WO2025022207A1 - Electrode lead positioning - Google Patents

Abstract

Devices, systems, and techniques are disclosed for positioning electrode leads. A system may include processing circuitry configured to receive, for at least one electrode implanted within each patient of a patient population, efficacy data indicative of an effectiveness of electrical stimulation therapy delivered via each respective electrode of the at least one electrode and an anatomical position of the respective electrode within the respective patient. The processing circuitry may be further configured to determine, based on the efficacy data for the patient population, a plurality of efficacy indications including a respective efficacy indication for at least some anatomical positions of the plurality of anatomical positions. The processing circuitry may be further configured to generate, based on the efficacy indications, a visual model depicting the plurality of efficacy indications for each anatomical position of the plurality of anatomical positions in a map, and output, for display, the visual model.

Description

ELECTRODE LEAD POSITIONING

TECHNICAL FIELD

[0001] This Application claims priority from U.S. Provisional Patent Application 63/516,038 filed 27 July 2023, the entire content of which is incorporated herein by reference.

[0002] The present disclosure generally relates to electrical stimulation, and positioning medical leads that deliver electrical stimulation.

BACKGROUND

[0003] Medical devices may be external or implanted, and may be used to deliver electrical stimulation therapy to various tissue sites of a patient to treat a variety of symptoms or conditions such as chronic pain, tremor, Parkinson’s disease, dystonia, other movement disorders, epilepsy, headache, psychiatric disorders, memory dysfunction, urinary or fecal incontinence, sexual dysfunction, obesity and eating disorders, or gastroparesis. A medical device may deliver electrical stimulation therapy via one or more leads that include electrodes located proximate to target locations associated with the brain, the spinal cord, pelvic nerves, peripheral nerves, or the gastrointestinal tract of a patient. Hence, electrical stimulation may be used in different therapeutic applications, such as deep brain stimulation (DBS), occipital nerve stimulation (ONS), spinal cord stimulation (SCS), pelvic stimulation, sacral nerve stimulation, phrenic nerve stimulation, gastric stimulation, or peripheral nerve field stimulation (PNFS).

[0004] A clinician may select values for a number of programmable parameters in order to define the electrical stimulation therapy to be delivered by the implantable stimulator to a patient. For example, the clinician may select one or more electrodes for delivery of the stimulation, a waveform pattern, a polarity of each selected electrode, a voltage or current amplitude, a pulse width, and a pulse frequency as stimulation parameters in a multitude of modes continuous/cy cling and configurations. A set of parameters, such as a set including electrode combination and/or configuration, electrode polarity, voltage or current amplitude, pulse width and pulse rate, may be referred to as a program in the sense that they define the electrical stimulation therapy to be delivered to the patient. Several programs could be assimilated into one or more groups. SUMMARY

[0005] In general, this disclosure describes devices, systems, and techniques for positioning medical leads carrying one or more electrodes, for example, based on anatomical maps for electrode lead placement. For example, a system may receive efficacy data indicative of effectiveness of electrical stimulation therapy delivered via electrodes at various anatomical positions in a plurality of patients within a patient population (e.g., patients that have already received stimulation therapy). Leads may carry one or more electrodes, and the location and orientation of each lead may affect the anatomical position of electrodes carried by that lead. The system may determine a respective efficacy indication for each anatomical position, based on data associated with placement of electrodes at that anatomical position for a patient population. The system may generate and display a visual model depicting the efficacy indication for each anatomical position in a map. A clinician may use the visual model to compare the relative effectiveness of various anatomical positions of electrodes, and determine a candidate anatomical location to place one or more leads, and ultimately, electrodes, for electrical stimulation therapy. In some examples, the system may automatically determine a candidate anatomical location for one or more leads based on the efficacy indications and/or visual model.

[0006] In an example, a system includes processing circuitry configured to receive, for at least one electrode of one or more leads implanted within each patient of a patient population, efficacy data. The efficacy data may be indicative of an effectiveness of electrical stimulation therapy delivered via each respective electrode of the at least one electrode and an anatomical position of the respective electrode within the respective patient. A plurality of anatomical positions for a tissue region includes the anatomical position. The processing circuitry may be further configured to determine, based on the efficacy data for the patient population, a plurality of efficacy indications including a respective efficacy indication for at least some anatomical positions of the plurality of anatomical positions. The processing circuitry may be further configured to generate, based on the plurality of efficacy indications, a visual model depicting the plurality of efficacy indications for each anatomical position of the plurality of anatomical positions in a map. The processing circuitry may be further configured to output, for display, the visual model.

[0007] In another example, a method may include receiving, by a processing circuitry, for at least one electrode of one or more leads implanted within each patient of a patient population, efficacy data. The efficacy data may be indicative of an effectiveness of electrical stimulation therapy delivered via each respective electrode of the at least one electrode and an anatomical position of the respective electrode within the respective patient. A plurality of anatomical positions for a tissue region includes the anatomical position. The method may further include, determining, by the processing circuitry, based on the efficacy data for the patient population, a plurality of efficacy indications including a respective efficacy indication for at least some anatomical positions of the plurality of anatomical positions. The method may further include generating, by the processing circuitry, based on the plurality of efficacy indications, a visual model depicting the plurality of efficacy indications for each anatomical position of the plurality of anatomical positions in a map. The method may further include outputting, by the processing circuitry, for display, the visual model.

[0008] In another example, a non-transitory, computer-readable medium may include instructions, that when executed, are configured to cause a processor to receive, for at least one electrode of one or more leads implanted within each patient of a patient population, efficacy data. The efficacy data may be indicative of an effectiveness of electrical stimulation therapy delivered via each respective electrode of the at least one electrode and an anatomical position of the respective electrode within the respective patient. A plurality of anatomical positions for a tissue region includes the anatomical position. The instructions may be further configured to cause the processor to determine, based on the efficacy data for the patient population, a plurality of efficacy indications including a respective efficacy indication for at least some anatomical positions of the plurality of anatomical positions. The instructions may be further configured to cause the processor to generate, based on the plurality of efficacy indications, a visual model depicting the plurality of efficacy indications for each anatomical position of the plurality of anatomical positions in a map. The instructions may be further configured to cause the processor to output, for display, the visual model.

[0009] The details of one or more examples of the techniques of this disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniques will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF DRAWINGS

[0010] FIG. l is a conceptual diagram illustrating an example system that includes an implantable medical device (IMD) configured to deliver DBS to a patient according to an example of the techniques of the disclosure.

[0011] FIG. 2 is a block diagram of the example IMD of FIG. 1 for delivering DBS therapy according to an example of the techniques of the disclosure.

[0012] FIG. 3 is a block diagram of the external programmer of FIG. 1 for determining electrode placement and controlling delivery of DBS therapy according to an example of the techniques of the disclosure.

[0013] FIGS. 4 A and 4B are conceptual diagrams of example leads with respective electrodes carried by the lead.

[0014] FIGS. 5A, 5B, 5C, and 5D are conceptual diagrams of example electrodes disposed around a perimeter of a lead at a particular longitudinal location.

[0015] FIG. 6 illustrates an example scheme for generating a map of a plurality of anatomical positions based on placement of leads including electrodes in a patient population. [0016] FIG. 7 is a map representing effectiveness of electrodes at different anatomical positions.

[0017] FIG. 8 is a flowchart illustrating an example technique for generating a visual model depicting efficacy for a plurality of anatomical positions of electrodes.

DETAILED DESCRIPTION

[0018] The present disclosure describes devices, systems, and techniques for positioning leads, for example, based on anatomical maps for lead placement. A patient may suffer from one or more symptoms treatable by electrical stimulation therapy. For example, a patient may suffer from brain disorder such as Parkinson’s disease, Alzheimer’s disease, another type of movement disorder, neurological or psychiatric condition. Deep brain stimulation (DBS) may be an effective treatment to reduce the symptoms associated with such disorders. [0019] Electrical stimulation therapy may be delivered via one or more electrodes. The electrodes may be carried by leads. For example, a lead may include one or more electrodes, at different axial or circumferential locations along the lead. The location and orientation of the lead in tissue, for example, at a site for delivering electrical stimulation therapy, in turn affects the location and orientation of electrodes carried by the lead. An anatomical position of an electrode may include an anatomical location and a circumferential orientation of the electrode. Thus, two anatomical positions may differ in one or both of the anatomical location or the circumferential orientation.

[0020] However, a relatively large number of potential anatomical positions may be available to a clinician for implanting one or more leads. The clinician may select an implant location for a lead based on anecdotal data and experience of the clinician in treating the condition of the patient. Since the clinician may determine the implant location of the lead, and the electrodes carried thereon, based on a limited set of information, the lead implant location may not be optimized for the patient and/or the condition intended to be treated by the lead to be implanted.

[0021] As described herein, the system may generate a visual model indicative of efficacy indications for electrical stimulation therapy delivered at different anatomical positions which can provide a guide for a clinician in planning implantation of a lead. For example, the clinician may assess the accessibility and effectiveness of one or more positions, and determine candidate anatomical positions for placing one or more electrodes, or for one or more leads. For example, a clinician may select one, two, or more electrodes to be placed based on the visual model, and select one or more leads to position the electrodes. A system may generate the visual model based on efficacy data for electrodes across a plurality of historical patients, and output the visual model for display.

[0022] In an example, a system includes processing circuitry configured to receive, for at least one electrode of one or more leads implanted within each patient of a patient population, efficacy data. The efficacy data may be indicative of an effectiveness of electrical stimulation therapy delivered via each respective electrode of the at least one electrode and an anatomical position of the respective electrode within the respective patient. A plurality of anatomical positions for a tissue region includes the anatomical position. The processing circuitry may be further configured to determine, based on the efficacy data for the patient population, a plurality of efficacy indications including a respective efficacy indication for at least some anatomical positions of the plurality of anatomical positions. The processing circuitry may be further configured to generate, based on the plurality of efficacy indications, a visual model depicting the plurality of efficacy indications for each anatomical position of the plurality of anatomical positions in a map. The processing circuitry may be further configured to output, for display, the visual model.

[0023] The system may thus allow a clinician to visually compare the efficacy for electrodes placed at different anatomical positions, and select one or more anatomical positions for placing one or more electrodes. Instead of selecting electrode placement based on anecdotal data and experience, the clinician may base the selection on efficacy data from a patient population, which may increase the reliability and predictability of the delivered electrical stimulation therapy. The visual map may allow the clinician to rapidly compare and select suitable anatomical positions from a relatively number of potential anatomical positions. The visual map may also allow the clinician to determine a candidate anatomical location for a lead carrying a plurality of electrodes, by selecting a suitable lead that can place the plurality of electrodes at a set of anatomical positions having a relatively higher efficacy. For example, the clinician may determine an appropriate location and angle for the lead, in view of the resulting positions of electrodes, to align the electrodes with anatomical positions in the visual map associated with relatively higher efficacy than other anatomical positions. [0024] Although the present disclosure is directed to DBS therapy, the systems, devices, and techniques described herein may be used to position leads and electrodes implanted outside of the brain, such as near other nerves or muscles for different diagnostic or therapeutic applications, such as spinal cord stimulation (SCS), occipital nerve stimulation, pelvic stimulation, sacral nerve stimulation, phrenic nerve stimulation, gastric stimulation, or peripheral nerve field stimulation (PNFS). Moreover, a human patient is described for example purposes herein, but similar systems, devices, and techniques may be used for other animals in other examples.

[0025] FIG. 1 is a conceptual diagram illustrating an example system 100 that includes implantable medical device (IMD) 106 configured to deliver DBS to patient 112 according to an example of the techniques of the disclosure. As shown in the example of FIG. 1, example system 100 includes medical device programmer 104, implantable medical device (IMD) 106, lead extension 110, and leads 114A and 114B with respective sets of electrodes 116, 118. In the example shown in FIG. 1, electrodes 116, 118 of leads 114 A, 114B are positioned to deliver electrical stimulation to a tissue site within brain 120, such as a deep brain site under the dura mater of brain 120 of patient 112. In some examples, delivery of stimulation to one or more regions of brain 120, such as the subthalamic nucleus, globus pallidus or thalamus, may be an effective treatment to manage movement disorders, such as Parkinson’s disease. Some or all of electrodes 116, 118 also may be positioned to sense or record neurological brain signals within brain 120 of patient 112. In some examples, some of electrodes 116, 118 may be configured to sense or record neurological brain signals and others of electrodes 116, 118 may be configured to deliver adaptive electrical stimulation to brain 120. In other examples, all of electrodes 116, 118 are configured to both sense or record neurological brain signals and deliver adaptive electrical stimulation to brain 120. [0026] IMD 106 includes a therapy module (e.g., which may include processing circuitry, signal generation circuitry or other electrical circuitry configured to perform the functions attributed to IMD 106) that includes a stimulation generator configured to generate and deliver electrical stimulation therapy to patient 112 via a subset of electrodes 116, 118 of leads 114A and 114B, respectively. The subset of electrodes 116, 118 that are used to deliver electrical stimulation to patient 112, and, in some cases, the polarity of the subset of electrodes 116, 118, may be referred to as a stimulation electrode combination or configuration. The group of electrodes 116, 118 includes at least one electrode and can include a plurality of electrodes. In some examples, the plurality of electrodes 116 and/or 118 may have a complex electrode geometry such that two or more electrodes of the lead are located at different positions around the perimeter of the respective lead (e.g., different positions around a longitudinal axis or shaft of the lead). In some examples, at least one electrode includes at least two electrodes disposed at different axial positions along the lead in the patient. In some examples, at least one electrode includes at least two electrodes disposed at different axial positions along the lead, and may be disposed at a same or different circumferential position around a perimeter of the lead.

[0027] In some examples, the neurological signals (e.g., an example type of electrical signals) sensed or recorded within brain 120 may reflect changes in electrical current produced by the sum of electrical potential differences across brain tissue. Examples of neurological brain signals include, but are not limited to, electrical signals generated from local field potentials (LFP) sensed within one or more regions of brain 120, such as an electroencephalogram (EEG) signal, or an electrocorti cogram (ECoG) signal. Local field potentials, however, may include a broader genus of electrical signals within brain 120 of patient 112 (e.g., which signify brain state, disease state or symptom state).

[0028] In some examples, the neurological brain signals that are used to select a stimulation electrode combination may be sensed within the same region of brain 120 as the target tissue site for the electrical stimulation. As previously indicated, these tissue sites may include tissue sites within anatomical structures such as the thalamus, subthalamic nucleus or globus pallidus of brain 120, as well as other target tissue sites. The specific target tissue sites and/or regions within brain 120 may be selected based on the patient condition. Thus, due to these differences in target locations, in some examples, the electrodes used for delivering electrical stimulation may be different than the electrodes used for sensing neurological brain signals. In other examples, the same electrodes may be used to deliver electrical stimulation and sense brain signals. [0029] Electrical stimulation generated by IMD 106 may be configured to manage a variety of disorders and conditions. In some examples, the stimulation generator of IMD 106 is configured to generate and deliver electrical stimulation pulses to patient 112 via electrodes of a selected stimulation electrode combination. However, in other examples, the stimulation generator of IMD 106 may be configured to generate and deliver a continuous wave signal, e.g., a sine wave or triangle wave. In either case, a stimulation generator within IMD 106 may generate the electrical stimulation therapy for DBS according to a therapy program that is selected at that given time in therapy. In examples in which IMD 106 delivers electrical stimulation in the form of stimulation pulses, a therapy program may include a set of therapy parameter values (e.g., stimulation parameters), such as a stimulation electrode combination for delivering stimulation to patient 112, waveform pattern, pulse frequency, pulse width, and a current or voltage amplitude of the pulses. As previously indicated, the electrode combination may indicate the specific electrodes 116, 118 that are selected to deliver stimulation signals to tissue of patient 112 and the respective polarities of the selected electrodes. IMD 106 may deliver electrical stimulation intended to contribute to a therapeutic effect. In some examples, IMD 106 may also, or alternatively, deliver electrical stimulation intended to be sensed or recorded by other electrode and/or elicit a physiological response, such as an evoked compound action potential (ECAP) or resonant response, that can be sensed or recorded by electrodes.

[0030] IMD 106 may be implanted within a subcutaneous pocket below the clavicle, or, alternatively, on or within cranium 122 or at any other suitable site within patient 112. Generally, IMD 106 is constructed of a biocompatible material that resists corrosion and degradation from body fluids. IMD 106 may include a hermetic housing to substantially enclose components, such as a processor, therapy module, and memory.

[0031] As shown in FIG. 1, implanted lead extension 110 is coupled to IMD 106 via a connector 108 (also referred to as a connector block or a header of IMD 106). In the example of FIG. 1, lead extension 110 traverses from the implant site of IMD 106 and along the neck of patient 112 to cranium 122 of patient 112 to access brain 120. In the example shown in FIG. 1, leads 114A and 114B (collectively “leads 114”) are implanted within the right and left hemispheres, respectively, of patient 112 in order deliver electrical stimulation to and/or sense or record from one or more regions of brain 120, which may be selected based on the patient condition or disorder controlled by therapy system 100. The specific target tissue site and the stimulation electrodes used to deliver stimulation to the target tissue site, however, may be selected, e.g., according to the identified patient behaviors associated with one or more brain disorders and/or other sensed patient signals. Other lead 114 and IMD 106 implant sites are contemplated. For example, IMD 106 may be implanted on or within cranium 122, in some examples. Alternatively, leads 114 may be implanted within the same hemisphere or IMD 106 may be coupled to a single lead implanted in a single hemisphere. Although leads 114 may have ring or omnidirectional electrodes at different longitudinal positions as shown in FIG. 1, leads 114 may have electrodes disposed at different positions around the perimeter of the lead (e.g., different circumferential positions for a cylindrical shaped lead in a low resolution or high resolution segmented directional configuration for fractionalization of stimulation) as shown in the examples of FIGS. 4A, 4B, 5A, 5B, 5C, and 5D.

[0032] Leads 114 illustrate an example lead set that include axial leads carrying ring or omnidirectional electrodes disposed at different axial positions (or longitudinal positions). In other examples, leads may be referred to as “paddle” leads carrying planar arrays of electrodes on one side of the lead structure. In addition, as described herein, complex lead array geometries may be used in which electrodes are disposed at different respective longitudinal positions and different positions around the perimeter of the lead.

[0033] Although leads 114 are shown in FIG. 1 as being coupled to a common lead extension 110, in other examples, leads 114 may be coupled to IMD 106 via separate lead extensions or directly to connector 108. Leads 114 may be positioned to deliver electrical stimulation to and/or sense or record from one or more target tissue sites within brain 120 to manage patient symptoms. Leads 114 may be implanted to position electrodes 116, 118 at desired locations of brain 120 through respective burr holes in cranium 122. Leads 114 may be placed at any location within brain 120 such that electrodes 116, 118 are capable of providing electrical stimulation to and/or sense or record from target tissue sites within brain 120 during treatment. For example, electrodes 116, 118 may be surgically implanted under the dura mater of brain 120 or within the cerebral cortex of brain 120 via a burr hole in cranium 122 of patient 112, and electrically coupled to IMD 106 via one or more leads 114. [0034] In the example shown in FIG. 1, electrodes 116, 118 of leads 114 are shown as ring electrodes. Ring electrodes (annular having cylindrical symmetric design) may be used in DBS applications because they are relatively simple to program and are capable of delivering an omnidirectional electrical field to any tissue adjacent to electrodes 116, 118. In other examples, electrodes 116, 118 may have different configurations. For example, in some examples, at least some of the electrodes 116, 118 of leads 114 may have a complex electrode array geometry that is capable of producing shaped electrical fields. The complex electrode array geometry may include multiple electrodes (e.g., partial ring or segmented electrodes) around the outer perimeter of each lead 114, rather than one ring electrode, such as the examples shown in FIGS. 4A and 4B. In this manner, electrical stimulation may be fractionalized and directed in a specific direction from leads 114 to enhance therapy efficacy and reduce possible adverse side effects from stimulating a large volume of tissue and/or sense or record from target tissue. In some examples, a housing of IMD 106 may include one or more stimulation and/or sensing electrodes. In alternative examples, leads 114 may have shapes other than elongated cylinders as shown in FIG. 1. For example, leads 114 may be paddle leads, spherical leads, bendable leads, or any other type of shape effective in treating patient 112 and/or minimizing invasiveness of leads 114.

[0035] In the example shown in FIG. 1, IMD 106 includes a memory to store a plurality of therapy programs that each define a set of therapy parameter values. In some examples, IMD 106 may select a therapy program from the memory based on various parameters, such as sensed patient signals and the identified patient behaviors e.g., as patient behaviors associated with one or more brain disorders, and/or other sensed patient signals.

[0036] External programmer 104 wirelessly communicates with IMD 106 as needed to provide or retrieve therapy information. Programmer 104 is an external computing device that the user, e.g., a clinician and/or patient 112, may use to communicate with IMD 106. For example, programmer 104 may be a clinician programmer that the clinician uses to communicate with IMD 106 and program one or more therapy programs for IMD 106. Alternatively, programmer 104 may be a patient programmer that allows patient 112 to select programs or groups and/or view and modify allowable therapy parameters within a preset range in addition to triggering capture of a tagged/untagged sensing event. The clinician programmer may include more programming features than the patient programmer. In other words, more complex or sensitive tasks may only be allowed by the clinician programmer to prevent an untrained patient from making undesirable changes to IMD 106. Programmer 104 may enter a new programming session for the user to select new stimulation parameters for subsequent therapy.

[0037] When programmer 104 is configured for use by the clinician, programmer 104 may be used to transmit initial programming information to IMD 106. This initial information may include hardware information, such as the type of leads 114 and the electrode arrangement, the position of leads 114 within brain 120, the configuration of electrode array 116, 118, initial programs defining therapy parameter values, a known electrode orientation from a previous session if available and any other information the clinician desires to program into IMD 106. Programmer 104 may also be capable of completing functional tests (e.g., measuring the impedance of electrodes 116, 118 of leads 114). In some examples, programmer 104 may receive sensed signals or representative information and perform the same techniques and functions attributed to IMD 106 herein. In other examples, a remote server (e.g., a standalone server or part of a cloud service) may perform the functions attributed to IMD 106, programmer 104, or any other devices described herein.

[0038] The clinician may also store therapy programs within IMD 106 with the aid of programmer 104. During a programming session, the clinician may determine one or more therapy programs that may provide efficacious therapy to patient 112 to address symptoms associated with the patient condition, and, in some cases, specific to one or more different patient states, such as a sleep state, movement state or rest state. For example, the clinician may select one or more stimulation electrode combination with which stimulation is delivered to brain 120. During the programming session, the clinician may evaluate the efficacy of the specific program being evaluated based on feedback provided by patient 112 or based on one or more physiological parameters of patient 112 (e.g., muscle activity, muscle tone, rigidity, tremor, etc.) and/or sensed or recorded signals. Alternatively, identified patient behavior from video information may be used as feedback during the initial and subsequent programming sessions. Programmer 104 may assist the clinician in the creation/identification of therapy programs by providing a methodical system for identifying potentially beneficial therapy parameter values.

[0039] Programmer 104 may also be configured for use by patient 112. When configured as a patient programmer, programmer 104 may have limited functionality (compared to a clinician programmer) in order to prevent patient 112 from altering critical functions of IMD 106 or applications that may be detrimental to patient 112. In this manner, programmer 104 may only allow patient 112 to adjust values for certain therapy parameters or set an available range of values for a particular therapy parameter and/or triggering capture of a sensing event.

[0040] Programmer 104 may also provide an indication to patient 112 when therapy is being delivered, when patient input has triggered a change in therapy or when the power source within programmer 104 or IMD 106 needs to be replaced or recharged. For example, programmer 104 may include an alert LED, may flash a message to patient 112 via a programmer display, generate an audible sound or somatosensory cue to confirm patient input was received, e.g., to indicate a patient state or to manually modify a therapy parameter. Programmer 104, such as the patient programmer, may be used to trigger sensing/recording of events through physician configured electrodes for varying lengths of time.

[0041] Therapy system 100 may be implemented to provide chronic stimulation therapy to and /or sense or record from patient 112 over the course of several months or years. However, system 100 may also be employed on a trial basis to evaluate therapy before committing to full implantation. If implemented temporarily, some components of system 100 may not be implanted within patient 112. For example, patient 112 may be fitted with an external medical device, such as a trial stimulator, rather than IMD 106. The external medical device may be coupled to percutaneous leads or to implanted leads via a percutaneous extension. If the trial stimulator indicates DBS system 100 provides effective treatment to patient 112, the clinician may implant a chronic stimulator within patient 112 for relatively long-term treatment.

[0042] Although IMD 106 is described as delivering electrical stimulation therapy to brain 120, IMD 106 may be configured to direct electrical stimulation to other anatomical regions of patient 112 in other examples. In other examples, system 100 may include an implantable drug pump in addition to, or in place of, IMD 106. Further, an IMD may provide other electrical stimulation such as spinal cord stimulation, or tissue stimulation at other sites. [0043] According to the techniques of the present disclosure, system 100 may generate a visual model indicative of the effectiveness of anatomical positions for electrode placement. The visual model may depict a plurality of efficacy indications for each anatomical position of the plurality of anatomical positions in a map. A clinician may use the visual model to guide electrode placement. System 100 may generate the visual model based on efficacy of electrode placement data for a population of patients. For example, IMD 106, programmer 104, a different external device, or any combination thereof, may receive, for each electrode of each lead implanted within each patient of the population of patients, efficacy data. IMD 106 may include memory to store the received efficacy data. The efficacy data may be indicative of an effectiveness of electrical stimulation therapy delivered via the respective electrode and an anatomical position of the respective electrode within the respective patient during delivery of the electrical stimulation therapy. The efficacy data may include user input indicating a perceived relative effectiveness of the stimulation therapy. In addition, or alternatively, the efficacy data may include sensor data indicating a measured parameter of a symptom of the patient in response to the stimulation therapy.

[0044] Each anatomical position may include an anatomical location and an electrode circumferential orientation. For example, the anatomical location may be a location of an end of an electrode, or a mid-point of an electrode, along a longitudinal axis of the lead. The electrode circumferential orientation may be a circumferential location of the electrode relative to the longitudinal axis, or relative to a target site. Each anatomical position may include an anatomical position relative to a subthalamic nucleus (STN) of a brain of the patient.

[0045] IMD 106 may be further configured to determine, based on the efficacy data across the population of patients, a plurality of efficacy indications including a respective efficacy indication for each anatomical position. In some examples, the efficacy indication may include a binary indication of one of (i) an effective anatomical position or (ii) an ineffective anatomical position. For example, each effective anatomical position may be assigned an efficacy indication of 1, while each effective anatomical position may be assigned an efficacy indication of 0. Any suitable alternative binary scheme may be used. In other examples, the efficacy indication may be in a range from a low efficacy to a high efficacy. For example, the efficacy indication may be assigned two or more values, such as discrete numerical values, between the low and high efficacy. In some examples, the efficacy indication may assume any continuous value between the low and high efficacy. For example, a higher numerical value of the efficacy indication may be associated with a higher efficacy, and a lower value may be associated with a lower efficacy.

[0046] IMD 106 may be further configured to generate, based on the efficacy indications, a visual model depicting the plurality of efficacy indications for each anatomical position in a map. The memory of IMD 106 may be further configured to store the visual model. IMD 106 may be further configured to output, for display, the visual model. The visual model may be displayed as numeric data, for example, tabulated data, or as graphical data, for example in a visual map. The map may include a two-dimensional or three-dimensional representation of anatomical positions and efficacy indications for different positions. For example, the efficacy indications may be alphanumeric or graphical symbols displayed at positions corresponding to respective anatomical positions, a grayscale or color shading or gradient, or a color-coded map, for example, a “heat map.”

[0047] Thus, IMD 106 (or another device, such as programmer 104) may generate a visual model depicting efficacy indications for each anatomical position, and a clinician may select one or more anatomical positions depending on the number of electrodes. If a subset of the anatomical positions is alignable with electrodes of a single lead, the clinician may position the lead such that electrodes of that lead are substantially placed along the subset of anatomical positions. [0048] In addition to generating a visual model based on historical electrode placement, system 100 may optionally determine and output a candidate anatomical location for an electrode intended to be placed by a clinician. For example, IMD 106 may receive, as user input, an indication of a target electrode placement for a selected lead including a plurality of electrodes for delivery of the electrical stimulation therapy to a future patient. IMD 106 may determine, based on the plurality of efficacy indications, a candidate anatomical location for the selected lead. The candidate anatomical position may be associated with a greater efficacy for the lead than at least one other anatomical location. For example, IMD 106 may select an anatomical position associated with a relatively high efficacy for a predetermined electrical stimulation therapy, based on efficacy data for that therapy. IMD 106 may output the candidate anatomical location for the selected lead.

[0049] If multiple electrodes are present (whether on a single lead or on different leads) the candidate anatomical location is configured to provide more effective positions than other potential locations. In some examples, the efficacy indication may be a numeric score, and the candidate anatomical position may be configured to maximize a sum of efficacy indications for all electrodes.

[0050] IMD 106 may further provide surgical guidance information to guide tissue or site access. For example, IMD 106 may determine, based on the candidate anatomical position, a candidate anatomical surgical access site. Alternatively, a clinician may provide an input to IMD 106 indicative of the candidate anatomical surgical access site. IMD 106 may generate, based on the candidate anatomical surgical access site, surgical guidance information indicative of an implant procedure. IMD 106 may further output, for display, the candidate anatomical surgical access site, the surgical guidance information, and the candidate anatomical position. The surgical guidance information may include a visual model of a body of the patient indicating the surgical access site on the body of the patient and the candidate anatomical position within the body of the patient.

[0051] The architecture of system 100 illustrated in FIG. 1 is shown as an example. The techniques as set forth in this disclosure may be implemented in the example system 100 of FIG. 1, as well as other types of systems not described specifically herein. Nothing in this disclosure should be construed so as to limit the techniques of this disclosure to the example architecture illustrated by FIG. 1.

[0052] FIG. 2 is a block diagram of the example IMD 106 of FIG. 1 for delivering DBS therapy. In the example shown in FIG. 2, IMD 106 includes processor 210, memory 211, stimulation generator 202, sensing module 204, telemetry module 208, sensor 212, and power source 220. Each of these modules may be or include electrical circuitry configured to perform the functions attributed to each respective module. For example, processor 210 may include processing circuitry, sensing module 204 may include sensing circuitry, and telemetry module 208 may include telemetry circuitry. Memory 211 may include any volatile or non-volatile media, such as a random-access memory (RAM), read only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, and the like. Memory 211 may store computer-readable instructions that, when executed by processor 210, cause IMD 106 to perform various functions. Memory 211 may be a storage device or other non-transitory medium.

[0053] In the example shown in FIG. 2, memory 211 stores therapy programs 214 that include respective stimulation parameter sets that define therapy. Each stored therapy program 214 defines a particular set of electrical stimulation parameters (e.g., a therapy parameter set), such as a stimulation electrode combination, electrode polarity, waveform pattern, current or voltage amplitude, pulse width, and pulse rate. In some examples, individual therapy programs may be stored as a therapy group, which defines a set of therapy programs with which stimulation may be generated. The stimulation signals defined by the therapy programs of the therapy group may be delivered together on an overlapping or nonoverlapping (e.g., time-interleaved) basis.

[0054] In some examples, the sense and stimulation electrode combinations may include the same subset of electrodes 116, 118, a housing of IMD 106 functioning as an electrode, or may include different subsets or combinations of such electrodes. Thus, memory 211 can store a plurality of sense electrode combinations and, for each sense electrode combination, store information identifying the stimulation electrode combination that is associated with the respective sense electrode combination or vice versa. The associations between sense and stimulation electrode combinations can be determined, e.g., by a clinician or automatically by processor 210. In some examples, corresponding sense and stimulation electrode combinations may include some or all of the same electrodes. In other examples, however, some or all of the electrodes in corresponding sense and stimulation electrode combinations may be different. For example, a stimulation electrode combination may include more electrodes than the corresponding sense electrode combination in order to increase the efficacy of the stimulation therapy. In some examples, as discussed above, stimulation may be delivered via a stimulation electrode combination to a tissue site that is different than the tissue site closest to the corresponding sense electrode combination but is within the same region, e.g., the thalamus, of brain 120 in order to mitigate any irregular oscillations or other irregular brain activity within the tissue site associated with the sense electrode combination. In other examples, the electrodes that deliver stimulation may be carried by a lead implanted in a different region of the brain than a different lead that carries the sensing electrodes.

[0055] IMD 106 may include a memory 211 configured to store visual model data 216 indicative of effectiveness of electrical stimulation therapy delivered via electrodes at a plurality of anatomical positions. In some examples, memory 211 may be configured to store a plurality of efficacy indications including a respective efficacy indication for each anatomical position. In some examples, the memory 211 may be configured to store visual model data 216. Memory 211 may be further configured to store received efficacy data.

[0056] Stimulation generator 202, under the control of processor 210, generates stimulation signals for delivery to patient 112 via selected combinations of electrodes 116, 118. An example range of electrical stimulation parameters believed to be effective in DBS to manage a movement disorder of patient may include:

1. Pulse Rate, i.e., Frequency: between approximately 0.1 Hertz and approximately 500 Hertz, such as between approximately 0.1 to 10 Hertz, approximately 40 to 185 Hertz, or such as approximately 140 Hertz.

2. In the case of a voltage-controlled system, Voltage Amplitude: between approximately 0.1 volts and approximately 50 volts, such as between approximately 2 volts and approximately 3 volts.

3. In the alternative case of a current-controlled system, Current Amplitude: between approximately 0.2 milliamps to approximately 100 milliamps, such as between approximately 1.3 milliamps and approximately 2.0 milliamps.

4. Pulse Width: between approximately 10 microseconds and approximately 5000 microseconds, such as between approximately 100 microseconds and approximately 1000 microseconds, or between approximately 20 microseconds and approximately 450 microseconds.

[0057] Accordingly, in some examples, stimulation generator 202 generates electrical stimulation signals in accordance with the electrical stimulation parameters noted above. Other ranges of therapy parameter values may also be useful, and may depend on the target stimulation site within patient 112. While stimulation pulses are described, stimulation signals may be of any form, such as continuous-time signals (e.g., sine waves) or the like. Stimulation signals configured to elicit ECAPs or other evoked physiological signals (e.g., resonant response) may be similar or different from the above parameter value ranges. [0058] Processor 210 may include fixed function processing circuitry and/or programmable processing circuitry, and may include, for example, any one or more of a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), discrete logic circuitry, or any other processing circuitry configured to provide the functions attributed to processor 210 herein may be embodied as firmware, hardware, software or any combination thereof. Processor 210 may control stimulation generator 202 according to therapy programs 214 stored in memory 211 to apply particular stimulation parameter values specified by one or more of programs, such as waveform pattern, voltage amplitude or current amplitude, pulse width, or pulse rate.

[0059] In the example shown in FIG. 2, the set of electrodes 116 includes electrodes 116A, 116B, 116C, and 116D, and the set of electrodes 118 includes electrodes 118A, 118B, 118C, and 118D. Processor 210 may control stimulation generator 202, which may include independently controllable current sources and sinks, to apply the stimulation signals to respective electrodes 116, 118. For example, processor 210 may control stimulation generator 202 to gate transistors on at the sources or sinks as desired. In this manner, stimulation generator 202 may be configured to selectively source or sink two or more electrodes to form an electrode combination/configuration for delivering electrical stimulation to the patient via the respective electrodes. Processor 210 may control one or more switches to couple or decouple sensing module 204 from electrodes 116, 118 to enable sensing from one or more electrodes and/or isolate sensing module 204 from delivered stimulation generated by stimulation generator 202 (e.g., during a blanking period to avoid recording stimulus artifact).

[0060] In other examples, IMD 106 may include a switch module (not shown) that may couple stimulation signals to selected conductors within leads 114, which, in turn, deliver the stimulation signals across selected electrodes 116, 118. The switch module may be a switch array, switch matrix, multiplexer, or any other type of switching module configured to selectively couple stimulation energy to selected electrodes 116, 118 and, in some examples, to selectively sense neurological brain signals with selected electrodes 116, 118. Hence, stimulation generator 202 may be coupled to electrodes 116, 118 via the switch module and conductors within leads 114. The switch module may be used for single channel or multichannel stimulation generators.

[0061] Stimulation generator 202 may be a multi-channel stimulation generator with independent current sources and sinks as described above. In particular, stimulation generator 202 may be capable of delivering a single stimulation pulse, multiple stimulation pulses, or a continuous signal at a given time via a single electrode combination or multiple stimulation pulses at a given time via multiple electrode combinations. In some examples, however, stimulation generator 202 may be configured to deliver multiple channels on a time-interleaved basis. For example, stimulation generator 202 may include multiple voltage or current sources and sinks that are coupled to respective electrodes to drive the electrodes as cathodes or anodes. In this example, IMD 106 may not require the functionality of a switch module or time-interleaved multiplexing of stimulation via different electrodes.

[0062] Electrodes 116, 118 on respective leads 114 may be constructed of a variety of different designs. For example, one or both of leads 114 may include two or more electrodes at each longitudinal location along the length of the lead, such as multiple electrodes at different perimeter locations around the perimeter of the lead at each of the locations A, B, C, and D.

[0063] Although sensing module 204 may be incorporated into a common housing with stimulation generator 202 and processor 210 in FIG. 2, in other examples, sensing module 204 may be in a separate housing from IMD 106 and may communicate with processor 210 via wired or wireless communication techniques.

[0064] Sensor 212 may include one or more sensing elements that sense values of a respective patient parameter. For example, sensor 212 may include one or more accelerometers, optical sensors, chemical sensors, temperature sensors, pressure sensors, or any other types of sensors. Sensor 212 may output patient parameter values that may be used as feedback to control delivery of therapy. IMD 106 may include additional sensors within the housing of IMD 106 and/or coupled via one of leads 114 or other leads. In addition, IMD 106 may receive sensor signals wirelessly from remote sensors (e.g., wearable sensors) via telemetry module 208, for example. In some examples, one or more of these remote sensors may be external to patient (e.g., carried on the external surface of the skin, attached to clothing, or otherwise positioned external to the patient). For example, IMD 106 may determine from these one or more additional sensors the brain state (or disease state or symptom state) of the patient and sense signals for determining electrode movement during a brain state of lower fluctuation or lower noise to improve signal detection. In other examples, IMD 106 may employ an inertial sensor to determine when the patient is at rest (e.g., lying down and/or sleeping) and sense signals for determining lead movement during a time of rest to reduce noise or other motion artifacts in the sensed signals. In some examples, IMD 106 may sense signals for determining lead movement in response to receiving an indication that the patient received a dose of medication or the patient has entered a physician appointment.

[0065] Telemetry module 208 supports wireless communication between IMD 106 and an external programmer 104 or another computing device under the control of processor 210. Processor 210 of IMD 106 may receive, as updates to programs, values for various stimulation parameters such as magnitude and electrode combination/configuration, from programmer 104 via telemetry module 208. The updates to the therapy programs may be stored within therapy programs 214 portion of memory 211. In addition, processor 210 may control telemetry module 208 to transmit alerts or other information to programmer 104 that indicate a lead moved with respect to tissue. Telemetry module 208 in IMD 106, as well as telemetry modules in other devices and systems described herein, such as programmer 104, may accomplish communication by radiofrequency (RF) communication techniques. In addition, telemetry module 208 may communicate with external medical device programmer 104 via proximal inductive interaction of IMD 106 with programmer 104. Accordingly, telemetry module 208 may send information to external programmer 104 on a continuous basis, at periodic intervals, or upon request from IMD 106 or programmer 104.

[0066] Power source 220 delivers operating power to various components of IMD 106. Power source 220 may include a small rechargeable or non-rechargeable battery and a power generation circuit to produce the operating power. Recharging may be accomplished through proximal inductive interaction between an external charger and an inductive charging coil within IMD 220. In some examples, power requirements may be small enough to allow IMD 220 to utilize patient motion and implement a kinetic energy-scavenging device to trickle charge a rechargeable battery. In other examples, traditional batteries may be used for a limited period of time.

[0067] According to the techniques of the disclosure, processor 210 of IMD 106 delivers, via electrodes 116, 118 interposed along leads 114, electrical stimulation therapy to patient 112. The electrical stimulation therapy, (for example, DBS therapy) is defined by one or more therapy programs 214 having one or more parameters stored within memory 211. For example, the one or more parameters include a current amplitude (for a current-controlled system) or a voltage amplitude (for a voltage-controlled system), a waveform pattern, a pulse rate or frequency, and a pulse width, or quantity of pulses per cycle. In examples where the electrical stimulation is delivered according to a “burst” of pulses, or a series of electrical pulses defined by an “on-time” and an “off-time,” the one or more parameters may further define one or more of a number of pulses per burst, an on-time, and an off-time (e.g., as in cycling).

[0068] According to one or more techniques of the disclosure, processor 210 of IMD 106 receives, for at least one electrode of one or more leads implanted within each patient of a patient population, efficacy data. The efficacy data may be indicative of an effectiveness of electrical stimulation therapy delivered via each respective electrode of the at least one electrode and an anatomical position of the respective electrode within the respective patient during delivery of the electrical stimulation therapy. A plurality of anatomical positions for a tissue region may include the anatomical position. Processor 210 may be configured to determine, based on the efficacy data for the patient population, a plurality of efficacy indications including a respective efficacy indication for at least some anatomical positions of the plurality of anatomical positions. Processor 210 may generate, based on the efficacy indications, a visual model depicting the plurality of efficacy indications for each anatomical position of the plurality of anatomical positions in a map. Processor 210 may output, for display, the visual model.

[0069] FIG. 3 is a block diagram of the external programmer 104 of FIG. 1 for determining electrode placement in tissue and controlling delivery of DBS therapy according to an example of the techniques of the disclosure. Although programmer 104 may generally be described as a hand-held device, programmer 104 may be a larger portable device or a more stationary device. In some examples, programmer 104 may be referred to as a tablet computing device. In addition, in other examples, programmer 104 may be included as part of a bed-side monitor, an external charging device or include the functionality of an external charging device. As illustrated in FIG. 3, programmer 104 may include a processor 310, memory 311, user interface 302, telemetry module 308, and power source 320. Memory 311 may store instructions that, when executed by processor 310, cause processor 310 and external programmer 104 to provide the functionality ascribed to external programmer 104 throughout this disclosure. Each of these components, or modules, may include electrical circuitry that is configured to perform some or all of the functionality described herein. For example, processor 310 may include processing circuitry configured to perform the processes discussed with respect to processor 310.

[0070] In general, programmer 104 includes any suitable arrangement of hardware, alone or in combination with software and/or firmware, to perform the techniques attributed to programmer 104, and processor 310, user interface 302, and telemetry module 308 of programmer 104. In various examples, programmer 104 may include one or more processors, which may include fixed function processing circuitry and/or programmable processing circuitry, as formed by, for example, one or more microprocessors, DSPs, ASICs, FPGAs, or any other equivalent integrated or discrete logic circuitry, as well as any combinations of such components. Programmer 104 also, in various examples, may include a memory 311, such as RAM, ROM, PROM, EPROM, EEPROM, flash memory, a hard disk, a CD-ROM, a DVD including executable instructions for causing the one or more processors to perform the actions attributed to them. Moreover, although processor 310 and telemetry module 308 are described as separate modules, in some examples, processor 310 and telemetry module 308 may be functionally integrated with one another. In some examples, processor 310 and telemetry module 308 correspond to individual hardware units, such as ASICs, DSPs, FPGAs, or other hardware units.

[0071] Memory 311 (e.g., a storage device) may store instructions that, when executed by processor 310, cause processor 310 and programmer 104 to provide the functionality ascribed to programmer 104 throughout this disclosure. For example, memory 311 may include instructions that cause processor 310 to obtain a parameter set from memory, determine a visual model for electrode placement, provide an interface that recommends or otherwise facilitates parameter value selection, or receive a user input and send a corresponding command to IMD 106, or instructions for any other functionality. In addition, memory 311 may include a plurality of programs, where each program includes a parameter set that defines stimulation therapy.

[0072] According to one or more techniques of the disclosure, processor 310 of programmer 104 may receive efficacy data of tissue of the patient that receives electrical stimulation via the electrodes 116, 118 of leads 114. Processor 310 may perform the same or similar functions as described with respect to processor 210 of IMD 106. Processor 310 may generate, based on the efficacy data, a visual model representative of efficacy indications associated with anatomical positions (see e.g., FIGS. 6 and 7). In some examples, the processor 210 may determine based on the efficacy data, a candidate position for at least one electrode, or a candidate location for at least one lead, with respect to tissue of the patient. [0073] User interface 302 may include a button or keypad, lights, a speaker for voice commands, a display, such as a liquid crystal (LCD), light-emitting diode (LED), or organic light-emitting diode (OLED). In some examples the display may be a touch screen. User interface 302 may be configured to display any information related to the delivery of stimulation therapy, identified patient behaviors, sensed patient signal or parameter values, patient behavior criteria, or any other such information. User interface 302 may also receive user input via user interface 302. The input may be, for example, in the form of pressing a button on a keypad or selecting an icon from a touch screen or a gesture.

[0074] Telemetry module 308 may support wireless communication between IMD 106 and programmer 104 under the control of processor 310. Telemetry module 308 may also be configured to communicate with another computing device via wireless communication techniques, or direct communication through a wired connection. In some examples, telemetry module 308 provides wireless communication via an RF or proximal inductive medium. In some examples, telemetry module 308 includes an antenna, which may take on a variety of forms, such as an internal or external antenna. In some examples, IMD 106 and/or programmer 104 may communicate with remote servers via one or more cloud-services in order to deliver and/or receive information between a clinic and/or programmer.

[0075] Examples of local wireless communication techniques that may be employed to facilitate communication between programmer 104 and IMD 106 include RF communication according to the 802.11 or Bluetooth specification sets or other standard or proprietary telemetry protocols. In this manner, other external devices may be capable of communicating with programmer 104 without needing to establish a secure wireless connection. As described herein, telemetry module 308 may be configured to transmit efficacy data or other stimulation parameter values to IMD 106 for delivery of stimulation therapy.

[0076] According to the techniques of the disclosure, in some examples, processor 310 of external programmer 104 defines the parameters of a homeostatic therapeutic window, stored in memory 311, for delivering DBS to patient 112. In one example, processor 311 of external programmer 104, via telemetry module 308, issues commands to IMD 106 causing IMD 106 to deliver electrical stimulation therapy via electrodes 116, 118 via leads 114.

[0077] FIGS. 4 A and 4B are conceptual diagrams of example leads 400 and 410, respectively, with respective electrodes carried by the lead. As shown in FIGS. 4A and 4B, leads 400 and 410 are embodiments of leads 114 shown in FIG. 1. As shown in FIG. 4 A, lead 400 includes four electrode levels 404 (includes levels 404A-404D) mounted at various lengths of lead housing 402 (along the lead shaft). Lead 400 may be inserted into through cranium 122 to a target position within brain 18.

[0078] Lead 400 may be implanted within brain 120 at a location determined by the clinician to be near an anatomical region to be stimulated. Electrode levels 404A, 404B, 404C, and 404D may be equally spaced along the axial length of lead housing 402 at different axial positions. Each electrode level 404 may have one, two, three, or more electrodes located at different angular positions around the circumference (e.g., around the perimeter or the lead shaft) of lead housing 402. As shown in FIG. 4A, electrode level 404A and 404D include a single respective ring electrode, and electrode levels 404B and 404C each include three electrodes at different circumferential positions. This electrode pattern may be referred to as a 1-3 -3-1 lead in reference to the number of electrodes from the proximal end to the distal end of lead 400. Electrodes of one circumferential location may be lined up on an axis parallel to the longitudinal axis of lead 400. Alternatively, electrodes of different electrode levels may be staggered around the circumference of lead housing 402. In addition, lead 400 or 410 may include asymmetrical electrode locations around the circumference, or perimeter, of each lead or electrodes of the same level that have different sizes. These electrodes may include semi-circular electrodes that may or may not be circumferentially aligned between electrode levels.

[0079] Lead housing 402 may include a radiopaque stripe (not shown) along the outside of the lead housing. The radiopaque stripe corresponds to a certain circumferential location that allows lead 400 to the imaged when implanted in patient 112. Using the images of patient 112, the clinician can use the radiopaque stripe as a marker for the exact orientation of lead 400 within the brain of patient 112. Orientation of lead 400 may be needed to easily program the stimulation parameters by generating the correct electrode configuration to match the stimulation field defined by the clinician. In other embodiments, a marking mechanism other than a radiopaque stripe may be used to identify the orientation of lead 400. These marking mechanisms may include something similar to a tab, detent, or other structure on the outside of lead housing 402. In some embodiments, the clinician may note the position of markings along a lead wire during implantation to determine the orientation of lead 400 within patient 112.

[0080] FIG. 4B illustrates lead 410 that includes multiple electrodes at different respective circumferential positions at each of levels 414A-414D. Similar to lead 400, lead 410 may be inserted through a burr hole in cranium 122 to a target location within brain 120. Lead 410 includes lead housing 412. Four electrode levels 414 (414A-414D) are located at the distal end of lead 410. Each electrode level 414 is evenly spaced from the adjacent electrode level and includes two or more electrodes. In one embodiment, each electrode level 414 includes three, four, or more electrodes distributed around the circumference of lead housing 412. Therefore, lead 410 includes 414 electrodes in a preferred embodiment. Each electrode may be substantially rectangular in shape. Alternatively, the individual electrodes may have alternative shapes, e.g., circular, oval, triangular, rounded rectangles, or the like. [0081] In alternative embodiments, electrode levels 404 or 414 are not evenly spaced along the longitudinal axis of the respective leads 400 and 410. For example, electrode levels 404C and 404D may be spaced approximately 3 millimeters (mm) apart while electrodes 404A and 404B are 10 mm apart. Variable spaced electrode levels may be useful in reaching target anatomical regions deep within brain 120 while avoiding potentially undesirable anatomical regions. Further, the electrodes disposed at adjacent levels need not be aligned in the direction as the longitudinal axis of the lead, and instead may be oriented diagonally with respect to the longitudinal axis.

[0082] Leads 400 and 410 may be substantially rigid to prevent the implanted lead from varying from the expected lead shape. Leads 400 or 410 may be substantially cylindrical in shape. In other embodiments, leads 400 or 410 may be shaped differently than a cylinder. For example, the leads may include one or more curves to reach target anatomical regions of brain 120. In some embodiments, leads 400 or 410 may be similar to a flat paddle lead or a conformable lead shaped for patient 112. Also, in other embodiments, leads 400 and 410 may be any of a variety of different polygonal cross sections (e.g., triangle, square, rectangle, octagonal, etc.) taken transverse to the longitudinal axis of the lead.

[0083] As shown in the example of a passive tip lead 400, the plurality of electrodes of lead 400 includes a first set of three electrodes disposed at different respective positions around the longitudinal axis of the lead and at a first longitudinal position along the lead (e.g., electrode level 404B), a second set of three electrodes disposed at a second longitudinal position along the lead different than the first longitudinal position (e.g., electrode level 404C), and at least one ring electrode disposed at a third longitudinal position along the lead different than the first longitudinal position and the second longitudinal position (e.g., electrode level 404A and/or electrode level 404D). In some examples, electrode level 404B may have at least two electrodes disposed at different positions around a perimeter of the lead. In some examples, at least two electrodes are disposed at different axial positions along the lead (404B, 404C). In some examples, electrode level 404D may be a bullet/active tip or cone shaped electrode that covers the distal end of lead 402.

[0084] FIGS. 5A-5D are transverse cross-sections of example stimulation leads having one or more electrodes around the circumference of the lead. As shown in FIGS. 5A-5D, one electrode level, such as one of electrode levels 404 and 414 of leads 400 and 410, are illustrated to show electrode placement around the perimeter, or around the longitudinal axis or shaft, of the lead. FIG. 5A shows electrode level 500 that includes circumferential electrode 502. Circumferential electrode 502 encircles the entire circumference of electrode level 500 and may be referred to as a ring or omnidirectional electrode in some examples. Circumferential electrode 502 may be utilized as a cathode or anode or for sensing/recording as configured by the user interface.

[0085] FIG. 5B shows electrode level 510 which includes two electrodes 512 and 514. Each electrode 512 and 514 wraps approximately 170 degrees around the circumference of electrode level 510. Spaces of approximately 10 degrees are located between electrodes 512 and 514 to prevent inadvertent coupling of electrical current between the electrodes. Smaller or larger spaces between electrodes (e.g., between 10 degrees and 30 degrees) may be provided in other examples. Each electrode 512 and 514 may be programmed to act as an anode or cathode or for sensing/recording.

[0086] FIG. 5C shows electrode level 520 which includes three equally sized electrodes 522, 524 and 526. Each electrode 522, 524 and 526 encompass approximately 110 degrees of the circumference of electrode level 520. Similar to electrode level 510, spaces of approximately 10 degrees separate electrodes 522, 524 and 526. Smaller or larger spaces between electrodes (e.g., between 10 degrees and 30 degrees) may be provided in other examples. Electrodes 522, 524 and 526 may be independently programmed as an anode or cathode for stimulation or for sensing/recording.

[0087] FIG. 5D shows electrode level 530 which includes four electrodes 532, 534, 536 and 538. Each electrode 532, 534, 536 and 538 covers approximately 80 degrees of the circumference with approximately 10 degrees of insulation space between adjacent electrodes. Smaller or larger spaces between electrodes (e.g., between 10 degrees and 30 degrees) may be provided in other examples. In other embodiments, up to ten or more electrodes may be included within an electrode level. In alternative embodiments, consecutive electrode levels of lead 114 may include a variety of electrode levels 500, 510, 520, and 530. For example, lead 114 (or any other lead described herein) may include electrode levels that alternate between electrode levels 510 and 530 depicted in FIGS. 5B and 5D. In this manner, various stimulation field shapes may be produced within brain 120 of patient 112. Leads could have low- or high-resolution segmented electrode designs. Further the above-described sizes of electrodes within an electrode level are merely examples, and the invention is not limited to the example electrode sizes.

[0088] FIG. 6 illustrates an example scheme 600 for generating map 602 of a plurality of anatomical positions 604 based on placement of leads 606 including electrodes 608 in a patient population. Separate images or charts 610, each indicative of effectiveness of anatomical positions of electrodes placed in a single patient. For example, efficacy data for electrodes 608 in images 610 may be represented by shading, color-coding, or other indicia providing an efficacy indication. Images 610 are combined to generate map 602 showing a plurality of positions. For example, intermediate images 612 may be generated from images 610 using statistical mapping. In some examples, intermediate images 612 include a two- dimensional representation of aggregated anatomical features. Plurality of anatomical positions 604 may be overlaid on the aggregated two-dimensional representation to generate map 602. The electrode and lead positions and associated efficacy indications may be superimposed or otherwise combined into a visual representation as shown in map 602. A clinician may compare efficacy indications associated with different anatomical positions of electrodes 608 in map 602 and select one or more target positions for implanting one or more electrodes or target locations and orientations for implanting one or more leads.

[0089] FIG. 7 is a map 700 representing effectiveness of electrodes at different anatomical positions 702. The lighter-colored positions 704 represent a better efficacy, while the darker-colored positions 706 represent a lower efficacy. A clinician may, at a glance, discern and contrast anatomical positions of higher and lower efficacies. Map 700 may be manipulated by the clinician in three-dimensions, or may include one or more two- dimensional views of a three-dimensional representation. The clinician may select one or more anatomical positions based on their efficacies, and further select one or more target positions for implanting electrodes or target locations and orientations for implanting one or more leads.

[0090] FIG. 8 is a flowchart illustrating an example technique for generating a visual model depicting efficacy indications for a plurality of anatomical positions of electrodes. The technique of FIG. 8 will be described with respect to processor 210 of IMD 106 in FIG. 2. However, other processors, devices, or combinations thereof, may perform the techniques of FIG. 8 in other examples.

[0091] Processor 210 may receive, for at least one electrode of one or more leads implanted within each patient of a patient population, efficacy data (800). The efficacy data may be indicative of an effectiveness of electrical stimulation therapy delivered via each respective electrode of the at least one electrode and an anatomical position of the respective electrode within the respective patient, for example, during delivery of the electrical stimulation therapy. A plurality of anatomical positions for a tissue region may include the anatomical position. Each anatomical position may include an anatomical location and an electrode circumferential orientation. [0092] Processor 210 may determine, based on the efficacy data for the patient population, a plurality of efficacy indications including a respective efficacy indication for at least some anatomical positions of the plurality of anatomical positions (802). Processor 210 may generate, based on the plurality of efficacy indications, a visual model depicting the plurality of efficacy indications for each anatomical position of the plurality of anatomical positions in a map (804). Processor 210 may further output, for display, the visual model (806).

[0093] Processor 210 may receive, as user input, an indication of a target electrode placement for a selected lead including a plurality of electrodes for delivery of electrical stimulation therapy to a future patient (808). Processor 210 may determine, based on the plurality of efficacy indications, a candidate anatomical location for the selected lead (810). The candidate anatomical location may be associated with a greater efficacy for the lead than at least one other anatomical location. Processor 210 may output, for display, the candidate anatomical location (812). System 100 may or may not perform the receiving of user input (808), the determining (810), or the outputting (812).

[0094] Processor 210 may further determine, based on the candidate anatomical location, a candidate anatomical surgical access site. Processor 210 may generate, based on the candidate anatomical surgical access site, surgical guidance information indicative of an implant procedure. Processor 210 may output, for display, the candidate anatomical surgical access site, the surgical guidance information, and the candidate anatomical position. The surgical guidance information may include a visual model of a body of the future patient indicating the surgical access site on the body of the future patient and the candidate anatomical position within the body of the future patient.

[0095] The stimulation therapy controlled by processor 210 may include deep-brain stimulation (DBS) therapy. Each anatomical position may include an anatomical position relative to a subthalamic nucleus (STN) of a brain of the patient.

[0096] The following examples are described herein.

[0097] Example 1 : A system including processing circuitry, the processing circuitry configured to: receive, for at least one electrode of one or more leads implanted within each patient of a patient population, efficacy data indicative of an effectiveness of electrical stimulation therapy delivered via each respective electrode of the at least one electrode and an anatomical position of the respective electrode within the respective patient, where a plurality of anatomical positions for a tissue region includes the anatomical position; determine, based on the efficacy data for the patient population, a plurality of efficacy indications including a respective efficacy indication for at least some anatomical positions of the plurality of anatomical positions; generate, based on the plurality of efficacy indications, a visual model depicting the plurality of efficacy indications for each anatomical position of the plurality of anatomical positions in a map; and output, for display, the visual model.

[0098] Example 2: The system of example 1, where each anatomical position includes an anatomical location and an electrode circumferential orientation.

[0099] Example 3 : The system of any of examples 1 or 2, where the efficacy indication includes a binary indication of one of (i) an effective anatomical position or (ii) an ineffective anatomical position.

[0100] Example 4: The system of any of examples 1 or 2, where the efficacy indication is in a range from a low efficacy to a high efficacy.

[0101] Example 5: The system of any of examples 1 through 4, where the processing circuitry is further configured to: receive, as user input, an indication of a target electrode placement for a selected lead including a plurality of electrodes for delivery of electrical stimulation therapy to a future patient; determine, based on the plurality of efficacy indications, a candidate anatomical location for the selected lead, the candidate anatomical position associated with a greater efficacy for the lead than at least one other anatomical location; and output, for display, the candidate anatomical location.

[0102] Example 6: The system of example 5, where the candidate anatomical location is configured to provide more effective positions than other potential locations.

[0103] Example 7: The system of any of examples 5 or 6, where the efficacy indication is a numeric score, and where the processing circuitry is configured to determine the candidate anatomical location to maximize a sum of efficacy indications for all electrodes of the selected lead.

[0104] Example 8: The system of any of examples 5 through 7, where the processing circuitry is further configured to: determine, based on the candidate anatomical location, a candidate anatomical surgical access site; generate, based on the candidate anatomical surgical access site, surgical guidance information indicative of an implant procedure; and output, for display, the candidate anatomical surgical access site, the surgical guidance information, and the candidate anatomical location.

[0105] Example 9: The system of example 8, where the surgical guidance information includes a visual model of a body of the future patient indicating the surgical access site on the body of the future patient and the candidate anatomical position within the body of the future patient. [0106] Example 10: The system of any of examples 1 through 9, where the efficacy data includes user input indicating a perceived relative effectiveness of the stimulation therapy. [0107] Example 11 : The system of any of examples 1 through 10, where the efficacy data includes sensor data indicating a measured parameter of a symptom of the respective patient in response to the electrical stimulation therapy.

[0108] Example 12: The system of any of examples 1 to 11, where the stimulation therapy includes deep-brain stimulation (DBS) therapy.

[0109] Example 13: The system of example 12, where each anatomical position includes an anatomical position relative to a subthalamic nucleus (STN) of a brain of each respective patient.

[0110] Example 14: A method including: receiving, by a processing circuitry, for at least one electrode of one or more leads implanted within each patient of a patient population, efficacy data indicative of an effectiveness of electrical stimulation therapy delivered via each respective electrode of the at least one electrode and an anatomical position of the respective electrode within the respective patient, where a plurality of anatomical positions for a tissue region includes the anatomical position; determining, by the processing circuitry, based on the efficacy data for the patient population, a plurality of efficacy indications including a respective efficacy indication for at least some anatomical positions of the plurality of anatomical positions; generating, by the processing circuitry, based on the plurality of efficacy indications, a visual model depicting the plurality of efficacy indications for each anatomical position of the plurality of anatomical positions in a map; and outputting, by the processing circuitry, for display, the visual model.

[0111] Example 15: The method of example 14, where each anatomical position includes an anatomical location and an electrode circumferential orientation.

[0112] Example 16: The method of any of examples 14 or 15, further including: receiving, by the processing circuitry, as user input, an indication of a target electrode placement for a selected lead including a plurality of electrodes for delivery of electrical stimulation therapy to a future patient; determining, by the processing circuitry, based on the plurality of efficacy indications, a candidate anatomical location for the selected lead, the candidate anatomical location associated with a greater efficacy for the lead than at least one other anatomical location; and outputting, by the processing circuitry, for display, the candidate anatomical location.

[0113] Example 17: The method of example 16, further including: determining, by the processing circuitry, based on the candidate anatomical location, a candidate anatomical surgical access site; generating, by the processing circuitry, based on the candidate anatomical surgical access site, surgical guidance information indicative of an implant procedure; andoutputting, by the processing circuitry, for display, the candidate anatomical surgical access site, the surgical guidance information, and the candidate anatomical location. [0114] Example 18: The method of example 17, where the surgical guidance information includes a visual model of a body of the future patient indicating the surgical access site on the body of the future patient and the candidate anatomical position within the body of the future patient.

[0115] Example 19: The method of any of examples 14 through 18, where the stimulation therapy includes deep-brain stimulation (DBS) therapy, and where each anatomical position includes an anatomical position relative to a subthalamic nucleus (STN) of a brain of the patient.

[0116] Example 20: A non-transitory, computer-readable medium including instructions, that when executed, are configured to cause a processor to: receive, for at least one electrode of one or more leads implanted within each patient of a patient population, efficacy data indicative of an effectiveness of electrical stimulation therapy delivered via each respective electrode of the at least one electrode and an anatomical position of the respective electrode within the respective patient, where a plurality of anatomical positions for a tissue region includes the anatomical position; determine, based on the efficacy data for the patient population, a plurality of efficacy indications including a respective efficacy indication for at least some anatomical positions of the plurality of anatomical positions; generate, based on the plurality of efficacy indications, a visual model depicting the plurality of efficacy indications for each anatomical position of the plurality of anatomical positions in a map; and output, for display, the visual model.

[0117] The techniques described in the present disclosure may be implemented, at least in part, in hardware, software, firmware or any combination thereof. For example, various aspects of the described techniques may be implemented within one or more processors, such as fixed function processing circuitry and/or programmable processing circuitry, including one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or any other equivalent integrated or discrete logic circuitry, as well as any combinations of such components. The term “processor” or “processing circuitry” may generally refer to any of the foregoing logic circuitry, alone or in combination with other logic circuitry, or any other equivalent circuitry. A control unit including hardware may also perform one or more of the techniques of the present disclosure.

[0118] Such hardware, software, and firmware may be implemented within the same device or within separate devices to support the various operations and functions described in this disclosure. In addition, any of the described units, modules or components may be implemented together or separately as discrete but interoperable logic devices. Depiction of different features as modules or units is intended to highlight different functional aspects and does not necessarily imply that such modules or units must be realized by separate hardware or software components. Rather, functionality associated with one or more modules or units may be performed by separate hardware or software components, or integrated within common or separate hardware or software components.

[0119] The techniques described in this disclosure may also be embodied or encoded in a computer-readable medium, such as a computer-readable storage medium, containing instructions. Instructions embedded or encoded in a computer-readable storage medium may cause a programmable processor, or other processor, to perform the method, e.g., when the instructions are executed. Computer readable storage media may include random access memory (RAM), read only memory (ROM), programmable read only memory (PROM), erasable programmable read only memory (EPROM), electronically erasable programmable read only memory (EEPROM), flash memory, a hard disk, a CD-ROM, a DVD, a floppy disk, a cassette, magnetic media, optical media, or other computer readable media.

[0120] Various examples have been described. These and other examples are within the scope of the following claims.

Claims

WHAT IS CLAIMED IS:

1. A system comprising processing circuitry, the processing circuitry configured to: receive, for at least one electrode of one or more leads implanted within each patient of a patient population, efficacy data indicative of an effectiveness of electrical stimulation therapy delivered via each respective electrode of the at least one electrode and an anatomical position of the respective electrode within the respective patient, wherein a plurality of anatomical positions for a tissue region comprises the anatomical position; determine, based on the efficacy data for the patient population, a plurality of efficacy indications comprising a respective efficacy indication for at least some anatomical positions of the plurality of anatomical positions; generate, based on the plurality of efficacy indications, a visual model depicting the plurality of efficacy indications for each anatomical position of the plurality of anatomical positions in a map; and output, for display, the visual model.

2. The system of claim 1, wherein each anatomical position comprises an anatomical location and an electrode circumferential orientation.

3. The system of any of claims 1 or 2, wherein the efficacy indication comprises a binary indication of one of (i) an effective anatomical position or (ii) an ineffective anatomical position.

4. The system of any of claims 1 or 2, wherein the efficacy indication is in a range from a low efficacy to a high efficacy.

5. The system of any of claims 1 through 4, wherein the processing circuitry is further configured to: receive, as user input, an indication of a target electrode placement for a selected lead comprising a plurality of electrodes for delivery of electrical stimulation therapy to a future patient; determine, based on the plurality of efficacy indications, a candidate anatomical location for the selected lead, the candidate anatomical position associated with a greater efficacy for the lead than at least one other anatomical location; and output, for display, the candidate anatomical location.

6. The system of claim 5, wherein the candidate anatomical location is configured to provide more effective positions than other potential locations.

7. The system of any of claims 5 or 6, wherein the efficacy indication is a numeric score.

8. The system of claim 7, wherein the processing circuitry is configured to determine the candidate anatomical location to maximize a sum of efficacy indications for all electrodes of the selected lead.

9. The system of any of claims 5 to 8, wherein the processing circuitry is further configured to: determine, based on the candidate anatomical location, a candidate anatomical surgical access site; generate, based on the candidate anatomical surgical access site, surgical guidance information indicative of an implant procedure; and output, for display, the candidate anatomical surgical access site, the surgical guidance information, and the candidate anatomical location.

10. The system of claim 9, wherein the surgical guidance information comprises a visual model of a body of the future patient indicating the surgical access site on the body of the future patient and the candidate anatomical position within the body of the future patient.

11. The system of any of claims 1 to 10, wherein the efficacy data comprises user input indicating a perceived relative effectiveness of the stimulation therapy.

12. The system of any of claims 1 through 11, wherein the efficacy data comprises sensor data indicating a measured parameter of a symptom of the respective patient in response to the electrical stimulation therapy.

13. The system of any of claims 1 to 12, wherein the stimulation therapy comprises deepbrain stimulation (DBS) therapy.

14. The system of claim 13, wherein each anatomical position comprises an anatomical position relative to a subthalamic nucleus (STN) of a brain of each respective patient.

15. A non-transitory, computer-readable medium comprising instructions, that when executed, are configured to cause processing circuitry to perform any of the functions of any of claims 1 through 14.