Conversion between bipolar and monopolar electrical stimulation therapy

Abstract

Devices, systems, and techniques are described for switching between electrical stimulation with a bipolar electrode combination and electrical stimulation with a unipolar electrode combination. In one example, a processing circuit is configured to receive a first set of stimulation parameters including a bipolar electrode combination defining a first electrical stimulation, estimate a neural activation volume (VNA) corresponding to the first set of stimulation parameters, determine a second set of stimulation parameters including a unipolar electrode combination defining a second electrical stimulation based on the first VNA, and determine a neural activation volume corresponding to the second set of stimulation parameters based on the second set of stimulation parameters. And controlling the implantable medical device to deliver the second electrical stimulation rather than the first electrical stimulation.

Description

[0001] This application is a PCT application claiming priority to and the benefit of U.S. Provisional Patent Application No. 63 / 369,737, filed on July 28, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to medical devices, and more particularly to medical devices that deliver electrical stimulation therapy. Background Art

[0003] Medical devices can be used to treat a variety of medical conditions. For example, a medical electrical stimulation device can deliver electrical stimulation therapy to a patient via electrodes. Electrical stimulation therapy can include stimulating nerves, muscles, brain tissue, or other tissue in the patient's body. The electrical stimulation device can be fully implanted in the patient's body. For example, the electrical stimulation device can include an implantable electrical stimulation generator and one or more implantable leads carrying electrodes. The electrical stimulation device can include a leadless stimulator. In some cases, the implantable electrodes can be coupled to an external electrical stimulation generator via one or more percutaneous leads or fully implanted leads.

[0004] Medical electrical stimulators can be used to deliver electrical stimulation therapy to patients to relieve various symptoms or conditions, such as chronic pain, tremors, Parkinson's disease, depression, epilepsy, urinary or fecal incontinence, pelvic pain, sexual dysfunction, obesity, or gastroparesis. The electrical stimulator can be configured to deliver electrical stimulation therapy via leads that include electrodes near the patient's spinal cord, pelvic nerves, gastrointestinal organs, peripheral nerves, or within the patient's brain. Stimulation near the spinal cord and within the brain is commonly referred to as spinal cord stimulation (SCS) and deep brain stimulation (DBS), respectively. Summary of the invention

[0005] In general, the present disclosure describes devices, systems, and techniques for converting an electrode combination from a bipolar electrode combination to a monopolar electrode combination. Electrical stimulation can be delivered in a bipolar electrode configuration that includes current delivered between two or more electrodes in close proximity to each other, such as electrodes disposed on the same lead. Such a bipolar electrode configuration can result in a patient's volume of neural activation (VNA), which can be configured to reduce one or more symptoms associated with one or more disorders of the patient, such as tremor or Parkinson's disease in the example of DBS.

[0006] However, a physician may desire to use a monopolar electrode configuration to deliver electrical stimulation with a similar VNA. Electrical stimulation delivered using a monopolar electrode combination includes current delivered from one or more cathodes to one or more anodes that are distal to or further from the cathodes. For example, one or more cathodes may be located on a lead, while an anode is located on a housing of an implantable medical device (IMD) coupled to the lead.

[0007] The system described herein can be configured to convert a bipolar electrode combination to a monopolar electrode combination while maintaining a similar VNA. For example, the system can compare the VNA from the bipolar electrode combination with the VNA corresponding to the corresponding monopolar electrode combination to identify the appropriate monopolar electrode combination. In some examples, the system can be converted to a monopolar electrode combination by switching all electrodes of the bipolar electrode combination to the cathode and then adding a remote anode. The system can then adjust the current amplitude of one or more cathodes in the cathode to approximate the VNA of the bipolar electrode combination. The system may include a user interface having a conversion button that, when selected, causes the system to determine a monopolar electrode combination and switch from a bipolar electrode combination to the monopolar electrode combination.

[0008] In one example, the present disclosure describes a system comprising a memory and a processing circuit operably coupled to the memory and configured to: receive a first stimulation parameter set comprising a bipolar electrode combination defining a first electrical stimulation; estimate a neural activation volume (VNA) corresponding to the first stimulation parameter set; determine a second stimulation parameter set comprising a monopolar electrode combination defining a second electrical stimulation based on the first VNA; and control an implantable medical device to deliver the second electrical stimulation instead of the first electrical stimulation.

[0009] In another example, the present disclosure describes a method comprising receiving, by a processing circuit, a first stimulation parameter set including a bipolar electrode combination that defines a first electrical stimulation; estimating, by the processing circuit, a neural activation volume (VNA) corresponding to the first stimulation parameter set; determining, by the processing circuit, a second stimulation parameter set including a monopolar electrode combination that defines a second electrical stimulation based on the first VNA; and controlling, by the processing circuit, an implantable medical device to deliver the second electrical stimulation instead of the first electrical stimulation.

[0010] In another example, the present disclosure describes a system comprising a memory including a first stimulation parameter set defining a first electrical stimulation; and a processing circuit operably coupled to the memory and configured to: control a user interface to present a representation of the first electrical stimulation defined by the first stimulation parameter set including a bipolar electrode combination; control the user interface by the processing circuit to present a selectable icon associated with converting the first electrical stimulation defined by the first stimulation parameter set including the bipolar electrode combination into a second electrical stimulation defined by the second stimulation parameter set including a monopolar electrode combination; receive, by the processing circuit, a user selection of the selectable icon; and in response to receiving the user selection of the selectable icon, convert the first electrical stimulation into a second electrical stimulation defined by the second stimulation parameter set including the monopolar electrode combination.

[0011] In another example, the present disclosure describes a method comprising controlling, by a processing circuit, a user interface to present a representation of a first electrical stimulation defined by a first stimulation parameter set including a bipolar electrode combination; controlling, by a processing circuit, a user interface to present a selectable icon associated with converting the first electrical stimulation defined by the first stimulation parameter set including a bipolar electrode combination into a second electrical stimulation defined by a second stimulation parameter set including a monopolar electrode combination; receiving, by the processing circuit, a user selection of the selectable icon; and in response to receiving the user selection of the selectable icon, converting the first electrical stimulation into the second electrical stimulation defined by the second stimulation parameter set including a monopolar electrode combination.

[0012] The details of one or more examples of the disclosed techniques are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of these techniques will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a conceptual diagram illustrating an example therapy system including an electrical stimulator coupled to stimulation leads in accordance with various techniques of the present disclosure.

[0014] Figure 2 is shown in more detail Figure 1 Block diagram of an example programmer.

[0015] Figure 3 is shown in more detail Figure 1 Block diagram of an example electrical stimulator.

[0016] Figure 4 is shown in more detail Figure 3 A block diagram of an example of an electrical stimulation generating circuit of an electrical stimulator.

[0017] Figure 5 is a flow chart illustrating example operations for switching from bipolar stimulation to monopolar stimulation.

[0018] Figure 6 is a flow diagram illustrating example operations for converting bipolar stimulation to monopolar stimulation in response to user input.

[0019] FIG. 7A to FIG. 7B is a conceptual diagram of a screen illustrating an example user interface according to the technology of this disclosure.

[0020] Like reference numerals refer to like elements throughout the drawings and the specification. DETAILED DESCRIPTION

[0021] This article describes devices, systems, and techniques for changing electrical stimulation from a bipolar electrode combination to a monopolar electrode combination. When programming deep brain stimulation (DBS) therapy, a clinician can specify an electrode configuration, and then define the delivery of electrical stimulation via the electrode configuration by assigning values ​​of one or more therapy parameters to each electrode and / or adjusting the values ​​of these therapy parameters. The clinician typically selects one or more electrodes to be used as a cathode and one or more electrodes to be used as an anode, which specifies the path of the current during stimulation. This electrode combination is selected from electrodes of one or more leads that can be used in proximity to a target tissue location, and can be referred to as a bipolar electrode combination. A bipolar electrode combination is typically used to describe an anode and cathode located on one or more leads in proximity to a target tissue, which may be referred to as a multipolar electrode combination in some examples. The clinician can also identify other parameter values ​​that define stimulation, such as the voltage or current amplitude, pulse frequency, pulse width, etc., of each electrode of the bipolar electrode combination.

[0022] The bipolar electrode combination enables stimulation to be delivered between one or more cathodes and one or more anodes that are relatively close to each other and near the target tissue. From a spatial point of view, the resulting stimulation can be relatively precise because the current and electric field do not travel very far through the tissue. This spatial control may be beneficial for certain anatomical locations (such as in the brain), where the efficacy of the therapy may depend on affecting some neural networks and avoiding other neural networks. However, due to the proximity of the anode to the cathode, the energy efficiency of the bipolar electrode combination may be low. Since the anode and cathode can be very close, such as within a few millimeters of each other, some current can effectively travel directly between the anode and the cathode, rather than affecting the tissue. Therefore, some energy does not reach the target tissue, which results in higher current or voltage amplitudes in order to reach the target tissue.

[0023] As described herein, the system may be configured to convert a bipolar electrode configuration for electrical stimulation to a monopolar electrode combination. In some examples, the system may utilize neural activation volume (VNA) modeling to determine an appropriate monopolar electrode combination and other parameter values ​​for switching from a bipolar electrode configuration. The electrical stimulation generated using a bipolar electrode configuration may result in a patient's neural activation volume (VNA), which may be configured to reduce one or more symptoms associated with one or more disorders of the patient (such as tremor or Parkinson's disease in the example of DBS). The system may model or estimate the VNA based on the cathode and anode of the bipolar electrode combination and other parameter values ​​(such as current amplitude). The system may then determine a monopolar electrode combination and other parameter values ​​that will produce a VNA similar to the VNA of the bipolar electrode combination. Since the VNA may not be precisely matched, the system may weight one or more characteristics of the VNA matching process more heavily than other characteristics.

[0024] Additionally, or alternatively, the system can convert a bipolar electrode combination to a monopolar electrode combination by switching all electrodes of the bipolar electrode combination to cathodes and then adding remote anodes. In this way, all cathodes of the bipolar electrode combination will remain cathodes, and all anodes of the bipolar electrode combination will switch to cathodes. The remote anodes can be one or more anodes on another lead that is away from the target tissue or attached to a portion of the housing of the IMD coupled to the lead. In this way, the remote electrodes can absorb current from the cathodes. The system can then adjust the current amplitude of one or more of the cathodes to approximate the VNA of the bipolar electrode combination.

[0025] In some examples, a physician may desire to deliver electrical stimulation with a VNA-like configuration using a monopolar electrode configuration. The system may include a user interface, such as a user interface presented on a clinician's external programmer, having a switch button that, when selected, causes the system to determine a monopolar electrode combination and switch from a bipolar electrode combination to the monopolar electrode combination. In other examples, the system may automatically suggest switching to a monopolar electrode combination to save power. The system may present a notification requesting the user to confirm the switch from a bipolar electrode combination to a monopolar electrode combination.

[0026] The electrical stimulation delivered using a monopolar electrode combination can provide similar therapeutic efficacy while reducing power consumption. This reduced power consumption may be due to one or more factors, such as the anode is not adjusted for a monopolar electrode configuration, where clearance is not required and there is a small voltage drop across the circuit. In addition, or alternatively, the anode can be a larger surface area on the housing of the IMD or another larger electrode that reduces the resistance to the current flow from the cathode. In addition, or alternatively, the current is transmitted over a larger distance from the cathode to the remote anode to avoid shunting (direct current flow) that can occur between the cathode and the anode positioned close together, rather than causing tissue activation. In addition, compared to the cathode, the anode voltage from the anode in the bipolar electrode configuration may be less efficient for activating neurons. Due to one or all of these reasons, the system can achieve benefits by delivering electrical stimulation using a monopolar electrode combination. In addition, since clinicians can use a bipolar electrode combination for comfortable programming therapy, clinicians can continue to identify effective bipolar electrode combinations and then convert those combinations to monopolar electrode combinations that can be more energy efficient.

[0027] Figure 1is a conceptual diagram illustrating an example therapy system 2 including an electrical stimulator 4 coupled to a stimulation lead 10 according to various techniques of the present disclosure. The therapy system 2 can be configured to deliver stimulation therapy to a patient 6. The patient 6 is typically, but not necessarily, a person. Typically, the therapy system 2 includes an electrical stimulator 4 (e.g., an implantable medical device (IMD)) that delivers electrical stimulation to the patient 6 via one or more electrodes disposed on a stimulation lead extension 10. The electrical stimulator 4 delivers stimulation therapy, for example, in the form of electrical stimulation, via one or more electrodes 48 disposed along one or more medical leads 12A and 12B connected to the lead extension 10. For purposes of description, the electrodes 48 are described as implantable electrodes. However, the example techniques are not limited to implantable electrodes.

[0028] Electrode 48 can be deployed on one or more medical leads such as medical leads 12A and 12B, and in some cases deployed on housing electrodes. Electrical stimulation can be in the form of controlled current pulses or voltage pulses or substantially continuous current waveforms or voltage waveforms. The stimulation program can define various parameters of the pulses or waveforms. The pulses or waveforms can be delivered substantially continuously or in bursts, segmented or patterned, and can be delivered alone or in combination with pulses or waveforms defined by one or more other stimulation programs. In some examples, one or more of the electrodes may be located on housing 14 of electrical stimulator 4. In addition, implantable electrodes may be deployed on leadless stimulators.

[0029] In some examples, electrical stimulator 4 can deliver, for example, deep brain stimulation (DBS) or cortical stimulation (CS) therapy to patient 6 via electrodes carried by leads 12. Figure 1 A particular stimulation environment (e.g., DBS) is shown, but the technology of the present disclosure is not limited thereto, and the electrical stimulator 4 can deliver stimulation therapy to other parts of the patient 6, such as the spinal cord of the patient 6. For example, other electrical stimulation systems can be configured to deliver electrical stimulation to gastrointestinal organs, the spinal cord, pelvic nerves or muscles, peripheral nerves, or other stimulation sites. In addition, although Figure 1 A fully implantable electrical stimulator 4 is shown, but the techniques described in this disclosure may be applied to external stimulators having electrodes deployed via percutaneous leads.

[0030] exist Figure 1 In the example shown, the electrical stimulator 4 is implanted in the clavicle region of the patient 6. The electrical stimulator 4 generates programmable electrical stimulation (e.g., a current waveform or voltage waveform or current pulses or voltage pulses) and delivers the stimulation via a medical lead 10 carrying an array of stimulation electrodes 48. Generally, for purposes of illustration, the delivery of electrical stimulation using controlled current pulses will be described in this disclosure. In some cases, the electrical stimulator may include multiple leads. Figure 1In the example of the embodiment of the present invention, the distal end of lead 10 is bifurcated and includes two leads 12A and 12B (collectively referred to as "leads 12"). Leads 12A and 12B each include a set of electrodes that form part of an array of electrodes 48. In various examples, leads 12A and 12B can each carry four, eight, or sixteen electrodes. Figure 1 In FIG. 1 , each lead 12A, 12B carries four electrodes configured as ring electrodes at different axial positions near the distal end of the lead 12 .

[0031] In other examples, one or more leads in lead 12A or 12B may include different electrode arrays, such as complex electrode array geometries. For example, lead 12A may include electrodes at different positions around the periphery of the lead. In one example, three, four or more electrodes may be at the same axial position but at different circumferential positions around the lead. These electrodes at different circumferential positions may be referred to as "segmented electrodes" because they represent the "segmentation" of the ring around the lead. These electrodes at the same axial position may be referred to as being arranged at the same "layer" of the lead. In some examples, the lead may include one or more layers of multiple electrodes, and in addition to one or more layers of multiple electrodes, one or more complete rings (or cylindrical electrodes) may also be included. The example lead may include a proximal ring electrode, three electrodes in the first layer, three electrodes in the second layer, and a distal ring electrode from the proximal end to the distal end of the lead. In other examples, the lead may include four layers of electrodes, each layer having two, three, four or more electrodes. The electrodes may be aligned circumferentially or offset between layers.

[0032] Figure 1 A housing electrode 13 is further depicted. The housing electrode 13 can be integrally formed with an outer surface of a hermetically sealed housing 14 of the electrical stimulator 4 or otherwise coupled to the housing 14. In one example, the housing electrode 13 is described as an active, non-detachable electrode on the electrical stimulator 4. In some examples, the housing electrode 13 is defined by an uninsulated portion of an outwardly facing portion of the housing 14 of the electrical stimulator 4. Other separations between the insulated and non-insulated portions of the housing 14 can be used to define two or more housing electrodes. In some examples, the housing electrode 13 includes substantially all of the housing 14, a side of the housing 14, a portion of the housing 14, or multiple portions of the housing 14.

[0033] In some examples, the electrical stimulator 4 can be coupled to one or more leads that may or may not be bifurcated. In such examples, the leads can be coupled to the electrical stimulator 4 directly or via a common lead extension (such as lead extension 10) or a separate lead extension. The proximal end of the lead extension 10 can be coupled to the head on the electrical stimulator 4. The conductor in the lead body can electrically connect the stimulation electrode located on the lead 12 to the electrical stimulator 4. The lead extension 10 passes from the implantation site of the electrical stimulator 4 along the neck of the patient 6 before coupling to the leads 12A and 12B. Leads 12A and 12B continue to pass through to the brain 16 of the patient 6. In some examples, leads 12A and 12B can be implanted in the right and left hemispheres, respectively, so as to deliver electrical stimulation to more than one area of ​​the brain 16.

[0034] Leads 12A, 12B may be implanted in a desired location in brain 16 through corresponding holes in the skull of patient 6. Leads 12A, 12B may be placed at any location within brain 16 such that electrodes located on leads 12A, 12B are capable of providing electrical stimulation to target tissue. The electrodes of leads 12A, 12B are shown as ring electrodes. In some examples, the electrodes of leads 12A, 12B may have different configurations. For example, the electrodes of leads 12A, 12B may have a complex electrode array geometry that is capable of generating a shaped electric field. The complex electrode array geometry may include multiple electrodes (e.g., partial rings or electrode "segments") surrounding the perimeter of each lead 12A, 12B. In some examples, lead 12 may have a plurality of electrodes other than the following: Figure 1 For example, lead 12 may be a paddle lead, a spherical lead, a bendable lead, or any other type of shape that is effective for treating patient 6. Additionally, the electrodes may be electrode pads on a paddle lead, circular electrodes surrounding the lead body, conformable electrodes, cuff electrodes, segmented electrodes, or any other type of electrode that can form a monopolar, bipolar, multipolar, etc. electrode configuration.

[0035] In some examples, the electrical stimulator 4 delivers stimulation at a given time according to a set of programs. Each program in such a program group may include a corresponding value for each therapy parameter in a plurality of therapy parameters. The therapy parameter may include, for example, one of current amplitude or voltage amplitude, pulse width, pulse shape, pulse rate or pulse frequency, number of pulses, or electrode configuration (e.g., electrode combination and polarity). The electrical stimulator 4 may interleave pulses or other signals according to different programs in the program group. In such examples, the programmer 40 may be used to create programs and assemble these programs into program groups. In some examples, the programmer 40 may be used to adjust the stimulation parameters of one or more programs in the program group, and select a program group as the current program group to control the delivery of the stimulation performed by the electrical stimulator 4.

[0036] Generally speaking, the system 2 delivers stimulation therapy to the patient 6 in the form of a constant current or voltage waveform or a constant current or voltage pulse. The shape of the pulse can vary according to different design goals, and can include ramp or trapezoidal pulses, sinusoidal or otherwise curved pulses, step pulses with two or more discrete amplitudes, closely spaced pulse pairs, and any of the above biphasic (a waveform with positive and negative directions in a single pulse) or monophasic (only positive waveforms or only negative waveforms in a single pulse) changing waveforms. In the case of current-based stimulation, the electrical stimulator 4 adjusts the current provided or absorbed by one or more electrodes, which are called adjustment electrodes. In some examples, one or more of the electrodes may be unregulated. In such a configuration, the housing electrode and / or the lead electrode may be an unregulated electrode. For example, in a monopolar electrode combination, one or more anodes may be unregulated in the sense that they absorb the current delivered from the regulated cathode. For a bipolar electrode combination, both the anode and the cathode may be regulated.

[0037] A source current may refer to a positive current flowing out of an electrode (anode), while a sink current may refer to a negative current flowing into an electrode (cathode). Regulated source currents may be combined to produce a larger total source current (e.g., currents from multiple source currents are combined together to produce a total source current). Similarly, regulated sink currents may be added to produce a larger total sink current (e.g., currents from multiple sink currents are added together to produce a total sink current). Regulated source currents and regulated sink currents may partially or completely offset each other, thereby producing a net difference in the form of a net source current or sink current in the case of partial offset. In some examples, an unregulated current path may produce or sink a current approximately equal to the net difference. In some examples, the regulated source current and regulated sink current may be substantially balanced.

[0038] In some example implementations (e.g., bipolar (or multipolar) arrangements), one or more electrodes 48 may be configured to act as an anode and provide current, while one or more different electrodes 48 may be configured to act as a cathode and absorb current. In another example implementation (e.g., a monopolar arrangement), the housing electrode 13 (e.g., a remote electrode away from the target tissue) may be configured to act as an anode and provide current, while one or more electrodes 48 on one or more leads typically located near the target tissue are configured to act as a cathode and absorb current. The technology of the present disclosure can be implemented using a monopolar arrangement or a bipolar / multipolar arrangement as described.

[0039] The therapy system 2 may include a programmer 40, such as an external programmer operated by a clinician or a patient. In some examples, the programmer 40 may be a handheld computing device that allows a clinician to program stimulation therapy for a patient 6 via a user interface. For example, using the programmer 40, a clinician may specify stimulation parameters for delivering stimulation therapy, and receive a user request to convert a bipolar electrode combination to a monopolar electrode combination, and vice versa. The programmer 40 may support telemetry using the electrical stimulator 4 to download programs, and optionally, upload operational data or physiological data stored by the electrical stimulator 4. The programmer 40 may also include a display and input keys to allow the patient 6 or clinician to interact with the programmer 40 and the electrical stimulator 4. In this way, the programmer 40 provides a user interface to the patient 6 for controlling the stimulation therapy delivered by the electrical stimulator 4. For example, the patient 6 may use the programmer 40 to start, stop, or adjust electrical stimulation. In particular, the programmer 40 may allow the patient 6 to adjust stimulation parameters of the program, such as duration, current or voltage amplitude, pulse width, pulse shape, and pulse rate. Patient 6 may also select a program (eg, from a plurality of stored programs) as a current program to control the delivery of stimulation by electrical stimulator 4 .

[0040] In some cases, programmer 40 may be considered a physician or clinician programmer 40. For example, if programmer 40 is primarily intended for use by a physician or clinician, programmer 40 may include a clinician programmer. In other cases, if programmer 40 is primarily intended for use by a patient, programmer 40 may be considered a patient programmer. Generally, a physician or clinician programmer may support a clinician in selecting and generating programs for use with stimulator 4, while a patient programmer may support adjustment and selection of such programs by a patient during ordinary use as permitted by the clinician or clinician programmer.

[0041] Regardless of whether the programmer 40 is configured for use by a clinician or a patient, the programmer 40 can communicate with the electrical stimulator 4 or any other computing device via wireless communication. For example, the programmer 40 can communicate with the electrical stimulator 4 via wireless communication using RF telemetry techniques known in the art. The programmer 40 can also communicate with another programmer or computing device via a wired or wireless connection using any of a variety of local wireless communication techniques, such as radio frequency (RF) communications according to the 802.11 or Bluetooth specification set, infrared communications according to the Infrared Data Association (IrDA) specification set, or other standard or proprietary telemetry protocols. The programmer 40 can also communicate with another programmer or computing device via the exchange of removable media (such as a disk or optical disk or a memory card or stick). In addition, the programmer 40 can communicate with the electrical stimulator 4 and other programming devices via remote telemetry techniques known in the art, such as via a local area network (LAN), a wide area network (WAN), a public switched telephone network (PSTN), or a cellular telephone network.

[0042] A user, such as a clinician or patient 6, can interact with a user interface of the programmer 40 to program the electrical stimulator 4. According to various techniques described in the present disclosure, the programmer 40 can be used to receive user input via the user interface, which specifies one or more therapy parameters for defining the electrical stimulation therapy delivered by the electrical stimulator 4. The programmer 40 can control the electrical stimulator 4 so that the electrical stimulator 4 delivers the electrical stimulation therapy according to the specified therapy parameters, as described in more detail below, or otherwise program the stimulator 4. Programming the electrical stimulator 4 can generally refer to generating and transmitting commands, programs, or other information for controlling the operation of the electrical stimulator 4. For example, the programmer 40 can transmit programs, parameter adjustments (such as electrode combinations), program selections, group selections, or other information to control the operation of the electrical stimulator 4. In addition, the programming of the stimulator 4 can include receiving user input indicating a target stimulation area or a bipolar electrode combination via the programmer 40, or a request to convert a bipolar electrode combination to a monopolar electrode combination.

[0043] The electrical stimulator 4 and the programmer 40 can communicate via a cable or wireless communication, such as Figure 1 For example, programmer 40 can communicate with electrical stimulator 4 via wireless communication using RF telemetry. Programmer 40 can also communicate with other programmers using any of a variety of local wireless communication technologies, such as those based on 802.11 or Bluetooth. TM Programmer 40 may include a transceiver that allows two-way communication with electrical stimulator 4, such as RF communication according to a standard set, infrared communication (e.g., according to the IrDA standard), or other standard or proprietary telemetry protocols. Programmer 40 may include a transceiver that allows two-way communication with electrical stimulator 4.

[0044] According to the technology of the present disclosure, system 2 may include a processing circuit configured to convert a bipolar electrode combination into a monopolar electrode combination, and vice versa. A bipolar electrode combination may be an electrode combination having one or more anodes and one or more cathodes on the same lead or on one or more leads disposed near the target tissue. A bipolar electrode combination may also be referred to as a multipolar electrode combination. In a bipolar electrode combination, an electric current flows a relatively short distance between the anode and cathode of the bipolar electrode combination. In some examples, the bipolar electrode combination includes an adjusted anode and an adjusted cathode to control the current provided and absorbed to each electrode. A monopolar electrode combination includes one or more electrodes (such as cathodes) near the target tissue of one polarity, and one or more electrodes away from the target tissue, so that the target tissue is usually affected by the nearby monopolar electrodes. In some examples, the electrodes (such as one or more cathodes) close to each other may be adjusted and absorbed to one or more unregulated anodes away from the target tissue.

[0045] System 2 may be configured to receive a first stimulation parameter set including a bipolar electrode combination defining a first electrical stimulation. The bipolar electrode combination may be selected by a user, or automatically selected based on instructions stored in a memory or otherwise programmed. System 2 may estimate a neural activation volume (VNA) corresponding to the first stimulation parameter set. The VNA may be modeled based on a bipolar electrode combination, other stimulation parameter values, and tissue characteristics that may be general or patient-specific. System 2 may then determine a second stimulation parameter set including a monopolar electrode combination defining a second electrical stimulation based on the first VNA. The second stimulation parameter set including the monopolar electrode combination may be associated with a second VNA that may be similar to or approximate to the first VNA. In other words, system 2 may be configured to identify a monopolar electrode combination and other parameter values ​​that may generate a VNA similar to the VNA of the bipolar electrode combination. Then, system 2 may control IMD 14 to deliver a second electrical stimulation from the monopolar electrode combination, rather than the first electrical stimulation from the bipolar electrode combination. Both the first stimulation parameter set and the second stimulation parameter set include at least one of a current or voltage amplitude, a pulse width, and a pulse frequency. In some examples, the first parameter set and the second parameter set may be identical except for the corresponding monopolar electrode combination and bipolar electrode combination. In other examples, for example, the first parameter set and the second parameter set may have one or more different parameter values, such as different amplitudes or pulse widths.

[0046] In some examples, system 2 can be configured to convert a bipolar electrode combination to a monopolar electrode combination based on an estimated VNA for the bipolar electrode combination and a VNA for a possible corresponding monopolar electrode combination. System 2 can attempt to identify a VNA that is similar for a monopolar electrode combination and for a bipolar electrode combination. In one example, system 2 can select one or more cathodes on a lead carrying a bipolar electrode combination. As discussed herein, a bipolar electrode combination can include electrodes on the same lead or on one or more leads adjacent to a target tissue. In contrast, a monopolar electrode combination can include one or more cathodes on one or more leads (such as a lead carrying a bipolar electrode combination) and at least one anode away from the one or more leads and the target tissue, such as an electrode on the housing of IMD 14.

[0047] System 2 may be configured to estimate a VNA corresponding to a stimulus generated by one or more monopolar electrode combinations. For example, system 2 may be configured to analyze different monopolar electrode combinations associated with a VNA having a shape and / or volume similar to that of a bipolar electrode combination VNA. System 2 may also be configured to identify amplitude values ​​of one or more cathodes, at which one or more characteristics of a second VNA correspond to one or more characteristics of a first VNA. The amplitude value at each cathode or anode may correspond to the distance that the VNA reaches away from the corresponding electrode. In other words, a larger amplitude may generally result in a larger VNA that extends a larger radius away from the electrode. The characteristics of the VNA that can be compared may include volume, shape, radius of the VNA from one or more electrodes in the electrode, etc. Once system 2 determines an appropriate monopolar electrode combination having a VNA similar to that of a bipolar electrode combination VNA, system 2 may generate a second stimulation parameter set to include one or more cathodes and amplitude values. In some examples, the amplitude value of at least one electrode or up to all electrodes in the electrodes of the monopolar electrode combination may be less than the amplitude value of the first stimulation parameter set and the bipolar electrode combination.

[0048] In some examples, system 2 can be configured to select one or more cathodes on the lead for a monopolar electrode combination by keeping any cathodes of the bipolar electrode combination and switching any anodes of the bipolar electrode combination to cathodes. In this way, all cathodes will use the same electrodes on the lead as the bipolar electrode combination. In addition, system 2 can add one or more anodes away from the lead, such as electrodes on the housing of IMD 14.

[0049] As described above, each VNA may include one or more characteristics, and the system 2 may compare the one or more characteristics with other VNAs to identify a monopolar electrode combination that may be a suitable alternative to a bipolar electrode combination. In some examples, the VNA characteristics may include one or more of the volume, the distance from the corresponding electrode, or the distance from the lead at the corresponding axial position. The system 2 may be configured to identify the amplitude value of one or more cathodes or one or more anodes, at which the one or more characteristics of the second VNA correspond to the one or more characteristics of the first VNA. In some examples, some characteristics of the VNA may be weighted differently for the purpose of comparing and identifying a suitable monopolar electrode combination for conversion from a bipolar electrode combination. In other words, characteristics that are more important for identifying a similar VNA may be weighted more highly than other characteristics that are less important to the patient. For example, the distance that the VNA extends radially from the electrode may be more important than the total volume of the VNA and is weighted more highly. Therefore, the system 2 can determine the best VNA and the corresponding best monopolar electrode combination and other parameter values ​​based on these weighted characteristics of the VNA. In one example, the system can identify amplitude values ​​for one or more cathodes of the monopolar electrode combination based on differently weighted characteristics of one or more characteristics of the first VNA of the bipolar electrode combination.

[0050] In some examples, system 2 can only identify a single VNA and a corresponding monopolar electrode combination. In other examples, system 2 can generate multiple different VNAs for one or more monopolar electrode combinations as candidate VNAs to compare the VNA of a bipolar electrode combination. Then, system 2 can compare VNAs to identify the closest or best fit of the VNA of the monopolar electrode combination to the bipolar VNA. In some examples, system 2 can present different options of VNAs generated for different monopolar electrode combinations and / or other parameter values ​​to the user for selection. System 2 can then receive user input for selecting a desired VNA or other representations of parameter values ​​associated with the desired VNA. In some examples, system 2 can sort candidate VNAs or candidate parameter values ​​based on the fit of the VNA with the bipolar electrode combination.

[0051] In some examples, a bipolar electrode combination includes at least one anode disposed on an implantable medical lead, such as leads 12A and 12B, and at least one cathode disposed on an implantable medical lead, such as lead 12A or 12B. For example, a monopolar electrode combination may include at least one cathode disposed on an implantable medical lead, such as leads 12A and 12B, and at least one anode disposed on IMD 14. In some examples, a bipolar electrode combination includes at least one electrode of a plurality of electrodes disposed at different locations around the perimeter of the lead.

[0052] System 2 may be configured to receive user input requesting to convert a bipolar electrode combination to a monopolar electrode combination. For example, programmer 40 may include a display, wherein the processing circuit is configured to control the display to present a selectable icon that, when selected, causes the processing circuit to determine a second set of stimulation parameters including a monopolar electrode combination defining a second electrical stimulation based on the first VNA of the bipolar electrode combination.

[0053] In some examples, the system 2 may be configured to control a user interface, such as a user interface presented by the programmer 40, to present a representation of a first electrical stimulation defined by a first stimulation parameter set including a bipolar electrode combination. The representation may be in the form of a graphical VNA, a numerical representation of one or more characteristics of the VNA (e.g., a radial distance from an electrode or volume), etc. The system 2 may control the user interface to present a selectable icon associated with converting a first electrical stimulation defined by a first stimulation parameter set including a bipolar electrode combination into a second electrical stimulation defined by a second stimulation parameter set including a monopolar electrode combination. In other words, the selection of the selectable icon may trigger the system 2 to convert the bipolar electrode combination into a monopolar electrode combination, or vice versa. The system 2 may then receive a user selection of the selectable icon, and in response to receiving the user selection of the selectable icon, convert the first electrical stimulation into a second electrical stimulation defined by a second stimulation parameter set including a monopolar electrode combination.

[0054] System 2 may control the user interface of programmer 2 to present visual representations of VNAs corresponding to electrical stimulation of bipolar electrode combinations and monopolar electrode combinations, either separately, adjacent to each other, or overlapping, to illustrate the differences between the VNAs. In some examples, system 2 may control the user interface to present one or more controls configured to receive user input for adjusting the values ​​of corresponding stimulation parameters of the second stimulation parameter set. Adjustable parameters may include amplitude, pulse width, or frequency. In some examples, user input may also be received to add electrodes to or remove electrodes from the electrode combination and / or to change electrodes from anodes to cathodes or from cathodes to anodes.

[0055] In some examples, selection of a selectable icon (e.g., a toggle button) can cause the system 2 to switch from the bipolar electrode combination in response to each selection, and back to the bipolar electrode combination again. In this way, the system 2 can be configured to switch between a first electrical stimulation including a bipolar electrode combination and a second electrical stimulation including a monopolar electrode combination in response to a user's selection of a selectable icon.

[0056] In some examples, programmer 40 (e.g., a clinician or patient programmer) may include processing circuitry and memory for performing the functions described herein, such as converting a bipolar electrode combination to a monopolar electrode combination. In other examples, another device (such as IMD 14 or an external server) may include processing circuitry and memory for performing these functions, or a combination of two or more devices may perform aspects of these functions in a distributed manner.

[0057] The technology disclosed herein can provide specific improvements in the field of computer-related neural stimulation therapy with practical applications. For example, the technology described herein enables a user or system to determine a monopolar electrode combination alternative from a bipolar electrode combination identified as providing therapy to a patient. In this way, a monopolar electrode combination can be used to deliver electrical stimulation that consumes less power and increases battery life when compared to the stimulation delivered from the original bipolar electrode combination. In addition, the technology described herein enables a user interface to receive a user request to change or convert from a bipolar electrode combination to a monopolar electrode combination that can produce a similar VNA for treating a patient. In this way, the user interface can reduce programming time while identifying an alternative parameter set that can reduce power consumption.

[0058] Figure 2 is shown in more detail Figure 1 A block diagram of an example programmer 40 is shown. Figure 2 As shown, the programmer 40 includes a processing circuit 53, a memory 55, a telemetry circuit 58, and a user interface 59. Typically, the processing circuit 53 controls the user interface 59, stores and retrieves data to and from the memory 55, and controls the transmission of data with the electrical stimulator 4 through the telemetry circuit 58. The processing circuit 53 may take the form of one or more microprocessors, controllers, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or equivalent discrete or integrated logic circuits. The functions attributed to the processing circuit 53 herein may be embodied in software, firmware, hardware, or any combination thereof.

[0059] The memory 55 can store various aspects that enable the processing circuit 53 to provide the functions attributed to the programmer 40 herein. The memory 55 can include any fixed or removable magnetic, optical or electrical media, such as random access memory (RAM), read-only memory (ROM), compact disk ROM (CD-ROM), magnetic storage, electronically erasable programmable ROM (EEPROM), non-volatile random access memory (NVRAM), flash memory, etc. The memory 55 may also include a removable memory portion, which can be used to update the memory or increase the memory capacity. The removable memory can also allow patient data to be easily transferred from the programmer 40 to another computing device. The memory 55 can also store information that controls the operation of the electrical stimulator 4.

[0060] The telemetry circuit 58 is configured to transmit data to and from the electrostimulator 4. The telemetry circuit 58 may communicate with the electrostimulator 4 automatically at a predetermined time or when the telemetry circuit 58 detects the proximity of the electrostimulator 4. Alternatively, the telemetry circuit 58 may communicate with the electrostimulator 4 when the user sends a signal notification through the user interface 59. To support RF communication, the telemetry circuit 58 may include appropriate electronic components such as amplifiers, filters, mixers, encoders, decoders, etc.

[0061] In some examples, programmer 40 can communicate wirelessly with electrical stimulator 4 using, for example, RF communication or proximal inductive interaction. Such wireless communication is possible using telemetry circuit 58, which can be coupled to an antenna. Programmer 40 can also be configured to communicate with another computing device via wireless communication technology or directly communicate with another computing device through a wired, such as a network connection. Examples of local wireless communication technologies that can be used to facilitate communication between programmer 40 and another computing device include RF communication based on 802.11 or Bluetooth specification sets, infrared communication.

[0062] The programmer 40 includes a user interface 59. A user (e.g., a clinician or patient 6) can interact with the programmer 40 via the user interface 59, such as manually selecting, changing, or modifying a program, adjusting one or more therapy parameters for a particular electrode 48 or multiple electrodes 48, or viewing stimulation data. As another example, the user interface 59 may display a VNA, a selected electrode, a toggle button that can be selected by the user to switch from a bipolar electrode combination to a monopolar electrode combination, etc. The user interface 59 may include one or more input devices and one or more output devices. The input devices of the user interface 59 may include communication devices such as a keyboard, a pointing device, a voice response system, a camera, a biometric detection / response system, a button, a sensor, a control pad, a microphone, a presence-sensitive screen, a touch-sensitive screen, or any other type of device for detecting input from a user.

[0063] The output device of the user interface 59 may include a communication unit, such as a display, a sound card, a video graphics adapter card, a speaker, a presence-sensitive screen, one or more USB interfaces, a video and / or audio output interface, or any other type of device capable of producing tactile, audio, video or other output. The output device of the user interface 59 may include a display device that can be used as an output device using the following technologies, including a liquid crystal display (LCD), a quantum dot display, a dot matrix display, a light emitting diode (LED) display, an organic light emitting diode (OLED) display, a cathode ray tube (CRT) display, electronic ink, or a monochrome, color, or any other type of display capable of producing tactile, audio and / or visual output. In other examples, the output device of the user interface 59 can generate output to the user in another way, such as via a sound card, a video graphics adapter card, a speaker, a presence-sensitive screen, one or more USB interfaces, a video and / or audio output interface, or any other type of device capable of producing tactile, audio, video or other output. In some examples, the output device of the user interface 59 may include a presence-sensitive display that can be used as a user interface device, and the presence-sensitive display operates as both one or more input devices and one or more output devices. Additional details regarding examples of user interface 59 are provided below with respect to Figure 5 , Figure 6 , Fig. 7A and Figure 7B Give a description.

[0064] According to an example technique of the present disclosure, the user interface 59 presents a representation of the plurality of electrodes 48 of the electrical stimulator 4. The user interface 59 presents, for example, values ​​of therapy parameters specific to each of the plurality of electrodes 48, a selection of a plurality of electrodes 48 defining a relationship (e.g., anodes and cathodes of a bipolar or monopolar electrode combination), a conversion button selectable by the user, and the like. The user interface 59 may provide a fillable field or other adjustment input device, such as an increase or decrease input key, that allows the user to input a therapy parameter of a given electrode 48 targeted for adjustment, a therapy parameter of a plurality of electrodes 48 targeted for adjustment, or a desired value for a master adjustment of the electrical stimulator 4. The processing circuit 53 may receive input from the user via the user interface 59 specifying an adjustment to the value of an individual therapy parameter by receiving an input specifying an increase or decrease of the corresponding value of the parameter displayed on the user interface 59. In addition, the processing circuit 53 may receive from the user an adjustment to one or more of the therapy parameters corresponding to each specific electrode 48 by receiving an input specifying an increase or decrease of the value of one or more therapy parameters displayed on the user interface of the programmer 40.

[0065] In operation, processing circuitry 53 receives a request from a user via user interface 59 to adjust one or more of the therapy parameters corresponding to each particular electrode 48. For example, processing circuitry 53 may receive an input specifying an increase or decrease in the value of one or more therapy parameters, such as amplitude, pulse width, frequency, or polarity (cathodic or anodic), displayed on a user interface of programmer 40. Processing circuitry 53 transmits the specified individual therapy parameters to electrical stimulator 4 via telemetry circuitry 58 to control electrical stimulator 4 to deliver electrical stimulation therapy via multiple electrodes 48 according to the corresponding therapy parameters for each of multiple electrodes 48.

[0066] Figure 3 is shown in more detail Figure 1 4. In some examples, the electrical stimulator 4 includes a processing circuit 50, a memory 52, a telemetry circuit 56, an antenna 57, and a stimulation generation circuit 60. The stimulation generation circuit 60 is also Figure 3 48A to 48Q (collectively referred to as "electrodes 48"). In some examples, electrodes 48A to 48P can be implantable and can be deployed on one or more leads 12. Figure 1 , leads 12A and 12B may carry electrodes 48A to 48H and electrodes 48I to 48P, respectively. In some cases, one or more additional electrodes may be located on or within the housing of the electrical stimulator 4, for example to provide a common electrode or ground electrode or housing anode. In some examples, the lead or leads carry eight electrodes to provide a 2×8 electrode configuration (two leads, each with 8 electrodes), providing a total of sixteen different electrodes.

[0067] In some examples, different electrode configurations may be provided including a single lead, two leads, three leads, or more. In addition, the electrode count may vary across the leads and may be the same or different between leads. Examples of other configurations include: one lead with eight electrodes (1×8); one lead with 12 electrodes (1×12), one lead with 16 electrodes (1×16); two leads with four electrodes (2×4), three leads with four electrodes each (3×4); three leads with eight electrodes each (3×8); three leads with four, eight, and four electrodes, respectively (4-8-4); two leads with 12 or 16 electrodes (2×12, 2×16); two or more leads with 11 or 13 electrodes; or other configurations. The processing circuit 50 may select different electrodes to form various electrode combinations. In addition, the processing circuit 50 may assign various polarities to selected electrodes to designate the electrodes as anodes or cathodes, and form additional electrode configurations therefrom. In other examples, fewer or more electrodes may be controlled by the electrical stimulator 4. For example, the stimulation generation circuit 60 may be coupled to 16 electrodes, 8 electrodes on each of the two leads. For example, each lead may include two ring electrodes and two layers of three electrodes at different circumferential locations around the perimeter of the lead.

[0068] Electrode 48Q represents one or more electrodes that can be carried on the housing of the electrical stimulator 4. Electrode 48Q can also be a dedicated short lead extending from the housing, or a proximal portion of one of electrodes 48A to 48P that carries electrodes. The proximal portion can be closely adjacent to the housing, for example, at or near the point where the lead is coupled to the housing. Electrode 48Q can be configured as an regulated or unregulated electrode for use in an electrode configuration having a selected regulated electrode and / or unregulated electrode between electrodes 48A to 48P, which, as described above, can be located on the lead body of one or more leads. Electrode 48Q can be formed together on a housing that carries the electrodes and houses components of the electrical stimulator 4, such as the stimulation generation circuit 60, the processing circuit 50, the memory 52, and the telemetry circuit 56.

[0069] The housing electrode 48Q can be configured to serve as an anode that provides current substantially simultaneously with one or more electrodes 48A to 48P, which are configured to serve as a cathode that absorbs current in a monopolar arrangement. As a specific example, electrodes 48A, 48B and housing electrode 48Q can each be configured to serve as an anode. Electrodes 48A, 48B can deliver electrical stimulation current substantially simultaneously with the electrical stimulation current delivered via housing electrode 48Q. In this illustration, one or more cathodes can be formed by other electrodes on the lead (e.g., any of electrodes 48C to 48P) to absorb the current provided by anodes 48A, 48B and 48Q.

[0070] The memory 52 may store instructions for execution by the processing circuit 50, stimulation therapy data, sensor data, instructions for converting a bipolar electrode combination to a monopolar electrode combination, and / or other information about a therapy for the patient 6. The processing circuit 50 may control the stimulation generation circuit 60 to deliver stimulation according to one or more selected programs or groups of programs from a plurality of programs or groups of programs stored in the memory 52. ​​The memory 52 may include any electronic data storage medium, such as RAM, ROM, EEPROM, NVRAM, flash memory, magnetic memory, etc. The memory 52 may store program instructions that, when executed by the processing circuit 50, cause the processing circuit to perform various functions attributed to the processing circuit 50 and the electrical stimulator 4 in the present disclosure.

[0071] The processing circuit 50 may include one or more microprocessors, DSPs, ASICs, FPGAs, or other digital logic circuits. The processing circuit 50 controls the operation of the electrical stimulator 4. For example, the processing circuit 50 may control the stimulation generation circuit 60 to deliver stimulation therapy according to a selected program or program group retrieved from the memory 52. ​​In some examples, the processing circuit 50 may control the stimulation generation circuit 60 to deliver an electrical signal having a current amplitude, pulse width (if applicable), and pulse rate specified by one or more stimulation programs, such as a stimulation pulse or a continuous waveform. The processing circuit 50 may also control the stimulation generation circuit 60 to selectively deliver stimulation via a subset of the electrodes 48 (also referred to as an electrode combination), and the polarity is specified by one or more programs. The functions attributed to the processing circuit 50 herein may be embodied as software, firmware, hardware, or any combination thereof.

[0072] When a particular program group is selected, the processing circuit 50 can control the stimulation generation circuit 60 to deliver stimulation according to the program in the group. If applicable, each program can specify a set of stimulation parameters (such as amplitude, pulse width, pulse rate and electrode combination). For continuous waveforms, parameters can include amplitude and frequency. In addition, each program can specify a specific electrode combination for the delivery of stimulation, as well as an electrode configuration according to the polarity of the electrode and the regulated / unregulated state. The electrode combination can specify specific electrodes in a single array or multiple arrays, and specific electrodes on a single lead or between multiple leads. The electrode combination may include at least one anode (e.g., electrode 48Q) on the housing of the electrical stimulator 4, at least one anode on the lead, and at least one cathode on the lead. If more than one lead is provided, the lead-bearing anode and cathode may be located on the same lead or on different leads. The program can be defined directly by selecting parameters and electrodes, or by zone-based programming, where the parameters and electrodes are automatically determined by the programmer in response to manipulation or positioning of the stimulation zone.

[0073] The stimulus generating circuit 60 is connected via corresponding leads (such as Figure 1 The stimulation generating circuit 60 may be electrically coupled to one or more housing electrodes 48Q via electrical conductors disposed within the housing of the electrical stimulator 4. The housing electrodes 48Q may be configured as regulated or unregulated electrodes to form an electrode configuration in combination with one or more of the electrodes 48A to 48P. The housing electrodes 48Q may be configured to function as an anode to provide current substantially simultaneously with one or more electrodes (e.g., any of the electrodes 48A to 48P) on one or more leads configured to function as an anode.

[0074] Stimulation generation circuitry 60 may include stimulation generation circuitry for generating stimulation pulses or waveforms, and circuitry for switching stimulation across different electrode combinations, e.g., in response to control by processing circuitry 50. Stimulation generation circuitry 60 generates electrical stimulation signals according to a program based on control signals from processing circuitry 50.

[0075] In one example implementation, the stimulation generation circuit 60 can be configured to deliver stimulation using one or more electrodes of the electrodes 48A to 48P and the housing electrode 48Q as stimulation electrodes (e.g., anodes). The anodes on the leads and housing can be used to deliver stimulation in combination with one or more cathodes on the leads. As an illustration, the electrode combination selected for delivering the stimulation current may include a housing anode and an anode on the lead, and a cathode on the same lead or on a different lead. In other examples, the electrode combination may include multiple anodes and / or multiple cathodes on one or more leads, and at least one anode on the housing 14. In some examples, the electrode combination may include one or more anodes on one or more leads, and one or more cathodes on the same lead or on different leads, such as a bipolar / multipolar arrangement.

[0076] Telemetry circuit 56 may include an RF transceiver to allow two-way communication between electrostimulator 4 and programmer 40. Telemetry circuit 56 may include antenna 57, which may take a variety of forms. For example, antenna 57 may be formed of a conductive coil or wire embedded in a housing associated with medical device 4. In some examples, antenna 57 may be mounted on a circuit board carrying other components of electrostimulator 4, or take the form of circuit traces on a circuit board. In this way, telemetry circuit 56 may allow communication with programmer 40. Figure 1 Telemetry circuit 56 may be similar to telemetry circuit 58 of programmer 40 .

[0077] Figure 4 is shown in more detail Figure 3 4. The stimulation generation circuit 60 can be used with the electrical stimulator, for example, to perform a reference Figure 3 The function of the stimulus generating circuit 60 is described. Figure 4 In the example of , the stimulation generation circuit 60 is selectively configured to deliver current stimulation pulses to the patient 6 via the electrode 48. However, the present disclosure is not limited to the example of delivering regulated current pulses. In other examples, the stimulation generation circuit 60 can provide a continuous, regulated current waveform instead of regulated current pulses. In some examples, the stimulation generation circuit 60 can deliver a combination of continuous waveforms and pulses, or selectively deliver continuous waveforms or pulses. The stimulation generation circuit 60 can generate constant current-based or constant voltage-based stimulation in the form of pulses or continuous waveforms. The stimulation generation circuit 60 can also be controlled to provide constant power (current-voltage product) or controlled charge stimulation pulses.

[0078] exist Figure 4 In the example shown, the stimulus generation circuit 60 includes a main current / voltage 64 and a current / voltage regulator array 68. In some examples, the stimulus generation circuit 60 may also include a switch array 66. The main current / voltage 64 may provide operating power to the current / voltage regulator array 68 and may include a regulated current or a regulated voltage that sets the level of the main current (e.g., the main current amplitude) or the main voltage. Figure 4 As shown, the main current / voltage 64 can be coupled to provide operating power to the current / voltage regulator array 68 and provide the main current or main voltage for connection to the electrode 48 when appropriate. The maximum operating current level and the main current level provided for regulating the current regulator array 68 can be different at any given time. For example, the main current amplitude can be less than the maximum operating current level, so that the main current amplitude can be increased or decreased according to the minimum and maximum operating conditions. In some examples, the user interface 59 of the external programmer 40 can display such information for user reference while adjusting the current amplitude of various electrodes.

[0079] The processing circuit 50 can control (e.g., via a stimulation controller) the switch array 66 and the current / voltage regulator array 68 to deliver stimulation via the electrodes 48. In operation, the processing circuit 50 can control the delivery of electrical stimulation according to one or more programs, which can specify stimulation parameters such as electrode combination, electrode polarity, stimulation current amplitude, pulse rate and / or pulse width, and the percentage of source current contributed by or distributed in the housing anode and one or more lead anodes on one or more leads, and the percentage absorbed by one or more cathodes. The program can be defined by the user via an external controller and downloaded to the electrical stimulator 4.

[0080] The current / voltage regulator array 68 includes a plurality of regulated current sources or current sinks. The current regulator may be used as a current source or current sink, or may be selectively configured to operate as a source or sink. In some examples, the current / voltage regulator array 68 may regulate voltage as a substitute or supplement to current. For convenience, in some cases, the term "current regulator" may be used to refer to a source or a sink. Therefore, each current regulator in the current regulators in the current / voltage regulator array 68 may operate as a regulated current source or a regulated current sink, the regulated current source delivering stimulation via a corresponding electrode in the electrode 48, the regulated current sink receiving current from a corresponding electrode in the electrode 48, wherein the electrode 48 may be arranged on a lead, on a stimulator housing, on a leadless stimulator, or in other arrangements. Although multiple current sources or current sinks are described herein, the electrical stimulator 4 may include a single current source or current sink in other examples, and still support locking multiple electrodes into a relationship of a ratio having values ​​of one or more therapy parameters.

[0081] Each current regulator may correspond to a plurality of current regulator branches. In some examples, the current regulator branches may be implemented in parallel, such as with parallel current regulator branches. The number of current regulator branches defines the resolution of each current regulator. For example, in some examples, the number of current regulator branches may be 64, so that the current amplitude may be adjusted for a given electrode in 1 / 64 increments (i.e., a resolution of 1 / 64). Although, for example, 64 current branches are used throughout the present disclosure, the technology of the present disclosure is not limited thereto, and the number of current branches may be greater than or less than 64 branches. For example, in some specific implementations, 128 current branches may be used, so that the current regulator of a particular electrode may be adjusted in 1 / 128 increments (i.e., a resolution of 1 / 128). In an illustrative example implementation with a resolution of 1 / 64, a full-output ring electrode may implement 64 branches (e.g., 64 / 64). In addition, the stimulation generation circuit 60 may be configured so that for each of the highest contributing electrodes in the highest intensity active zone, all 64 parallel current regulator branches are used.

[0082] In examples involving leads having electrodes at different circumferential positions around the perimeter of the lead (e.g., segmented electrodes or complex electrode arrays), the electrodes at various axial positions of the lead 12 can have a fractional maximum value approximately equal to the number of branches available for the electrode divided by the number of electrode segments in the ring of the segmented electrode. For example, in examples involving 64 current regulator branches, the ring electrode can have a maximum 64 / 64 fraction, while each of the N segmented electrodes in the ring of the segmented electrode can have a maximum of approximately 64 / N fractions. In an illustrative example, in the case of three segmented electrodes in the ring, each electrode can have a fractional maximum value of 21 / 64 fractions. In some examples, the fractional maximum value for any given electrode (including the ring electrode) can reach an integer number of current regulator branches (e.g., 64 branches). That is, the processing circuit 53 or the processing circuit 50 can be configured to apply any fractional maximum value based on the specific stimulation generation circuit 60 in use (e.g., the number of current regulator branches). For example, in the case of three segmented electrodes in a ring as in the previous example, each electrode can have a fractional maximum of X / X fraction (e.g., 64 / 64 fraction) or a fraction of X / X that is less than that which has been predefined by processing circuit 53 or processing circuit 50.

[0083] In examples including switch array 66, each switch of switch array 66 may couple a corresponding one of electrodes 48 to a corresponding bidirectional current regulator or main current / voltage 64 of current / voltage regulator array 68. In some examples, processing circuit 50 selectively opens and closes switches in switch array 66 to configure a housing electrode (e.g., electrode 48Q) and one or more of electrodes 48A to 48P on one or more leads as regulated electrodes by connecting to a regulated current source or current sink in current / voltage regulator array 68. In some examples, processing circuit 50 may selectively open and close switches in switch array 66 to configure a housing electrode (e.g., electrode 48Q) or an electrode on a lead as an unregulated electrode by connecting to main current / voltage 64. In addition, processing circuit 50 may selectively control individual regulated current sources or current sinks in current / voltage regulator array 68 to deliver stimulation current pulses to selected electrodes. In examples where the switch array 66 is not used, the electrodes 48 may still be coupled to the current / voltage regulator array 68 and / or the main current / voltage 64 .

[0084] The main current / voltage 64 can be a high voltage or a low voltage provided by a regulated power supply, depending on whether the electrode is programmed as an unregulated source (high voltage rail) or an unregulated sink (low voltage rail). Thus, the main current / voltage 64 can generate high and low main currents or main voltages as appropriate to selectively couple to an unregulated reference electrode as needed. The regulated power supply can generate one or more regulated voltage levels for use as the main current / voltage 64 and as a power rail for the current / voltage regulator array 68. Although the same main current / voltage 64 is shown coupled to Figure 4 , but different current amplitudes may be used for the main current coupled to the switch array 66 and the maximum current amplitude provided to the current regulator array 68. In any case, the regulated power supply may generate the regulated current amplitude from current provided by one or more power sources, such as one or more batteries (e.g., rechargeable batteries).

[0085] The processing circuit 50 controls the operation of the switch array 66 to produce the electrode configuration defined by the different stimulation programs. In some cases, the switches of the switch array 66 may be metal oxide semiconductor field effect transistors (MOSFETs) or other circuit components for switching electronic signals. The switches of the switch array 66 may be designed to carry a certain amount of unregulated current, which can be coupled to the corresponding electrode through an unregulated current path associated with the main current / voltage 64. In some examples, two or more regulated electrodes 48 may be intentionally programmed to deliver different amounts of current so that the regulated electrodes produce an unbalanced current distribution. In other examples, the regulated source current and the sink current may be balanced so that substantially all current can be provided and absorbed via the corresponding regulated current source and current sink.

[0086] To provide individual control of electrodes 48 as regulated electrodes or as unregulated reference electrodes, processing circuitry 50 controls the operation of switch array 66 and current / voltage regulator array 68. When stimulation is delivered to patient 6 (e.g., current pulses), processing circuitry 50 controls switch array 66 to couple selected stimulation electrodes of a desired electrode combination to corresponding current regulators or main current / voltage 64 of current / voltage regulator array 68 as needed. Processing circuitry 50 controls regulated bidirectional current sources of current / voltage regulator array 68 coupled to regulated electrodes to source or sink a specified amount of current. For example, processing circuitry 50 may control a selected current source or current sink on a pulse-by-pulse basis to deliver current pulses to corresponding electrodes.

[0087] The processing circuit 50 also disables a regulated bidirectional current regulator of the current / voltage regulator array 68 that is coupled to a non-active electrode, such as an electrode that is non-active as a regulated electrode in a given electrode configuration. Each regulated bidirectional current regulator of the current / voltage regulator array 68 may include an internal enable switch controlled by the processing circuit 50 that disconnects regulated power from the current regulator or otherwise disables the current source when the corresponding electrode is not used as a regulated electrode.

[0088] The use of stimulation generation circuit 60 enables the delivery of current in fractional amounts according to the fractional use of the current regulators of current / voltage regulator array 68 and switch array 66. In this way, electrical stimulator 4 can deliver electrical stimulation via each of electrodes 48 with, for example, a fractional current amplitude of the current amplitude of each other electrode 48. Thus, the use of stimulation generation circuit 60 allows the adjustment of therapy parameters defining the electrical stimulation therapy delivered by electrodes 48, while also allowing electrical stimulator 4 to maintain the ratio of the values ​​of each therapy parameter for each of electrodes 48 to each other.

[0089] For example, Figure 1 The external programmer 40 of the electrical stimulator 4 defines a relationship between multiple electrodes in the multiple electrodes 48 of the electrical stimulator 4. The relationship defines a ratio of the value of the therapy parameter of one or more electrodes to the value of one or more other electrodes 48 used to deliver stimulation. The therapy parameter defines the electrical stimulation delivered via the electrode 48 and may include, for example, one of the current amplitude or voltage amplitude, the electrical stimulation pulse count, the frequency, etc. The external programmer 40 performs a master adjustment to adjust each value of the therapy parameter of each electrode in the multiple electrodes 48 by an amount specified by the relationship to maintain the ratio of the values ​​of the therapy parameter of the multiple electrodes 48. The external programmer 40 controls the electrical stimulator 4 to deliver electrical stimulation therapy to the patient 6 according to the master adjustment. The electrical stimulator 4 may use the stimulation generation circuit 60 to deliver electrical stimulation with, for example, a fractional current amplitude of the current amplitude of each other electrode 48 via each of the electrodes 48 in order to achieve the master adjustment.

[0090] Figure 5 is a flow chart illustrating example operations for switching from bipolar stimulation to monopolar stimulation. Specifically, Figure 5 Example operations for determining a monopolar electrode combination based on a VNA corresponding to a bipolar electrode combination are shown. Figure 1 and Figure 2 The programmer 40 and the processing circuit 53 are Figure 5 Give a description.

[0091] exist Figure 5In an example of, the processing circuit 53 receives a first stimulation parameter set (502) including a bipolar electrode combination. The first stimulation parameter set can be selected by a user or automatically selected by the processing circuit 53 to treat one or more symptoms of the patient. In particular, one or more parameters, including the bipolar electrode combination, can be selected to achieve symptomatic treatment and / or reduce potential undesirable side effects. For example, a clinician can select the placement of the anode and cathode, and in some examples select the amplitude, pulse width and / or frequency to generate an electric field that activates a desired nerve or neuron.

[0092] The processing circuit 53 may then estimate a VNA (504) corresponding to the first stimulation parameter set. This process may be initiated by a user selecting a selectable icon (e.g., a conversion button) associated with converting a bipolar electrode combination to a monopolar electrode combination or an automated process associated with identifying an energy-saving electrode combination or an alternative for therapy. In some examples, the processing circuit 53 may generate a VNA that can calculate an electric field generated by the parameter set and apply the electric field to a tissue model that is common or specific to the patient. Based on this first VNA, the processing circuit 53 may determine a second stimulation parameter set (506) including a monopolar electrode combination. In this process, the processing circuit 53 may calculate several VNAs for multiple monopolar electrode combinations, and compare these VNAs with the first VNA to identify the best fit or otherwise select a similar VNA and an associated monopolar electrode combination. In some examples, the processing circuit 53 may reversely calculate a parameter set using a monopolar electrode combination that implements a similar VNA.

[0093] In response to determining that the second stimulation parameter set includes a monopolar electrode combination, processing circuitry 53 may control IMD 14 to deliver the second electrical stimulation using the monopolar electrode combination instead of delivering the first electrical stimulation using the bipolar electrode combination (508). In some examples, processing circuitry 53 may enable a user to select an icon that causes processing circuitry 53 to revert to a previous bipolar electrode combination and parameter set to return to a previous stimulation therapy when desired.

[0094] Figure 6 is a flow chart illustrating example operations for converting bipolar stimulation to monopolar stimulation in response to user input. Specifically, Figure 6 Example operations for determining a monopolar electrode combination from a bipolar electrode combination in response to a user request are shown. Figure 1 and Figure 2 The programmer 40 and the processing circuit 53 are Figure 6 Give a description.

[0095] exist Figure 6In the example of , the processing circuit 53 controls the user interface 59 to present a representation of a first electrical stimulation defined by a first stimulation parameter set including a bipolar electrode combination (602). The representation can be a graphical depiction of a VNA corresponding to the first electrical stimulation, one or more numerical representations of the VNA, or even just the first stimulation parameter set. The processing circuit 53 can also control the user interface 59 to present a selectable icon (e.g., a conversion button) that is configured to convert the first electrical stimulation to a second electrical stimulation including a monopolar electrode combination (604). The selectable icon can be displayed before or after presenting the representation of the first electrical stimulation.

[0096] In response to receiving a user selection of the selectable icon (606), processing circuit 53 converts the first electrical stimulation to a second electrical stimulation defined by a second set of stimulation parameters including a monopolar electrode combination (608). Processing circuit 53 may convert the electrical stimulation by any of the techniques described herein, such as by comparing candidate VNAs from corresponding monopolar electrode combinations, switching all anodes to cathodes and adding anodes away from the leads and / or target tissue, or any combination thereof. Processing circuit 53 may control IMD 14 to deliver the second electrical stimulation using the monopolar electrode combination instead of delivering the first electrical stimulation using the bipolar electrode combination (508). In some examples, processing circuit 53 may enable the user to select the selectable icon again, which causes processing circuit 53 to revert to the previous bipolar electrode combination and parameter set to return to the previous stimulation therapy when desired.

[0097] FIG. 7A to FIG. 7B is a conceptual diagram showing a screen of an example user interface according to the technology of the present disclosure. User interface 800 may be Figure 2 An example of a user interface 59 of a programmer 40. Fig. 7A As depicted in the example of , user interface 800 depicts representations of electrode icons 848A, 848B-1, 848B-2, 848B-3, 848C-1, 848C-2, 848C-3, and 848D (hereinafter, “electrode icons 848”) disposed on leads 812 within display area 820. Fig. 7A and Figure 7B In the example of FIG. 8A , each of the electrode icons 848A to 848D corresponds to Figure 1 and Figure 3 The corresponding electrode in the electrode 48, and the lead icon 812 corresponds to Figure 1 Lead 12.

[0098] exist Fig. 7AIn the example of FIG. 1 , electrode icons 848B-1, 848B-2, 848B-3 (collectively referred to as “electrode icons 848B”) represent a first subset of electrodes 48 disposed at different circumferential locations around lead 12. Similarly, electrode icons 848C-1, 848C-2, 848C-3 (collectively referred to as “electrode icons 848C”) represent a second subset of electrodes 48 disposed at different circumferential locations around lead 12. Fig. 7A In the example of FIG. 1 , each of the first subset of electrodes 48 and the second subset of electrodes 48 is represented by three electrode icons (e.g., electrode icons 848B-1, 848B-2, 848B-3 in the first subset and electrode icons 848C-1, 848C-2, 848C-3 in the second subset), but in other examples, each subset of electrodes 48 may have any number of electrodes (e.g., more or less than 3 electrodes per subset). In addition, although in Fig. 7A In the example, lead icon 812 has two rings of subsets of electrode icons 848, but in other examples, lead icon 812 may have more rings, fewer rings, or no rings of electrode icons 848, each ring including one or more subsets of electrodes 848, depending on the actual configuration of lead 12.

[0099] exist Fig. 7A In the example of FIG. 8 , electrode icons 848B-1, 848B-2, and 848B-3 indicate that the corresponding electrode 48 is selected to be used as a cathode for Figure 1 The electrical stimulator 4 delivers electrical stimulation. Ring electrode 848A and electrodes 848C-1, 848C-2, 848C-3 indicate that the corresponding electrode 48 is selected as the anode. Fig. 7A In this configuration, the selected electrodes are in a bipolar electrode configuration to generate VNAs 802, 804, and 806. In some examples, VNAs 802, 804, and 806 may be referenced and / or displayed as a single VNA regardless of whether there is overlap between portions of the VNA. Display area 820 further depicts representations of VNAs 802, 804, and 806 generated by delivery of electrical stimulation by the electrical stimulator 4 according to therapy parameters selected for electrodes corresponding to electrode icons 848B-1, 848B-2, 848B-3, 848C-1, 848C-2, 848C-3, and 848A. Although VNAs 802, 804, and 806 are in Fig. 7A In the examples of , the VNAs are shown as discrete VNAs, but in some examples they may be collectively referred to as a single VNA.

[0100] The user interface 800 includes a toggle button 838 that allows the clinician to activate or deactivate the delivery of electrical stimulation by the electrical stimulator 4 according to the therapy parameters selected for the electrodes identified as cathode and anode. The user interface 800 also includes an electrode status window 826 that displays a side view of the status of the electrodes 48. For example, Fig. 7A As depicted in the example of , electrode status window 826 depicts electrode icons 848B-1, 848B-2, 848B-3, 848C-1, 848C-2, and 848C-3, thereby indicating that the corresponding electrode 48 is used as an anode for delivery of electrical stimulation by electrical stimulator 4. For specific implementations where lead 12 includes a subset of electrodes 48 disposed in a ring around lead 12, such as, for example, for electrodes corresponding to electrode icons 848B-1, 848B-2, 848B-3, 848C-1, 848C-2, and 848C-3, use of electrode status window 826 can assist a clinician in viewing the status of each of electrodes 48, where one or more of electrode icons 848 may be obscured from view by the 3-dimensional depiction of lead icon 812 within display area 820. For example, as Fig. 7A As depicted in the example of , electrode icons 848B- 1 and 848C- 1 are at least partially obscured by the 3-dimensional depiction of lead icon 812 within display window 820 .

[0101] The user interface 800 also includes an electrode selection panel 824. Fig. 7A As depicted in FIG. 8 , electrode selection panel 824 includes indicators 858A, 858B-1, 858B-2, 858B-3, 858C-1, 858C-2, 858C-3, and 858D, each of which depicts a selection state of a corresponding axial representation (e.g., cross-sectional views of different axial positions corresponding to the electrode position) of one of electrode icons 848A, 848B-1, 848B-2, 848B-3, 848C-1, 848C-2, 848C-3, and 848D. Fig. 7AAs depicted in , indicator 858B (black shading) represents that the clinician has selected the electrode corresponding to electrode icon 858B for therapy parameter adjustment (e.g., via therapy parameter control panel 822). As depicted in electrode selection panel 824, the clinician has set the current amplitude of the electrical stimulation delivered via each of the electrodes corresponding to electrode icon 858B to a value of 3.0 mA. Indicators 858C and 858A (gray shading) represent that the clinician has selected electrodes 48 corresponding to electrode icons 858C and 858A for delivery of stimulation, but therapy parameters for such electrodes are not currently being adjusted. As depicted in electrode selection panel 824, the clinician has previously set the current amplitude of the electrical stimulation delivered via each of the electrodes 48 corresponding to electrode icons 848C-1, 848C-2, and 848C-3 to a value of 0.5 mA, and set a value of 1.5 mA for electrode 848A. Indicator 858D (white shading) represents that electrode 48 corresponding to electrode icon 858D is not currently being used to deliver stimulation. Fig. 7A The anode and cathode indicated as active in the examples are an example bipolar electrode combination.

[0102] In some examples, when active, the indicator 858 displays the magnitude and value of the marker when both are in the interactive and selected state. The indicator 858 control is a single-select option, for example, clicking the second button switches from the first button to the second button. Each indicator 858 displays the magnitude of the corresponding single electrode 48. In some examples, the display window 820 displays the total magnitude of each ring or the magnitude of each electrode within each ring.

[0103] Electrode selection panel 824 also includes ring switching buttons 828B and 828C. Ring switching buttons 828B and 828C allow clinicians to turn on or off all electrodes of the ring with one button. For example, a clinician can select ring switching button 828B to convert each electrode in the electrode 48 corresponding to electrode icons 848B-1, 848B-2, and 848B-3 into an "on" state. In some examples, when ring switching button 828B is selected, each electrode in the electrode corresponding to electrode icons 848b-1, 848B-2, and 848B-3 that were previously in an "off" state can be converted to an "on" state and use a predefined value of a therapy parameter (e.g., initial current amplitude) for delivery of electrical stimulation. In addition, a clinician can select ring switching button 828B for a second time to convert each electrode in the electrode corresponding to electrode icons 848B-1, 848B-2, and 848B-3 into an "off" state.

[0104] In some examples, each ring toggle button 828B, 828C selects only available electrodes active on the same ring. For example, if only two segments 858C-1 and 858C3 are part of the configuration, the ring toggle button 828C selects only 858C-1 and 858C3 and not 858C-2.

[0105] The user interface 800 also includes a therapy parameter control panel 822 that allows the clinician to adjust the value of one or more therapy parameters of the currently selected electrodes 48. Fig. 7A In the example of FIG. 8 , the clinician has selected electrodes 48 corresponding to electrode icons 848B-1, 848B-2, and 848B-3, and set a value of 1.0 milliamps for the current amplitude of the electrical stimulation delivered via the electrodes. The therapy parameter control panel 822 can be operated so that the user can adjust the value of the therapy parameter of the electrodes 48 corresponding to the electrode icons 848B-1, 848B-2, and 848B-3 by pressing the increment button 832, the decrement button 834, the maximum button 830, or the minimum button 836. In addition, the clinician can select the type of therapy parameter (e.g., current amplitude, pulse duration, or pulse frequency) by selecting the corresponding therapy parameter type button such as the milliamp button 840, the pulse duration button 842, or the pulse frequency button 844.

[0106] The status color (e.g., black, gray, or white) of the indicator 858 indicates the current status of therapy delivery by the electrical stimulator 4 using the corresponding electrode 48. As an example, where the user interface 800 is a touch-sensitive display, the clinician can select a specific electrode 48 to adjust via the therapy parameter control panel 822 by pressing the indicator 858 corresponding to the desired electrode 48. In addition, the therapy parameter control panel 822 can automatically update to display the value of the therapy parameter for the currently selected electrode 48. Provide Fig. 7A The colors are for ease of illustration only, and other colors may be used to indicate various states or configurations of the electrodes 48.

[0107] Electrode selection panel 824 includes a toggle button 801. As described herein, user selection of toggle button 801 may cause processing circuit 53 to Fig. 7A 802, 804, and 806. For example, user selection of the conversion button 801 may cause the user interface 800 to change to a monopolar electrode combination that may have a VNA similar to the VNAs 802, 804, and 806. Figure 7B .

[0108] like Figure 7B As shown in the example of Fig. 7A The bipolar electrode combination is converted to Figure 7BAs described herein, the processing circuit 53 can identify a monopolar electrode combination and other parameter values ​​(such as amplitude) that result in a VNA similar to a previous bipolar electrode combination VNA. Figure 7B In the example of , this conversion has resulted in changing electrodes 848C-1, 848C-2, 848C-3, and 848A from anodes to cathodes. In addition, an anode has been assigned to electrode 849, which is shown as a representation of the housing of IMD 14.

[0109] VNA 810 is a Figure 7B 858B-1, 858B-2, and 858B-3 indicate that these electrodes are selected and can be controlled by pressing the increment button 832 or the decrement button 834. In this way, the processing circuit can adjust individual or all electrodes at once as selected by the user. Figure 7B In the example, a total of 2.4 mA may be delivered from the selected cathode, which may be less than Fig. 7A 802, 804, and 806, while still achieving a VNA 810 similar in total to VNAs 802, 804, and 806. A user's selection of the toggle button 801 again can cause the processing circuit 53 to revert to the previous bipolar electrode combination. In some examples, selection of the toggle button 801 can cause stimulation to be turned off so that the user can check the monopolar combination before starting stimulation again. In other examples, stimulation can continue when switching to determine whether the patient can perceive a difference in the change in stimulation.

[0110] The following embodiments are described herein.

[0111] Embodiment 1: A system comprising: a memory; a processing circuit operably coupled to the memory and configured to: receive a first stimulation parameter set including a bipolar electrode combination defining a first electrical stimulation; estimate a neural activation volume (VNA) corresponding to the first stimulation parameter set; determine a second stimulation parameter set including a monopolar electrode combination defining a second electrical stimulation based on the first VNA; and control an implantable medical device to deliver the second electrical stimulation instead of the first electrical stimulation.

[0112] Embodiment 2: A system according to embodiment 1, wherein the processing circuit is configured to determine the second stimulation parameter set by at least the following items: selecting one or more cathodes on the lead carrying the bipolar electrode combination, the monopolar electrode combination including the one or more cathodes and at least one anode away from the lead; estimating a second VNA corresponding to the stimulation generated by the monopolar electrode combination; identifying amplitude values ​​of the one or more cathodes at which one or more characteristics of the second VNA correspond to one or more characteristics of the first VNA; and generating the second stimulation parameter set to include the one or more cathodes and the amplitude values.

[0113] Embodiment 3: The system according to embodiment 2, wherein the amplitude value is a second amplitude value that is smaller than the first amplitude value of the first stimulation parameter set.

[0114] Embodiment 4: The system of any one of Embodiments 2 and 3, the processing circuit being configured to select the one or more cathodes on the lead by at least maintaining any cathode of the bipolar electrode combination and switching any anode of the bipolar electrode combination to a cathode.

[0115] Embodiment 5: A system according to any one of Embodiments 2 to 4, wherein the one or more characteristics include at least one of volume, distance from a corresponding electrode, or distance from a lead at a corresponding axial position, and wherein the processing circuit is configured to identify the amplitude value of the one or more cathodes at which one or more characteristics of the second VNA correspond to one or more characteristics of the first VNA.

[0116] Embodiment 6: A system according to any one of Embodiments 2 to 5, wherein the one or more characteristics of the second VNA include multiple characteristics of the second VNA, wherein the one or more characteristics of the first VNA include multiple characteristics of the first VNA, and wherein different characteristics identify the amplitude values ​​of the one or more cathodes based on different weighted characteristics of the one or more characteristics of the first VNA.

[0117] Embodiment 7: The system according to any one of embodiments 1 to 6, wherein the bipolar electrode combination includes at least one anode disposed on the implantable medical lead and at least one cathode disposed on the implantable medical lead.

[0118] Embodiment 8: A system according to any one of Embodiments 1 to 7, wherein the monopolar electrode combination includes at least one anode disposed on the housing of the implantable medical device and at least one cathode disposed on an implantable medical lead coupled to the implantable medical device.

[0119] Embodiment 9: The system according to any one of embodiments 1 to 8, wherein the second set of stimulation parameters includes at least one of amplitude, pulse width and pulse frequency.

[0120] Embodiment 10: The system of any one of embodiments 1 to 9, wherein the bipolar electrode combination comprises at least one electrode of a plurality of electrodes disposed at different locations around the circumference of the lead.

[0121] Embodiment 11: The system of any one of embodiments 1 to 10, further comprising a lead comprising a plurality of electrodes, a subset of electrodes from the plurality of electrodes corresponding to the bipolar electrode combination.

[0122] Embodiment 12: The system according to any one of embodiments 1 to 11, the system further comprising an external programmer, the external programmer comprising a processing circuit and a memory.

[0123] Embodiment 13: A system according to any one of Embodiments 1 to 12, wherein the system further comprises a display, and wherein the processing circuit is further configured to control the display to present a selectable icon, which, when selected, causes the processing circuit to determine, based on the first VNA, the second stimulation parameter set including the monopolar electrode combination that defines the second electrical stimulation.

[0124] Embodiment 14: A method comprising receiving, by a processing circuit, a first stimulation parameter set including a bipolar electrode combination that defines a first electrical stimulation; estimating, by the processing circuit, a neural activation volume (VNA) corresponding to the first stimulation parameter set; determining, by the processing circuit based on the first VNA, a second stimulation parameter set including a monopolar electrode combination that defines a second electrical stimulation; and controlling, by the processing circuit, an implantable medical device to deliver the second electrical stimulation instead of the first electrical stimulation.

[0125] Embodiment 15: A method according to Embodiment 14, wherein determining the second stimulation parameter set comprises: selecting one or more cathodes on a lead carrying the bipolar electrode combination, the monopolar electrode combination comprising the one or more cathodes and at least one anode remote from the lead; estimating a second VNA corresponding to the stimulation generated by the monopolar electrode combination; identifying amplitude values ​​of the one or more cathodes at which one or more characteristics of the second VNA correspond to one or more characteristics of the first VNA; and generating the second stimulation parameter set to include the one or more cathodes and the amplitude values.

[0126] Embodiment 16: The method according to Embodiment 15, wherein the amplitude value is a second amplitude value that is smaller than the first amplitude value of the first stimulation parameter set.

[0127] Embodiment 17: The method of any one of Embodiments 15 and 16, wherein selecting the one or more cathodes on the lead comprises maintaining any cathode of the bipolar electrode combination and switching any anode of the bipolar electrode combination to a cathode.

[0128] Embodiment 18: A method according to any one of Embodiments 15 to 17, wherein the one or more characteristics include at least one of volume, distance from a corresponding electrode, or distance from a lead at a corresponding axial position, and the method further includes identifying amplitude values ​​of the one or more cathodes at which one or more characteristics of the second VNA correspond to one or more characteristics of the first VNA.

[0129] Embodiment 19: A method according to any one of Embodiments 15 to 18, wherein the one or more characteristics of the second VNA include multiple characteristics of the second VNA, wherein the one or more characteristics of the first VNA include multiple characteristics of the first VNA, and wherein different characteristics identify the amplitude values ​​of the one or more cathodes based on different weighted characteristics of the one or more characteristics of the first VNA.

[0130] Embodiment 20: The method according to any one of Embodiments 14 to 19, wherein the bipolar electrode combination includes at least one anode disposed on the implantable medical lead and at least one cathode disposed on the implantable medical lead.

[0131] Embodiment 21: A method according to any one of Embodiments 14 to 20, wherein the monopolar electrode combination includes at least one anode disposed on the housing of the implantable medical device and at least one cathode disposed on an implantable medical lead coupled to the implantable medical device.

[0132] Embodiment 22: The method according to any one of Embodiments 14 to 21, wherein the second set of stimulation parameters includes at least one of amplitude, pulse width and pulse frequency.

[0133] Embodiment 23: The method of any one of Embodiments 14 to 22, wherein the bipolar electrode combination comprises at least one electrode of a plurality of electrodes disposed at different locations around the periphery of the lead.

[0134] Embodiment 24: According to the method described in any one of Embodiments 14 to 23, the method also includes controlling the display to present a selectable icon, which, when selected, causes the processing circuit to determine the second stimulation parameter set including the monopolar electrode combination that defines the second electrical stimulation based on the first VNA.

[0135] Embodiment 25: A system comprising: a memory comprising a first stimulation parameter set defining a first electrical stimulation; and a processing circuit configured to control a user interface to present a representation of the first electrical stimulation defined by the first stimulation parameter set including a bipolar electrode combination; the processing circuit controlling the user interface to present a selectable icon associated with converting the first electrical stimulation defined by the first stimulation parameter set including the bipolar electrode combination into a second electrical stimulation defined by a second stimulation parameter set including a monopolar electrode combination; the processing circuit receiving a user selection of the selectable icon; and in response to receiving the user selection of the selectable icon, converting the first electrical stimulation into the second electrical stimulation defined by the second stimulation parameter set including the monopolar electrode combination.

[0136] Embodiment 26: The system of Embodiment 25, wherein the processor is configured to convert the first electrical stimulation into the second electrical stimulation by at least comparing a second neural activation volume (VNA) associated with the second electrical stimulation with a first VNA associated with the first electrical stimulation.

[0137] Embodiment 27: The system of any one of Embodiments 25 and 26, wherein the representation comprises a visual representation of the VNA, and wherein the processor is configured to control the user interface to present the visual representation of the VNA corresponding to the second electrical stimulation.

[0138] Embodiment 28: A system according to any one of Embodiments 25 to 27, wherein the processing circuit is configured to control the user interface to present one or more controls, and the one or more controls are configured to receive user input to adjust the value of the corresponding stimulation parameter of the second stimulation parameter set.

[0139] Embodiment 29: A system according to any one of Embodiments 25 to 28, wherein the processing circuit is configured to switch between the first electrical stimulation comprising the bipolar electrode combination and the second electrical stimulation comprising the monopolar electrode combination in response to a user selection of the selectable icon.

[0140] Embodiment 30: The system according to any one of Embodiments 25 to 29, further comprising a display configured to present the user interface including the selectable icon.

[0141] Embodiment 31: According to any one of embodiments 26 to 30, the system also includes an external programmer, and the external programmer includes the processing circuit and the display.

[0142] Embodiment 32: According to any one of Embodiments 25 to 31, the system further comprises an implantable medical device configured to deliver the first electrical stimulation and the second electrical stimulation.

[0143] Embodiment 33: A method, comprising controlling, by a processing circuit, a user interface to present a representation of a first electrical stimulation defined by a first stimulation parameter set including a bipolar electrode combination; controlling, by the processing circuit, a user interface to present a selectable icon associated with converting the first electrical stimulation defined by the first stimulation parameter set including the bipolar electrode combination into a second electrical stimulation defined by a second stimulation parameter set including a monopolar electrode combination; receiving, by the processing circuit, a user selection of the selectable icon; and in response to receiving the user selection of the selectable icon, converting the first electrical stimulation into the second electrical stimulation defined by the second stimulation parameter set including the monopolar electrode combination.

[0144] Embodiment 34: The method of Embodiment 33, wherein converting the first electrical stimulation into the second electrical stimulation comprises comparing a second volume of neural activation (VNA) associated with the second electrical stimulation with a first VNA associated with the first electrical stimulation.

[0145] Embodiment 35: The method of any one of Embodiments 33 and 34, wherein the representation comprises a visual representation of the VNA, and wherein the method further comprises controlling the user interface to present the visual representation of the VNA corresponding to the second electrical stimulation.

[0146] Embodiment 36: According to the method described in any one of Embodiments 33 to 35, the method further comprises controlling the user interface to present one or more controls, wherein the one or more controls are configured to receive user input for adjusting the value of the corresponding stimulation parameter of the second stimulation parameter set.

[0147] Embodiment 37: According to the method described in any one of Embodiments 33 to 36, the method further comprises switching between the first electrical stimulation comprising the bipolar electrode combination and the second electrical stimulation comprising the monopolar electrode combination in response to a user's selection of the selectable icon.

[0148] Embodiment 38: According to the method described in any one of Embodiments 33 to 37, the method further comprises presenting the user interface including the selectable icon by a display.

[0149] It should be understood that the various aspects disclosed herein may be combined in combinations different from those specifically presented in the specification and drawings. It should also be understood that, depending on the example, certain actions or events of any of the processes or methods described herein may be performed in a different order, may be added, merged, or omitted entirely (e.g., not all described actions or events may be required to perform these techniques). In addition, although for clarity, certain aspects of the present disclosure are described as being performed by a single module or unit, it should be understood that the techniques of the present disclosure may be performed by a combination of units or modules associated with, for example, a medical device.

[0150] In one or more examples, the described techniques can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions can be stored as one or more instructions or codes on a computer-readable medium and executed by a hardware-based processing unit. The computer-readable medium may include a non-transitory computer-readable medium that corresponds to a tangible medium, such as a data storage medium (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 can be accessed by a computer).

[0151] 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 circuits. Thus, the term "processor" as used herein may refer to any of the aforementioned structures or any other physical structure suitable for implementing the described techniques. Additionally, these techniques may be fully implemented in one or more circuits or logic elements.

Claims

1. A system, comprising: Memory; and a processing circuit operatively coupled to the memory and configured to: receiving a first set of stimulation parameters including a bipolar electrode combination defining a first electrical stimulation; estimating a volume of neural activation (VNA) corresponding to the first stimulation parameter set; determining a second stimulation parameter set including a monopolar electrode combination defining a second electrical stimulation based on the first VNA; and The implantable medical device is controlled to deliver the second electrical stimulation instead of the first electrical stimulation.

2. The system of claim 1 , wherein the processing circuit is configured to determine the second set of stimulation parameters by at least: selecting one or more cathodes on a lead carrying the bipolar electrode assembly, the monopolar electrode assembly comprising the one or more cathodes and at least one anode remote from the lead; estimating a second VNA corresponding to the stimulus generated by the monopolar electrode combination; identifying amplitude values ​​of the one or more cathodes at which one or more characteristics of the second VNA correspond to one or more characteristics of the first VNA; and The second stimulation parameter set is generated to include the one or more cathodes and the amplitude value.

3. The system of claim 2, wherein the amplitude value is a second amplitude value that is less than a first amplitude value of the first stimulation parameter set.

4. A system according to any one of claims 2 and 3, wherein the processing circuit is configured to select the one or more cathodes on the lead by at least maintaining any cathode of the bipolar electrode combination and switching any anode of the bipolar electrode combination to a cathode.

5. A system according to any one of claims 2 to 4, wherein the one or more characteristics include at least one of volume, distance from a corresponding electrode, or distance from a lead at a corresponding axial position, and wherein the processing circuit is configured to identify the amplitude value of the one or more cathodes at which one or more characteristics of the second VNA correspond to one or more characteristics of the first VNA.

6. The system of any one of claims 2 to 5, wherein the one or more characteristics of the second VNA include multiple characteristics of the second VNA, wherein the one or more characteristics of the first VNA include multiple characteristics of the first VNA, and wherein different characteristics identify the amplitude values ​​of the one or more cathodes based on different weighted characteristics of the one or more characteristics of the first VNA.

7. The system of any one of claims 1 to 6, wherein the bipolar electrode combination comprises at least one anode disposed on an implantable medical lead and at least one cathode disposed on the implantable medical lead.

8. The system of any one of claims 1 to 7, wherein the monopolar electrode combination comprises at least one anode disposed on a housing of the implantable medical device and at least one cathode disposed on an implantable medical lead coupled to the implantable medical device.

9. The system of any one of claims 1 to 8, wherein the second set of stimulation parameters comprises at least one of amplitude, pulse width, and pulse frequency.

10. The system of any one of claims 1 to 9, wherein the bipolar electrode combination includes at least one electrode of a plurality of electrodes disposed at different locations around the circumference of the lead.

11. The system of any one of claims 1 to 10, further comprising a lead comprising a plurality of electrodes, a subset of electrodes from the plurality of electrodes corresponding to the bipolar electrode combination.

12. The system of any one of claims 1 to 11, further comprising an external programmer, the external programmer comprising the processing circuit and the memory.

13. The system according to any one of claims 1 to 12, wherein the system further comprises a display, and Wherein the processing circuit is further configured to control the display to present a selectable icon which, when selected, causes the processing circuit to determine, based on the first VNA, the second set of stimulation parameters including the monopolar electrode combination defining the second electrical stimulation.

14. The system of claim 13, wherein the processing circuit is configured to: receiving a selection of the selectable icon after determining the second set of stimulation parameters; and In response to receiving said selection of said selectable icon, reverting to said first set of stimulation parameters.

15. A computer readable medium comprising instructions which, when executed, cause the processing circuit to perform the functions of any one of claims 1 to 14.

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