it is believed that this reduction may be related to one or more factors, such as degradation (corrosion) of one or more electrodes 200 and / or nerve fatigue. Generally, the device 100 should be configured and arranged such that the cathode charge Q1 (the peak current of the first cathode pulse 525 multiplied by its duration) is substantially equal to the anode charge Q2 (the peak current of the first anode pulse 550 multiplied by its duration).

[0133] i525×t525(Q1)=i550×t550(Q2).

[0134] The second embodiment 510 of the pulse energy controller should preferably provide a current source with high accuracy regarding the output currents i525, i550 and accurate pulse durations t525, t550. Generally, requiring higher accuracy increases cost. Furthermore, when implemented in ASIC technology, higher accuracy typically requires more components, which may mean requiring more square millimeters. Similarly, this may make miniaturization of the device 100 more difficult.

[0135] Additional problems may arise related to the reversal or balancing pulse (here, the anodic pulse). If the supplied charge Q2 is too high, the tissue near the stimulating electrode 200 may be stimulated to an undesirable degree. As discussed by Constandinou, Georgiou, and Toumazou in "A Partial-Current-Steering Biphasic Stimulation Driver for Vestibular Prostheses" published in IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS, Vol. 2, No. 2, June 2008 (doi:10.1109 / TBCAS.2008.92723), using an extended anodic pulse with reduced amplitude can compensate for the charge distribution and reduce the risk of diminished therapeutic efficacy.

[0136] This is publicly available. Figure 3B Another example of a biphase, cathode leader pulse is depicted. The first cathode pulse 525 and... Figure 3A The same applies. The second anode pulse 551 is... Figure 3A The first anode pulse 550 is a double form (its duration is essentially twice as long) with essentially the same charge. More specifically:

[0137] At t0, the current i is essentially zero.

[0138] At t1, the current supplied to electrode 200 is driven as a negative current i525 for a duration of t525, also known as the cathode leader pulse 525. During t525, charge Q1 is injected to stimulate the tissue.

[0139] At t2, i.e., at t1+t525, the current i of the first cathode pulse 525 becomes substantially zero and remains substantially zero during the pulse interval (tINT). This interval is... Figure 3A The same as in.

[0140] At t3, i.e., at t2+tlNT, the current supplied to electrode 200 is driven as a positive current i551 for a duration of t551, which is the second anode (balancing) pulse 551. Therefore, during t551, an opposite charge Q2 is injected, which is configured and arranged to at least partially balance Q1. Most preferably, Q2 is substantially equal to Q1 to provide a high degree of balance.

[0141] At t4, that is, at t3+t551, the current i of the second anode pulse 551 becomes substantially zero and remains substantially zero until the end of the depicted time period t1'.

[0142] At t1', the current is driven negative to initiate the subsequent cathode pulse. The time interval t4 to t1' can be used as follows: Figure 3A The aforementioned neutralization.

[0143] So in Figure 3B middle:

[0144] The peak current i525 of the first cathode pulse is approximately twice the peak current i551 of the second anode pulse (the ratio of average amplitude is 2:1).

[0145] The duration t551 of the second anode pulse is approximately twice the duration t525 of the first cathode pulse (the duration ratio is 1:2).

[0146] Generally, the device 100 should be configured and arranged such that the cathode charge Q1 (the peak current of the first cathode pulse 525 multiplied by its duration) is substantially equal to the anode charge Q2 (the peak current of the second anode pulse 551 multiplied by its duration).

[0147] i525×t525(Q1)=i551×t551(Q2).

[0148] For pain treatment using peripheral nerve stimulation (PNS), appropriate pulse parameters could be:

[0149] The peak current i525 of the first cathode pulse is approximately 4 mA, and the peak current i551 of the second anode pulse is approximately 2 mA.

[0150] The duration of the first cathode pulse, t525, is approximately 250 μs (microseconds), and the duration of the second anode pulse, t551, is approximately 500 μs.

[0151] The time or interval tINT between the trailing edge of the first cathode pulse 525 and the leading edge of the second anode pulse 551 is approximately 10-100 μs (microseconds).

[0152] - The time or repetition rate (tl to t1') between the leading edge of the first cathode pulse 525 and the leading edge of the subsequent cathode pulse is approximately 50-400 Hz.

[0153] Other values ​​of the second anode pulse 551 can be used, predetermined, and / or controlled such that the charge Q2 (i551 × t551) is substantially the same. For example:

[0154] -i551 is approximately 1 mA, and t551 is approximately 1000 μs.

[0155] -i551 is approximately 0.5mA, and t551 is approximately 2000μs.

[0156] Figure 3B The stimulation control described herein can be implemented using two power supplies—one configured to provide a first cathode pulse 525 and the other configured and arranged to provide a second anode pulse 551. To achieve an acceptable level of charge neutralization or charge balance, the currents i525, i551 and the durations t525, t551 should be predetermined and / or controlled as accurately as possible. Typically, a programmable power supply is used.

[0157] In applications where the cathode and anode pulses tend to be substantially the same for all treatments, additional calibration steps can be included during manufacturing to provide high accuracy regarding current i525, i551 and duration t525, t551. These calibration steps can be repeated periodically to compensate for any drift. However, such calibration steps are not always accurate for implantable devices because they may be performed in environments such as a factory, which are very different from the environments in which they are used. This is a particular issue for implantable devices. Additionally, implantable devices are designed to operate for months or even years, during which time components may age, further reducing the accuracy of current i525, i551 and duration t525, t551. The environments in which they are used may not be constant, and other factors, such as the characteristics of the power source, may also need to be compensated for. Typically, the power supply used includes additional components to perform in-situ calibration and / or additional components to monitor the actual current and duration of the pulses. Additionally or alternatively, anode and / or cathode charges may be monitored. As mentioned, any additional components increase the size and cost of the electronics.

[0158] In other applications, the cathode and anode pulses are designed to vary for different treatments or at different stages of the same treatment. To provide a higher degree of accuracy, additional components may be required in each power supply and / or each pulse generator to achieve this level of flexibility.

[0159] Regardless of the cause, inaccuracies in pulse amplitude and duration can result in a lower degree of charge neutralization or charge balance. Conventional methods of improving this require additional components and / or additional manufacturing and / or maintenance steps. Additional manufacturing steps can further increase costs. Additional maintenance steps can further increase operating costs or be inconvenient for users of such devices, potentially requiring them to consult a healthcare professional. In some cases, replacement of the implantable device may even be necessary.

[0160] Figure 4A Another example of a biphase, cathode leader pulse is depicted. The second cathode pulse 526 and the third cathode pulse 527 are provided substantially simultaneously, providing... Figure 3B The first cathode pulse 525 has a cathode charge Q1 that is essentially the same. Figure 4A The anode pulses 526* and 527* in the middle have the same characteristics as... Figure 3B The first anode pulse 551 has essentially the same charge Q2. More specifically:

[0161] At t0, the current i is essentially zero.

[0162] At t1, the current supplied to one or more electrodes 200 is driven as a negative current i526 by a second cathode pulse 526 for a duration t526. Essentially simultaneously, the current supplied to the electrodes 200 is further driven as a negative current i527 by a third cathode pulse 527 for a duration t527. Providing the second cathode pulse 526 and the third cathode pulse 527 simultaneously or for the same duration (this is how they are described—approximately simultaneously) may be convenient, but not necessary. Simultaneity means that they highly overlap in time, such that the total average amplitude of the provided cathode pulses is determined by combining the individual currents i526, i527. In this example, the two pulses 526, 527 have the same polarity (cathode), so the total average amplitude is approximately the sum of the individual currents i526, i527. During t526, t527, a cathode charge Q1 is injected to stimulate the tissue.

[0163] At t2, which in this example is t1+t526, t527, the current i of the second cathode pulse 526 and the third cathode pulse 527 becomes essentially zero, and remains essentially zero during the pulse interval, i.e., during tINT. This interval is... Figure 3B The same as in.

[0164] At t3, i.e., at t2+tINT, the current supplied to one or more electrodes 200 is driven as a positive current i526* for duration t526, and further driven as a positive current i527* for duration t527—the anode (equilibrium) pulse comprises pulses 526* and 527*. The anode pulse comprises two sub-pulses 526* and 527*, which have durations t526 and t527 substantially the same as the second cathode pulse 526 and the third cathode pulse 527. The average amplitude of the two sub-pulses i526* and i527* is substantially the same as that of the second cathode pulse i526 and the third cathode pulse i527, except that they provide opposite polarities.

[0165] Providing the anode pulses 526* and 527* individually or immediately after each other (this is how they are described—roughly consecutively) may be convenient, but it is not necessary. Providing them individually means that they do not highly overlap in time, such that the average amplitude of the provided anode pulse is determined by the individual currents i526*, i527*. In this example, the two pulses 526*, 527* are consecutive, so the total duration of the anode pulse is approximately the sum of the individual durations t526, t527.

[0166] Therefore, during the period from t3 to t4 (described here as t526, then t527), an opposite charge Q2 is injected, which is configured and arranged to at least partially balance Q1. Most preferably, Q2 is substantially equal to Q1 to provide a high degree of balance.

[0167] At t4, that is, at t3+t526+t527, the current i of the anode pulses 526* and 527* becomes essentially zero and remains essentially zero until the end of the depicted time period t1'.

[0168] At t1', the current is driven negative to initiate the subsequent cathode pulse. The time interval t4 to t1' can be used as follows: Figure 3A The aforementioned neutralization.

[0169] Therefore, as Figure 4A Described:

[0170] The peak current of the cathode pulse is essentially the same as the peak current of the second cathode pulse 526 i526 added to the peak current i527 of the third cathode pulse 527. It is essentially twice the peak current of the anode sub-pulses 526*, 527* (the ratio of the average amplitude of the cathode to anode pulses is 2:1).

[0171] The durations t526 and t527 of the anode sub-pulses are substantially the same as the durations t526 and t527 of the cathode sub-pulses. As depicted, anode sub-pulses 526* and 527* are provided immediately after each other, so the total duration t526+t527 is approximately twice the duration of the combined cathode pulses t526 and t527.

[0172] - Generally speaking, the device 100 should be configured and arranged such that the cathode charge Q1 (peak cathode current multiplied by cathode duration) is substantially equal to the anode charge Q2 (peak anode current multiplied by anode duration).

[0173] If cathode sub-pulses 526 and 527 are provided essentially simultaneously, then:

[0174] Ql = [i526 + i527] × [t526 or t527].

[0175] If the anode pulse is provided substantially continuously and the average amplitudes of the sub-pulses i526* and i527* are approximately the same, then

[0176] Q2 = [i526 or i527] × [t526 + t527].

[0177] However, one of the insights upon which this invention is based is that it is possible to more simply control charge neutralization by considering subpulses as components (or building blocks) of charge, each subpulse having a predetermined and / or controlled average amplitude and a duration provided by a separate power supply. By applying only subpulses of opposite polarity, the applied charge remains approximately balanced.

[0178] So in Figure 4A In the example, the charge provided by the cathode pulse is:

[0179] Q1 = Sub-pulse [i526×t526] + Sub-pulse [i527×t527]

[0180] And the charge provided by the cathode pulse is:

[0181] Q2 = sub-pulse [i526*×t526] + sub-pulse [i527*×t527].

[0182] By providing the same sub-pulses with opposite polarities during both the cathode and anode pulses, the accuracy required to control the average amplitude, duration, and timing is reduced. In this configuration, the most critical factor affecting the degree of charge neutralization is the stability (or repeatability) between the use of each sub-pulse of the cathode and anode pulses. Because this interval is short, a simpler power supply section can be used with fewer components. This can potentially mean reduced cost and a smaller footprint.

[0183] Alternatively, as described below, the degree of time separation between cathode sub-pulses 526 and 527 can be used to generate more complex cathode waveforms.

[0184] Additionally or alternatively, the degree of time overlap between the anode sub-pulses 526* and 527* can be used to generate more complex waveforms.

[0185] Figure 4A The stimulus control described in the text can be implemented in the following ways:

[0186] - A first energy / power supply unit, configured and arranged to provide cathode polarity for sub-pulse 526, and / or to provide anode polarity for sub-pulse 526*, and

[0187] - A second energy / power supply unit, which is configured and arranged to provide cathode polarity for sub-pulse 527 and / or provide anode polarity for sub-pulse 527*.

[0188] The device 100, and in particular the pulse energy controller 510, can be configured and arranged such that:

[0189] - The first supply unit can provide a specific peak current i526, i526* to the sub-pulse 526 for a specific duration t526; and

[0190] - The second supply unit can provide a specific peak current i527, i527* for sub-pulse 527 for a specific duration t527.

[0191] By connecting the first supply unit and the second supply unit substantially simultaneously to one or more electrodes 200, a leading cathode pulse is provided at t1.

[0192] If the peak currents i526 and i527 have the same polarity, then the combined peak current is approximately the sum of the constituent currents i526 + i527 (e.g., Figure 4A (As shown). If the peak currents i526 and i527 have opposite polarities, the combined peak current is the difference between the constituent currents i526 and i527.

[0193] By switching the polarity i526* and connecting the first supply unit to one or more electrodes 200, and then switching the polarity i527* and connecting the second supply unit to one or more electrodes 200, a balancing pulse is provided at t3. If pulses 526* and 527* are applied substantially continuously, the combined duration is the sum of durations t526 and t527 (e.g., Figure 4A (As shown). If pulses 526* and 527* are applied with temporal overlap (at least partially continuous) and the same polarity, the combined peak current is the sum of the pulse peak currents i526* and i527* during the time period of pulse overlap.

[0194] The energy output of each supply unit can be kept substantially constant—the only difference in use is the polarity applied to one or more electrodes 200. Since the cathode and anode pulses use the same supply unit, the anode and cathode charges are substantially equal. By applying the cathode pulses substantially simultaneously and the anode pulses substantially continuously, the average amplitude of the anode pulse can be approximately half the average amplitude of the cathode pulse, thus reducing the possibility of diminished therapeutic effect.

[0195] Despite Figure 4AThe diagram depicts sub-pulses with identical average amplitudes i526, i527 and durations t526, t527, but this is not mandatory. Different average amplitudes i526, i527 and different durations t526, t527 can be used, as long as the total charge applied by each power supply during the cathode pulse is substantially the same as the total charge applied during the anode pulse, achieving a high degree of charge neutralization. Those skilled in the art will also recognize that the pulses are schematically depicted as square waves to explain the principles of the invention—the waveforms actually used may be more complex and less ideal. However, those skilled in the art will be able to determine the charge supplied during each sub-pulse through calculation, simulation, and / or measurement.

[0196] The programmable power supply unit can provide additional flexibility in pre-determining and / or controlling the average amplitude and / or pulse duration.

[0197] Figure 4B Another example of a biphase, cathode leader pulse is depicted. It is similar in principle to... Figure 4A The difference is that it uses four sub-pulses and four power supplies instead of two sub-pulses and two power supplies.

[0198] Essentially, the fourth cathode pulse 528, the fifth cathode pulse 529, the sixth cathode pulse 530, and the seventh cathode pulse 531 are provided simultaneously, thereby providing the cathode charge Q1. More specifically:

[0199] At t0, the current i is essentially zero.

[0200] At t1, the current supplied to electrode 200 is driven negative by substantially simultaneous sub-pulses. In this example, they have the same polarity, so the total average amplitude of the cathode pulses is approximately the sum of the average amplitudes of the cathode sub-pulses:

[0201] - Drive current i528 with fourth cathode pulse 528, duration t528;

[0202] - Drive current i529 with the fifth cathode pulse 529, duration t529;

[0203] - Driven by the sixth cathode pulse 530, current i530, duration t530; and

[0204] - Driven by the seventh cathode pulse 531, current i531, duration t531.

[0205] The cathodic charge Ql injected to stimulate the tissue is:

[0206] [i529×t529]+[i530×t530]+[i531×t531]+[i528×t528].

[0207] like Figure 4A As shown, the cathode sub-pulses are depicted as being provided approximately simultaneously, but this is not required. At t2, which in this example is t1+t528, t529, t530, t531, the current i of the cathode sub-pulse becomes essentially zero and remains essentially zero during the pulse interval (which is tING). This interval is related to... Figure 4A The same as in.

[0208] At t3, i.e., at t2+tINT, the current supplied to one or more electrodes 200 is driven positive by independent sub-pulses. In this example, they have the same polarity and are supplied immediately after each other (e.g., ...). Figure 4A As shown (this is not necessary), the total duration of the anode pulse is approximately the sum of the individual durations:

[0209] - Current i528*, duration t528, as anode sub-pulse 528*;

[0210] - Current i529*, duration segment t529, as anode sub-pulse 529*;

[0211] - Current i530*, duration t530, as anode sub-pulse 530*; and

[0212] - Current i531*, duration segment t531, as anode sub-pulse 531*.

[0213] An opposite charge Q2 is injected, which is configured and arranged to at least partially balance Q1. Most preferably, Q2 is substantially equal to Q1 to provide a high degree of balance. As depicted, Q2 is:

[0214] [i528*×t528]+[i529*×t529]+[i530*×t530]+[i531*×t531].

[0215] At t4, or in this example at t3+t538+t529+t530+t531, the current i of the anode pulse becomes essentially zero and remains essentially zero until the end of the depicted period t1'.

[0216] At t1', the current is driven negative to initiate the subsequent cathode pulse. The time interval t4 to t1' can be used as follows: Figure 3A The aforementioned neutralization.

[0217] Figure 4B The stimulus control described in the text can be achieved in the following ways:

[0218] - A first energy / power supply unit, which is configured and arranged to provide cathode polarity for sub-pulse 528, and / or to provide anode polarity for sub-pulse 528*;

[0219] - A second energy / power supply unit, which is configured and arranged to provide cathode polarity for sub-pulse 529, and / or to provide anode polarity for sub-pulse 529*;

[0220] - A third energy / power supply unit, configured and arranged to provide cathode polarity for sub-pulse 530*, and / or to provide anode polarity for sub-pulse 530*, and

[0221] - A fourth energy / power supply unit, which is configured and arranged to provide cathode polarity for sub-pulse 531 and / or provide anode polarity for sub-pulse 531*.

[0222] The device 100, and in particular the pulse energy controller 510, can be configured and arranged such that:

[0223] - The first supply unit can provide a specific peak current i528, i528* to the sub-pulse 528 for a specific duration t528;

[0224] - The second supply unit can provide a specific peak current i529, i529* to the sub-pulse 529 for a specific duration t529;

[0225] - The third supply unit can provide a specific peak current i530, i530* to the sub-pulse 530 for a specific duration t530; and

[0226] - The fourth supply unit can provide a specific peak current i531, i531* to the sub-pulse 531 for a specific duration t531.

[0227] By connecting the first, second, third, and fourth supply sections substantially simultaneously to one or more electrodes 200, a leading cathode pulse is provided at t1. If the peak currents i528, i529, i530, and i531 have the same polarity, the combined peak current is approximately the sum of the constituent currents i528 + i529 + i530 + i531 (e.g., ...). Figure 4B (As shown). If the peak currents i528, i529, i530, and i531 have opposite polarities, then the combined peak current is the difference between the constituent currents i528 and i531.

[0228] By switching polarity i528* and connecting the first supply unit to one or more electrodes 200, then switching polarity i529* and connecting the second supply unit to one or more electrodes 200, then switching polarity i530* and connecting the third supply unit to one or more electrodes 200, and then switching polarity i531* and connecting the fourth supply unit to one or more electrodes 200, a balancing pulse is provided at t3. If pulses 528*, 529*, 530*, and 531* are applied substantially continuously, the combined duration is the sum of durations t528 + t529 + t530 + t531 (e.g., ...). Figure 4B (As depicted). If pulses 528*, 529*, 530*, and 531* are applied with temporal overlap (at least partially continuous) and the same polarity, the combined peak current is the sum of the pulse peak currents i528*+i529*+i530*+i531* during the time period of pulse overlap.

[0229] By applying the cathode pulses substantially simultaneously and the anode pulses substantially continuously, the average amplitude of the anode pulses can be approximately one-quarter of the average amplitude of the cathode pulses, further reducing the likelihood of reduced therapeutic efficacy.

[0230] The energy / power supply unit can be, for example, a current source. Each current source can be programmed; for example, the nominal output current can be set using 6-bit instructions, with a step size of 40µA, and each supply unit can provide up to 2.5mA of current. The charge to be supplied by each power supply unit can be predetermined and / or controlled. During operation, the nominal output current remains substantially constant, applied for a fixed duration during the cathode pulse and for the same duration with the opposite polarity during the anode pulse.

[0231] For example, by using cascaded Nfet switches, the current source can preferably be configured to have a large output impedance. A large output impedance can provide a higher degree of source stability during stimulation and balancing pulses.

[0232] Figure 8 Another example of a biphase, cathode leader pulse is depicted. It is similar in principle to... Figure 4B The example differs in that the nominal average amplitudes of the four power supplies are different, allowing for the provision of complex waveforms.

[0233] Essentially, the eighth cathode pulse 532, the ninth cathode pulse 533, the tenth cathode pulse 534, and the eleventh cathode pulse 535 are provided simultaneously, thereby providing the cathode charge Q1. More specifically:

[0234] At t0, the current i is essentially zero.

[0235] At t1, the current supplied to electrode 200 is driven negative by substantially simultaneous sub-pulses. In this example, they have the same polarity, so the total average amplitude of the cathode pulses is approximately the sum of the average amplitudes of the cathode sub-pulses:

[0236] - Current i535, duration t535;

[0237] - Current i534, duration t534, where current i534 is approximately twice the current i535 (=2x i535);

[0238] - Current i533, duration t533, where current i533 is approximately twice the current i534 (=4 x i535); and

[0239] - Current i532, duration t532, where current i532 is approximately twice the current i533 (=8x i535);

[0240] The cathodic charge Ql injected to stimulate the tissue is:

[0241] [i532×t532]+[i533×t533]+[i534×t534]+[i535×t535].

[0242] like Figure 4B As shown, the cathode sub-pulses are depicted as being provided approximately simultaneously, but this is not required.

[0243] At t2, which in this example is t1+t532, t533, t534, t535, the current i of the cathode sub-pulse becomes essentially zero and remains essentially zero during the pulse interval (which is tING). This interval is... Figure 4B The same as in.

[0244] At t3, i.e., at t2+tINT, the current supplied to one or more electrodes 200 is driven positive by independent sub-pulses. In this example, they have the same polarity and are supplied immediately after each other (e.g., ...). Figure 4B As shown (this is not necessary), the total duration of the anode pulse is approximately the sum of the individual durations:

[0245] - Current i535*, duration t535, as anode sub-pulse 535*;

[0246] - Current i534*, duration segment t534, as anode sub-pulse 534*;

[0247] - Current i533*, duration t533, as anode sub-pulse 533*; and

[0248] - Current i532*, duration t532, as anode sub-pulse 532*.

[0249] In this case, the order of the anode sub-pulses is selected to provide a stable increase in average amplitude from i535* to i532*.

[0250] An opposite charge Q2 is injected, which is configured and arranged to at least partially balance Q1. Most preferably, Q2 is substantially equal to Q1 to provide a high degree of balance. As depicted, Q2 is:

[0251] [i535*×t535]+[i534*×t534]+[i533*×t533]+[i532*×t532].

[0252] At t4, or in this example at t3+t535+t534+t533+t532, the current i of the eighth anode pulse 557 becomes essentially zero and remains essentially zero until the end of the depicted period t1'.

[0253] At t1', the current is driven negative to initiate the subsequent cathode pulse. The time interval t4 to t1' can be used as follows: Figure 3A The aforementioned neutralization.

[0254] So in Figure 8 middle:

[0255] The peak current of the cathode pulse is basically the same as the peak current of the cathode sub-pulse, which is approximately 15 × i535.

[0256] It is approximately fifteen times the peak current of the first part of the anode pulse (535*) and approximately twice the peak current of the last part of the anode pulse (532*).

[0257] Those skilled in the art will recognize that the second embodiment 510 of the pulse energy controller can be optionally modified to operate with one or more DC blocking capacitors, which are electrically connected in series with one or more loop electrodes 400.

[0258] Additionally, the pulse energy controllers 500 and 510 can also be configured and arranged to receive parameters and / or instructions from the user interface. Alternatively or additionally, the user interface may be included in a mobile device, such as a mobile phone.

[0259] One or more parameters and / or instructions may be predetermined and / or control one or more corresponding characteristics of one or more electrical stimulation pulses. For example: average pulse amplitude, pulse width, period, duty cycle, number of pulses to be provided, number of pulses to be repeated, pulse duration, start time, end time, voltage, current, energy, charge, dose, or any combination thereof.

[0260] Most examples and embodiments in this disclosure describe biphasic operation, where a stimulating charge is provided, followed by a balancing charge. A first pulse for stimulation is described as a cathode pulse, followed by a second anodic pulse. Alternatives include:

[0261] - The first pulse can be anode-based, and the second pulse (balancing pulse) can be cathode-based;

[0262] - The first and second pulses can have the same polarity; and

[0263] - The duration and average magnitude may vary for each supply unit.

[0264] Figure 9 An alternative approach is described, in which the balancing pulse can be divided into two pulse portions—one pulse portion 590 can be provided before the stimulation pulse 580, and the other pulse portion 595 can be provided afterward. In other words, a predetermined and / or controlled time interval is provided between the two balancing pulse portions 590, 595; and the stimulation pulse 580 is provided during this time interval. This can also be described as three-phase. The pulse portions 590, 595 can be substantially the same or different—however, for a high charge balance, the total charge of the balancing pulses 590, 595 is substantially the same as the charge of the stimulation pulse 580.

[0265] This can be advantageous because it reduces any residual charge that accumulates over multiple cycles. For example, tissue impedance has a Faraday component that can lead to “leakage”—which can be a significant cause of residual charge when the delay between stimulation pulses is long (e.g., much greater than 100 microseconds). In applications where action potential is measured after a biphasic pulse cycle, removing any residual charge can be beneficial.

[0266] Technicians will also recognize that the stimulation pulse can be divided into two pulse portions (not depicted) – one pulse portion can be provided before the balancing pulse, and the other pulse portion afterward. In other words, a predetermined and / or controlled time interval is provided between the two stimulation pulse portions; and the balancing pulse is provided during this time interval. This can also be described as three-phase. The stimulation pulse portions can be substantially the same or different – ​​however, for a high degree of charge balance, the total charge of the stimulation pulses is substantially the same as the charge of the balancing pulse.

[0267] Typically, device 100 can be considered to have three main design constraints:

[0268] - The distal end can be substantially configured and positioned to be implanted near the tissue to be stimulated;

[0269] - The near end can be substantially configured and arranged to provide suitable electrical power; and

[0270] - One or more electrical connections between the proximal and distal ends of the device 100.

[0271] Depending on the type of stimulation and the implantation site in the human or animal body, the device 100 can be optimized to meet one of the design constraints, or may be manufactured based on two or more design constraints. For example, when stimulating nerves in the forehead, a longer substrate 300 (longer leads) can be used, allowing the proximal end to be positioned close to the ear or the back of the head. Those skilled in the art will also recognize that one or more stimulation electrodes 200 can be provided close to the pulse energy controllers 500, 510.

[0272] Figure 5 and Figure 6 An example is depicted of a nerve that can be stimulated using a device 100 with a suitable configuration that can be implanted distally. It can provide nerve stimulation to treat, for example, headaches or primary headaches.

[0273] Figure 5 The left supraorbital nerve 910 and right supraorbital nerve 920 are depicted as being electrically stimulated using a device with appropriate configuration. Figure 6 The left greater occipital nerve 930 and right greater occipital nerve 940 can also be electrically stimulated using a device 100 with appropriate configuration.

[0274] Based on the size of the area to be stimulated and the dimensions of the portion of the device to be implanted, an appropriate location is determined to provide the electrical stimulation required for treatment. The approximate implantation location of the distal portion of the stimulation device, including the stimulation device 100, is depicted as the area:

[0275] - Position 810 for left supraorbital stimulation and position 820 for right supraorbital stimulation for the treatment of chronic headaches (such as migraines and cluster headaches).

[0276] - Positions 830 for left occipital stimulation and 840 for right occipital stimulation for the treatment of chronic headaches (such as migraines, cluster headaches, and occipital neuralgia).

[0277] In many cases, these will be the approximate locations 810, 820, 830, and 840 of the implantable portions of devices 100 and 150.

[0278] A separate stimulation system can be used for each implantation site 810, 820, 830, 840. When implantation sites 810, 820, 830, 840 are close together or even overlap, a single stimulation system can be configured to stimulate at more than one implantation site 810, 820, 830, 840.

[0279] Multiple stimulation devices 100 can operate individually, simultaneously, sequentially, or in any combination thereof to provide the desired treatment.

[0280] Figure 7 Further examples are depicted of nerves that can be stimulated using a suitably configured stimulation device 100 to provide nerve stimulation for the treatment of other conditions. Figure 5 and Figure 6 The positions depicted in the middle (810, 820, 830, 840) are also depicted in Figure 7 middle.

[0281] Based on the size of the area to be stimulated and the dimensions of the part of the device to be implanted, a suitable location is determined to provide the electrical stimulation required for treatment. The approximate implantation location of the part of the stimulation device, including the stimulating electrodes, is depicted as the area:

[0282] - Position 810, which is used for cortical stimulation in the treatment of epilepsy;

[0283] - Position 850, used for deep brain stimulation for tremor control in Parkinson's disease patients; treatment of dystonia, obesity, essential tremor, depression, epilepsy, obsessive-compulsive disorder, Alzheimer's disease, anxiety disorder, bulimia, tinnitus, traumatic brain injury, Tourette syndrome, sleep disorders, autism, bipolar disorder, and stroke recovery.

[0284] - Position 860, which is used to treat epilepsy, depression, anxiety, bulimia, obesity, tinnitus, obsessive-compulsive disorder and heart failure through vagus nerve stimulation;

[0285] - Position 860, which is used to treat hypertension by stimulating the carotid artery or carotid sinus;

[0286] - Position 860, which is used to treat sleep apnea by stimulating the hypoglossal and phrenic nerves;

[0287] - Position 865, which is used for the treatment of chronic neck pain through brain and spinal cord stimulation;

[0288] - Position 870, which is used for peripheral nerve stimulation to treat limb pain, migraine, and limb pain;

[0289] - Position 875, which is used to treat chronic lower back pain, angina pectoris, asthma, and general pain by spinal cord stimulation;

[0290] - Position 880, which is used to treat obesity, bulimia, and gastric irritation caused by interstitial cystitis;

[0291] - Position 885, which is used for sacral and pudendal nerve stimulation to treat interstitial cystitis;

[0292] - Position 885, which is used to treat sacral nerve stimulation for urinary incontinence and fecal incontinence;

[0293] - Position 890, which is used for sacral nerve modulation in bladder control therapy; and

[0294] - Position 895, which is used for peroneal nerve stimulation to treat gait or foot drop.

[0295] Other treatable conditions include gastroesophageal reflux disease and inflammatory diseases.

[0296] The description herein should not be construed as prescribing a fixed order in which the method steps described herein shall be performed. Rather, the method steps may be performed in any feasible order. Similarly, the examples are used to explain algorithms and are not intended to represent the only implementations of these algorithms; those skilled in the art will be able to conceive of many different ways to achieve the same functionality provided by the embodiments described herein.

[0297] It will be apparent to those skilled in the art that this method can be implemented on any type of standalone device, distributed system, client-server compatible system, or any combination thereof, including any type of client, network, server, processor, memory, and / or database element.

[0298] Specifically, the stimulation device can function as two or more separate hardware components connected via suitable wired and / or wireless connections. Such hardware components can be configured and arranged for implantation and / or external placement.

[0299] Typically, embodiments of the apparatus described in this disclosure can be configured and arranged to stimulate one or more nerves, one or more muscles, one or more organs, spinal cord tissue, and any combination thereof.

[0300] Typically, for any configuration described and depicted in this disclosure, any electrode 200, 400 can be connected as either a stimulating electrode 200 or a loop electrode 400. This may be advantageous if it is uncertain whether the implantable distal end is above or below the target tissue (e.g., above or below a nerve).

[0301] Although the invention has been described in conjunction with specific exemplary embodiments, it should be understood that various changes, substitutions and alterations can be made to the disclosed embodiments without departing from the spirit and scope of the invention as set forth in the appended claims.

[0302] For example, a suitable device for operation according to the method described herein is a tissue stimulation device comprising: one or more stimulation electrodes configured to transmit energy in one or more stimulation pulses to human or animal tissue during use; a pulse energy controller configured and arranged to transmit electrical energy in one or more electrical stimulation pulses to one or more stimulation electrodes during use; wherein the pulse energy controller further comprises two or more stimulation energy supply units configured and arranged to supply electrical energy from the two or more stimulation energy supply units substantially simultaneously to one or more stimulation electrodes as a first pulse; and to supply electrical energy from the two or more stimulation energy supply units to one or more stimulation electrodes respectively as a second pulse.

[0303] Reference figures used in the attached figures:

[0304] 100 Stimulation Device

[0305] 200 One or more stimulation electrodes

[0306] 250 One or more electrical interconnects

[0307] 300 elongated substrate

[0308] 310 First, essentially flat transverse surface

[0309] 320 Second, essentially flat transverse surface

[0310] 400 One or more loop electrodes

[0311] 425 One or more DC blocking capacitors

[0312] First embodiment of a 500-pulse energy controller

[0313] Second embodiment of the 510 pulse energy controller

[0314] 525 First Cathode Pulse

[0315] i525 First cathode pulse peak current

[0316] Duration of the first cathode pulse of T525

[0317] 526 Second cathode pulse

[0318] i526 Peak current of the second cathode pulse

[0319] Duration of the second cathode pulse of t526

[0320] 527 Third Cathode Pulse

[0321] i527 Third cathode pulse peak current

[0322] Duration of the third cathode pulse in T527

[0323] 528 Fourth Cathode Pulse

[0324] Peak current of the fourth cathode pulse of i528

[0325] Duration of the fourth cathode pulse (t528)

[0326] 529 Fifth Cathode Pulse

[0327] Peak current of the fifth cathode pulse of i529

[0328] Duration of the fifth cathode pulse (t529)

[0329] 530 Sixth Cathode Pulse

[0330] Peak current of the sixth cathode pulse of i530

[0331] Duration of the sixth cathode pulse of T530

[0332] 531 Seventh Cathode Pulse

[0333] Peak current of the seventh cathode pulse of i531

[0334] Duration of the seventh cathode pulse (t531)

[0335] 550 First Anode Pulse

[0336] i550 First Anode Pulse Peak Current

[0337] Duration of the first anode pulse of T550

[0338] 551 Second Anode Pulse

[0339] i551 second anode pulse peak current

[0340] Duration of the second anode pulse of t551

[0341] 580 stimulation pulses

[0342] 590 First Pulse Section – Balanced Pulse

[0343] 595 Second Pulse Section – Balanced Pulse

[0344] tINT (inter-pulse interval)

[0345] 700 vertical axis

[0346] 720 First horizontal axis

[0347] 750 Second horizontal axis

[0348] 810 is the location used for stimulation of the left supraorbital nerve or cortex.

[0349] 820 is the location used for right supraorbital stimulation.

[0350] 830 is the location used for left occipital nerve stimulation.

[0351] 840 Location for right occipital nerve stimulation

[0352] 850 Locations for Deep Brain Stimulation

[0353] 860 is the location for stimulating the vagus nerve, carotid artery, carotid sinus, phrenic nerve, or hypoglossal nerve.

[0354] 865 is the location used for brain and spinal cord stimulation.

[0355] 870 is the location used for peripheral nerve stimulation.

[0356] 875 Location for spinal cord stimulation

[0357] 880 is the location for stomach stimulation.

[0358] 885 is the location used for sacral and pudendal nerve stimulation.

[0359] 890 Location for sacral nerve modulation

[0360] 895 Location for peroneal nerve stimulation

[0361] 910 Left supraorbital nerve

[0362] 920 Right supraorbital nerve

[0363] 930 Left occipital nerve

[0364] 940. Right occipital nerve.

Claims

1. A method for controlling electrical energy supplied by a stimulation device (100) to one or more stimulation electrodes (200) included in the device (100), the device (100) comprising: The first stimulating electrode (200) is configured to transmit energy as one or more stimulating pulses during use; A pulse energy controller (500, 510) is configured and arranged to deliver electrical energy as one or more electrical stimulation pulses to the first stimulation electrode (200) during use. The pulse energy controller (500, 510) also includes two or more stimulation energy supply units; The method includes: Electrical energy is supplied substantially simultaneously from each of the two or more stimulation energy supply units to the first stimulation electrode (200) as a first pulse (526, 527, 528, 529, 530, 531); and Electrical energy is supplied individually to the first stimulation electrode (200) from each of the two or more stimulation energy supply units as a second pulse (526*, 527*, 528*, 529*, 530*, 531*).

2. The method according to claim 1, wherein, The method includes: Each of the two or more energy supply units is configured and arranged to provide pulses as anode energy pulses and / or cathode energy pulses.

3. The method according to claim 1 or 2, wherein, The method includes: Each of the two or more energy supply units is configured and arranged to provide electrical energy in the following manner: substantially simultaneous, at least partially simultaneous, substantially continuous, at least partially continuous, having a predetermined and / or controlled time interval between pulses, or any combination of these terms.

4. The method according to claim 1 or 2, wherein, The method includes: The two or more energy supply units are configured and arranged to provide the first pulse (526, 527, 528, 529, 530, 531) and the second pulse (526*, 527*, 528*, 529*, 530*, 531*), wherein the average amplitude ratio of the first pulse and the second pulse is less than or equal to 1:

2.

5. The method according to claim 1 or 2, wherein, The method includes: Each of the two or more energy supply units is configured and arranged to provide energy pulses of substantially opposite polarity, such that the net charge transferred is substantially zero.

6. A stimulation device (100), comprising: The slender implantable distal device includes a flexible substrate (300) having multiple polymer layers and one or more interconnect layers (250), the substrate (300) further including a first stimulating electrode (200) configured to deliver energy as one or more stimulating pulses to human or animal tissue in use. The stimulation device (100) further includes: One or more loop electrodes (400) are located adjacent to the first stimulating electrode (200) and configured to provide a corresponding electrical circuit to the first stimulating electrode (200) in use; and The proximal end includes a pulse energy controller (500, 510) configured and arranged to deliver electrical energy as one or more electrical stimulation pulses to the first stimulation electrode (200) via the one or more interconnect layers (250) during use. in: The pulse energy controller (500, 510) further includes two or more stimulation energy supply units, which are configured and arranged as follows: Electrical energy is supplied substantially simultaneously from each of the two or more stimulation energy supply units to the first stimulation electrode (200) as a first pulse (526, 527, 528, 529, 530, 531); and Electrical energy is supplied to the first stimulation electrode (200) from each of the two or more stimulation energy supply units as a second pulse (526*, 527*, 528*, 529*, 530*, 531*).

7. The stimulation device according to claim 6, wherein, The first pulse (526, 527, 528, 529, 530, 531) and the second pulse (526*, 527*, 528*, 529*, 530*, 531*) have substantially different polarities.

8. The stimulation device according to claim 6 or 7, wherein, Each of the two or more stimulation energy supply units is configured and arranged to supply electrical energy substantially simultaneously as the first pulse (526, 527, 528, 529, 530, 531).

9. The stimulation device according to claim 6 or 7, wherein, Each of the two or more stimulation energy supply units is configured and arranged to supply electrical energy substantially continuously as the second pulse (526*, 527*, 528*, 529*, 530*, 531*).

10. The stimulation device according to claim 6 or 7, wherein, The two or more energy supply units are configured and arranged to provide the first pulse (526, 527, 528, 529, 530, 531) and the second pulse (526*, 527*, 528*, 529*, 530*, 531*), wherein the average amplitude ratio of the first pulse and the second pulse is determined at least in part by the number of energy supply units that can be operated substantially simultaneously.

11. The stimulation device according to claim 6 or 7, wherein, Each of the two or more energy supply units is configured and arranged to individually supply electrical energy to the first stimulation electrode (200) as a third pulse (590).

12. The stimulation device according to claim 11, wherein, The two or more energy supply units are configured and arranged to provide the second pulse (526*, 527*, 528*, 529*, 530*, 531*) and the third pulse (590), the second pulse and the third pulse having a polarity substantially different from the first pulse (526, 527, 528, 529, 530, 531).

13. The stimulation device according to claim 6 or 7, wherein, The device (100) further includes: One or more DC blocking capacitors (425) are connected in series with one or more loop electrodes (400).

14. The stimulation device according to claim 6 or 7, wherein, The device (100) is also configured and arranged to electrically short-circuit the first stimulating electrode (200) with one or more loop electrodes (400) after providing one or more pulses (526, 527, 528, 529, 530, 531, 526*, 527*, 528*, 529*, 530*, 531*).

15. The apparatus according to claim 6 or 7, wherein, The one or more loop electrodes (400) are included in the distal end, arranged close to the first stimulation electrode (200), included in the proximal end, arranged close to the pulse energy controller (500), or any combination of these.

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