Method and system for tracking and visualizing medical devices

Abstract

An electroanatomical mapping system tracks and visualizes an item of interest, such as a medical device or anatomical structure, as it moves within a non-ionizing localization field. The system localizes the item within the localization field and determines an initial position of the item relative to a field of view of an imaging device (e.g., an intracardiac echocardiography catheter). If the item is within the field of view, the system displays a region of the field of view that contains the initial position of the item. If the item is not within the field of view, the system can output a notification. As the item moves, the system can update the displayed region to keep it focused on the item and can output a notification when the item exits the field of view. The displayed region can include one or more two-dimensional image slices, which are optionally output as a three-dimensional volumetric image.

Description

Technical Field

[0001] This disclosure generally relates to medical procedures, such as cardiac diagnostic and therapeutic procedures, including electrophysiological mapping and cardiac ablation. In particular, this disclosure relates to tracking and visualizing medical devices, such as electrophysiological mapping and ablation catheters, during such procedures using ultrasound imaging techniques. Background Technology

[0002] Catheters are being used in an increasing number of procedures. To name just a few, catheters are used in a variety of electrophysiological procedures, including diagnostic, therapeutic, and ablation procedures. Typically, catheters are manipulated through the patient's vascular system and / or body organs to reach the intended site, such as inside the patient's heart.

[0003] Visualization (i.e., images) of intracardiac catheters is often required for physicians. While ionizing radiation can be used to provide such images, visualization of sites of interest using ultrasound is also known. In many such applications, an ultrasound transducer is mounted in the catheter, similar to the previous description of electrophysiological catheters, which can be navigated to the site of interest through the patient's vascular system and / or body organs.

[0004] One application of ultrasound imaging is intracardiac echocardiography (ICE). ICE technology can be used to generate three-dimensional volumetric images of the patient's heart or other anatomical structures from multiple two-dimensional ultrasound images taken from inside the patient's heart. Advantageously, ICE imaging modality can provide high-resolution real-time visualization of cardiac structures and continuous monitoring of the orientation of intracardiac catheters, and also helps in the early identification of potential complications.

[0005] However, it should be understood that, at any given location and orientation, an ICE catheter can only image a certain volume (referred to herein as the ICE catheter's "field of view"). Therefore, if a medical device (e.g., an electrophysiological catheter), anatomical structure, or other object of interest moves out of the ICE catheter's field of view, the physician must manipulate the ICE catheter until the object of interest is reacquired (i.e., the physician must manipulate the ICE catheter until the field of interest is again contained within the object of interest). Summary of the Invention

[0006] This disclosure provides a method for tracking a medical device within a non-ionizing localization field using an electroanatomical mapping system. The method includes the electroanatomical mapping system performing the following operations: positioning the medical device within the non-ionizing localization field; determining whether the medical device falls within the field of view of an intracardiac echocardiography catheter; and, when determining that the medical device falls within the field of view, displaying the area of ​​the field of view containing the medical device. The method may further include: the electroanatomical mapping system outputting a negative imaging notification when it determines that the medical device does not fall within the field of view.

[0007] In embodiments of this disclosure, the method further includes: an electroanatomical mapping system positioning an intracardiac echocardiography catheter within a non-ionizing positioning field.

[0008] The displayed field of view may include a two-dimensional image slice or multiple adjacent two-dimensional slices, the latter of which may optionally be displayed as a volumetric image.

[0009] According to several aspects of this disclosure, the method also includes the following operations performed by the electroanatomical mapping system: determining that the medical device has been moved to a new orientation within the field of view; and displaying an updated area of ​​the field of view containing the new orientation of the medical device.

[0010] In other aspects of this disclosure, the method includes the following operations performed by the electroanatomical mapping system: determining that the medical device has been moved to a new location outside the field of view; and outputting a negative imaging notification.

[0011] This paper also discloses a method for visualizing an item of interest (IOI) as it moves within a non-ionizing localization field using an electroanatomical mapping system. The method includes the electroanatomical mapping system performing the following operations: positioning the IIOI at an initial orientation within the non-ionizing localization field; determining the initial position of the IIOI within the field of view of an intracardiac echocardiographic catheter based on the initial orientation; and displaying an initial region of the field of view containing the initial position of the IIOI.

[0012] The method also includes the following operations performed by the electroanatomical mapping system: locating the item of interest at a subsequent orientation within a non-ionizing localization field; determining the subsequent position of the item of interest within the field of view of the intracardiac echocardiography catheter based on the subsequent orientation; and displaying the subsequent region of the field of view containing the subsequent position of the item of interest.

[0013] Furthermore, the method may include the following operations performed by the electroanatomical mapping system: locating the item of interest at a subsequent orientation within a non-ionizing localization field; determining, based on the subsequent orientation, that the item of interest is outside the field of view of the intracardiac catheter; and outputting a negative imaging notification.

[0014] It is envisioned that the step of determining the initial position of the item of interest within the field of view of the intracardiac echocardiography catheter based on the initial orientation may include the following operations performed by an electroanatomical mapping system: positioning the intracardiac echocardiography catheter in a non-ionizing positioning field; and determining the initial position of the item of interest based on the positioning and initial orientation of the intracardiac echocardiography catheter.

[0015] The initial region displayed may include a two-dimensional image slice or multiple adjacent two-dimensional image slices, the latter of which may optionally be displayed as a volumetric image.

[0016] The item of interest can be a medical device such as an electrophysiological catheter, or an anatomical feature such as a pulmonary vein. Regarding anatomical features, the steps of locating the item of interest at an initial orientation within a non-ionizing localization field can include: the electroanatomical mapping system receiving user input identifying the item of interest via a graphical user interface.

[0017] This disclosure also provides an electroanatomical mapping system for tracking a medical device within a non-ionizing positioning field. The system includes a tracking and visualization module configured to: position the medical device within the non-ionizing positioning field; determine whether the medical device falls within the field of view of an intracardiac echocardiography catheter; and, when the medical device is determined to be within the field of view, display the area of ​​the field of view containing the medical device. The tracking and visualization module can also be configured to output a negative imaging notification when it is determined that the medical device is not within the field of view.

[0018] The above and other aspects, features, details, uses, and advantages of the invention will become apparent from reading the following description and claims and by referring to the accompanying drawings. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of an exemplary electroanatomical mapping system.

[0020] Figure 2 This is a schematic diagram of an embodiment of the present disclosure, illustrating the interconnection between an ultrasound imaging device, an electrophysiological catheter, an electroanatomical mapping system, and an ultrasound control console.

[0021] Figure 3 This is a flowchart of representative steps that can be performed according to various aspects of this disclosure.

[0022] Figure 4A The illustration shows a device for tracking and visualizing embodiments of the invention using two-dimensional image slices.

[0023] Figure 4B The illustration shows an apparatus for tracking and visualizing according to an embodiment disclosed herein using three-dimensional volumetric images.

[0024] While several embodiments have been disclosed, other embodiments of this disclosure will become apparent to those skilled in the art from the following detailed description showing and illustrating illustrative embodiments. Therefore, the drawings and detailed description should be considered illustrative in nature and not restrictive. Detailed Implementation

[0025] This disclosure provides systems, devices, and methods for tracking and visualizing medical devices that may be necessary during electrophysiological studies. For illustrative purposes, the use of ICE catheters, such as ViewFlex from Abbott Laboratories (Abbott Technology Park, Illinois), will be incorporated. TM Xtra ICE catheter) tracking and visualization of ablation catheters (such as the FlexAbility from Abbott) TM ablation catheter, Sensor Enabled TM This disclosure will describe several aspects using the term ). Furthermore, it will describe the use of electroanatomical mapping systems (such as EnSite Precision, also from Abbott). TM Cardiac mapping system or Ensite TM Exemplary embodiments are described in the context of performing electrophysiological surgery using an X EP system. However, those skilled in the art will understand how the teachings herein can be well applied in other situations and / or relative to other devices.

[0026] Figure 1 A schematic diagram of an exemplary electroanatomical mapping system 8 for performing cardiac electrophysiological procedures such as electrophysiological mapping and ablation is shown. For example, system 8 can be used to create an anatomical model of a patient's heart 10 using one or more electrodes. System 8 can also be used to measure electrophysiological data at multiple points along the surface of the heart and store measurement data associated with the orientation information of each measurement point to create, for example, a diagnostic data map of the patient's heart 10.

[0027] As those skilled in the art will recognize, System 8 typically determines the orientation (and in some respects, orientation) of an object in three-dimensional space and represents these orientations as positional information determined relative to at least one reference. This is referred to herein as “positioning”.

[0028] like Figure 1 As shown and described herein, System 8 can be a hybrid system combining impedance-based and magnetic field-based positioning capabilities. In some embodiments, System 8 is Abbott's EnSite. TM Velocity TM Or EnSite Precision TM Cardiac mapping system or Ensite TM The X EP system. However, other electroanatomical mapping systems can also be used in conjunction with this teaching, including, for example, the RRHYTHMIA HDX from Boston Scientific Corporation (Marlborough, MA). TMThe calibration system, Biosense Webster, Inc.'s (Irvine, California) CARTO navigation and positioning system, and Northern Digital Inc.'s (Waterloo, Ontario, Canada) Systems and Stereotaxis, Inc. (St. Louis, Missouri) Magnetic navigation system.

[0029] The positioning and mapping systems described in the following patents (the full text of which is incorporated herein by reference) may also be used in conjunction with this teaching: U.S. Patents 6,990,370, 6,978,168, 6,947,785, 6,939,309, 6,728,562, 6,640,119, 5,983,126, and 5,697,377.

[0030] The aforementioned system and the mode by which it is used to locate medical devices are well known to those skilled in the art. Therefore, ICE imaging will be described only to the extent necessary for understanding this disclosure, with regard to the basic operation of such systems as known to those skilled in the art.

[0031] For simplicity, patient 11 is schematically depicted as an oval. Figure 1 In the illustrated embodiment, three sets of surface electrodes (e.g., patch electrodes) 12, 14, 16, 18, 19, and 22 are shown applied to the surface of patient 11, defining three generally orthogonal axes in pairs, referred herein to as the x-axis (12, 14), y-axis (18, 19), and z-axis (16, 22). In other embodiments, the electrodes may be positioned in other arrangements, such as multiple electrodes on a particular body surface. As a further alternative, the electrodes do not need to be on the body surface but may be positioned inside the body. Regardless of the configuration, the patient's heart 10 is situated within the electric field generated by the patch electrodes 12, 14, 16, 18, 19, and 22.

[0032] Figure 1 A magnetic source 30 coupled to a magnetic field generator is also depicted. For clarity, Figure 1 Only two magnetic field generators 32 and 33 are depicted, but it should be understood that additional magnetic field generators (e.g., a total of six magnetic field generators defining three generally orthogonal axes, similar to the three generally orthogonal axes defined by patch electrodes 12, 14, 16, 18, 19 and 22) may be used without departing from the scope of this teaching.

[0033] An additional surface reference electrode (e.g., an “abdominal patch”) 21 provides a reference electrode and / or a ground electrode for system 8. The abdominal patch electrode 21 may be an alternative to the fixed intracardiac electrode 31, which will be described in further detail below. A magnetic patient reference sensor-anterior (“PRS-A”) may also be positioned on the patient’s chest as a reference, similar to the surface reference electrode 21 and / or the intracardiac reference electrode 31, for magnetic field-based positioning patterns.

[0034] Furthermore, it should be understood that patient 11 may have most or all of the conventional electrocardiogram (“ECG” or “EKG”) system leads in place. For example, in some embodiments, a standard set of 12 ECG leads may be used to sense the electrocardiogram of patient 10. This ECG information is available to system 8 (e.g., it can be provided as input to computer system 20). Since ECG lead lines are readily understood, in the accompanying drawings, for clarity, Figure 1 Only a single lead 6 and its connection to the computer 20 are shown in the diagram.

[0035] Figure 1 Representative catheters 13 and 40 are also schematically shown. In various aspects of this disclosure, catheter 13 may be an ablation catheter, such as Abbott's FlexAbility. TM ablation catheter, Sensor Enabled TM Furthermore, catheter 40 can be an intracardiac echocardiography (ICE) catheter, such as Abbott's ViewFlex. TM Xtra ICE catheters. Catheters 13 and 40 each include one or more sensors 17 and 42 for sensing electric fields generated by patch electrodes 12, 14, 16, 18, 19 and 22 and / or magnetic fields generated by magnetic field generators 32 and 33.

[0036] In some embodiments, an optional fixed reference electrode 31 (e.g., attached to the wall of the heart 10) is shown on another catheter 29. Typically, the reference electrode 31 is placed in the coronary sinus and defines the origin of a coordinate system that the system 8 can refer to for positioning the catheters 13, 40.

[0037] Computer 20 may include, for example, a conventional general-purpose computer, a special-purpose computer, a distributed computer, or any other type of computer. Computer 20 may include one or more processors 28, such as a single central processing unit (“CPU”), or multiple processing units generally referred to as a parallel processing environment, which can execute instructions to practice the various aspects described herein.

[0038] In addition, computer system 8 can interpret measurements of magnetic and / or electric fields generated by sensors 17 and 42, respectively, from magnetic field generators 32 and 33 and patch electrodes 12, 14, 16, 18, 19, and 22, to determine the position and orientation of catheters 13 and 40 within the heart 10. The term “positioning” is used herein to describe determining the position and orientation of an object such as catheter 13 within this field of view.

[0039] The ultrasound imaging catheter 40 can be used to generate a three-dimensional volumetric image of the heart 11 (or other anatomical structures) from multiple two-dimensional images using any of several techniques, including those disclosed in U.S. Patent Application Publication 2006 / 0241445 (which is incorporated herein by reference, as if fully set forth herein). In some embodiments of this disclosure, the ultrasound imaging catheter 40 ( Figure 2 The field of view 44 (as depicted) is approximately 90 degrees by approximately 90 degrees by approximately 12 cm, but these dimensions are merely exemplary and it is foreseeable that the dimensions of the field of view 44 may vary without departing from the scope of this disclosure.

[0040] Those skilled in the art will understand that various echocardiographic imaging modalities, such as B-mode ultrasound and color Doppler echocardiography, can be used to acquire two-dimensional image slices, which are then combined into a three-dimensional volumetric image. In this regard, the ultrasound imaging catheter 40 can be coupled to the ultrasound control console 46, such as Abbott's ViewMate. TM An ultrasound control console, which can then be coupled to, for example, Figure 2 System 8 is shown.

[0041] The above discussion of ICE imaging is general, as many aspects of ICE imaging (including its use in conjunction with electrophysiological procedures) are well known to those skilled in the art and do not require detailed description herein. See, for example, Enriquez et al., “Use of Intracardiac Echocardiography in Interventional Cardiology,” Circulation, Vol. 137, Issue 21, pp. 2278-2294 (May 22, 2018). Therefore, ICE imaging will be described herein only to the extent necessary for understanding this disclosure.

[0042] Several aspects of this disclosure relate to tracking and visualizing the catheter 13 as it moves relative to the field of view of the ultrasound imaging catheter 40 (e.g., on the display 23 and / or the ultrasound console 46). Therefore, the system 8 may include a tracking and visualization module 58. According to some embodiments of this disclosure, the tracking and visualization module 58 operates to automatically track and visualize the catheter 13 as it moves relative to the field of view of the ultrasound imaging catheter 40.

[0043] References Figure 3 The flowchart 300, showing representative steps, is used to explain an exemplary method according to various aspects of this disclosure. For example, in some embodiments, flowchart 300 may represent a method that can be... Figure 1 Several exemplary steps are performed by the electroanatomical mapping system 8 (e.g., by the processor 28 and / or the tracking and visualization module 58). It should be understood that the representative steps described below can be implemented in hardware or software. For ease of explanation, the term "signal processor" is used herein to describe both hardware-based and software-based implementations taught herein.

[0044] In block 302, system 8 positions conduit 13 within the electric and / or magnetic fields generated by patch electrodes 12, 14, 16, 18, 19 and 22 and / or magnetic field generators 32, 33. The positioning of conduit 13 is as described above and is well known to those skilled in the art.

[0045] In decision block 304, system 8 uses the positioning of catheter 13 to determine whether catheter 13 is within or outside the field of view 44 of ICE catheter 40. For example, in some embodiments of this disclosure, system 8 may position ICE catheter 40 within the electric and / or magnetic fields generated by patch electrodes 12, 14, 16, 18, 19 and 22 and / or magnetic field generators 32, 33, as also described above. The positioning of ICE catheter 40 further enables system 8 to determine the extent of field of view 44 relative to system 8's coordinate system (referred to herein as the "coordinate envelope" of field of view 44). This, in turn, enables system 8 to determine whether catheter 13 is positioned within or outside field of view 44 (e.g., if the positioning coordinates of catheter 13 are within the coordinate envelope of field of view 44, then catheter 13 is within field of view 44; otherwise, it is outside field of view 44).

[0046] When it is determined that catheter 13 is outside the field of view 44 (exit decision box 304, select "No"), system 8 may output a notification that catheter 13 is not in the field of view 44 (box 306). This notification is referred to herein as a "negative imaging notification" and may be audible (e.g., sounding like an alarm), tactile (e.g., vibration output in the handle of catheter 13), visual (e.g., shown on display 23), or any other suitable notification or combination of notifications to the physician.

[0047] If necessary, the physician can adjust the position and / or orientation of the ICE catheter 40 until the field of view 44 includes the catheter 13. It is also foreseeable that, in some embodiments of this disclosure, the system 8 can provide prompts to the physician to assist in such adjustments (e.g., providing instructions on the display 23 to guide the physician to rotate and / or deflect the ICE catheter 40 by a certain amount in a certain direction).

[0048] On the other hand, when it is determined that the catheter 13 is within the field of view 44 (exit decision box 304 and select "Yes"), the system 8 may display (e.g., on the display 23 and / or the ultrasound console 46) the area of ​​the field of view 44 that includes the catheter 13. The displayed area may include a single two-dimensional image slice (e.g., a two-dimensional image slice of the location through the catheter 13) or multiple adjacent two-dimensional image slices assembled into a three-dimensional volumetric image.

[0049] Figure 4A The illustration schematically shows a single two-dimensional image slice including catheter 13. (See image for details.) Figure 4A As shown, the conduit 13 intersects the two-dimensional image slice 402 at orientation a within the field of view 44. Therefore, the system 8 displays the two-dimensional image slice 402.

[0050] Figure 4B The illustration shows a display of multiple two-dimensional image slices 402 as a three-dimensional volumetric image. For example... Figure 4B As shown, each of the displayed image slices 402 intersects with the catheter 13. However, it is also foreseeable that additional two-dimensional slices that do not intersect with the catheter 13 may be displayed for contextual purposes or as a reference (e.g., to show the position and orientation of the catheter 13 relative to certain anatomical structures that a physician may be interested in). Figure 4B As shown, multiple slices can be displayed as a volumetric image 403.

[0051] Those skilled in the art will understand that system 8 can monitor the movement of catheter 13 within the patient's body. Therefore, in embodiments of the invention and consistent with the foregoing teachings, system 8 can detect when catheter 13 moves to a new position within the field of view 44 or when it exits the field of view 44.

[0052] In the latter case (e.g., catheter 13 has been moved out of the field of view 44), system 8 can output a negative imaging notification and optionally instruct the physician to reposition and / or reorient the ICE catheter 40 to reacquire catheter 13 within the field of view 44.

[0053] In the former case (e.g., the conduit 13 has moved but is still within the field of view 44), the system 8 can display an updated area of ​​the field of view 44 including the new orientation of the conduit 13. As described above, the displayed updated area may include one or more two-dimensional image slices. Reference Figure 4A For example, if the conduit 13 moves from orientation "a" to orientation "b", the system 8 can switch from displaying two-dimensional image slice 402 to displaying two-dimensional image slice 404.

[0054] Although several embodiments have been described above with a degree of specificity, those skilled in the art can make several modifications to the disclosed embodiments without departing from the spirit or scope of the invention.

[0055] For example, the teachings in this paper can be applied not only to tracking and visualizing electrophysiological catheters or other medical devices within the field of view of an ICE catheter, but also to tracking and visualizing other objects of interest within the field of view of an ICE catheter, including anatomical structures. If an object of interest cannot be directly located by System 8 (e.g., it is an anatomical structure and therefore does not include electrodes, magnetic coils, or other sensors that can be used for location), it can be identified by a physician through a graphical user interface (e.g., on display 23). For example, a physician can “click” on an anatomical structure of interest (e.g., the pulmonary vein orifice) using a mouse or other input device, and System 8 can use image recognition algorithms to track the structure as it moves (e.g., when the heart beats and / or when the patient breathes).

[0056] All directional references (e.g., up, down, upward, downward, left, right, leftward, rightward, top, bottom, above, below, vertical, horizontal, clockwise, and counterclockwise) are for illustrative purposes only to aid the reader's understanding of the invention and do not constitute limitation, particularly regarding location, orientation, or the intended use of the invention. Connection references (e.g., attachment, coupling, connection, etc.) will be interpreted broadly and may include intermediate members between connected elements and relative movement between elements. Similarly, a connection reference does not necessarily mean that two elements are directly connected and fixed to each other.

[0057] Therefore, all content contained in the above description or shown in the accompanying drawings is intended to be illustrative rather than restrictive. Changes in detail or structure may be made without departing from the spirit of the invention as defined in the appended claims.

Claims

1. An electroanatomical mapping system for tracking medical devices in a non-ionizing positioning field, the system comprising: The tracking and visualization module is configured as follows: The medical device is positioned within the non-ionizing positioning field; The positioning of the medical device is used to determine whether the medical device falls within the field of view of the intracardiac echocardiography catheter; and When it is determined that the medical device falls within the field of view, the area of ​​the field of view containing the medical device is displayed.

2. The electroanatomical mapping system according to claim 1, wherein, The tracking and visualization module is also configured to output a negative imaging notification when it is determined that the medical device has not fallen into the field of view.

3. The electroanatomical mapping system according to claim 1, wherein, The tracking and visualization module is also configured to position the intracardiac echocardiography catheter within the non-ionizing positioning field.

4. The electroanatomical mapping system according to claim 1, wherein, The region of the field of view includes two-dimensional image slices.

5. The electroanatomical mapping system according to claim 4, wherein, The region of the field of view includes multiple adjacent two-dimensional image slices.

6. The electroanatomical mapping system according to claim 5, wherein, The multiple adjacent two-dimensional slices are displayed as a volumetric image.

7. The electroanatomical mapping system according to claim 1, wherein, The tracking and visualization module is also configured to: Determine that the medical device has been moved to a new position within the field of view; as well as The updated area of ​​the field of view, including the new orientation of the medical device, is displayed.

8. The electroanatomical mapping system according to claim 1, wherein, The tracking and visualization module is also configured to: It has been determined that the medical device has been moved to a new location outside the field of view; and Output negative imaging notification.

9. An electroanatomical mapping system for visualizing an item of interest as it moves within a non-ionizing positioning field, the system comprising: The tracking and visualization module is configured as follows: Position the item of interest at its initial orientation within the non-ionizing positioning field; The initial position of the item of interest within the field of view of the intracardiac echocardiography catheter is determined based on the initial orientation. as well as The initial region of the field of view containing the initial location of the item of interest is displayed.

10. The electroanatomical mapping system according to claim 9, wherein, The tracking and visualization module is also configured to: Position the item of interest at a subsequent location within the non-ionizing positioning field; The subsequent location of the item of interest within the field of view of the intracardiac echocardiography catheter is determined based on the subsequent orientation; and The field of view displays the subsequent area containing the subsequent location of the item of interest.

11. The electroanatomical mapping system according to claim 9, wherein, The tracking and visualization module is also configured to: Position the item of interest at a subsequent location within the non-ionizing positioning field; The item of interest is determined to be outside the field of view of the intracardiac catheter based on the subsequent orientation; as well as Output negative imaging notification.

12. The electroanatomical mapping system according to claim 9, wherein, Determining the initial position of the item of interest within the field of view of the intracardiac echocardiography catheter based on the initial orientation includes the following operations performed by the tracking and visualization module: Positioning the intracardiac echocardiography catheter within the non-ionizing positioning field; and The initial position of the item of interest is determined based on the positioning and initial orientation of the intracardiac echocardiography catheter.

13. The electroanatomical mapping system according to claim 9, wherein, The initial region comprises two-dimensional image slices.

14. The electroanatomical mapping system according to claim 13, wherein, The initial region comprises multiple adjacent two-dimensional image slices.

15. The electroanatomical mapping system according to claim 14, wherein, The multiple adjacent two-dimensional image slices are displayed as volumetric images.

16. The electroanatomical mapping system according to claim 9, wherein, The items of interest include electrophysiological catheters.

17. The electroanatomical mapping system according to claim 9, wherein, The items of interest include anatomical features.

18. The electroanatomical mapping system according to claim 17, wherein, Locating the item of interest at its initial orientation within the non-ionizing positioning field includes: the tracking and visualization module receiving user input identifying the item of interest via a graphical user interface.

Images