# Patent

## Title
Capture and visualization of clinical effects data in relation to a lead and/or locus of stimulation

## Abstract

A system and method for outputting historical stimulation information includes a processor configured to assign individual display regions, e.g., pixels or voxels, (or a larger region) a score based on those volumes of activations (VOA) in which the individual display region had been included and the scores assigned to those VOAs, and display in a display device a map of varying graphical indicia based on the different scores assigned to the elemental display regions.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority to U.S. Provisional Patent Application Ser. Nos. 61/693,866 filed on Aug. 28, 2012, 61/699,135 filed on Sep. 10, 2012, 61/699,115 filed on Sep. 10, 2012, and 61/753,232 filed on Jan. 16, 2013, the content of all of which is hereby incorporated by reference herein in their entireties.


FIELD OF THE INVENTION
The present invention relates to a system and method for generating and outputting clinical effects and/or side-effects maps as a visual history of anatomic tissue stimulations provided by an electrode leadwire. Such maps can be provided on a patient-specific basis. The leadwire can be, e.g., of a Deep Brain Stimulation (DBS) device or a Spinal Cord Stimulation (SCS) device. The present invention relates to methods and systems for determining target stimulation electrical stimulation parameters of an anatomical region of the body.
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 may include stimulation of the thalamus or basal ganglia and may be used to treat disorders such as essential tremor, Parkinson's disease (PD), and other physiological disorders, including psychiatric disorders. DBS may 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'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 may be the same for all of the electrodes of the leadwire, or which may 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 '330 application”), U.S. patent application Ser. No. 12/454,312, filed May 15, 2009 (“the '312 application”), U.S. patent application Ser. No. 12/454,340, filed May 15, 2009 (“the '340 application”), U.S. patent application Ser. No. 12/454,343, filed May 15, 2009 (“the '343 application”), and U.S. patent application Ser. No. 12/454,314, filed May 15, 2009 (“the '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.
Such 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'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'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.
SUMMARY
According to example embodiments of the present invention, the VOA is a two-dimensional or three-dimensional model. For example, in an example embodiment, the VOA is a three-dimensional model composed of voxels, a volume element within a three-dimensional grid. The VOA identifies a tissue region that is estimated to be active for a given stimulation.
In an example embodiment, the system records in a memory clinical effects of a stimulations represented by a respective VOA are recorded. For example, one or more sensors are used to obtain physiological information of a patient on whom a stimulation is performed, which stimulation is estimated by the system to produce a VOA, with which VOA the sensor information is used. Alternatively or additionally, the system includes a user interface via which the system is configured to receive user input of clinical effects information for a given stimulation which the system stores in association with a VOA which the system estimates for the stimulation.
In an example embodiment, the system assigns a score to the VOA based on such clinical effects data. In an example embodiment, the system assigns individual pixels (or pixel regions) and/or three-dimensional voxels (or voxel regions) a score based on clinical effects data of the VOA(s) of which they have been a part, e.g., based on scores of the VOA(s) of which they have been a part. For example, in an example embodiment, the pixel and/or voxel scores are based on any combination of the clinical data for the graphical regions, for example, an average of recorded values.
According to an alternative example embodiment, Neural Element Models are directly scored in a manner to that described above for voxels. These models are expected to be more faithful to neural function.
According to example embodiments of the present invention, a leadwire includes multiple electrodes, for each of which a respective independent current source is provided, by which current can be “steered” longitudinally and/or rotationally about the leadwire for localization of stimulation at points along the lead wire. Example embodiments of the present invention provide a visual interface that includes a graphical representation of the effects of stimulation on the anatomy of a particular patient or group of patients. However, prior to initial programming of the leadwire, no direct information about a patient's response to stimulation is known. In an example embodiment, the absence of information is also represented. For example, in an example embodiment, the system displays an anatomical map with a “fog-of-war” feature by which areas of the anatomical map for which a VOA has been estimated for a conducted stimulation are displayed in a fully revealed manner, whereas other areas of the anatomical map are left blacked out or in a haze, e.g., with less brightness. In an example embodiment, the system displays in a fully revealed manner only those regions corresponding to VOAs associated with stimulations for which the system has obtained clinical effects information, e.g., via sensor or via user input. Such a map can be generated for a patient population. In an example embodiment, the map is patient specific. (While the described embodiments refer to an anatomical map, e.g., formed of an anatomical atlas background or a background of medical images, in alternative example embodiments, the map is of a region relative to an implanted leadwire, e.g., even without representations of anatomical structures, and it is to be understood that the described features can be implemented with such a leadwire centric map.)
For example, in an example embodiment, the system generates an anatomical map with graphical indicia for distinguishing between different regions of the map based on clinical effect, where the respective clinical effect indicated for a respective region depends on the clinical effects information obtained by the system for a VOA estimated to include the respective region, and further based on whether the respective region has been included in such a VOA. Such indicia can include variations in color, brightness, hatching, transparency, shading, etc. According to an example embodiment, the map includes areas that are not revealed to the user until information regarding the effects of stimulation in that anatomical area have been obtained by exploring the area with electrical stimulation. For example, the region is blacked out. Subsequent to performance of a stimulation whose estimated VOA covers the region, and, for example, for which VOA clinical effects information is obtained, the formerly blacked out region which is part of the VOA is displayed in a non-blacked out manner in a subsequently generated information map. In an example embodiment, the region is displayed in the non-blacked out manner, even if clinical effects information is not obtained. However, graphical indicia representing respective clinical effects information is not displayed for the now non-blacked out region until such information is obtained for a VOA inclusive of the respective region.
The clinical effects information can include therapeutic effect information indicating the effectiveness of respective stimulations associated with VOAs for providing a therapeutic effect and/or adverse side-effect information indicating adverse side effects caused by respective stimulations associated with VOAs. The clinical effects information is captured and made available to the user in the map to provide a visualization of the degree of therapeutic effect and/or adverse side effect using gradations in graphical indicia within the map. Such a map can help facilitate the subsequent choosing of stimulation parameters for programming the leadwire in a more informed way. For example, parameters can be selected which are estimated to produce a VOA corresponding to a target region, which target region is selected as a portion of the map graphically associated with a certain level of therapeutic effect and with less than some maximum tolerated adverse side effect.
According to example embodiments of the present invention, the graphical representation of the effects of stimulation on the anatomy of a particular group of patients (or a specific patient) includes a mean (or other statistical combination) of clinical and/or side-effect values obtained for each anatomical location. These mathematical methods may be less useful for single-patient representations because of the small data sampling on which the base the map, but it is still possible. According to example embodiments of the present invention, the graphical representation of the effects of stimulation on the anatomy of a patient population of a particular patient includes a maximum or minimum value of therapeutic effect and/or side-effect values obtained for each anatomical location. For example, a voxel can be part of a plurality of different VOAs associated with different sets of stimulation parameters that have been used to perform respective stimulations for which different clinical effects information had been obtained, and the map, according to an example embodiment, provides graphical indicia at the voxel based on the VOA for which a maximum score, or, alternatively, a minimum score had been obtained for a therapeutic effect, or, alternatively, an adverse side effect. Such information can be based on all therapeutic or adverse side effects or for a selected one or more particular therapeutic and/or side effects.
Use of maximum or minimum score values for a voxel provides an advantage of informing the user of threshold values that are required to achieve a therapeutic effect or to avoid an adverse side-effect. However, this can also have the effect of diluting the importance of a location that may have appeared more promising using a more complex statistical analysis which takes into account a combination of scores with which the voxel is associated.
According to example embodiments of the present invention, the graphical representation of the effects of stimulation on the anatomy of a particular patient includes an overall value (therapeutic effect+side-effect) of therapeutic and/or side-effect values obtained for each anatomical location based on historical stimulations of the patient, in order to accomplish the dual objective of maximizing clinical effect and minimizing adverse side-effects. For example, the system calculates a blended score. According to alternative example embodiments of the present invention, the graphical representation of the effects of stimulation on the anatomy of a particular group of patients includes a maximum or minimum value of an overall value (therapeutic effect+side-effect) of therapeutic and/or side-effect values obtained for each anatomical location based on historical stimulations of a patient population, e.g., of all recorded patient stimulations or of those of a selected sub-group of the patient population, e.g., selected based on medical indications and/or patient demographics.
Thus, according to example embodiments of the present invention, the graphical representation of the effects of stimulation on the anatomy of a particular patient includes an estimated therapeutic effect and/or side-effect value for a given location based on known information, e.g. statistical data for the anatomical location compared to a library of data.
According to example embodiments of the present invention, the graphical representation of the effects of stimulation on the anatomy of a particular patient includes a graphical representation of a binary (OK, Not OK) side-effects threshold for a given location based on known information. According to example embodiments of the present invention, the graphical representation of a binary (OK, Not OK) side-effects threshold for a given location is overlaid on other graphical indicia of therapeutic effects of stimulation on the anatomy of a particular patient or group of patients. According to alternative example embodiments of the present invention, the representations of the side-effects values that are overlaid on the graphical indicia of the therapeutic effects indicate a plurality of side effect scores, (e.g., using different hatching or dot densities).
According to example embodiments of the present invention, the graphical representation of the effects of stimulation on the patient anatomy includes three-dimensional representations of clinical effects volumes, for example, in which the clinical effect values are represented as three-dimensional surfaces based on threshold values for therapeutic effects and/or adverse side-effects. These 3-D surfaces can include some transparency so that anatomical and/or leadwire features are not completely obscured. The “fog-of-war” regions (the regions not explored with stimulations) in three dimensions is represented as, for example, a darkness or fog which can include some transparency so that anatomical and/or leadwire features are not completely obscured.
According to an alternative example embodiment, the graphical representation of the effects of stimulation on the anatomy includes two-dimensional representations of clinical effects volumes in which the clinical effect values are represented as 2-D planes indicated with, e.g., color, hatching, patterning, etc., and the user can select which plane is being displayed, for example, by selection of plane direction, and plane slice in the selected direction. The “fog-of-war” in 2 dimensions is represented as, for example, a color (e.g., black or white) or patterning.
According to example embodiments of the present invention, the graphical representation of the effects of stimulation on the anatomy includes three-dimensional representations of a volume including therein modeled anatomical fibers, e.g., modeled neurons of a Neural Element Model (NEM), presented as a 3-D map in which the clinical effect values are represented as lines or 3-D neural objects graphically distinguished from each other based on estimated activation regions for respective stimulations for which clinical effects information had been previously obtained. These 3-D objects can include some transparency so that anatomical and/or leadwire features are not completely obscured. The “fog-of-war” in 3 dimensions is represented as, for example, a darkness or fog which can include some transparency so that anatomical features, including modeled anatomical fibers, and/or leadwire features are not completely obscured. According to example embodiments of the present invention, the graphical representation of the effects of stimulation includes two-dimensional representations of clinical effects volumes graphically representing the anatomical fibers, where the clinical effect values are represented with, e.g., color, hatching, patterning, etc., of the two-dimensionally rendered fiber models, where the user can select the plane to be displayed. The “fog-of-war” in two dimensions is represented as, for example, a color (e.g., black or white) or patterning within the fiber map.
Thus, according to an example embodiment of the present invention, the graphical representation of the effects of stimulation on the anatomy of a patient population of a particular patient includes representations of a clinical effects map, including variations for indicating differences in therapeutic effect and/or side-effects, which maps can be in two dimensions or three dimensions, and which can include indicia in volumes relative to anatomical tissue and/or an implanted leadwire, and/or relative to or in the form of modeled anatomical fibers. Moreover, information can be categorized, e.g., into therapeutic effects information and side effects information, or other categories (e.g., by type of therapeutic effect and/or type of side effect), with gradations in different graphical indicia being used for the different categories of information, which different indicia are displayed in separate maps or overlaid on each other in a single map.



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 graphs of information concerning suitable stimulation amplitude parameters for directional electrodes in a three-dimensional perspective, according to an example embodiment of the present invention.
FIGS. 2A and 2B show user interface displays of the graphs of FIG. 1 in a two-dimensional perspective, according to an example embodiment of the present invention.
FIGS. 3A to 3C show example VOAs all centered at a same location about a leadwire, for which VOAs clinical effects data are recorded, according to an example embodiment of the present invention.
FIG. 3D show a clinical effects graph based on the clinical effects information obtained for the VOAs of FIGS. 3A to 3C, according to an example embodiment of the present invention.
FIGS. 4A to 4C show example VOAs centered at different longitudinal positions of a leadwire, for which VOAs clinical effects data are recorded, according to an example embodiment of the present invention.
FIG. 4D show a clinical effects graph based on the clinical effects information obtained for the VOAs of FIGS. 4A to 4C, according to an example embodiment of the present invention.
FIGS. 5A to 5C show example VOAs about a leadwire for which VOAs clinical effects data are recorded, according to an example embodiment of the present invention.
FIG. 5D show a clinical effects graph based on the clinical effects information obtained for the VOAs of FIGS. 5A to 5C, according to an example embodiment of the present invention.
FIGS. 6A and 6B show example VOAs about a leadwire for which VOAs side effects data are recorded, according to an example embodiment of the present invention.
FIG. 6C shows a graph of side-effect information for stimulation provided at a single longitudinal location along a leadwire with cylindrically symmetrical electrodes overlaid on a graph of therapeutic effect information for stimulation plotted relative to the leadwire, according to an example embodiment of the present invention.
FIG. 7 shows a three-dimensional graph of therapeutic effect information for stimulation provided at a rotational location about a leadwire that includes directional electrodes arranged rotationally about the leadwire, according to an example embodiment of the present invention.
FIG. 8 is a drawing illustrative of a 3-D graph of anatomical regions of a patient including neural elements in a vicinity of a leadwire that includes electrodes for stimulation of the neural elements, which neural elements can be displayed according to therapeutic and/or adverse effect information, according to an example embodiment of the present invention.



DETAILED DESCRIPTION
FIG. 1 shows an example graphical display of output according to an example embodiment of the present invention. According to an example embodiment, the system is configured to output, in a single plane, graphs for both therapeutic effect and adverse side effect reactions to electric field stimulation in a patient's tissue, which graphs can overlap depending on the respective minimum and maximum amplitude values of the graphs in the different directions about the leadwire. The graphs include shaded voxels and a “fog” (e.g., formed using color, pattern, transparency, etc.) is used to indicate voxels for which there is no clinical data yet available. According to example embodiments, a user can use the fog to determine where to “steer” a current field longitudinally and/or rotationally about the leadwire for localization of stimulation in order to obtain new information regarding the effects of stimulation at that region.
In an example embodiment, the system is configured to mark a graph region determined to be suitable for stimulation based on the relationship between the area of the two graphs (where the graphs do indicate the existence of such a region). A user can thereby determine a range of amplitudes and an angular range about the leadwire at which to set the stimulation.
For example, FIG. 1 shows a therapeutic effect map 100 and a side effects map 102 within a plane at longitudinal position z1 along a leadwire. In an example embodiment, the system outputs indicia indicating which map represents clinical effect values and which map represents side effects, each by line type or color and/or textual indicia, etc. It further includes a cross-hatched region 105, the cross-hatching indicating that region to be suitable for stimulation because it can be stimulated to produce a (threshold minimum) therapeutic effect without producing a (threshold) adverse side effect. Any other suitably appropriate region indicia can be used, e.g., highlighting, coloring, or textual indicia, etc. In the example of FIG. 1, the cross-hatched region is determined to represent suitable parameters because the region lies within the area indicated to be associated with VOAs of the therapeutic effect map 100 and outside of the area indicated to associated with VOAs of the side-effect map 102). FIG. 1 further shows a therapeutic effects map 108 and a side effects map 110 within a plane at longitudinal position z2 along the leadwire. No cross-hatched region is included because there is no suitable range of stimulation parameters at longitudinal position z2, since, in all directions about the leadwire, intolerable side effects set in at lower amplitudes than those at which therapeutic clinical effects are first attained.
It is noted that that there may be certain adverse side effects that are tolerable and there may be certain therapeutic effects that are insignificant. The system is programmed to produce the graphical information for certain predetermined side effects and/or therapeutic effects. Additionally, in an example embodiment, the system includes a user interface via which a user can select one or more side effects and/or one or more therapeutic effects on which basis to generate the maps.
When the maps are provided in a three-dimensional perspective about the model of the leadwire, the leadwire model can partially obscure portions of the graphs. Example embodiments provide a control for rotating the model, so that the maps can be rotated and viewed at the different angles, a user may desire to view entire maps at a time for the respective longitudinal positions at which they are generated. Additionally, when the maps are provided in a three-dimensional perspective, precise dimensions of the map shape are distorted to account for depth in a two-dimensional display screen, for example, as can be seen by a comparison of the maps in FIG. 1 and their two-dimensional perspective counterparts shown in FIGS. 2A and 2B. Accordingly, in an example embodiment of the present invention, the system is configured to display the maps in a two dimensional view, in which the maps of a single longitudinal position (or other two-dimensional perspective) are displayed such that planes formed by the maps are parallel to the surface of the display area, e.g., parallel to the surface of a display screen. For example, FIG. 2A shows the maps 100 and 102 in a two-dimensional view with the leadwire virtually extending perpendicularly to the display screen, and FIG. 2B shows the maps 108 and 110 in a two-dimensional view with the leadwire virtually extending perpendicularly to the display screen. In an example embodiment of the present invention, a two-dimensional view of the maps is displayed for only a single one of the longitudinal positions of the leadwire at any one time. Alternatively, in an example embodiment, different two-dimensional map views for a plurality of longitudinal positions are simultaneously displayed in different respective display areas of the display screen, e.g., each area including respective indicia indicating the respective longitudinal position to which it corresponds. Example two dimensional planes, e.g., of a patient brain, which can be displayed include, a plane at a given inferior/superior level and running between the left and right sides and between the anterior and posterior sides, a plane at a given right/left point and running between the superior and inferior sides and between the anterior and posterior sides, and a plane at a given anterior/posterior position and running between the inferior and superior sides and between the left and right sides. Other two-dimensional planes can be similarly selected relative to the implanted leadwire (which may be implanted at an angle relative the anterior/posterior, inferior/superior, and/or left/right directions of the patient anatomy). For example, orthogonal and longitudinal cross-sections of the leadwire can be alternatively selected according to an example embodiment of the present invention.
In an example embodiment of the present invention, the system displays a model of the leadwire 300, and further displays one or more maps as shown in FIGS. 3A-D (as described below). The maps can be displayed in a display area separate from that in which the model of the leadwire 300 is displayed, or can be displayed overlaid on the model of the leadwire 300. The maps shown in FIGS. 3A to 3C are VOAs estimated for respective stimulations and for which clinical data has been obtained. At a plurality of points about the leadwire, the therapeutic efficacy and/or adverse side-effects of stimulations are evaluated based on historical stimulations for which those VOAs had been estimated to cover those points. For example, if the patient exhibits undesirable side-effects, the user can annotate a VOA corresponding to the stimulation at which the side-effect(s) occurred as being in a “side-effect range” by clicking on a button or menu item of a user interface. Similarly, if the patient exhibits good symptom relief or therapeutic efficacy, the user can annotate a VOA corresponding to the stimulation at which the therapeutic effect occurred as being in an “efficacy range” by clicking on a button or menu item. It is noted that both a side effect and a therapeutic effect may occur for a same stimulation. Such information can be binary, or can be input as a value from a large scale of values.
According to an example embodiment, information concerning therapeutic effect and/or adverse side effect is additionally or alternatively obtained using sensors. For example, a sensor can be used to sense patient tremor, speed, stability, heart rate, reaction time, etc., based on which sensed information conclusions concerning therapeutic effect and/or side effect are automatically made and recorded.
Similar to that shown in FIGS. 2A-B, FIGS. 3A-C show an example graphical display of a two-dimensional map 304 of a VOA corresponding to a stimulation using a leadwire 300 with cylindrically symmetrical electrodes 302, for which a therapeutic effect had been recorded. While the two-dimensional map 304 is shown according to a view with the leadwire extending parallel to the display screen, in an example embodiment the cross-sectional plane of a three-dimensional clinical effect map 304 can be selected by the user for a particular view. For example, the plane can be selected to scrub in the anterior-posterior direction, the medial-lateral direction, and the superior-inferior direction; to scrub in lead-centric views; and to scrub in relative to target anatomical volumes or structures. According to an example embodiment of the present invention, the system displays controls selectable by a user, which controls are respectively associated with predetermined ones of the indicated views. In an example embodiment of the present invention, the two-dimensional planes of the selected view are user-navigable between two dimensional slices. While the VOAs are being described as actually displayed maps, they need not be displayed, but rather the information for such maps are used by the processor to generate the clinical effects map described below with respect to FIG. 3D.
The clinical effects maps are based on the recorded information regarding a respective plurality of actual locations (e.g., voxels that have been part of one or more VOAs corresponding to historically conducted stimulations) for which clinical effect data has already been captured. For example, FIGS. 3A-C show the voxels of VOAs estimated for three different stimulation parameter settings, for which VOAs respective clinical effect values were assigned or determined. Those VOAs can be estimated for different stimulations that have all occurred at different points of time. The VOAs can be of different size or shape. For example, the illustrated VOAs of FIGS. 3A-C are shown to be of different sizes (these are not intended to show actual estimated VOAs, but rather are intended to illustrate that the VOAs can be of different sizes). The VOAs can have overlapping regions and can have non-overlapping regions. For example, certain voxels can be part of all of the VOAs of FIGS. 3A-3D, some in only two of them, and some in only one of them.
For example, the VOAs 304 of FIGS. 3A-3C are all centered at the same location but are of different sizes in each of FIGS. 3A-C, which could happen if the pulse-width or amplitude is varied. Furthermore, each of the VOAs 304 represent voxels assigned different clinical effect values indicated by numbers (1-3) within the area of the respective VOA 304 in each of FIGS. 3A-C. The clinical effect values can be indicated by other indicia, such as coloring, shading, hatching, etc., as described below, and as shown in FIG. 3D.
According to an example embodiment, a combined therapeutic effects map 305, as shown in FIG. 3D, is generated and displayed based on the information obtained for the respective VOAs 304 in each of FIGS. 3A-C. In the combined map 305, clinical effect values are assigned or determined for each voxel based on the collected data available from all available VOAs 304 including therapeutic effect information for the respective voxel. In the example embodiment shown in FIG. 3D, each voxel is assigned the minimum therapeutic effect value the voxel has been assigned in any of the VOAs 304 in each of FIGS. 3A-C. (While minimum therapeutic value, discussed herein with respect to FIGS. 3A-6C, refers to the least therapeutic effect, in other terminology, minimum therapeutic value can be thought of as producing the least degree of a symptom for which the therapy is performed, under which alternative terminology, the minimum value is the best therapeutic effect, and according to which terminology, FIG. 3D would be considered to show the maximum values.) Using a metric like Max or Min provides the advantage that only one clinical effect value per voxel need be retained and the values can be readily updated during programming via a straightforward comparison of old and new values for each voxel.
For example, according to an example embodiment in which only maximum values are represented, for each new VOA, for each voxel of the VOA, the system compares the effect value for the current VOA to the effect value stored in association with the voxel, and updates the voxel value only if the new value is greater than the previously stored value. Similarly, according to an example embodiment in which only minimum values are represented, for each new VOA, for each voxel of the VOA, the system compares the effect values for the current VOA to the effect value stored in association with the voxel, and updates the voxel value only if the new value is less than the previously stored value. According to an example embodiment in which the system provides the option for viewing a map based on minimum values and maximum values, the system would store only two values per voxel. However, as discussed below, in other example embodiments, other mathematical functions, e.g., an average, can be used to score a voxel, which may require retaining more, e.g., all, historical values for the voxel.
An advantage of use of the Min metric is that it indicates the volumes one might expect to be required to be stimulated for achieving a certain level of therapeutic effect. Because information pertaining to several VOAs are being displayed together in FIG. 3D, the use of textual information, such as numbers, to indicate the therapeutic effect values, as in FIGS. 3A-C, can be insufficient as there can be insufficient clarity of the volumes to which the text corresponds, and therefore a clinical effects legend is provided, according to an example embodiment, e.g., as shown in FIG. 3D, so that the numerical therapeutic effect values of VOAs 304 of FIGS. 3A-C can be displayed using other graphical indicia, such as coloring, shading, and/or hatching in the combined therapeutic effect map 305 of FIG. 3D. A specific graphical indicia (the color black in FIG. 3D) is provided to indicate the “unexplored” areas of the patient anatomy for which no clinical effect information is yet available. These blacked-out areas are not shown in the figures for the purpose of clarity.
Similar to the VOAs and therapeutic effect map shown in FIGS. 3A-C, FIGS. 4A-C also show example VOAs of different sizes and an example therapeutic effect map. However, unlike FIGS. 3A-C, the VOAs 304 of FIGS. 4A-C are not centered on the same location in each of FIGS. 4A-C.
Similar to the VOAs and therapeutic effect map shown in FIGS. 4A-C, FIGS. 5A-C also show example VOAs of different sizes centered at different locations of the leadwire and show an example therapeutic effect map. However, unlike FIG. 4D, the therapeutic effect map 305 of FIG. 5D is constructed based on maximum historical therapeutic effect values for the voxels, i.e., the maximum therapeutic effect value a respective voxel has been assigned in any of the maps 304 in each of FIGS. 5A-C. The use of the Max metric for assigning clinical effect values to voxels provides the benefit of better showing where it might be beneficial to center the stimulation on the leadwire 300. It also indicates the minimum region expected to be required for achieving a certain threshold effect. However, construction of the therapeutic effect map 305 based on the Max metric can obscure information regarding volumes which would practically be required to be stimulated for obtaining a threshold therapeutic effect. Therefore, according to an example embodiment of the present invention, the system is configured to display maps 305 based on both the minimum and maximum values, e.g., in different display regions, frames, or windows, or at different times, e.g., depending on a user-selectable option.
FIGS. 6A-B show an example graphical display of VOAs 306 estimated for stimulations for which adverse side-effect data has been obtained. (Although, such VOAs are being described separate from the VOAs for which therapeutic effect data are obtained, as noted above, both therapeutic effect and adverse side effect data can be obtained for a same VOA.) For example, FIGS. 6A-B show the estimated VOAs under two different stimulation parameter settings and the respective side-effect values (1 and 2) that were assigned or determined for the estimated VOAs. The VOAs 306 of FIGS. 6A-B are centered on the same location in each of FIGS. 6A-B and are also of different sizes in each of 6A-B, which as explained above, could happen if the pulse-width or amplitude were varied. The side-effect values can be indicated by other indicia, such as coloring, shading, hatching, etc., as described below. As described with respect to the therapeutic effects maps of FIGS. 3D, 4D, and 5D, an adverse side effects map (not shown alone) can be similarly constructed.
According to an example embodiment, a combined clinical effects map 305 is formed, as shown in FIG. 6C, based on the information associated with the VOAs 306 of FIGS. 6A-B and the therapeutic effects map 305 of FIG. 3D. In the combined clinical map 305 of FIG. 6C, minimum side-effect values recorded for each voxel based on a plurality of VOAs of which they were a part, and minimum therapeutic effect values recorded for each voxel based on a plurality of VOAs of which they were a part are represented in a combined map. The graphical indicia representing the side effects values are shown to be overlaid on the graphical indicia representing the therapeutic effect values. However, in an example embodiment of the present invention, the side effects indicia are displayed with transparencies so that they do not obscure the graphical indicia representative of the therapeutic effect values. Additionally, while FIG. 6C shows the same types of graphical indicia (hatchings) to be used to show variations in both therapeutic effect and adverse side effect values, in an alternative example embodiment, different types of graphical indicia are used for therapeutic effect and for adverse side effect values. For example, in an example embodiment, variations in color are used for corresponding variations in therapeutic effect scores and variations in hatching are used for corresponding variations in adverse side effect scores. Alternatively, different sets of hatchings can be used for indicating therapeutic effects than those used for indicating adverse side effects. In the example embodiment shown in FIG. 6C, each voxel is assigned the minimum side-effect value the voxel has been assigned in any of the VOAs 306 of FIGS. 6A-B.
The described figures show independent graphical representations for therapeutic information and side effect information. According to an example embodiment of the present invention, a single score is calculated based on both therapeutic values and side effect values scored for a voxel. For example, an equation can be used by which a therapeutic value positively impacts the voxel's overall score and a side effect value negatively impacts the voxel's overall score. Side effect and therapeutic effect values can be equally weighted or differently weighted. Similarly, while the figures have been described as reflecting minimum or maximum values, in an example embodiment of the present invention, all of a voxel's scores (i.e., the scores of all VOAs of which a voxel has been a part) are considered in an equation which outputs an overall score. In an example embodiment, a combination of these features of integrating both therapeutic and side effect values and of considering all historical voxel values is used.
As shown in FIG. 7, in an example embodiment of the present invention, the system is configured to output, a three-dimensional clinical effect map showing a volume of voxels whose scores meet a selected threshold, e.g., a minimum therapeutic effect, a minimum adverse side effect, or a minimum overall score. In FIG. 7 a rotationally asymmetrical leadwire 300, i.e., including directional electrodes 302, for which associated clinical effect values have been recorded is shown. The three dimensional clinical effects volume 305 is shown to be biased towards one side of the leadwire 300, which can occur particularly using a directional lead, since the stimulations produced by the leadwire 300 that includes directional electrodes 302 often are biased towards a particular rotational direction from the leadwire 300.
The threshold on which basis the volume is generated can be a pre-programmed threshold or can be user-selected. The volume is generated based on a combination of voxels whose scores meet the threshold. In FIG. 7, there is a region separating the displayed volume 305 and the model of the leadwire 300. This can occur, for example, because the region between the leadwire and the volume includes voxels associated with many VOAs for which an insufficient score was assigned. For example, there may be many VOAs estimated for stimulations at those intermediate voxels with a low therapeutic effect, but, once a region further away from the leadwire is stimulated, the therapeutic effect for such a stimulation can be much greater. The same can be true with respect to adverse side effects.
Once the voxels whose scores (e.g., minimum or overall score) meet the threshold are determined, the system, according to this example embodiment, displays a representation of the volume, e.g., relative to a model of the leadwire, and/or relative to anatomical structures, e.g., atlas structures or medical image structures.
While threshold volumes are shown in FIG. 7 as a three-dimensional volume, in an alternative example embodiment, the volume can be represented in a two-dimensional plane. Similarly, while the therapeutic and side-effect maps of FIGS. 3D, 4D, 5D, and 6C are shown as two-dimensional planes, in an example embodiment, the system is configured to render also those volumes three-dimensionally.
FIG. 8 is a drawing illustrative of an example of a 3-dimensional NEM model of a patient's anatomy, where programmed assumptions about the anatomy of a patient, e.g., the placement of cells, axons and/or terminals of other types of fiber structures with respect to the location of the leadwire, are used for generating the model. For example, FIG. 8 illustrates a representation of an NEM model of a patient's anatomy showing neural populations 305, of which some can be stimulated using a leadwire 300 with electrodes 302a-c. According to an example embodiment, the activated neurons for which clinical effects and/or side-effects data is captured is displayed in a manner that represents those clinical effects and/or side effects data. The clinical effect and/or side-effect values for the activated neurons can be shown via coloring or other graphical indicia as described above with respect to the therapeutic effect, adverse side effect, or combination volume maps. According to this alternative example embodiment, instead providing such graphical indicia on an entire continuous volume, the indicia are placed on individual modeled fibers. For example, different ones of the fibers 305 are displayed with different colors and/or intensities depending on such data. According to an example embodiment, different parts of a single fiber can be displayed differently depending on the area in which the respective parts of the single fiber lie with respect to the therapeutic and adverse side effect data. According to an alternative example embodiment, each of the fibers is categorized as a whole.
In an example embodiment of the present invention, the described maps are continuously updated as more data points are added so that the “fog” of unexplored areas of an anatomy of a patient (or group of patients) can be removed to provide a clearer and more complete picture of the patient reactions to stimulation. Additionally, the maps can be updated over time to reflect changes in values with which voxels are associated.
In an example embodiment of the present invention, the system includes a control selectable for toggling between a three dimensional view of the graphs and two dimensional views of the graphs.
As noted above, there may be certain adverse side effects that are tolerable for a certain subject and there may be certain therapeutic effects that are insignificant for said subject. Therefore, in an example embodiment, the system includes a user interface via which a user can select one or more side effects and/or one or more therapeutic effects on which basis to generate the graphs.
In an example embodiment of the present invention, the granularity with which the graphical indicia of the historical maps vary is by each individual change in score. According to an alternative example embodiment, a single graphical indicium is used for a range of scores, variations in the graphical indicia occurring between different ranges of scores.
According to an example embodiment of the present invention, the clinical effects data of stimulations performed on a patient are stored in an implanted pulse generator (IPG) used for generating the pulses that cause the leadwire to produce a stimulation and/or are stored on a remote control used for input of the stimulation settings with which the leadwire is programmed. According to an example embodiment, the system access the data from the IPG or the remote control and generates the above-described maps based on the obtained data.
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 '330, '312, '340, '343, and '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, having stored thereon 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.
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. 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.

## Claims

1. A computer-implemented method for outputting a stimulation history map corresponding to a plurality of stimulations that have been performed using a stimulation device implanted in an anatomical region, the method comprising:
for each of a plurality of display elements, where each of the display elements is recorded as having been part of each one of a plurality of scored estimated volumes of tissue activated (VOAs) by the plurality of stimulations, determining, by a computer processor, a score for the display element based on scores of the plurality of VOAs of which the display element has been recorded as being a part, wherein each of the plurality of VOAs comprises multiple ones of the display elements; and
generating and outputting, by the processor, a map including the plurality of display elements graphically marked based on the respective scores determined for the display elements.

2. The method of claim 1, wherein the display elements are pixels.

3. The method of claim 2, wherein the pixels represent an anatomical region in which the stimulation device is implanted.

4. The method of claim 2, wherein the pixels represent an atlas of an anatomical region in which the stimulation device is implanted.

5. The method of claim 1, wherein the display elements are voxels.

6. The method of claim 5, wherein the voxels represent an anatomical region in which the stimulation device is implanted.

7. The method of claim 5, wherein the voxels represent an atlas of an anatomical region in which the stimulation device is implanted.

8. The method of claim 1, wherein the display elements represent tissue fibers.

9. The method of claim 1, wherein the display elements represent neural elements.

10. The method of claim 1, wherein the determining includes, for each of the display elements, determining the score for the display element as a maximum score for that display element from the plurality of VOAs of which the display element has been recorded as being a part.

11. The method of claim 1, wherein the determining includes, for each of the display element, determining the score for the display element as a minimum score for that display element from the plurality of VOAs of which the display element has been recorded as being a part.

12. The method of claim 1, wherein the determining includes calculating an average of scores of all of the plurality of VOAs of which the respective display element has been recorded as being a part.

13. The method of claim 1, wherein the scores of the VOAs depend on a degree of therapeutic effect recorded as having been caused by the respective VOAs.

14. The method of claim 13, further comprising:
receiving input of one of a plurality of therapeutic effects as a filter criterion, wherein, in accordance with the filter criterion, only those of the scores of the VOAs which correspond to the therapeutic effect are used for the determination of the scores for the display elements.

15. The method of claim 1, wherein the scores of the VOAs depend on a degree of adverse side effect recorded as having been caused by the respective VOAs.

16. The method of claim 15, further comprising:
receiving input of one of a plurality of adverse side effects as a filter criterion, wherein, in accordance with the filter criterion, only those of the scores of the VOAs which correspond to the adverse side effect are used for the determination of the scores for the display elements.

17. The method of claim 1, wherein scores of the VOAs reflecting a degree of therapeutic effect caused by the stimulations to which the VOAs correspond and scores of the VOAs reflecting a degree of adverse side effect caused by the stimulations to which the VOAs correspond are used for the determination of the scores for the display elements.

18. The method of claim 1, wherein the scores of the VOAs are affected by degrees of therapeutic effect and degrees of adverse side effect recorded as having been caused by stimulations to which the VOAs correspond.

19. The method of claim 1, wherein display elements not having recorded as having been included in a scored VOA are blocked out from view in the map.

20. The method of claim 1, wherein the graphical markings include indicia defined by at least one of color and shading.

21. A computer-implemented method for outputting a stimulation history map corresponding to a plurality of stimulations that have been performed using a stimulation device implanted in an anatomical region, the method comprising:
for each of a plurality of display elements, where each of the display elements is recorded as having been part of each one of a plurality of scored estimated volumes of tissue activated (VOA) by the plurality of stimulations:
determining, by a computer processor, a score for the display element based on scores of the plurality of VOAs of which the display element has been recorded as being a part, wherein each of the plurality of VOAs comprises multiple ones of the display elements; and
determining, by the processor, whether the score determined for the display element meets a threshold; and

generating and outputting, by the processor, a map of the display elements, wherein the display elements whose respective scores have been determined to meet the threshold are graphically distinguished from those of the display elements whose respective scores have been determined not to meet the threshold and from those of the display elements for which a score has not been determined.

22. The method of claim 21, wherein the map is three-dimensional.