Abstract:
A system and method for graphically identifying candidate electrodes of a leadwire for stimulation of a patient anatomy includes a processor obtaining data corresponding to an anatomic region, identifying a spatial relationship between electrodes of the leadwire to the anatomic region, based on the identifying, selecting a subset of the electrodes of the leadwire, generating, based on the obtained data and the selected subset, a graphical output arrangement that includes a model of the leadwire including graphical representations of at least some of the electrodes and a graphical selection marking identifying the selected subset of the electrodes.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims the benefit of U.S. Prov. Pat. App. Ser. No. 61/793,773 (“the &#39;773 application”), filed Mar. 15, 2013. 
     The present application is also a continuation-in-part of U.S. patent application Ser. No. 13/481,524 (“the &#39;524 application”), filed May 25, 2012, which claims the benefit of 61/491,092 (“the &#39;092 application”), filed May 27, 2011. 
     The present application is also a continuation-in-part of U.S. patent application Ser. No. 13/481,497 (“the &#39;497 application”), filed May 25, 2012, which claims the benefit of the &#39;092 application. 
     The present application is also a continuation-in-part of each of U.S. patent application Ser. No. 14/011,817 (“the &#39;817 application”), Ser. No. 14/011,836 (“the &#39;836 application”), and Ser. No. 14/011,870 (“the &#39;870 application”), each of which was filed Aug. 28, 2013 and claims the benefit of each of U.S. Prov. Pat. App. Ser. No. 61/693,866 (“the &#39;866 application”), filed Aug. 28, 2012, 61/699,115 (“the &#39;115 application”), filed Sep. 10, 2012, 61/699,135 (“the &#39;135 application”), filed Sep. 10, 2012, and 61/753,232 (“the &#39;232 application”), filed Jan. 16, 2013. 
     The contents of all of the &#39;773, &#39;524, &#39;092, &#39;497, &#39;817, &#39;836, &#39;870, &#39;866, &#39;115, &#39;135, and &#39;232 applications are incorporated by reference herein in their entireties. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a system and method for generating and outputting therapeutic stimulation-related information in relation to electrodes of an implanted leadwire usable for electrically stimulating an anatomical region. Such output can be provided on a patient-specific basis and/or on an implant-position basis. The leadwire can be, e.g., of a Deep Brain Stimulation (DBS) device or a Spinal Cord Stimulation (SCS) device. Features of the present invention can aid the selection of electrical stimulation parameters for performing anatomic stimulation using the leadwire. 
     BACKGROUND 
     Stimulation of anatomical regions of a patient is a clinical technique for the treatment of disorders. Such stimulation can include deep brain stimulation (DBS), spinal cord stimulation (SCS), Occipital NS therapy, Trigemenal NS therapy, Vagus NS therapy, peripheral field stimulation therapy, sacral root stimulation therapy, or other such therapies. For example, DBS can include stimulation of the thalamus or basal ganglia and may be used to treat disorders such as essential tremor, Parkinson&#39;s disease (PD), and other physiological disorders, including psychiatric disorders. DBS can also be useful for traumatic brain injury and stroke. Pilot studies have also begun to examine the utility of DBS for treating dystonia, epilepsy, and obsessive-compulsive disorder. 
     However, understanding of the therapeutic mechanisms of action remains elusive. The stimulation parameters, electrode geometries, or electrode locations that are best suited for existing or future uses of DBS also are unclear. 
     For conducting a therapeutic stimulation, a neurosurgeon can select a target region within the patient anatomy, e.g., within the brain for DBS, an entry point, e.g., on the patient&#39;s skull, and a desired trajectory between the entry point and the target region. The entry point and trajectory are typically carefully selected to avoid intersecting or otherwise damaging certain nearby critical structures or vasculature. A stimulation electrode leadwire used to provide the stimulation to the relevant anatomical region is inserted along the trajectory from the entry point toward the target region. The stimulation electrode leadwire typically includes multiple closely-spaced electrically independent stimulation electrode contacts. 
     The target anatomical region can include tissue that exhibit high electrical conductivity. For a given stimulation parameter setting, a respective subset of the fibers are responsively activated. A stimulation parameter can include a current amplitude or voltage amplitude, which can be the same for all of the electrodes of the leadwire, or which can vary between different electrodes of the leadwire. The applied amplitude setting results in a corresponding current in the surrounding fibers, and therefore a corresponding voltage distribution in the surrounding tissue. The complexity of the inhomogeneous and anisotropic fibers makes it difficult to predict the particular volume of tissue influenced by the applied stimulation. 
     A treating physician typically would like to tailor the stimulation parameters (such as which one or more of the stimulating electrode contacts to use, the stimulation pulse amplitude, e.g., current or voltage depending on the stimulator being used, the stimulation pulse width, and/or the stimulation frequency) for a particular patient to improve the effectiveness of the therapy. Parameter selections for the stimulation can be achieved via tedious and variable trial-and-error, without visual aids of the electrode location in the tissue medium or computational models of the volume of tissue influenced by the stimulation. Such a method of parameter selection is difficult and time-consuming and, therefore, expensive. Moreover, it may not necessarily result in the best possible therapy. 
     Systems have been proposed that provide an interface that facilitates parameter selections. See, for example, U.S. patent application Ser. No. 12/454,330, filed May 15, 2009 (“the &#39;330 application”), U.S. patent application Ser. No. 12/454,312, filed May 15, 2009 (“the &#39;312 application”), U.S. patent application Ser. No. 12/454,340, filed May 15, 2009 (“the &#39;340 application”), U.S. patent application Ser. No. 12/454,343, filed May 15, 2009 (“the &#39;343 application”), and U.S. patent application Ser. No. 12/454,314, filed May 15, 2009 (“the &#39;314 application”), the content of each of which is hereby incorporated herein by reference in its entirety. 
     The leadwire can include cylindrically symmetrical electrodes, which, when operational, produce approximately the same electric values in all positions at a similar distance from the electrode in any plane that cuts through the electrode. Alternatively, the leadwire can include directional electrodes that produce different electrical values depending on the direction from the electrode. For example, the leadwire can include multiple separately controllable electrodes arranged cylindrically about the leadwire at each of a plurality of levels of the leadwire. Each electrode may be set as an anode or cathode in a bipolar configuration or as a cathode, with, for example, the stimulator casing being used as ground, in a monopolar arrangement. 
     When programming a leadwire for tissue stimulation, e.g., DBS, the clinical standard of care is often to perform a monopolar review (MPR) upon activation of the leadwire in order to determine the efficacy and side-effect thresholds for all electrodes on the leadwire, on an electrode-by-electrode basis. Monopolar review, rather than bipolar review, is performed because monopolar stimulation often requires a lower stimulation intensity than bipolar stimulation to achieve the same clinical benefit. The MPR can inform the selection of a first clinical program (parameters for stimulation) for treating a patient. 
     Example systems for programming a leadwire for tissue stimulation display a graphical representation of an area within which it is estimated that there is or could be tissue activation, referred to herein as a volume of activation (VOA), that results from input stimulation parameters. For example, the VOA can be calculated as a region outside of which stimulation is estimated to be unlikely. The VOA can be displayed relative to an image or model of a portion of the patient&#39;s anatomy. 
     Generation of the VOA may be based on Neural Element Models such as a model of fibers, e.g., axons, and a voltage distribution about the leadwire and on detailed processing thereof. Performing such processing to provide a VOA preview in real-time response to a clinician&#39;s input of parameters is not practical because of the significant required processing time. Therefore, conventional systems pre-process various stimulation parameter settings to determine which axons are activated by the respective settings. 
     Those systems also provide interfaces via which to input selections of the stimulation parameters and notes concerning therapeutic and/or side effects of stimulations associated with graphically represented VOAs. The systems also allow user input of, or automatically determine, a target stimulation region, e.g., within or encompassing one or more defined anatomic structures, or allow user input of, or automatically determine, a target defined anatomic structure, which target region or structure is targeted for stimulation. 
     SUMMARY 
     Example embodiments of the present invention provide a system and method that generates a map including a representation of stimulation leadwire electrodes and graphical markings visually indicating most significant ones of the electrodes with respect to particular stimulation-related information. In an example embodiment, the stimulation-related information represents an anatomic structure, e.g., the sub-thalamic nucleus (STN), targeted for stimulation. In an alternative example embodiment, the stimulation-related information represents an anatomic region targeted for stimulation. In an alternative example embodiment, the stimulation-related information represents regions that, when stimulated, are estimated to result in therapeutic success to achieve a good clinical effect, and/or a gradient in degree of such success. In an alternative example embodiment, the stimulation-related information represents regions that, when stimulated, are estimated to result in an adverse side effect, and/or a gradient in degree of such adverse side effects. In an example embodiment, the system and method generates the map based on a combination of two or more of the above-indicated types of stimulation-related information. 
     In an example embodiment of the present invention, the map includes a marking visually indicating a range of most significant electrodes and a further marking indicating the single most significant one of the electrodes with respect to the relevant stimulation-related information. 
     In an example embodiment of the present invention, the respective degrees of significance of different ones of the electrodes with respect to the relevant stimulation-related information, determined for the purpose of generating the map, is based on the respective proximities of the electrodes to an anatomic region associated with the stimulation-related information. In an example embodiment, in an instance where the leadwire does not pass through the associated anatomic region, proximity is determined based on the length of a ray that is perpendicular to the longitudinal axis of the leadwire and extends from the electrode to the associated anatomic region. 
     In an example embodiment of the present invention, the marking(s) provided in the generated map are provided in a grid formed by a first axis representing the different electrodes and a second axis representing a range of values of a selected stimulation parameter, e.g., stimulation amplitude. In an example embodiment of the present invention, the system records data pertaining to stimulations associated with particular values of the selected stimulation parameter using particular ones of the electrodes. Such data can include, for example, a therapeutic effect and/or adverse side effect determined or indicated to have occurred or estimated to occur, e.g., using particular ones of the values of the selected stimulation parameter at particular ones of the electrodes. In the example embodiment, the system plots graphical markings corresponding to respective ones of such recorded data at the electrode/stimulation value pair for which the respective datum had been recorded. In an example embodiment, the marking(s) indicating which of the electrodes are significant with respect to the stimulation-significant anatomic region are provided within the grid that includes the markings representing the recorded data, thereby providing an indication of the relationship of those electrodes which are or can be assumed to be significant with respect to the stimulation-significant anatomic region to the recorded data. 
     For example, in an example embodiment, the grid includes plotted therein a graphical marking representing a recorded occurrence of an adverse side effect of a stimulation centered at one of the electrodes at a particular stimulation amplitude. The marking is placed in the grid at the location corresponding to the electrode at which the stimulation was centered and corresponding to the amplitude of the stimulation. The grid also includes therein a marking showing which one or more of the electrodes correspond to a target stimulation region or structure, which therefore provides a visual indication of which one or more electrodes are most likely best able to be used for stimulating the target region or structure and how stimulation using those one or more electrodes might cause an adverse side effect. Since the grid plots the adverse side effect markers according to stimulation amplitude, the markings can help the user determine the electrode at which to center stimulation and the amplitude settings to avoid. Similarly, if the grid instead plots the markings representing the adverse side effects against a different stimulation setting, the grid would give the user an idea of which values to use or avoid for such other stimulation setting. 
     Therefore, according to an example embodiment of the present invention, the system and method provides in a graphical user interface an input component with which the user can select the stimulation parameter to be represented in the grid. The user can switch between different parameter types and, based on the plots of the markings in the different grids corresponding to the different parameter types, tailor stimulation settings. 
     In an example embodiment, the number of markings representing the side effects in the grid depends on the number of side effects that have been recorded, the severity of the recorded side effects, and/or filter criteria by which to filter which side effects to display. For example, such filter criteria can include age, sex, and/or condition of the patient whose stimulation resulted in the recorded side effect; severity of the side effect; and/or number of instances of the side effect at the particular stimulation location and stimulation parameter value, etc. 
     In an example embodiment, the markings representing the side effects are displayed to indicate the severity or, and/or the number, of the recorded adverse side effects corresponding to the grid position. For example, a number or making size can be used to represent the number of recorded side effects, or a number or marking size can be used to represent the severity of the recorded side effects (e.g., an average of all recorded side effects corresponding to the grid location). Alternatively, for example, a size can be used to indicate severity and a number can be used to indicate the number of recorded side effects. For example, the number can be the marking, and its size can vary depending on severity. Other indicia can be used instead or in addition. For example, degrees of transparency or different colors can be used to represent different severities or numbers. 
     As noted above, the markings can represent adverse side effects or therapeutic effect, number and severity being indicated according to an example embodiment regardless of which is represented. In an example embodiment, makings can be included for both therapeutic effect and side effect. The markings can be differently output depending on whether they represent therapeutic effect or adverse side effect. For example, different colors and/or shapes can be used depending on whether a marking represents a therapeutic effect or a side effect. 
     In an example embodiment of the present invention, the effect markings are selectable, in response to which selection additional details are provided regarding the corresponding therapeutic effects and/or adverse side effects. For example, the &#39;330, &#39;312, &#39;340, &#39;343, and &#39;314 applications describe notes entered by a user using a graphical user interface components. In an example embodiment, in response to selection of a marking in the grid, which marking represents a therapeutic or adverse side effect, the system outputs, e.g., displays in a graphical user interface, such a note previously input in association with the effect, or outputs a further interface component by which such a note is selectable for viewing. 
     In an example embodiment of the present invention, information on which basis the markings representing the therapeutic and/or side effects are based are obtained automatically using sensors and/or by user input, for example, as described in any of the &#39;330, &#39;312, &#39;340, &#39;343, &#39;314, &#39;866, and &#39;135 applications. 
     In an example embodiment of the present invention, the markings visually indicating most significant ones of the electrodes with respect to particular stimulation-related information such as a target region, and/or the markings representing recorded information associated with stimulations centered at one or more of the electrodes at particular stimulation parameter settings, as described above, are displayed in a graphical user interface display including a plurality of tabs and are displayed in association with a first one of the plurality of tabs, where others of the tabs are selectable for display of other stimulation-related information. In an example embodiment of the present invention, one of the other tabs is selectable for display, in response to its selection, of volume of activation (VOA) information, for example, as described in the &#39;330, &#39;312, &#39;340, &#39;343, &#39;314, &#39;115, and &#39;232 applications. For example, in an example embodiment, the other tab is selectable for display of a representation of the target region for which the first tab indicates the electrodes most likely to be relevant, the target region being displayed relative to a displayed representation of anatomic regions of a patient. Such a representation of the target region can be in a two-dimensional format or a three-dimensional format. In an alternative example embodiment, the other tab is selectable for display of a volume representing gradations in therapeutic and/or adverse side effects relative to anatomic regions of a patient. Such a representation can be in a two-dimensional format or a three-dimensional format. In an example embodiment, one of the other tabs is selectable for display of the target region relative to anatomic structures and another of the other tabs is selectable for display of the volume representing the described gradations. The user can accordingly quickly switch between a number of views, each providing different types of information concerning possible stimulations, and accordingly decide on which stimulation parameters to set for the leadwire electrodes to produce a stimulation of tissue in a patient. 
     An example embodiment of the present invention is directed to one or more processors, which can be implemented using any conventional processing circuit and device or combination thereof, e.g., a Central Processing Unit (CPU) of a Personal Computer (PC) or other workstation processor, to execute code provided, e.g., on a hardware computer-readable medium including any conventional memory device, to perform any of the methods described herein, alone or in combination, and to generate any of the user interface displays described herein, alone or in combination. The one or more processors can be embodied in a server or user terminal or combination thereof. The user terminal can be embodied, for example, as a desktop, laptop, hand-held device, Personal Digital Assistant (PDA), television set-top Internet appliance, mobile telephone, smart phone, etc., or as a combination of one or more thereof. Specifically, the terminal can be embodied as a clinician programmer terminal, e.g., as referred to in the &#39;330, &#39;312, &#39;340, &#39;343, and &#39;314 applications. Additionally, some of the described methods can be performed by a processor on one device or terminal and using a first memory, while other methods can be performed by a processor on another device and using, for example, a different memory. 
     The memory device can include any conventional permanent and/or temporary memory circuits or combination thereof, a non-exhaustive list of which includes Random Access Memory (RAM), Read Only Memory (ROM), Compact Disks (CD), Digital Versatile Disk (DVD), and magnetic tape. 
     An example embodiment of the present invention is directed to one or more hardware computer-readable media, e.g., as described above, on which are stored instructions executable by a processor to perform the methods and/or provide the user interface features described herein. 
     An example embodiment of the present invention is directed to a method, e.g., of a hardware component or machine, of transmitting instructions executable by a processor to perform the methods and/or provide the user interface features described herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. 
         FIG. 1  shows an example stimulation and programming system according to an example embodiment of the present invention. 
         FIG. 2  shows an example display screen generable by the system, including a marking showing one or more electrodes that are proximal to a stimulation significant region, according to an example embodiment of the present invention. 
         FIG. 3A  illustrates the passing of a leadwire through a stimulation significant region on which basis display screens are generable according to example embodiments of the present invention. 
         FIG. 3B  illustrates a region considered to be significant, according to an example embodiment of the present invention, for generating the described display screens, in an instance where the leadwire does not pass through the stimulation significant region. 
         FIG. 4  shows an example display screen including a marking identifying the locationally relevant electrodes and an additional marking identifying the electrode corresponding to a sub-area within the stimulation significant region, according to an example embodiment of the present invention. 
         FIG. 5  shows an example display screen in which variations in therapeutic and/or side effect scores are graphically identified by variations in opacity/transparency, according to an example embodiment of the present invention. 
         FIG. 6  shows an example display screen including a two-dimensional leadwire model and a parameter recommendation marking indicating a recommended value for a predetermined or selected stimulation parameter, according to an example embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an example system according to an example embodiment of the present invention. In an example embodiment, a system  100  includes a clinician programmer terminal  105  that includes a telemetry module  106  and a user interface generation module  107 . The telemetry module is in communication with an implanted pulse generator (IPG)  110 . The user interface generation module  107  includes software executable by a processor for generating graphical user interface displays. In an example embodiment, interaction with one or more graphical user interface displays and/or a hardware input device is usable for input of one or more stimulation parameter settings in accordance with which the telemetry module  106  outputs instructions to the IPG  110 , the IPG  110  accordingly controlling a leadwire  120  to activate one or more electrodes  121   a - 121   g  to produce electric pulses at specified amplitudes. For example, the leadwire  120  is implanted in a patient, e.g., in the patient&#39;s brain, and the electric pulses are intended to activate anatomic fibers to produce a therapeutic effect, e.g., as described in further detail in the &#39;330, &#39;312, &#39;340, &#39;343, and &#39;314 applications. The electrodes  121   a - 121   g  can include one or more directional electrodes which can be controlled to direct stimulation in a particular radial direction from the central longitudinal axis of the leadwire  120  and/or can include one or more cylindrical electrodes that produce essentially the same stimulation in all directions rotationally about the cylindrically symmetrical stimulation about the central longitudinal axis of the leadwire  120 . 
       FIG. 2  shows an example of a user interactive graphical user interface display screen  200 , according to an example embodiment of the present invention. The example display screen  200  includes a leadwire model  204  that represents a leadwire, e.g., the implanted leadwire  120 . The leadwire model  204  includes representations of each of a plurality of electrodes of the leadwire. In the example display screen  200 , each of eight electrodes arranged at eight different locations along the longitudinal axis of the leadwire  120  are represented by respectively numbered vertically stacked regions of the leadwire model  204 . Although shown vertically stacked, in an alternative example embodiment, the leadwire model  204  can be horizontally orientated, in which the respectively number regions would be arranged horizontally beside one another. 
     The example display screen  200  further includes a region marking  206  that vertically (since the leadwire model  204  is vertically arranged in the illustrated embodiment) spans those of the electrode representing regions that correspond to electrodes determined by the processor, e.g., by a currently performed calculation or by look-up of previously recorded data, to most closely correspond to an anatomic region or structure of significance with respect to particular stimulation-related information. For example, in an example embodiment, the anatomic region or structure of significance is that which is targeted for stimulation, e.g., as manually defined by user input or as automatically determined by the processor. 
     In an example embodiment, in an instance where at least one of the electrodes of the leadwire  120  passes through the region or structure of significance, an electrode is deemed by the processor to be sufficiently closely related to the region or structure of significance to be indicated as such conditional upon that the respective electrode is one of the electrodes that pass through the region or structure of significance. For example,  FIG. 3A  shows an example stimulation significant region  300  through which the leadwire  120  passes, an example instance in which region marking  206  would identify only those electrodes that are at least partially within the stimulation significant region  300 . According to an alternative example embodiment, at least where at least one of the electrodes is completely within the stimulation significant region  300 , the region marking  206  would identify only those electrodes that are completely within the stimulation significant region  300 . 
     However, it can occur that the stimulation significant region  300  is offset from the leadwire  120  as shown in  FIG. 3B , where the leadwire  120  does not pass through the stimulation significant region  300 , and therefore none of the electrodes  121   a - 121   g  are contained within the stimulation significant region  300 . According to an example embodiment of the present invention, in such an instance, the processor deems an electrode to be sufficiently closely related to the region or structure of significance to be indicated as such by the region marking  206  conditional upon that the electrode is within a boundary  302  whose boundary lines are drawn perpendicular to the central longitudinal axis of the leadwire  120  and define upper and lower limits of the stimulation significant region  300  with respect to the orientation of the boundary  302 . 
     The region marking  206  shown in  FIG. 2  is a box whose upper and lower limits are drawn such that all of the electrodes deemed to be sufficiently closely related to the stimulation significant region  300  are beside the box. In an alternative example embodiment, the region marking  206  is formed of two horizontal lines (where the leadwire model  204  has a vertical orientation) drawn such that all of the electrodes deemed to be sufficiently closely related to the stimulation significant region  300  are beside the region that is between the two horizontal lines. In an alternative example embodiment, the region marking  206  is a single vertical line (e.g., the left vertical line of the box shown in  FIG. 2 ) that extends beside all of the electrodes deemed to be sufficiently closely related to the stimulation significant region  300 . 
     As noted above, according to example embodiments, whether an electrode is deemed sufficiently closely related to the stimulation significant region  300  is based on proximity of the electrode to the stimulation significant region  300  (in that it either passes through the region in the case shown in  FIG. 3A  or is within the boundary  302  in the case shown in  FIG. 3B ). This information is important for a user because greater proximity of a first electrode to the stimulation significant region  300  than a second electrode suggests that the first electrode is likely a better candidate than the second electrode for contributing to the stimulation of the stimulation significant region  300 . The user may accordingly test settings with activation of the first electrode, e.g., at greater amplitude than that at which the second electrode is set, for the stimulation. 
     However, proximity to the stimulation significant region  300  is not necessarily all that is considered to determine which electrodes to activate and the amplitudes at which the electrodes are to be set. According to an example embodiment, the region marking  206  is therefore presented as a two dimensional element, e.g., a box as shown in  FIG. 2  or two horizontal lines bounding a region, such that the element covers a region in which other information is presented which can further factor into the user&#39;s decision for setting the stimulation parameters of the leadwire  120 . 
     For example, in  FIG. 2 , the leadwire model  204  and its numbered regions are arranged as values of the ordinate of a graph  208 , and values for a particular stimulation parameter are arranged as the abscissa values of the graph  208 . Specifically,  FIG. 2  shown amplitude values as stimulation settings  210  for the abscissa of the graph  208 . In alternative embodiments, values of other stimulation parameters can be used as the abscissa values. In alternative example embodiment, the processor provides a user interface via which a user can select one of a plurality of stimulation parameters to use for the abscissa. As noted above, in an alternative example embodiment, the leadwire model  204  can be horizontally arranged, in which case the electrodes would form the abscissa values and the values of the used parameter would form the ordinate values. 
     According to these example embodiments in which values of a stimulation parameter are arranged in a graph against the leadwire model  204 , although not shown in  FIG. 2 , data corresponding to a stimulation associated with a particular electrode (or region to which the particular electrode is proximal) and associated with a particular one of the values of the represented stimulation parameter is plotted in the graph at the corresponding values (corresponding electrode and corresponding parameter value). For example, if an adverse side effect had been recorded to have occurred at a stimulation centered about electrode  3  at an amplitude of 3 mA, in an example embodiment, a node is plotted in the graph at the intersection of electrode  3  and 3 mA. By identifying which electrodes are most likely relevant for stimulating the target stimulation region, while also identifying which combinations of electrodes and stimulation amplitudes previously produced an adverse side effect, the user can identify which electrodes and amplitude settings are best candidates for stimulating the target region without producing an adverse side effect. 
     According to an example embodiment, the recorded information is information previously recorded for the current patient for whom the target stimulation region has been identified and for whom stimulation parameters are being selected based on the output data. According to an alternative example embodiment, information recorded for other patients is also represented. 
     Different types of information can be recorded in association with the electrode parameter value combinations. For example, particularly good therapeutic effects can be recorded. According to an example embodiment of the present invention, more than one data category is representable in the graph. For example, where both adverse side effects information and therapeutic effect information is recorded, the processor outputs graph nodes for both adverse side effects and therapeutic effects records. For example, different graphical markings can be used depending on the type of information, e.g., adverse side effect versus therapeutic effect, being represented. Additionally, according to an example embodiment, the graphical markings representing the graph nodes are differently presented depending on variations in degree. For example, as described with respect to FIG. 6 of the &#39;135 application, aside from inputting occurrences of an adverse side effect and/or therapeutic effects, degrees of such effects can also be input and recorded. Accordingly, the way in which a graph node representing, for example, an adverse side effect is displayed depends on the indicated severity of the adverse side effect. Similarly, the way in which a graph node representing, for example, a therapeutic effect is displayed depends on the indicated degree of therapeutic effect. It is possible for an adverse side effect or therapeutic effect to be recorded without an indication of degree of such effect. In an example embodiment, were no degree is indicated, the node is output in a manner specifically for an instance in which degree has not been indicated. Alternatively, where no degree is specified, a default degree is assigned to the data. 
     For example, in an example embodiment, a green node is used to represent a therapeutic effect and a red node is used to represent an adverse side effect. Also, for example, the greater degree of the effect, the larger the displayed node. Alternatively, for example, different transparencies are used depending on degree. For example, the greater the degree of the adverse side effect, the more opaque the red node. Alternatively, a scale of color is used, where the greater the degree of the effect, the deeper the red or the green used for the display of the corresponding node. 
     According to an example embodiment of the present invention, instead of or in addition to graphically demarcating all electrodes that are within or are proximate to the stimulation significant region  300 , the system graphically indicates the single electrode that intersects or is closest to (with respect to a region drawn perpendicularly to the central longitudinal axis of the leadwire  120  and that bounds upper and lower boundaries of the stimulation significant region  300 ) a significant sub-area within the stimulation significant region  300 , e.g., the center or centroid of the stimulation significant region  300  or a region that has been user-indicated to have particular significance. For example,  FIG. 4  shows a GUI display screen  400 , similar to GUI display screen  200  shown in  FIG. 2 , but display screen  400  further includes an electrode marking  402  corresponding to a single electrode level corresponding to the significant sub-area within the stimulation significant region  300 . 
     In an example embodiment of the present invention, instead of providing the region marking  206  and/or electrode marking  402  such that they correspond to particular electrodes, they are provided to correspond to particular locations or levels of the leadwire with respect to its longitudinal axis. For example, the region marking  206  in  FIG. 2  does not correspond to the entirety of electrodes  3  to  5 , but rather includes the entirety of electrode  4 , most of electrode  3 , and approximately half of electrode  5 , for example, because only parts of electrodes  3  and  5  are within stimulation significant region  300  or within boundary  302 . Similarly, in  FIG. 4 , electrode marking  402  is at the very top of electrode  2 . Further, in an example embodiment, if the relevant upper and lower limits of the stimulation significant region  300  and/or significant sub-area within the stimulation significant region  300  corresponds to a level of the leadwire  120  at which there is no electrode, e.g., between electrodes, the upper and lower edges of the region marking  206  and/or the electrode marking  402  is placed at the relevant leadwire level at which none of the electrodes are represented, e.g., between two electrode representations. It is noted that settings of multiple electrodes can be set to center a stimulation between electrodes, such a center location being a virtual electrode location as described in the &#39;135 application. Accordingly, for example, where the electrode marking  402  is positioned between two electrode representations, a user might therefore consider setting stimulation parameter settings for those two electrodes to center a stimulation at the virtual electrode position between them, which corresponds to the leadwire level at which the electrode marking  402  is drawn. 
     Although display of a leadwire model  204  with a marking showing those electrodes that are significant based on proximity to a stimulation significant region  300 , such as a selected target stimulation region, in a graph that plots information corresponding to the electrodes (or virtual electrodes) at particular values of a selected stimulation parameter, provides a quick reference for a user to visually ascertain those electrodes for which settings can quickly and easily be ascertained, e.g., by trial and error, for producing a stimulation that will likely stimulate the target region, it is also of benefit to provide other interface displays with more detailed and/or other types of information relevant for selecting stimulation parameters, e.g., displays as described in the &#39;330, &#39;312, &#39;340, &#39;343, &#39;314, and/or &#39;232 applications. For example, such other displays can include one or more stimulation significant three-dimensional volumes. Additionally, it is useful for the user to be able to separately view such detailed graphical representations and the core electrode-location information described with respect to  FIGS. 2 and 4  to observe how they relate to each other. 
     Therefore, according to an example embodiment of the present invention, the system outputs a user interface with which a user can quickly switch between two (or more views) including the different graphical information. For example,  FIGS. 2 and 4  show tabs  202   a  and  202   b , where the above-described core electrode-location information is shown when the tab  202   a  is selected. The user can select the tab  202   b  to view other types of information. For example, in example embodiment, when tab  202   b  is selected, the system displays one or more of the graphical displays described with respect to the figures of the &#39;232 application, e.g., including detailed three-dimensional side effect and/or therapeutic effect regions and/or gradients. 
     In an example embodiment of the present invention, instead of using a target stimulation region as the stimulation significant region  300 , a region associated with adverse side effect and/or therapeutic effect is used as the stimulation significant region. For example, within an anatomical region, in an example embodiment of the present invention, voxels are assigned respective scores, e.g., based on the number of stimulation regions associated with therapeutic effect in which the respective voxels were included and the number of stimulation regions associated with adverse side effect in which the respective voxels were included. For example, a score threshold can be selected, and, in an example embodiment, the region marking  206  is based on a region in which all or a majority of voxels are assigned scores that meet the threshold. 
     In an example embodiment, the regions of adverse side effect are regions recorded to have been associated with at least a threshold level of adverse side effect. In an alternative example embodiment, the regions of adverse side effect are regions recorded to have been associated with at least a threshold level of adverse side effect without at least a threshold level of therapeutic effect. In an alternative example embodiment, as described above, the regions of adverse side effect are regions assigned a score associated with adverse side effect, where the score is based on recorded data of adverse side effect and therapeutic effect, where recorded adverse side effects negatively impact the score and recorded therapeutic effects positively impact the score. 
     In an example embodiment, recorded data concerning adverse side effects and/or therapeutic effects are associated with tissue regions that have been previously stimulated. Often, adverse side effects are recorded for stimulation regions in which there is one or more smaller stimulation regions that resulted from other stimulations, which other smaller stimulation regions have been associated with therapeutic effect. 
     Therefore, recorded adverse side effect regions can be separated by a therapeutic effect region. In an example embodiment, multiple region markings  206  are output, each corresponding to a respective stimulation significant region  300 . For example, for a region associated with therapeutic effect that is bounded by regions associated with adverse side effects, resulting in two or more separate regions of adverse side effect, in an example embodiment, a respective region marking  206  is output for each of the separate regions of adverse side effect. 
     According to an example embodiment of the present invention, as shown in  FIG. 5 , of the region whose voxels satisfy the score threshold, a gradient of the score is further graphically represented in the user interface display. For example,  FIG. 5  shows a GUI display screen  500  including a region marking  206   a  showing the vertical position, relative to the leadwire  120 , of the anatomic region whose scores satisfy the score threshold. The region marking  206   a  is a two-dimensional marking including a shaded area, in which transparency/opacity varies in accordance with changes in score. 
     For example, in an example embodiment, the better the score, the more opaque the part of the region marking  206   a  corresponding to the electrode location that is closest to that voxel. 
     An electrode might intersect both voxels of high score and low score. Therefore, according to an example embodiment, for an electrode that intersects voxels to which different scores are assigned, the opacity corresponding to the part of the region marking  206   a  that corresponds to the electrode is based on an average of the voxels&#39; scores. Alternatively, another mathematical calculation can be used for selecting the opacity corresponding to the electrode (or leadwire level). 
     Similarly, where the leadwire does not intersect the region whose voxel scores satisfy the score threshold, an electrode might be close to both voxels of high score and low score. According to an example embodiment, in such a case, the processor performs a mathematical function whose input are the scores of all voxels within a region formed by planes drawn perpendicularly to the central longitudinal axis of the leadwire  120  and including the electrode, but assigns different weights to the voxel scores depending on proximity of the voxel to the electrode, where the closer the voxel is to the electrode, the greater its score is weighted. 
     According to an alternative example embodiment of the present invention, if an electrode intersects more than one voxel or, where the leadwire does not intersect the relevant region and therefore non-intersecting voxels are considered, the opacity/transparency is selected based on the highest scored voxel corresponding to the electrode (or leadwire level). 
     An example embodiment has been described above in which a region marking  206  corresponds to a target stimulation region, and an example embodiment has been described above in which a region marking  206   a  corresponds to a therapeutic effect region. According to an alternative example embodiment a region marking  206   a  is provided based on a combination of such information. For example, a target stimulation region is used as the boundary of the region marking  206   a  and variations in opacity/transparency within the region marking  206   a  are based on variations of voxel score within the target stimulation region. (It is noted that score threshold can itself be a factor for selecting the target stimulation region) 
     In example embodiments of the present invention more than one region marking  206  or  206   a  is displayed, e.g., where more than one region is targeted for stimulation or where more than one region of voxels satisfies the score threshold. 
     Referring to  FIG. 5 , aside from variations of opacity/transparency vertically within the region marking  206   a , in an example embodiment, opacity/transparency is also varied horizontally (not shown) within the region marking  206   a  depending on differences in voxel score depending on a selected parameter setting, e.g., amplitude, to the values of which the abscissa of the graph  208  corresponds. For example, in an example embodiment, the opacity of the region marking  206   a  at a part of the graph  208  that corresponds to electrode  2  and 6 mA is based on scores of voxels corresponding to electrode  2  as described above, but limited to stimulations at 6 mA. 
     According to an example embodiment of the present invention, the system is configured to display a parameter recommendation marking  602  as shown in GUI display screen  600  of  FIG. 6 . The parameter recommendation marking  602  is displayed at a level corresponding to a part of stimulation significant region  300 , e.g., a target stimulation region or structure, e.g., the center or centroid thereof, and is extended at that level until a point of the graph  208  that corresponds to a relevant value for a predetermined (or user-selected) stimulation parameter. For example, in  FIG. 6 , the abscissa of graph  208  corresponds to amplitude values, and the parameter recommendation marking  602  terminates at an amplitude value (between 2 and 3 mA) recommended for stimulation of the target region or structure. For example, according to an example embodiment, such a recommendation is obtained based on an algorithm that estimates an ideal amplitude setting for stimulating a region that best corresponds, e.g., based on, and, according to an example embodiment, considering a trade-off between, overlap and spill, to the target region or structure, e.g., as described in detail in U.S. Prov. Pat. App. Ser. No. 61/651,282 (“the &#39;282 application”), filed Aug. 28, 2012, the content of which is incorporated by reference herein in its entirety. 
     According to an alternative example embodiment, the parameter recommendation marking is displayed at a level corresponding to an electrode (or virtual electrode) recommended to be used. 
     According to an example embodiment of the present invention, and as shown in  FIG. 6 , the system displays both the parameter recommendation marking  602  and the region marking  206 , e.g., as described with respect to any of  FIGS. 2, 4, and 5  (the marking  206  described with respect to  FIG. 2  being shown in  FIG. 6 ). Additionally, as noted above, the region marking  206  or  206   a , according to example embodiments of the present invention, show boundaries of an adverse side effect or therapeutic effect region. According to those embodiments, the parameter recommendation marking  602  shows the relationship between those electrodes corresponding to the adverse side effect or therapeutic effect region and the electrode corresponding to the target region or location or that is recommended to be used for stimulating the target region or location. 
     The above description is intended to be illustrative, and not restrictive. Those skilled in the art can appreciate from the foregoing description that the present invention can be implemented in a variety of forms, and that the various embodiments can be implemented alone or in combination. For example, the graph nodes corresponding to records of side effects and/or therapeutic effect described above with respect to  FIG. 2  can also be output in any of the display screens described above with respect to  FIGS. 4-6 . Therefore, while the embodiments of the present invention have been described in connection with particular examples thereof, the true scope of the embodiments and/or methods of the present invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification, and following claims.