Systems and methods for tissue resection margin measurement devices

Abstract

[0006] Embodiments of the present invention provide systems and methods for resecting a tissue mass. The system for resecting a tissue mass includes a first sensor for measuring a signal corresponding to the position and orientation of the tissue mass. The first sensor is sized to fit within or adjacent to the tissue mass. The system also includes a second sensor attached to the surgical device configured to measure the position and orientation of the surgical device. A controller communicates with the first sensor and the second sensor, and the controller executes a stored program to calculate the distance between the first sensor and the second sensor. Thus, visual, auditory, tactile, or other feedback is provided to the clinician to guide the surgical device to the surgical margin.

Description

[Technical Field]

[0001] <Reference to prior pending patent applications> This patent application claims the benefit of (1) prior pending U.S. Provisional Patent Application No. 62 / 923,137, filed October 18, 2019, by Raphael Bueno et al., entitled "System and Method for Tissue Resection Margin Measurement Device" (Attorney Docket No. 129319.00702.BWH22238), and (2) prior pending U.S. Provisional Patent Application No. 63 / 054,921, filed July 22, 2020, by Raphael Bueno et al., entitled "System and Method for Tissue Resection Margin Measurement Device" (Attorney Docket No. 129319.00734.BWH2020-564).

[0002] The two above-mentioned patent applications are incorporated herein by reference.

[0003] The present invention relates generally to surgery, and more particularly to computer-assisted surgery. [Background technology]

[0004] Minimally invasive surgical resection of a lesion involves precisely removing the lesion while sparing the surrounding healthy, vital tissue. Some examples include, but are not limited to, breast-conserving surgery and video-assisted thoracic surgery (VATS). Surgical resection of a lesion requires the removal of a margin of tissue surrounding the lesion to ensure complete removal of diseased cells and improved long-term survival. The default margin depends on the type of lesion and its microinvasion into the surrounding tissue. This is particularly true for cancer, where the size of the original lesion and the margin of normal tissue removed along with the lesion are related to survival, but it also applies to noncancerous lesions. High viscoelasticity, physiological movement (such as lung collapse, respiratory or pulsatile motion), or significant deformation of tissue due to tissue manipulation can make localization and precise removal of the lesion difficult. This can result in insufficient resection, which can lead to recurrence of the lesion locally or via metastasis (in cancer), and insufficient long-term benefit compared to when adequate margins are achieved. Two surgical applications are listed below as examples. However, the disclosed systems and methods may also be applied to the resection or biopsy of other lesions, using minimally invasive or image-guided techniques or open surgery, or a combination of techniques.

[0005] <Lung lesion surgery> Current practice for removing lung tissue fragments involves opening the chest by cutting the sternum or by spreading the ribs apart. Often, the ribs are fractured, and the fragments are surgically removed during these procedures. Orthopedic trauma alone can present significant pain and complicate the patient's recovery process. Thoracic pain of this magnitude also complicates the recovery of patients from general anesthesia, as the body adapts to forced ventilation and pain can interfere with natural chest rhythm. Patients would dramatically benefit from procedures performed through small incisions or ports in the chest without this orthopedic trauma.

[0006] Although minimally invasive or VATS techniques are well known to benefit patients by minimizing trauma and reducing recovery time compared to open procedures, a significant number of open procedures are still performed today, at least in part due to the limited number of instruments specifically designed to facilitate such thoracic procedures.

[0007] However, lung cancer surgery is transitioning to minimally invasive techniques using VATS and smaller anatomical or non-anatomical lung resections (e.g., wedge resections or segmentectomies), especially for small lesions. However, traditional methods of performing VATS collapse the lung during surgery, making it difficult to identify the exact location of the lesion and determine the resection margins. Furthermore, due to minimally invasive approaches to surgery, palpation of lung tissue is not always possible (especially for smaller or early-stage cancers). Inaccurate surgical resection can result in incomplete resection and subsequent lesion recurrence.

[0008] <Breast Lesion Surgery> Breast-conserving surgery (BCS) involves removing the lesion while sparing the healthy breast parenchyma surrounding it. Studies have shown that BCS, combined with chemotherapy, has similar long-term benefits to mastectomy and additional cosmetic advantages. However, identifying and removing the entire lesion is a challenging task due to the highly deformable nature of the breast. Achieving negative margins with minimal damage to healthy parenchyma is not easy due to the soft tissue nature of the breast. In fact, studies have shown that up to 25% of mastectomies leave positive margins, requiring retreatment.

[0009] Therefore, there is a need for a tissue resection margin measurement device that overcomes the above-mentioned limitations by providing an improved technique for accurately locating lesions and determining resection margins. Summary of the Invention

[0010] The present invention relates to a system and method for resecting tissue masses while compensating for tissue deformation due to tissue elastic properties and physiologically induced motion. By way of non-limiting example, the present invention enables minimally invasive surgical procedures by providing an apparatus and method for performing tissue resection that identifies traumatic critical tissue and accurately determines resection margins. Additionally, auditory, visual, and tactile cues can be provided to the surgeon to identify and more accurately measure lesion margins and critical structures around the lesion to ensure complete and safe resection of the lesion.

[0011] Some embodiments of the present invention provide a system for resecting a tissue mass. The system includes a surgical device and a first sensor for measuring a first signal. The first sensor is sized to fit within or adjacent (e.g., proximate to) the target lesion / tissue mass, typically at a location between the tissue mass and the final resection margin. The system also includes a second sensor for measuring a second signal, the second sensor coupled to the surgical device. A controller communicates with the first sensor and the second sensor, and the controller executes an internal program to calculate the distance between the first sensor and the second sensor based on the first signal and the second signal.

[0012] In some embodiments, the system can further include a sleeve dimensioned to engage with at least one of the housing of the surgical device and the second sensor. The second sensor can be coupled to the housing of the surgical device, for example, by adhesive. The surgical device can be, for example, a stapler, Bovi pencil, or cutting device configured to cut along a resection margin surrounding a target tissue mass, which can be a lesion (e.g., a tumor, nodule, etc.). The resection margin can be included within the calculated distance between the first sensor and the second sensor. Other factors, such as the distance between the tissue mass and the first sensor and the configuration of the tissue mass, can be included in the margin calculation.

[0013] In one embodiment, a first signal received by a first sensor can indicate the position and orientation of the tissue mass relative to the surgical device in real time. Similarly, a second signal received by a second sensor can indicate the position and orientation of the surgical device relative to the tissue mass. In one embodiment, the second sensor indicates the position and orientation of the surgical device in the same reference frame as the first sensor. The first sensor can be a fiducial marker (sometimes referred to as a fiducial sensor or fiducial tracker) embedded in an anchor made from a superelastic material, and the second sensor can be an instrument sensor (sometimes referred to as an instrument tracker). In one embodiment, the first sensor can be configured to measure the position and orientation of the tissue mass, and the second sensor can be configured to measure the position and orientation of the surgical device.

[0014] In one embodiment, the system can further include a third sensor for measuring a third signal, the third sensor being sized to fit adjacent the tissue mass opposite the first sensor, such that the third signal received by the third sensor can indicate the position and orientation of the tissue mass relative to the first sensor.

[0015] In one embodiment, the first sensor may be embedded within a hook structure made of a superelastic material, such as Nitinol. The hook structure may be in the form of a T-bar or J-bar and may be sized to fit inside a delivery needle and / or sheath. The delivery needle and / or sheath may be configured to guide the first sensor, and the hook structure may be configured to secure the first sensor within the tissue mass. In one embodiment, the first sensor embedded within the hook structure may be inserted into the tissue mass under real-time image guidance.

[0016] In one embodiment, the first sensor is embedded within a hook structure including multiple branches, and the first sensor may be sized to fit inside a delivery needle and / or sheath. The delivery needle and / or sheath may be configured to guide the first sensor, and the multiple branches may be configured to secure the first sensor within the tissue mass. The hook structure may further include multiple extensions extending from a tubular portion of the hook structure, and the multiple extensions may be sized to receive the first sensor.

[0017] The system may further include a display in communication with the controller. The display may be coupled to the surgical device and configured to display the distance between the first sensor and the second sensor as calculated by a stored program executed by the controller, which may also be configured to include additional calculations. Distances from the base, middle, and tip of the surgical device (e.g., a cutting instrument such as a stapler) may also be displayed. The display may be, but is not limited to, an OLED display or an LCD display. In one embodiment, the system may include an audio source for emitting an audible signal. The audio source may be in communication with the controller configured to execute the stored program to modify the audible signal based on the distance between the first sensor and the second sensor. In one embodiment, the stored program is a navigation system.

[0018] The system may further include a piezoelectric actuator coupled to the handle of the surgical device. The piezoelectric actuator may be configured to emit a tactile signal. The piezoelectric actuator may be in communication with a controller configured to execute a stored program to modify the tactile signal based on the distance between the first sensor and the second sensor.

[0019] In some embodiments, the system can further include a monitor for emitting a visual signal. The monitor can be in communication with a controller configured to execute a stored program to modify the visual signal based on the distance between the first sensor and the second sensor. Additionally or alternatively, the system can include a monitor for displaying a video overlay. The monitor can be in communication with a controller configured to execute a stored program to fuse a laparoscopic, thoracoscopic, or endoscopic image (i.e., a "scope image") with a virtual model image (i.e., a computer-generated image from a virtual model of the anatomical structure) to create a video overlay of the scope image and the virtual model image. The video overlay can be configured to identify the location of the tissue mass and the first sensor.

[0020] In one embodiment, the present invention provides a method for resecting a tissue mass within a patient. The method includes inserting a first sensor within or adjacent to (e.g., proximate to) a target tissue mass and recording at least one image of the first sensor implanted within or adjacent to (e.g., proximate to) the tissue mass. A resection margin around the tissue mass is calculated using the at least one image. A surgical device is inserted into the patient, and the surgical device is coupled to a second sensor. The second sensor is tracked relative to the resection margin, and the surgical device is used to cut the resection margin. The surgeon determines the best possible margin to achieve based on the diagnosis and the size of the tissue mass. This information may also be used to determine the exact procedure required.

[0021] In some embodiments, the method can further include sizing the sleeve to engage with at least one of the housing of the surgical device and the second sensor. Alternatively, the second sensor can be coupled to the housing of the surgical device, for example, by adhesive. In another embodiment, the sensor can be embedded within the device / instrument, or the sensor can be incorporated into the device / instrument. The surgical device can be, for example, a stapler, Bovi pencil, or cutting device configured to cut along a resection margin surrounding a tissue mass, which can be a lesion (e.g., a tumor, nodule, etc.). The resection margin can be included within the calculated distance between the first sensor and the second sensor.

[0022] In some embodiments, a first signal received by a first sensor can indicate the position and orientation of the first sensor relative to the surgical device (and thus the position and orientation of the tissue mass) in real time. Similarly, a second signal received by a second sensor can indicate the position and orientation of the surgical device relative to the tissue mass. In one embodiment, the second sensor indicates the position and orientation of the surgical device in the same reference frame as the first sensor. The first sensor can be a fiducial marker constructed from a superelastic material, and the second sensor can be an instrument sensor. In one embodiment, the first sensor can be configured to measure the position and orientation of the tissue mass, and the second sensor can be configured to measure the position and orientation of the surgical device.

[0023] In one embodiment, the method can further include providing a third sensor for measuring a third signal, the third sensor being sized to fit adjacent the tissue mass opposite the first sensor, such that the third signal received by the third sensor can indicate the position and orientation of the tissue mass relative to the first sensor.

[0024] In some embodiments, the first sensor may be embedded within a hook structure. The hook structure may be in the form of a T-bar or J-bar and may be sized to fit inside a delivery needle and / or sheath. The delivery needle and / or sheath may be configured to guide the first sensor, and the hook structure may be configured to secure the first sensor within the tissue mass. In one embodiment, the first sensor embedded within the hook structure may be inserted into the tissue mass under real-time image guidance or direct visual guidance.

[0025] In one embodiment, the first sensor is embedded within a hook structure including multiple branches, and the first sensor may be sized to fit inside a delivery needle and / or sheath. The delivery needle and / or sheath may be configured to guide the first sensor, and the multiple branches may be configured to secure the first sensor within the tissue mass. The hook structure may further include multiple extensions extending from a tubular portion of the hook structure, and the multiple extensions may be sized to receive the first sensor.

[0026] The method may further include providing a display in communication with the controller. The display may be coupled to the surgical device and configured to display the distance calculated by the stored program executed by the controller. The display may be, but is not limited to, an OLED display or an LCD display. The display may also include information regarding the distance between the various sensors as well as the quality of the measurement. In some embodiments, the method may include emitting an audible signal from an audio source. The audio source may be in communication with the controller configured to execute the stored program to modify the audible signal based on the distance between the first sensor and the second sensor. In one embodiment, the stored program is a navigation method.

[0027] The method can further include emitting a tactile signal from a piezoelectric actuator coupled to a handle of the surgical device, the piezoelectric actuator being in communication with a controller configured to execute a stored program to modify the tactile signal based on the distance between the first sensor and the second sensor.

[0028] In some embodiments, the method can further include emitting a visual signal on the monitor. The monitor can be in communication with a controller configured to execute a stored program to modify the visual signal based on the distance between the first sensor and the second sensor. Additionally or alternatively, the method can include displaying a video overlay on the monitor. The monitor can be in communication with a controller configured to execute a stored program to fuse the laparoscopic / thoracoscopic / endoscopic image(s) with the virtual model image to create the video overlay. The video overlay can be configured to identify the location of the tissue mass and the first sensor.

[0029] In one form of the invention, the system can be used to identify the location of a particular airway. In this form of the invention, the system includes means for bronchoscopic positioning of a sensor within a pulmonary airway. This bronchoscopic positioning of the sensor in the pulmonary airway (e.g., by positioning the sensor on a bronchoscope or on a catheter within the bronchoscope and advancing the bronchoscope into the target airway) can be used during the actual surgery to define lobes, segments, or subsegmental bronchi for procedures such as segmentectomies, lobectomies, or wedge resections. This function can be independent of measuring lesion margins, and the location of the sensor identifying the bronchus can be correlated with the location of another device (e.g., a surgical device) carrying another sensor to allow the surgeon to define the correct bronchus for surgery from the thoracic side of the procedure. Thus, in this form of the invention, one sensor is placed on the bronchoscope or on a catheter placed within the bronchoscope that is inserted into a particular airway to define the location of the particular airway, and another sensor is placed on a surgical device that is advanced for surgery from the chest side of the procedure, and the system continuously tracks the position of the sensor on the surgical device relative to the position of the sensor on the bronchoscope, allowing the surgeon to continuously track the position of the surgical device relative to the target airway (identified by the sensor on the bronchoscope) to, for example, target the airway identified by the sensor on the bronchoscope, avoid the airway identified by the sensor on the bronchoscope, etc.

[0030] In one form of the invention, the system includes means for mapping and tracking the airways surrounding the lesion.

[0031] In one form of the invention, the system includes means for bronchoscopic placement of a reference sensor or another sensor in tissue (eg, bronchoscopic placement of a reference sensor in or near a tissue mass).

[0032] In one form of the invention, the system includes means for measuring articulation of the surgical stapler.

[0033] In one form of the invention, the system includes means for marking the boundary of the resection margin of the lesion and positioning a surgical stapler adjacent the boundary of the resection margin of the lesion.

[0034] In one form of the invention, there is provided a method for determining the position of an instrument relative to a selected lumen in an anatomical structure, comprising: positioning a tracked catheter in a selected lumen of an anatomical structure; where the tracked catheter is tracked relative to a given reference frame, A method is provided that includes determining the position of a tracked instrument relative to a tracked catheter, wherein the tracked instrument is tracked relative to a given reference frame, thereby determining the position of the tracked instrument relative to a selected lumen of an anatomical structure.

[0035] In another aspect of the invention, there is provided a system for determining the position of an instrument relative to a selected lumen in an anatomical structure, comprising: a catheter sized to be positionable in a selected lumen of the anatomical structure; a catheter tracking device carried by the catheter for providing a catheter signal indicative of the position of the catheter tracking device relative to a given frame of reference; Equipment and an instrument tracking device carried by the instrument for providing an instrument signal indicative of the position of the instrument tracking device relative to a given frame of reference; A system is provided that includes: a controller for determining a position of a tracked instrument relative to a tracked catheter, whereby when the tracked catheter is positioned in a selected lumen of the anatomical structure, the controller determines a position of the tracked instrument relative to a selected lumen in the anatomical structure.

[0036] In another aspect of the invention, there is provided a method for mapping and tracking multiple lumens in an anatomical structure, the anatomical structure being deformable, the method comprising: providing a virtual model of the anatomical structure when the anatomical structure is in a first configuration; positioning a tracked catheter in one of the lumens within the mapped and tracked anatomical structure when the anatomical structure is in a first configuration, determining a position of the tracked catheter in the lumen, and mapping the position of the lumen; repeating the above steps for each lumen within the anatomical structure to be mapped and tracked to map those lumens; supplementing the virtual model with the mapped lumen, thereby providing an augmented virtual model of the anatomical structure and the mapped lumen when the anatomical structure is in its first configuration; maintaining the tracked catheter in one of the mapped lumens of the anatomical structure while the anatomical structure transforms from its first configuration to its second configuration; determining a position of the tracked catheter within the anatomical structure when the anatomical structure is in a second configuration; modifying the augmented virtual model to represent the anatomical structure and the mapped lumen when the anatomical structure is in its second configuration, thereby providing a modified augmented virtual model; The above correction, determining a spatial transformation of the tracked catheter as the anatomical structure transforms from its first configuration to its second configuration; A method is provided in which the method is performed by applying the spatial changes of the tracked catheter to the mapped lumen of the augmented virtual model to provide a modified augmented virtual model of the anatomical structure and the mapped lumen when the anatomical structure is in its second configuration.

[0037] In another aspect of the invention, there is provided a method for mapping and tracking a selected lumen within an anatomical structure, the anatomical structure being deformable, the method comprising: positioning a tracked catheter in a selected lumen of the anatomical structure when the anatomical structure is in a first configuration; determining a position of the tracked catheter when the anatomical structure is in a first configuration; scanning the anatomical structure and a tracked catheter positioned in a selected lumen of the anatomical structure while the anatomical structure is in a first configuration; creating a virtual model of the scanned anatomical structure and a tracked catheter positioned within a selected lumen of the anatomical structure when the anatomical structure is in its first configuration; maintaining the tracked catheter at a position within the selected lumen of the anatomical structure while the anatomical structure transforms to a second configuration; determining a position and orientation of the tracked catheter when the anatomical structure is in its second configuration, thereby determining a position of the selected lumen of the anatomical structure when the anatomical structure is in the second configuration; adjusting the virtual model to represent the anatomical structure and the selected lumen when the anatomical structure is in its second configuration, thereby providing an adjusted virtual model; The above correction, determining a spatial change of the tracked catheter as the anatomical structure transforms from its first configuration to its second configuration; A method is provided in which the method is performed by applying spatial changes of the tracked catheter to the selected lumen of the virtual model to provide an adjusted virtual model of the anatomical structure and the selected lumen when the anatomical structure is in its second configuration.

[0038] In another aspect of the invention, there is provided a system for mapping and tracking multiple lumens in an anatomical structure, the anatomical structure being deformable; a catheter sized to be placed in a plurality of lumens of the anatomical structure to be mapped and tracked and configured to reside in selected lumens of the anatomical structure during deformation of the anatomical structure; a catheter tracking device carried by the catheter for providing a catheter signal indicative of the position of the catheter tracking device; a virtual model of the anatomical structure representing the anatomical structure when the anatomical structure is in a first configuration; a controller; The above controller is (i) determining a position of a tracked catheter to map the plurality of lumens when the tracked catheter is positioned within each of the plurality of lumens while the anatomical structure is in its first configuration; (ii) A system is provided that is configured to supplement the virtual model with the mapped lumen, thereby providing an augmented virtual model of the anatomical structure and the mapped lumen that represents the anatomical structure when the anatomical structure is in its first configuration.

[0039] In another aspect of the invention, there is provided a system for mapping and tracking a selected lumen within an anatomical structure, the anatomical structure being deformable; a catheter sized to be placed in a selected lumen of the anatomical structure and configured to remain in the selected lumen of the anatomical structure during deformation of the anatomical structure; a catheter tracking device carried by the catheter for providing a catheter signal indicative of the position of the catheter tracking device; a virtual model of the anatomical structure and a tracked catheter disposed in a selected lumen of the anatomical structure, the virtual model being created when the anatomical structure is in a first configuration; a controller; The above controller is (i) determining a position of the tracked catheter after the anatomy is in a second configuration; (ii) A system is provided that is configured to adjust a virtual model of the anatomical structure and the tracked catheter when the anatomical structure is in its second configuration so that the virtual model matches the position of the tracked catheter.

[0040] In another aspect of the invention, there is provided a method for tracking a tissue mass in or on an anatomical structure, the anatomical structure including at least one lumen; advancing the scope along at least one lumen until a distal end of the scope is positioned adjacent the selected tissue mass; advancing a reference sensor through the scope and into the anatomical structure and securing the reference sensor to the anatomical structure proximate the tissue mass; and detecting the location of the reference sensor within the anatomy.

[0041] In another aspect of the invention, there is provided a method for tracking a tissue mass in or on an anatomical structure, the anatomical structure including at least one lumen; providing a sensor assembly including a reference sensor and a lead extending distally from the reference sensor; and providing a positioning assembly including a needle cannula and a pusher; wherein a sensor assembly is slidably disposed within the needle cannula distal to the pusher; advancing the scope along at least one lumen until a distal end of the scope is positioned adjacent the selected tissue mass; advancing a needle cannula through the scope, into the anatomy, and through an exterior surface of the anatomy; retracting the needle cannula to expose a portion of the lead extending through the exterior of the anatomy; providing power to the reference sensor via a lead extending through an exterior surface of the anatomy; anchoring the reference sensor to an anatomical structure adjacent the tissue mass by advancing the pusher relative to the needle cannula or retracting the needle cannula relative to the pusher; and detecting the location of the reference sensor within the anatomy.

[0042] In another aspect of the invention, there is provided a system for determining the position of an instrument relative to a tissue mass carried by an anatomical structure, comprising: a wireless reference tracking device configured to be secured to an anatomical structure proximate the tissue mass, the wireless reference tracking device providing a reference signal indicative of a position of the wireless reference tracking device; Equipment and an instrument tracking device carried by the instrument for providing an instrument signal indicative of the position of the instrument tracking device; and a controller for determining the position of the tracked instrument relative to the wireless reference tracking device.

[0043] In another aspect of the invention, there is provided a system for determining the position of an instrument relative to a tissue mass carried by an anatomical structure, comprising: a reference tracker configured to be fixed within an anatomical structure proximate the tissue mass, the reference tracker providing a reference signal indicative of a position and orientation of the reference tracker; a conductor for supplying power to the reference tracking device, the conductor being removably connected to the reference tracking device; Equipment and an instrument tracking device carried by the instrument for providing an instrument signal indicative of the position of the instrument tracking device; and a controller for determining the position of the tracked instrument relative to the reference tracker.

[0044] In another aspect of the invention, there is provided a system for determining the position and orientation of an instrument relative to a tissue mass within or on an anatomical structure, comprising: a sensor assembly including a reference tracker configured to be anchored within an anatomical structure proximate the tissue mass, the reference tracker providing a reference signal indicative of a position of the reference tracker, and a lead extending distally from the reference tracker for providing power to the reference tracker; Equipment and an instrument tracking device carried by the instrument for providing an instrument signal indicative of the position and orientation of the instrument tracking device; and a controller for determining the position and orientation of the tracked instrument relative to the reference tracker.

[0045] In another aspect of the invention, there is provided a system for determining the position and orientation of an instrument relative to a tissue mass in or on an anatomical structure, comprising: a sensor assembly including a reference tracker configured to be anchored within an anatomical structure proximate the tissue mass for providing a reference signal indicative of a position of the reference tracker, and a lead extending distally from the reference tracker for providing power to the reference tracker; a positioning assembly including a needle cannula and a pusher, the sensor assembly being slidably disposed within the needle cannula distal to the pusher; Equipment and an instrument tracking device carried by the instrument for providing an instrument signal indicative of the position and orientation of the instrument tracking device; and a controller for determining the position and orientation of the tracked instrument relative to the reference tracker.

[0046] In another aspect of the invention, there is provided a method for determining the position of an end effector of an instrument relative to a tissue mass carried by an anatomical structure, the instrument including a shaft and an end effector, the position of the end effector relative to the shaft being adjustable; Tracking the location of the tissue mass; Tracking the shaft of the instrument; determining a placement of the end effector relative to the shaft; and determining a placement of the end effector relative to the tissue mass.

[0047] In another aspect of the invention, there is provided a system for determining the position of an end effector of an instrument relative to a tissue mass carried by an anatomical structure, comprising: a wireless reference tracking device configured to be secured to an anatomical structure proximate the tissue mass, the wireless reference tracking device for providing a reference signal indicative of a position of the wireless reference tracking device; an instrument including a shaft and an end effector, wherein the positioning of the end effector relative to the shaft is adjustable; an instrument tracking device carried by the shaft of the instrument for providing an instrument signal indicative of the position of the instrument tracking device; a sensor for detecting the positioning of the end effector relative to the shaft; and a controller for determining the position of the tracked instrument relative to the wireless reference tracking device.

[0048] In another aspect of the invention, there is provided a method for indicating the position of an instrument relative to a tissue mass carried by an anatomical structure, the method comprising: determining a tangent to the texture mass; Tracking the location of the tissue mass; Tracking the location of the instrument; determining the placement of the instrument relative to the tangent; directing movement of the instrument so that a portion of the instrument is aligned with the tangent line.

[0049] In another aspect of the invention, there is provided a system for indicating the position of an instrument relative to a tissue mass carried by an anatomical structure, comprising: a reference tracker configured to be fixed within an anatomical structure proximate the tissue mass, the reference tracker for providing a reference signal indicative of a position of the reference tracker; Equipment and an instrument tracking device carried by the instrument for providing an instrument signal indicative of the position of the instrument tracking device; and a controller for determining a tangent to the tissue mass and directing the position of the tracked instrument relative to the tangent.

[0050] These and other features, aspects and advantages of the present invention will become better understood with consideration of the following detailed description, drawings and appended claims. [Brief explanation of the drawings]

[0051] [Figure 1] FIG. 10 is a perspective view of an exemplary reference sensor positioned through a delivery needle in accordance with an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of the exemplary reference sensor of FIG. 1 positioned via a delivery needle adjacent to a tissue mass in accordance with one embodiment of the present invention (note that the reference sensor can be positioned adjacent to the tissue mass so that the reference sensor is in contact with the tissue mass, or the reference sensor can be slightly spaced from the tissue mass). [Figure 3] 1 and an exemplary reference sensor positioned through a delivery needle adjacent to a tissue mass, according to an embodiment of the present invention. [Figure 4] FIG. 10 is a perspective view of an exemplary reference sensor embedded within a hook structure in accordance with another embodiment of the present invention. [Figure 5] FIG. 3 is a perspective view of a reference sensor implanted in the tissue mass of FIG. 2 with a resection margin surrounding the tissue mass. [Figure 6] FIG. 3 is a perspective view of a reference sensor implanted next to the tissue mass of FIG. 2, with the resection margin surrounding the tissue mass (note that the reference sensor can be positioned adjacent to the tissue mass so that the reference sensor is in contact with the tissue mass, or the reference sensor can be slightly spaced from the tissue mass). [Figure 7] 1 is a partial perspective view of a conventional stapler device used to excise tissue masses. [Figure 8]8 is a partial perspective view of the stapler device of FIG. 7 having a sleeve including an instrument sensor on the housing of the stapler device in accordance with one embodiment of the present invention. [Figure 9] FIG. 9 is a perspective view of the stapler device of FIG. 8 inserted into a patient, illustrating the distance between the reference sensor and the instrument sensor. [Figure 10] 1 is an exemplary screenshot of a virtual endoscopic or "scope" view of a tissue mass overlaid on a laparoscopic view. [Figure 11] 1 is an exemplary screenshot of a laparoscopic view of a tissue mass. [Figure 12] 1 is a schematic diagram showing the tree-like structure of the airways in the lungs. [Figure 13] FIG. 1 is a schematic diagram illustrating how a bronchoscope can be used to position a tracked catheter (i.e., a catheter carrying a sensor) in a particular airway in the lung, thereby identifying the particular airway in the lung, and how a surgical device carrying another sensor can be directed relative to that airway (e.g., to target that airway, avoid that airway, etc.). [Figure 13A] FIG. 1 is a schematic diagram illustrating how a bronchoscope can be used to position a tracked catheter (i.e., a catheter carrying a sensor) in a particular airway in the lung, thereby identifying the particular airway in the lung, and how a surgical device carrying another sensor can be directed relative to that airway (e.g., to target that airway, avoid that airway, etc.). [Figure 13B] FIG. 1 is a schematic diagram illustrating how a bronchoscope can be used to position a tracked catheter (i.e., a catheter carrying a sensor) in a particular airway in the lung, thereby identifying the particular airway in the lung, and how a surgical device carrying another sensor can be directed relative to that airway (e.g., to target that airway, avoid that airway, etc.). [Figure 14] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 15] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 16]FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 17] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 18] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 19] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 20] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 21] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 22] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 23] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 24] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 25] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 26] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 27] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 28] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 29] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 30] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 31]FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 32] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 33] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 34] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 35] FIG. 1 is a schematic diagram illustrating a method of using a tracked catheter to identify the location of an airway. [Figure 36] FIG. 10 is a schematic diagram illustrating another way in which a tracked catheter can be used to identify the location of an airway. [Figure 37] FIG. 10 is a schematic diagram illustrating another way in which a tracked catheter can be used to identify the location of an airway. [Figure 38] 1 is a schematic diagram showing an anatomical site containing a lesion, a reference sensor, and a tracked catheter. [Figure 39] FIG. 1 is a schematic diagram showing a reference sensor placed using percutaneous access. [Figure 40] FIG. 1 is a schematic diagram showing a wireless reference sensor placed through a bronchoscope. [Figure 41] FIG. 1 is a schematic diagram showing a wireless reference sensor placed through a bronchoscope. [Figure 42] FIG. 1 is a schematic diagram showing a wire-based reference sensor placed through a bronchoscope and then pushed bronchoscopically through the lung parenchyma to the surface of the skin under image guidance. [Figure 43] FIG. 10 is a schematic diagram illustrating a wire-based reference sensor that is placed through a bronchoscope and then its wire is detached from the reference sensor and withdrawn into the airway. [Figure 44] 10 is a schematic diagram illustrating an apparatus for another approach for bronchoscopic placement of a reference sensor in tissue (e.g., bronchoscopic placement of a reference sensor in or near a tissue mass). [Figure 45] 10 is a schematic diagram illustrating an apparatus for another approach for bronchoscopic placement of a reference sensor in tissue (e.g., bronchoscopic placement of a reference sensor in or near a tissue mass). [Figure 46] 10 is a schematic diagram illustrating an apparatus for another approach for bronchoscopic placement of a reference sensor in tissue (e.g., bronchoscopic placement of a reference sensor in or near a tissue mass). [Figure 46A] 1 is a schematic diagram illustrating another apparatus for bronchoscopic placement of a reference sensor in tissue (e.g., bronchoscopic placement of a reference sensor in or near a tissue mass). [Figure 46B] 1 is a schematic diagram illustrating another apparatus for bronchoscopic placement of a reference sensor in tissue (e.g., bronchoscopic placement of a reference sensor in or near a tissue mass). [Figure 47] 47A-47C are schematic diagrams illustrating a method of using the apparatus of FIGS. 44-46 for bronchoscopic placement of a reference sensor in tissue (eg, bronchoscopic placement of a reference sensor in or near a tissue mass). [Figure 48] 47A-47C are schematic diagrams illustrating a method of using the apparatus of FIGS. 44-46 for bronchoscopic placement of a reference sensor in tissue (eg, bronchoscopic placement of a reference sensor in or near a tissue mass). [Figure 49] 47A-47C are schematic diagrams illustrating a method of using the apparatus of FIGS. 44-46 for bronchoscopic placement of a reference sensor in tissue (eg, bronchoscopic placement of a reference sensor in or near a tissue mass). [Figure 50] 47A-47C are schematic diagrams illustrating a method of using the apparatus of FIGS. 44-46 for bronchoscopic placement of a reference sensor in tissue (eg, bronchoscopic placement of a reference sensor in or near a tissue mass). [Figure 51] 47A-47C are schematic diagrams illustrating a method of using the apparatus of FIGS. 44-46 for bronchoscopic placement of a reference sensor in tissue (eg, bronchoscopic placement of a reference sensor in or near a tissue mass). [Figure 52]47A-47C are schematic diagrams illustrating a method of using the apparatus of FIGS. 44-46 for bronchoscopic placement of a reference sensor in tissue (eg, bronchoscopic placement of a reference sensor in or near a tissue mass). [Figure 52A] 10 is a schematic diagram illustrating a method for providing a temporary proximal electrical connection to a reference sensor, such as when the reference sensor is placed through a bronchoscope. [Figure 53] FIG. 1 is a schematic diagram illustrating a surgical stapler with an articulation sensor for detecting articulation of a head of the surgical stapler. [Figure 54] FIG. 1 is a schematic diagram illustrating a surgical stapler with an articulation sensor for detecting articulation of a head of the surgical stapler. [Figure 55] (i) Schematic diagram showing a model of the lesion. [Figure 56] (ii) Schematic showing a model of the resection margin combined with a model of the lesion. [Figure 57] 10A-10C are schematic diagrams illustrating a method for placing staples adjacent the resection margins of a lesion. [Figure 58] 10A-10C are schematic diagrams illustrating a method for placing staples adjacent the resection margins of a lesion. [Figure 59] 10A-10C are schematic diagrams illustrating a method for placing staples adjacent the resection margins of a lesion. [Figure 60] 10A-10C are schematic diagrams illustrating a method for placing staples adjacent the resection margins of a lesion. DETAILED DESCRIPTION OF THE INVENTION

[0052] Before describing any embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the specific details of construction and arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or carried out in other ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and are not to be regarded as limiting. The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof, as well as additional items. Unless otherwise specified or limited, the terms "mounted," "connected," "supported," and "coupled," and variations thereof, are used broadly and encompass both direct and indirect mounting, connecting, supporting, and coupling. Furthermore, "connected" and "coupled" are not restricted to physical or mechanical connections or couplings.

[0053] The following description is presented to enable those skilled in the art to make and use embodiments of the invention. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein may be applied to other embodiments and applications without departing from the scope of the invention. Thus, embodiments of the invention are not intended to be limited to the particular embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description should be read with reference to the drawings, in which like elements in different drawings have like reference numerals. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. Those skilled in the art will recognize that the examples provided herein have many useful alternatives, all of which are within the scope of the embodiments of the invention.

[0054] Tracking the position of tissue mass using a fiducial sensor 1-3 show an exemplary reference sensor 10 (also referred to as a fiducial marker or fiducial tracker) being inserted through a delivery needle 12. The reference sensor 10 may be, for example, a marker including a transmitter that measures the position and orientation of a tissue mass 18 in real time. The reference sensor 10 may be attached to a cable 14, as shown in FIGS. 1-3, or the reference sensor 10 may be wireless. The reference sensor 10 may be embedded within a hook structure 16, as shown in FIG. 1. The hook structure 16 of the reference sensor 10 may be made from a superelastic material, such as nitinol, stainless steel, or any other suitable material. This allows the reference sensor 10 to be inserted through the delivery needle 12 and positioned at or around the center of the tissue mass 18 through the opening 22 (i.e., lumen) of the delivery needle 12. The tissue mass 18 may be, for example, a lesion (e.g., a tumor, nodule, etc.).

[0055] As shown in FIG. 4, a more detailed view of the reference sensor 10 and hook structure 16 is shown. The hook structure 16 can include a tubing portion 15 having multiple extensions 17 extending from one end of the tubing portion 15 and multiple branches 20 extending from the opposite end of the tubing portion 15. The tubing portion 15 can be, for example, a Nitinol tube having an outer diameter D1 of about 0.6 millimeters to about 0.8 millimeters, and the hook structure 16 can have an overall length L of about 8 millimeters to about 12 millimeters. The tubing portion 15 can be laser micromachined into a cylindrical shape with multiple extensions 17 extending therefrom to secure the reference sensor 10 in place. In some embodiments, the reference sensor 10 can be an electromagnetic sensor attached to the proximal end of the hook structure 16 using a medical-grade epoxy adhesive, such as AA-Bond FDA22.

[0056] As shown in FIG. 4 , the multiple branches 20 may be configured to secure the hook structure 16, including the reference sensor 10, within or around a tissue mass, such as the tissue mass 18 of FIG. 2 . The multiple branches 20 may be constructed from a superelastic shape memory alloy, such as Nitinol. The multiple branches 20 may be curved, for example, and extend outward from the central axis Y of the hook structure 16. The multiple branches 20 may also be heat treated to ensure that the branches 20 retain their curved shape and that the phase structure of the Nitinol is, for example, martensitic. In the embodiment shown in FIG. 4 , the hook structure 16 includes three branches 20, but any suitable number of branches may be provided to secure the hook structure 16 within or around a tissue mass, such as the tissue mass 18.

[0057] The reference sensor 10, along with the hook structure 16, may be inserted through the distal end of the delivery needle 12, which may be, for example, an 18-gauge needle. The multiple prongs 20 of the hook structure 16 may first be inserted into the lumen 22 of the delivery needle 12. Advantageously, due to the superelastic properties of Nitinol, the hook structure 16 can be easily inserted into the lumen 22 of the delivery needle 12. The hook structure 16 may be deployed using a metal stylet (not shown) inserted through the lumen 22 of the delivery needle 12. Once fully deployed, the multiple prongs 20 resume their original curved shape and open to firmly secure the hook structure 16 in or around the tissue mass 18. The delivery needle 12 may then be removed after the hook structure 16 has been deployed.

[0058] In some embodiments, the reference sensor 10, along with the hook structure 16, can be inserted through the delivery needle 12 under real-time image guidance (e.g., CT, C-arm CT, MRI, ultrasound, etc.) and can be implanted within the tissue mass 18 as shown in FIG. 5 or next to (e.g., near) the tissue mass 18 as shown in FIG. 6. The reference sensor 10 can be implanted in or next to the tissue mass 18 before or during a surgical procedure. By using real-time image guidance, the spatial relationship (i.e., location and orientation) of the reference sensor 10 to the tissue mass 18 in three dimensions is always known. The hook structure 16 can be in the form of a T-bar or J-bar, for example, to secure the reference sensor 10 within or next to the tissue mass 18 to prevent movement. Advantageously, the force is centered on the T-bar 16 by the wire 14, thereby facilitating anchoring of the reference sensor 10 within or next to the tissue mass 18. The reference sensor 10 implanted within or adjacent to the tissue mass 18 measures the position and orientation of the tissue mass 18 in real time despite any deformations introduced due to soft tissue deformation or physiological motion, such as lung collapse or respiration, thereby easily identifying the location of the tissue mass 18, which is often difficult to determine.

[0059] In an alternative embodiment shown in FIG. 3 , a second reference sensor 11 (e.g., in the form of a T-bar assembly) can be placed at a different location near the tissue mass 18. As shown in FIG. 3 , the second reference sensor 11 can have a separate cable 14 from the first reference sensor 10, or the first reference sensor 10 and the second reference sensor 11 can share the same cable 14. The second reference sensor 11, or any other such device, can be used to improve the location measurement of the tissue mass 18 even when the tissue mass 18 is deformed. For example, the second reference sensor 11 can be placed on the opposite side of the tissue mass 18 from the first reference sensor 10 and recognized by the first reference sensor 10 by distortion of the electromagnetic field. Thus, by knowing that the tissue mass 18 is between these two sensors, the tissue mass 18 can be located despite changes in the soft tissue.

[0060] 5 and 6, once the location and orientation of the tissue mass 18 is known, a resection margin 24 having a predetermined distance D2 surrounding the tissue mass 18 is determined by creating a three-dimensional envelope around the tissue mass 18. The resection margin 24 can be manually set to a desired predetermined distance D2, for example, 2 centimeters, and is dependent on the surgeon's preference and the lesion type. The predetermined distance D2 defines a threshold such that an audio, visual, and / or tactile cue can be provided to the surgeon or surgical device 26 (e.g., a surgical stapler), described in further detail below, when the surgical device 26 is positioned below the threshold to ensure accurate and complete resection of the tissue mass 18.

[0061] Tracking the position of surgical devices using instrument sensors 7 , a conventional surgical device 26, such as a surgical stapler, Bovi pencil, Kitner, laparoscope, and / or any suitable cutting, resecting, or removal device, is shown. The surgical device 26 may include a handle 30 coupled to a fastener assembly 32 at an opposite end of the surgical device 26. The fastener assembly 32 may be a disposable component removably connected to the handle 30, i.e., the fastener assembly 32 may be a cartridge that is connected to the handle 30 and removed after use. The fastener assembly 32 includes a housing 34 that contains a plurality of fasteners 36 that are secured to tissue during resection of the tissue mass 18. The fastener assembly 32 also includes a blade slot 38 that receives a blade (not shown) for cutting along the resection margin 24 of the tissue mass 18.

[0062] In a preferred embodiment, the surgical device 26 includes a sleeve 40 sized to slide over the housing 34, as shown, for example, in FIG. 8 . The sleeve 40 may be, for example, any commercially available sleeve configured to cover the housing 34 of the surgical device 26. The instrument sensor 28 (sometimes referred to as an instrument tracker) may be attached to the sleeve 40, for example, by suturing. Alternatively, the instrument sensor 28 may be attached directly to the housing 34 of the surgical device 26 via any suitable adhesive, or may be integrated into the housing 34 itself. Regardless of whether the instrument sensor 28 is attached to the sleeve 40 or the housing 34, the instrument sensor 28 can measure the position and orientation of the surgical device 26 in the same imaging frame of reference as the reference sensor 10 implanted within or adjacent to the tissue mass 18. In other words, the position of the surgical device 26 can be accurately measured relative to the reference sensor 10 located within or adjacent to the tissue mass 18, as described in further detail below. Because both the reference sensor 10 and the instrument sensor 28 are measured in the same reference frame, errors introduced due to registration and calibration processes that require a change of reference axis can be minimized.

[0063] 9, the sleeve 40 can also include a display 42 that indicates to the user the distance D3 of the surgical device 26 from the resection margin 24, as described below. The display 42 may be attached to the handle 30 of the surgical device 26 and may be any commercially available organic light-emitting diode (OLED) display or liquid crystal display (LCD). In the case of an OLED display, for example, a reformatted CT image of the tissue mass 18 located at the tip of the surgical device 26 may be displayed to the user.

[0064] Guiding a surgical device into a tissue mass Referring now to FIG. 9 , as previously described, in operation, the reference sensor 10 is positioned next to or embedded within a tissue mass 18 using the multiple prongs 20 of the hook structure 16. For example, a CT / MRI / fluoroscopy / C-arm CT examination is performed to acquire images of the reference sensor 10 positioned next to or embedded within the tissue mass 18. The tissue mass 18 is then segmented from the preoperative diagnostic CT / MRI examination, and a three-dimensional model (not shown) of the tissue mass 18 is created. Intraoperative images acquired during placement of the reference sensor 10 can be registered to the patient's diagnostic examination, allowing the location of the reference sensor 10 to be estimated. As previously described, a resection margin 24 having a predetermined distance D2 surrounding the tissue mass 18 is displayed to the user on a monitor (not shown) as a three-dimensional envelope or proximity sphere around the tissue mass 18. The predetermined distance D2 of the resection margin 24 can be determined based on the surgeon's preference and the type of tissue mass 18.

[0065] Next, as shown in FIG. 9 , the surgical device 26 is inserted into the body 44 (i.e., the patient) to cut the tissue mass 18 along the resection margin 24. The reference sensor 10, implanted in or near the tissue mass 18, is in electrical or wireless communication with a controller 48. The controller 48 may be a programmable logic controller (PLC) and configured to interpret signals generated by the reference sensor 10. The reference sensor 10 may be, for example, an electromagnetic sensor that generates signals indicative of the position and orientation (e.g., one or more spatial coordinates) of the reference sensor 10. The signals generated by the reference sensor 10 may be, for example, electrical signals, which the controller 48 may interpret via a stored program 50. The stored program 50 may include, for example, a navigation system in communication with the reference sensor 10 and the instrument sensor 28.

[0066] Similarly, the instrument sensor 28 may be, for example, an electromagnetic sensor that generates a signal indicative of the position and orientation (e.g., one or more spatial coordinates) of the instrument sensor 28. The signal generated by the instrument sensor 28 may be, for example, an electrical signal, which the controller 48 may interpret via a stored program 50. The reference sensor 10 and the instrument sensor 28 communicate with the controller 48, which relays the position and orientation of the tissue mass 18 and the surgical device 26 using a navigation system. In some embodiments, the stored program 50 may be configured to execute a calibration and / or registration algorithm to track the distal tip of the surgical device 26 and a normal vector relative to the surgical device 26. The stored program 50 of the controller 48 then calculates a distance D3, shown in FIG. 9 , between the reference sensor 10 and the instrument sensor 28, and when the surgical device 26 falls below a D3 threshold, an auditory, visual, or tactile cue is generated for the user.

[0067] As the surgical device 26 navigates toward the resection margin 24 of the tissue mass 18, the surgical device 26 can remove the tissue mass 18 while minimizing damage to surrounding tissue due to the active tracking of both the reference sensor 10 and the instrument sensor 28. Minimal damage to surrounding healthy tissue can also ensure normal physiological function, such as pulmonary function. Using feedback from the reference sensor 10 and the instrument sensor 28 on the surgical device 26, the distance D3 from the tissue mass 18 and surgical device 26 is known to the user and is always visible on the display 42. As a result, the desired resection margin 24 can be constantly maintained, thereby ensuring complete resection of the tissue mass 18. In one embodiment, the position and orientation data of the tissue mass 18 and surgical device 26 can be used to lock or unlock the surgical device 26 to prevent erroneous resection of the tissue mass 18.

[0068] <Tissue Deformation Algorithm> In some embodiments, the stored programs 50 of the controller 48 may be configured to include one or more deformation algorithms that estimate or model changes that may occur to the resection margin 24 during a procedure as a result of deformation of the tissue mass 18 and / or surrounding tissue. The deformation algorithm attempts to account for any such changes to the resection margin 24 to provide the user with more accurate resection margins during surgery, which aids in complete resection of the tissue mass 18 while limiting damage to or removal of healthy surrounding tissue.

[0069] In one non-limiting example, the pre-installed program 50 includes a deformation algorithm that assumes that the tissue mass 18 (e.g., a breast lesion) is rigid and that the surrounding tissue (e.g., parenchyma) deforms. The algorithm assumes that all points on the tissue mass 18 move with the reference sensor 10, which is fixed to the tissue mass 18 as described above. In another non-limiting example, the pre-installed program 50 includes a deformation algorithm that assumes that the tissue mass 18 is a rigid object that moves through a viscoelastic or fluid medium. In yet another non-limiting example, patient-specific properties of the tissue mass 18 and surrounding tissue can be measured, for example, via CT / MRI / fluoroscopy, to predict deformations to the tissue mass 18 or resection margins 24 that will occur during surgery for that particular patient. It should be understood that the deformation algorithm of the pre-installed program 50 can operate in real time using the navigation system of the pre-installed program 50.

[0070] More specifically, the tissue mass 18 (e.g., a lesion) can be segmented from volumetric images obtained, for example, from a CT / MRI / fluoroscopy study, to create a surface model. Based on a default resection margin entered into the navigation system by the user, the segmented lesion label map can be extended to the desired resection margin to create a surface model corresponding to the resection margin. Deformation of the lesion and surrounding tissue, for example, due to patient movement, can change the resection margin. Therefore, a linear elastic volumetric finite element model ("FEM") mesh can be created from the surface model of the lesion and resection margin. The FEM model can be used to estimate the displacement of other nodes of the tissue mass 18 and the resection margin 24, taking into account real-time position measurements of the reference sensor 10. Stiffness values may not be completely accurate for the FEM model, and the FEM model may be constrained by the tissue mass 18 and surrounding tissue, in one example. Therefore, uncertainty measurements of the tissue mass 18 and surrounding tissue deformation can be provided to the user in real time based on the uncertainty in the estimated stiffness values of the FEM mesh.

[0071] Auditory, visual, quantitative and tactile cues As described above, auditory, visual, and tactile cues can be provided to the surgeon and / or surgical device 26 to identify the resection margin 24 and ensure accurate and complete resection of the tissue mass 18. For example, the audio source 52 can be configured to emit an audible signal. The audio source 52 can communicate with the controller 48, configured to execute a stored program 50, to modify the audible signal based on the distance D3 between the instrument sensor 28 and the reference sensor 10. The instrument sensor 28 uses the signal generated by the reference sensor 10 to enable the controller 48 to execute the stored program 50 to calculate the distance D3, shown in FIG. 9 , between the reference sensor 10 and the instrument sensor 28 and generate an audible signal when the surgical device 26 falls below a threshold value for D3. The audible signal can be, for example, a beep, a beep, or an alarm. The audible signal may also increase in frequency or duty cycle as the distance D3 decreases, such that the frequency or duty cycle of the audible signal increases when the surgical device 26 gets too close to the resection margin 24.

[0072] In addition to auditory cues, visual cues can also be provided to the user on one or more displays 54 in communication with the controller 48. The one or more displays 54 can include, for example, visual cues provided on an endoscope display or a separate monitor. For example, the endoscope display or separate monitor can be configured to emit a visual signal. The endoscope display or separate monitor can communicate with the controller 48, which is configured to execute a stored program 50, to modify the visual signal based on the distance D3 between the instrument sensor 28 and the reference sensor 10. The instrument sensor 28 uses the signal generated by the reference sensor 10 to enable the controller 48 to execute the stored program 50 to calculate the distance D3, shown in FIG. 9 , between the reference sensor 10 and the instrument sensor 28 (e.g., near the tip of the surgical device 26) and / or between the instrument sensor 28 (e.g., near the tip of the surgical device 26) and a normal vector to the hook structure 16, and generate a visual signal when the surgical device 26 falls below a D3 threshold. The visual signal may be, for example, a solid or flashing light shown on one or more displays 54, such as the endoscope display or a separate monitor. The visual signal may also increase in frequency or intensity, for example, as the distance D3 decreases, such that the frequency and / or intensity of the visual signal increases when the surgical device 26 gets too close to the resection margin 24. Furthermore, the distance from the tip, middle, or base of the instrument's cutting edge may also be determined based on a built-in program and displayed to the user. Such display of distance values is sometimes referred to herein as a quantitative cue.

[0073] In one non-limiting example, the visual cue may be shown, for example, as a color-changing sphere on one of the displays 54. The color-changing sphere may represent the tissue resection margin 24, for example, such that the color changes based on the distance D3 between the instrument sensor 28 and the reference sensor 10. Thus, for example, as the instrument sensor 28 approaches the reference sensor 10, the sphere may be shown on the display 54 in a first color. Similarly, as the instrument sensor 28 moves away from the reference sensor 10, the sphere may be shown on the display 54 in, for example, a second color, thereby allowing the surgeon to visually recognize the distance D3 between the instrument sensor 28 and the reference sensor 10.

[0074] Quantitative, visual, and audio cues can be provided to the clinician to identify the distance of the resection margin 24 from the surgical device 26, and the visual cues can further include a video overlay provided to the user on one or more of the displays 54 in communication with the controller 48. For example, as shown on the display 54 in FIG. 10, a video overlay can be performed to fuse laparoscopic and virtual endoscopic images to confirm the location of the reference sensor 10 and the tissue mass 18. Based on the position of the laparoscope 56, a virtual endoscopic video of the three-dimensional anatomy can be generated, as shown on the display 54 in FIG. 11. Focal length and field of view may be input to control the virtual endoscopic view generated, for example, using a three-dimensional view visualization toolkit camera.

[0075] Tactile cues may also be provided to the user on the surgical device 26. For example, a piezoelectric actuator 46 may be attached to the handle 30 of the surgical device 26 configured to emit a tactile signal. The piezoelectric actuator 46 may be in electrical communication with a controller configured to execute a stored program to modify the tactile signal based on the distance D3 between the instrument sensor 28 and the reference sensor 10. The instrument sensor 28 uses the signal generated by the reference sensor 10 to enable the controller to execute the stored program to calculate the distance D3, shown in FIG. 9 , between the reference sensor 10 and the instrument sensor 28 and generate a tactile signal when the surgical device 26 falls below a threshold value of D3. The tactile signal may be, for example, a vibration applied to the handle 30 of the surgical device 26. The tactile signal may also increase in amplitude and / or frequency as the distance D3 decreases, such that the amplitude and / or frequency of the tactile signal increases when the surgical device 26 gets too close to the resection margin 24.

[0076] <Application to lung cancer surgery> Nearly 230,000 new cases of lung cancer are diagnosed in the United States each year, resulting in an estimated cost to the healthcare system of $12.1 billion. The 1- and 5-year survival rates for lung cancer patients are 44% and 17%, respectively. For the treatment of small, early-stage lesions, parenchymal-sparing minimally invasive wedge resection (WRS) or segmentectomy is becoming the preferred method of surgical resection over lobectomy. Preserving healthy lung function becomes even more important when pulmonary physiology is impaired due to excessive smoking, advanced age, multiple lesions, previous lung surgery, cardiac comorbidities, or chronic obstructive pulmonary disease (COPD). While these procedures (i.e., WRS and segmentectomy) result in better lung function, the lesion recurrence rate is nearly twice that of lobectomy, and the 5-year survival rate is significantly lower. Furthermore, segmentectomy is associated with significant complications. Locoregional recurrence and complications associated with segmentectomy may be due to the difficulty of accurately localizing and resecting lesions in the collapsed lung and the difficulty of identifying intersegmental planes. To avoid perioperative and postoperative complications, precise anatomical landmarks (e.g., vascular and bronchial anatomical variations) need to be carefully identified and tracked.

[0077] The previous section teaches that a reference sensor 10 (e.g., a T-bar or J-bar assembly) is placed near a lesion 18 to track the lesion in real time. A surgical stapler (or other surgical device) 26 is also tracked in real time using an instrument sensor 28 to precisely guide the resection of the lung lesion 18. More specifically, the navigation software calculates the distance from the surgical stapler 26 to the reference sensor (e.g., a T-bar or J-bar assembly) and, therefore, the distance from the surgical stapler 26 to the lesion 18, and displays the distance measurements to the surgeon in real time to ensure complete resection of the lesion. Additionally, the distances from the reference sensor 10 or tumor surface to the leading, middle, and base of the stapler cut line (sometimes referred to herein as the resection line) can also be calculated and displayed in real time.

[0078] The system can be used to identify specific airways within the lungs to assist surgeons in identifying airways from the thoracic side of the procedure during surgery. The system can also be used to identify specific airways within the lungs to assist the surgeon in identifying airways from the thoracic side of the procedure during surgery.

[0079] More specifically, the airways of the lungs have a complex tree-like structure, see Figure 12.

[0080] When treating lung lesions, particularly when the treatment may involve resecting the lung to remove the lesion, it may be important to plan the resection relative to specific airways, i.e., to remove specific airways, to avoid specific airways, etc. Therefore, it may be important to know the location of the relevant airways when performing the resection surgery.

[0081] During bronchoscopy, the bronchoscope follows a descending path characterized by specific branches as it advances down the airway tree, making it possible to identify the bronchoscope's position relative to a particular airway. However, due to its size and the progressively decreasing size of the airways, the bronchoscope can typically only travel a limited distance through the lung's airways. Furthermore, visualization provided to the surgeon from the chest side of the procedure during surgery is limited to a direct view, and due to the limited view provided to the surgeon from the chest side, identifying a particular airway from the chest side can be very problematic.

[0082] The present invention can be used to identify specific airways within the lungs to assist the surgeon in identifying airways from the thoracic side of the procedure during surgery.

[0083] More specifically, turning now to FIGS. 13, 13A, and 13B, in this form of the invention, a bronchoscope 60 is used to position a catheter 65 carrying a sensor 70 (i.e., a "tracked catheter" 75) within the relevant airway of the lung. More particularly, in one preferred form of the invention, the bronchoscope 60 can be advanced through the airway under bronchoscopic guidance, or by some other form of guidance, such as CT imaging, C-arm imaging, etc., until the bronchoscope 60 has advanced as far as possible toward the relevant airway. See FIG. 13. The tracked catheter 75 (i.e., the catheter 65 carrying the sensor 70) is then advanced down the bronchoscope 60 and then out the end of the bronchoscope 60 into the relevant airway of the lung. See FIG. 13A. Note that to maintain maximum flexibility of the bronchoscope 60, preferably the tracked catheter 75 is not advanced through the bronchoscope 60 until after the bronchoscope 60 has been positioned in the lung. Once the tracked catheter 75 has exited the bronchoscope 60 and been advanced to a position within the relevant airway, the bronchoscope 60 can be withdrawn. See Figure 13B. Withdrawal of the bronchoscope 60 is generally desirable at this point, as the bronchoscope may interfere with ventilation.

[0084] Bronchoscopic positioning of the sensor in the relevant airway of the lung (i.e., by bronchoscopically positioning the tracked catheter in the relevant airway of the lung) can then be used to define the lobe, segment, or subsegmental bronchus for a procedure such as a segmentectomy, lobectomy, or wedge resection during the actual surgery. More specifically, the location of the sensor identifying the bronchus (i.e., sensor 70 on tracked catheter 75) can be correlated with the location of another device (e.g., surgical device) 80 (i.e., tracked instrument 90) carrying another sensor 85, such that the surgeon can use the system to identify the correct bronchus for surgery from the thoracic side of the procedure (where direct visualization is limited and often unclear regarding the particular airway). Thus, in this form of the invention, one sensor 70 is placed on a catheter 65 that is inserted into a particular airway to identify the location of the particular airway, and the other sensor 85 is placed on a surgical device 80 that is advanced for surgery from the thoracic side of the procedure, with the system then tracking the position of the surgical device 80 relative to the tracked catheter 75 (and thus relative to the location of the airway into which the tracked catheter 75 is placed). In this way, the surgeon can identify the position of the surgical device 80 relative to the target airway (identified by the sensor 70 on the tracked catheter 75), even though direct visualization from the thoracic side of the procedure may be limited or ambiguous with respect to the particular airway. As a result, the surgeon can use the system to target the airway identified by the sensor 70 on the tracked catheter 75, avoid the airway identified by the sensor 70 on the tracked catheter 75, etc.

[0085] Importantly, the tracked catheter 75 can be inserted into the relevant airway of the lung while the lung is in a first configuration (e.g., an inflated configuration) and maintained in position within that airway while the lung changes to a second configuration (e.g., a deflated configuration). This can be particularly advantageous when attempting to identify the relevant airway of the lung during limited access surgical procedures (e.g., when visualization is provided by a scope advanced within the chest) while the lung changes between the first and second configurations.

[0086] It should be noted that, if desired, the tracked catheter 75 may be inserted into the bronchoscope 60 before the bronchoscope 60 is advanced down the airways of the lungs. However, as noted above, it is generally desirable to insert the tracked catheter 75 into the bronchoscope 60 after the bronchoscope 60 is positioned within the lungs, as this provides the bronchoscope 60 with the greatest flexibility.

[0087] It should also be noted that, if desired, the bronchoscope 60 may be left in position within the lungs after the tracked catheter 75 has been advanced into the relevant airways, however, as noted above, it is often desirable to remove the bronchoscope 60 after the tracked catheter 75 has been advanced into the relevant airways, as this provides for better ventilation of the lungs.

[0088] In addition to the above, it should also be understood that, if desired, the bronchoscope 60 itself may carry sensors (not shown) so that the bronchoscope 60 itself can be tracked within the airways of the lungs. This approach may be useful when the bronchoscope 60 can be advanced to the airway of interest, for example, when the airway of interest is a relatively large airway that can be directly accessed by the bronchoscope 60.

[0089] It should be noted that, if desired, the tracked catheter 75 (and / or tracked bronchoscope) may also be used to map multiple airways within the lung while the lung is in a given configuration (e.g., a first inflated configuration).

[0090] In one form of the invention, a reference sensor 10 (e.g., a T-bar or J-bar assembly) is placed within the lung while the lung is in a first (e.g., inflated) configuration, a tracked catheter 75 is placed in a selected airway of the lung while the lung is in its first (e.g., inflated) configuration, the relative positioning of the reference sensor 10 and the tracked catheter 75 is determined while the lung is in its first (e.g., inflated) configuration, the lung is changed to a second (e.g., deflated) configuration, the relative positioning of the reference sensor 10 and the tracked catheter 75 is determined while the lung is in its second (e.g., deflated) configuration, and the change in relative positioning of the reference sensor 10 and the tracked catheter 75 is determined after the lung is changed from its first (e.g., inflated) configuration to its second (e.g., deflated) configuration and used to estimate the extent and location of deformation of the lung structure while the lung is in its second (e.g., deflated) configuration.

[0091] Ambulatory airway mapping and tracking The above-described system can be enhanced by mapping and tracking the surrounding airways (along with the lesion) to ensure the correct section of the lung is removed, since anatomical structures move during lung deflation and the tissue fragment being removed may not be apparent to the surgeon.

[0092] The procedure for mapping and tracking the airways of the lungs can be performed as follows.

[0093] First, the patient is placed in the supine position. Then, a flexible catheter 65 with an on-board catheter sensor 70 is bronchoscopically positioned in the nearest / target bronchus in the lung segment containing the lesion 18. This is done either by visually identifying the correct bronchus or by some form of guidance (e.g., CT imaging, C-arm imaging, etc.). The tracked catheter 75 is inserted into the target bronchus near the tissue mass of the lesion 18. Once the catheter 65 is inserted, a trajectory of the catheter 65 is recorded using the on-board catheter sensor 70 and an electromagnetic tracker system configured to identify the position and orientation of the catheter sensor 70 (and thus the position and orientation of the catheter 65). This trajectory indicates the position of the airway 95 within the coordinate space of the electromagnetic tracker system. See Figures 14-34. The successive detected positions of the catheter sensor 70 as the catheter 65 advances through the airway 95 can be concatenated to provide a centerline of the target airway. See Figure 35.

[0094] Alternatively, the catheter 65 may include multiple catheter tracking devices 70 positioned along its length to perform airway mapping by simply recording the positions of the various catheter sensors 70 after the catheter 65 is fully inserted into the airway. See Figures 36 and 37. Note that the catheter 65 may be advanced through the airway under bronchoscopic guidance or by some other form of guidance, such as CT imaging, C-arm imaging, etc.

[0095] This process can then be repeated in adjacent airways to map the airways surrounding the lesion.

[0096] Once mapping of the relevant airways is complete, the positions of the reference sensor 10 (e.g., a T-bar or J-bar assembly or similar tracking device) and the mapped airways are recorded in the inflated lung (and eventually in the deflated lung).

[0097] The lung is then collapsed prior to the start of surgery with a reference sensor 10 adjacent to the lesion 18 and a tracked catheter 75 placed in a critical airway near the lesion. The reference sensor 10 (e.g., a T-bar or J-bar assembly) and tracked catheter 75 are tracked in real time as the lung is collapsed. See FIG. 38. The positions of the reference sensor 10 (e.g., a T-bar or J-bar assembly) and critical airways (e.g., the airway containing the tracked catheter 75) are recorded in the deflated lung. A finite element-based particle filter or FEM deformation algorithm is used to estimate the spatial translation of the reference sensor 10 (e.g., a T-bar or J-bar assembly) and critical airways from an inflated state to a deflated state. A smooth deformation field around the critical airways is estimated. The deformation field is then applied to other airways mapped in the inflated lung to estimate the positions of other airways in the deflated lung. The "deformed" airway (i.e., the constricted lung airway), along with the lesion, is displayed to the surgeon in the guidance system to precisely guide the surgical stapler 26 to the optimal resection margin while ensuring that critical anatomical structures are spared. This technique also aids in defining the correct segment for resection (as well as the correct bronchial segment to resect or not resect as part of the planned procedure) even without stapler navigation. Once the appropriate bronchial segment has been identified from a thoracoscopic or thoracic perspective, the catheter 65 can be removed by simply withdrawing it from the airway via the mouth, nose, or endotracheal tube prior to any surgical resection.

[0098] In one aspect of the present invention, multiple lumens within a deformable anatomical structure may be mapped and tracked by the following steps: providing a virtual model of the anatomical structure when the anatomical structure is in a first configuration; positioning a tracked catheter in one of the lumens within the mapped and tracked anatomical structure when the anatomical structure is in a first configuration, determining a position of the tracked catheter in the lumen, and mapping the position of the lumen; repeating the above steps for each lumen in the anatomical structure to be mapped and tracked so that the lumen is mapped; supplementing the virtual model with the mapped lumen, thereby providing an augmented virtual model of the anatomical structure and the mapped lumen when the anatomical structure is in its first configuration; maintaining the tracked catheter in one of the mapped lumens of the anatomical structure while the anatomical structure transforms from its first configuration to its second configuration; determining a position of the tracked catheter within the anatomical structure when the anatomical structure is in a second configuration; The supplemented virtual model is modified to represent the anatomical structure and the mapped lumen when the anatomical structure is in its second configuration, thereby providing a modified supplemented virtual model. Here, the above correction is determining a spatial change of the tracked catheter as the anatomical structure transforms from its first configuration to its second configuration; This is done by applying the spatial changes of the tracked catheter to the mapped lumen of the augmented virtual model to provide a modified augmented virtual model of the anatomical structure and the mapped lumen when the anatomical structure is in its second configuration.

[0099] In another aspect of the present invention, a selected lumen within a deformable anatomical structure may be mapped and tracked by the following steps: positioning a tracked catheter in a selected lumen of the anatomical structure when the anatomical structure is in a first configuration; determining a position of the tracked catheter when the anatomical structure is in a first configuration; scanning the anatomical structure and a tracked catheter positioned in a selected lumen of the anatomical structure while the anatomical structure is in a first configuration; creating a virtual model of the scanned anatomical structure and a tracked catheter positioned within a selected lumen of the anatomical structure when the anatomical structure is in its first configuration; maintaining the tracked catheter at a position within the selected lumen of the anatomical structure while the anatomical structure transforms into a second configuration; determining a position and orientation of the tracked catheter when the anatomical structure is in its second configuration, thereby determining a position of the selected lumen of the anatomical structure when the anatomical structure is in the second configuration; The virtual model is adjusted to represent the anatomical structure and the selected lumen when the anatomical structure is in its second configuration, thereby providing an adjusted virtual model. Here, the above correction is determining a spatial change of the tracked catheter as the anatomical structure transforms from its first configuration to its second configuration; This is done by applying spatial changes of the tracked catheter to the selected lumen of the virtual model to provide an adjusted virtual model of the anatomical structure and the selected lumen when the anatomical structure is in its second configuration.

[0100] <Bronchoscopic placement of the reference sensor> In the above-described systems, the reference sensor 10 (e.g., a T-bar or J-bar assembly) is described as being placed percutaneously. See Figure 39. However, if desired, the reference sensor 10 (e.g., a T-bar or J-bar assembly) can be placed via a bronchoscopic approach, or an open-chest or VATS approach.

[0101] More specifically, the reference sensor 10 (e.g., a T-bar or J-bar assembly) is a metal anchor with a wireless electromagnetic sensor embedded within a hook-like structure. The metal anchor can be made of a superelastic material, such as nitinol, or can be made of stainless steel. The reference sensor 10 (e.g., a T-bar or J-bar assembly) is placed within a long, flexible, hollow tube with a beveled tip at its end. This hollow tube is inserted through the working channel of a bronchoscope 60. Under real-time image guidance using a navigation system, the wireless reference sensor 10 (e.g., a T-bar or J-bar assembly) is guided through the airway using the bronchoscope 60 and positioned near the lesion. See FIG. 40. Once the reference sensor 10 (e.g., a T-bar or J-bar assembly) is positioned near the lesion 18, the bronchoscope 60 (and the hollow tube extending through the working channel of the bronchoscope) is removed. See FIG. 41. The lung is then collapsed and the lesion 18 is tracked in real time using a reference sensor 10 (e.g., a T-bar or J-bar assembly). The surgical stapler (not shown) is also tracked in real time using an instrument sensor attached to the surgical stapler. Note that the surgical stapler is tracked in the same reference frame as the reference sensor 10 (e.g., a T-bar or J-bar assembly). The surgical stapler can then be guided to the optimal resection margin using a navigation system.

[0102] Alternatively, if desired, the reference sensor 10 (e.g., a T-bar or J-bar assembly) can carry a wire-based electromagnetic sensor. In this case, after the reference sensor 10 (e.g., a T-bar or J-bar assembly) is positioned, the wire 14 of the reference sensor is then pushed with a bronchoscope, under image guidance, through the lung parenchyma to the surface of the skin at the spot closest to the lesion 18 to mark the lesion 18. See FIG. 42.

[0103] In yet another form of the invention where the reference sensor 10 (e.g., a T-bar or J-bar assembly) carries a wire-based electromagnetic sensor, the wire 14 has a removable connection to the electromagnetic sensor. Then, after establishing the resection line using a stapler, the wire 14 is removed from the electromagnetic sensor and the airway is retracted. See FIG. 43.

[0104] In yet another aspect of the present invention, and with reference to FIGS. 44-52, a bronchoscopic sensor unit 100 is provided for bronchoscopic placement of a reference sensor 10 within or adjacent to a tissue mass 18.

[0105] More specifically, looking now at Figures 44-46, the bronchoscope sensor unit 100 (Figure 44) generally includes a J-bar and lead assembly 105 (Figure 45) and a positioning assembly 110 (Figure 46).

[0106] J-bar and lead assembly 105 generally includes J-bar assembly 115 and lead 120. J-bar assembly 115 includes the aforementioned hook structure 16 that carries the aforementioned reference sensor 10 and the aforementioned prong 20. One end 125 of lead 120 is connected to reference sensor 10 such that power supplied to lead 120 can power reference sensor 10. The other end 130 of lead 120 includes an atraumatic tip 135. Lead 120 is covered with a hydrophobic braid to allow for easy insertion and retraction of J-bar and lead assembly 105 through lumen 150 (see below) of positioning assembly 110.

[0107] Alternatively, if desired, instead of the atraumatic tip 135, the distal end of the J-bar and lead assembly 105 may include a second anchor that can prevent the lead 120 from re-entering the lung after the distal end of the lead 120 has exited the lung. In other words, this second anchor would prevent retrograde migration of the distal end of the lead 120 after deployment. Furthermore, in such a form of the invention, the branch 120 of the J-bar assembly 115 can have a configuration that prevents antegrade migration of the J-bar assembly 115 after it has been removed from the deployment assembly 110. See, for example, FIGS. 46A and 46B, which show a branch 135A at the distal end of the lead 120 and a branch 20A at the distal end of the J-bar assembly 115. The branch 135A prevents proximal migration of the distal end of the lead 120 after deployment, and the branch 20A prevents distal migration of the J-bar assembly 115 after deployment.

[0108] The placement assembly 110 includes a needle cannula 140 and a pusher 145. The needle cannula 140 includes a hollow tube 150 and terminates in a sharp tip 155. The pusher 145 includes a shaft 160. One end of the shaft 160 terminates in a blunt distal end 165. The other end of the shaft 160 terminates in a handle 170. The shaft 160 of the pusher 145 is sized to be slidably received in the lumen 150 of the needle cannula 140. It should be noted that the needle cannula 140 of the placement assembly 110 is sized so that it can be inserted through the working channel of a bronchoscope.

[0109] As seen in FIG. 44 , the J-bar and lead assembly 105 and the shaft 160 of the pusher 145 are initially positioned within the lumen 150 of the needle cannula 140, and the branches 20 of the J-bar assembly 115 are elastically deformed into a straight configuration and received within the lumen 150 of the needle cannula 140, with the proximal ends of the elastically deformed branches 20 just distal to the blunt end 165 of the pusher 145. Also, note that when the J-bar and lead assembly 105 is disposed within the lumen 150 of the needle cannula 140, the atraumatic tip 135 of the lead 120 elastically deforms to lie substantially straight within the needle cannula 140. (Note that FIG. 44 is intended to be schematic in nature; in reality, the lead 120 will have a diameter that more closely fills the lumen 150 of the needle cannula 140, such that the atraumatic tip 135 of the lead 120 will lie substantially straight when confined within the needle cannula 140, and will return to the coiled configuration shown in FIG. 45 when the atraumatic tip 135 is not confined within the needle cannula 140.) In this manner, the needle cannula 140 can carry the J-bar and lead assembly 105, and the needle cannula 140 shields the J-bar and lead assembly 105 from contact with surrounding structures (e.g., bronchoscope, tissue, etc.). However, distal movement of pusher 145 can eject J-bar and lead assembly 105 from lumen 150 of needle cannula 140 .

[0110] In a preferred method of use, the intended location of the J-bar and lead assembly 105 relative to the patient's anatomy is planned prior to placement in the lung using diagnostic or procedural CT, C-arm CT, MRI, or other imaging; i.e., the intended location of the J-bar assembly 115 and the exit point of the leads 120 as they exit the lung surface are pre-planned with diagnostic or procedural CT, C-arm CT, MRI, or other imaging. Electromagnetic (EM) tracking coordinates are mapped to the diagnostic / procedural imaging coordinates using image registration algorithms known in the art to track the bronchoscope and J-bar and lead assembly 105 within the imaging coordinates. The location of the J-bar assembly 115 is selected to be near the tumor, preferably along a line connecting the bronchoscope target location and the lead exit location, while the exit point of the leads 120 from the lung is selected according to either (i) the shortest path from the J-bar location to the lung surface (or interstitial surface), or (ii) the surgeon's preference.

[0111] By way of example and not limitation, in a preferred method of use, and looking now at FIGS. 47-52 , the bronchoscope 60 is advanced through the patient's airways until the distal tip of the bronchoscope 60 is positioned near the lesion (i.e., tissue mass) 18. See FIG. 47 . Note that the bronchoscope 60 can be advanced under direct visualization, and its position can be tracked using one or more sensors 180 carried by the bronchoscope 60. Alternatively, if a temporary electrical connection is provided to the J-bar assembly 115 (i.e., via an electrical connection extending through the interior of the needle cannula 140, such as by energizing a portion of the pusher 145), the J-bar assembly 115 can be used to track the position of the bronchoscope 60. The tracked position of the bronchoscope 60 can be mapped to imaging coordinates (see above) using image registration algorithms of the type known in the art to guide the bronchoscope 60 to the lesion 18.

[0112] Next, if not already done, a target point 185 is identified on the exterior surface of the lung as the point where needle cannula 140 is desired to exit the lung and enter the pleural cavity. See FIG.

[0113] Bronchoscope sensor unit 100 (including positioning assembly 110 and its passenger J-bar and lead assembly 105) is then advanced with its distal end through bronchoscope 60, through the lung, and into the pleural cavity through target point 185. See FIG. 49. Note that the distal end of bronchoscope sensor unit 100 can be visually guided through bronchoscope 60 and / or via scanner visualization (e.g., CT imaging, C-arm imaging, ultrasound imaging, etc.), or by using a temporarily electrically connected J-bar assembly 115 if a temporary electrical connection is established through the interior of needle cannula 140.

[0114] The pusher 145 of the placement assembly 110 can then be used to push the J-bar and lead assembly 105 distally so that (i) the atraumatic tip 135 and a portion of the lead 120 can exit the needle cannula 140 into the pleural space, and (ii) the J-bar assembly 115 can be positioned adjacent the lesion 18 (note, however, that at this point the J-bar assembly 115 and a portion of the lead 120 remain within the needle cannula 140). See FIG. 50.

[0115] Next, needle cannula 140 is retracted proximally while maintaining pusher 145 in place, thereby exposing (i) the portion of lead 120 extending from target point 185 to J-bar assembly 115, and (ii) J-bar assembly 115. Once needle cannula 140 is retracted past branch 20 of J-bar assembly 115, branch 20 is no longer constrained within lumen 150 of needle cannula 140 and is free to spring outward and implant into tissue, thereby anchoring J-bar assembly 115 (and thus reference sensor 10) adjacent lesion 18. See FIG. 51 . At this point, if J-bar assembly 115 was temporarily connected to power through the interior of needle cannula 140, the J-bar wires are severed and retracted into needle cannula 140. Note that this severing and retraction of the leads through needle cannula 140 is desirable to remove them from the intended ablation line.

[0116] A powered clamping tool 190 is then advanced into the pleural cavity and clamped onto the portion of the lead 120 extending from the lung, thereby powering the lead 120 and thus the reference sensor 10 of the J-bar assembly 115. See FIG. 52. Note that by powering the J-bar assembly 115 via a powered clamping tool 190 advanced into the pleural cavity from a point outside the body (rather than via a needle cannula 140 and bronchoscope 60 advanced through the bronchus), the lead does not cross the intended resection line.

[0117] The power clamp tool 190 can take a variety of forms. The power clamp tool 190 is essentially an elongated tool configured to extend from outside the body into the pleural cavity and make an electrical connection to the portion of the lead 120 extending from the lung into the pleural cavity, thereby providing power to the J-bar assembly 115. By way of example and not limitation, the power clamp tool 190 can include a pair of electrically connected jaws that can be closed around the portion of the lead 120 extending from the lung into the pleural cavity. Note that the power clamp tool 190 can be placed either through a needle extending through the skin or through a port formed in the skin surface. The power provided to the lead 120 by the power clamp tool 190 allows the J-bar assembly 115 to connect to an EM tracking system.

[0118] Once powered, the reference sensor 10 communicates with an electromagnetic (EM) tracking system so that the position of the reference sensor 10 (and therefore the position of the lesion 18 ) can be determined by the controller 48 .

[0119] At this point, surgical device 80 (carrying instrument sensor 85) can be used to achieve the desired resection line within the lung, thereby resecting lesion 18 from the remainder of the lung. Note that J-bar and lead assembly 105 extends from lesion 18 into the pleural cavity and is therefore contained within the tissue being resected and does not cross the resection line. In other words, J-bar and lead assembly 105 is always outside of lesion 18. As a result, reference sensor 10 of J-bar assembly 115 can remain powered throughout the resection procedure and does not interfere with the resection procedure, and J-bar and lead assembly 105 is removed along with the resected tissue after the resection is complete.

[0120] As mentioned above, in one form of the present invention, bronchoscope 60 is advanced through the patient's airway until the distal tip of bronchoscope 60 is positioned near lesion (i.e., tissue mass) 18. Also, as mentioned above, bronchoscope 60 can be advanced under direct visualization, and its position can be tracked using one or more sensors 180 carried by bronchoscope 60. Alternatively, if a temporary electrical connection is provided to J-bar assembly 115 (i.e., via an electrical connection extending through the interior of needle cannula 140, such as by energizing a portion of pusher 145), J-bar assembly 115 can be used to track the position of bronchoscope 60. Therefore, it may be desirable to provide a temporary electrical connection to J-bar assembly 115 (i.e., via an electrical connection extending through the interior of needle cannula 140, such as by energizing a portion of pusher 145) to power J-bar assembly 115 while it is within needle cannula 140.

[0121] It may be desirable to provide a temporary electrical connection to the J-bar assembly 115 (i.e., via an electrical connection extending through the interior of the needle cannula 140, such as by energizing a portion of the pusher 145) to power the J-bar assembly 115 before connecting the powered clamping tool 190 to the portion of the lead 120 extending from the lung.

[0122] 52A , in one preferred form of the invention, temporary electrical connections for J-bar assembly 115 can be provided as follows: Reference sensor 10 of J-bar assembly 115 includes proximal electrical connector 200 (as well as electrical leads 120 extending distally from reference sensor 10). Pusher 145 is inserted into the cannula and includes distal electrical connector 205. Power is provided to distal electrical connector 205 of pusher 145 by wire 210 (which connects to a power source, not shown) extending through pusher 145. While J-bar assembly 115 is seated in needle cannula 140, proximal electrical connector 200 of J-bar assembly 115 is connected to distal electrical connector 205 of pusher 145, thereby providing power to reference sensor 10. After J-bar assembly 115 is positioned within the patient's anatomy (and branch 20 is seated within tissue), pusher 145 is retracted, separating distal electrical connector 205 of pusher 145 from proximal electrical connector 200 of J-bar assembly 115, thereby disconnecting J-bar assembly 115 from the power supplied by wires 210 extending through pusher 145. However, it will be appreciated that power can still be supplied to J-bar assembly 115 via electrical leads 120 and power clamp tool 190 (which is connected to electrical leads 120).

[0123] <Measurement of stapler joint movement> The surgical stapler head can articulate about the axis of rotation 220 to provide a desired orientation during resection of a lesion. While the instrument sensor 28 can be located on the articulating head of the surgical stapler 26 (e.g., as shown in FIGS. 8 and 9 ), this can cause interference from ferromagnetic materials on the stapler head. Therefore, in practice, the instrument sensor 28 is typically located on the shaft of the surgical stapler 26 just proximal to the articulation point, e.g., about 10 cm from the stapler tip, to avoid interference from ferromagnetic materials on the stapler head. In this location, the instrument sensor 28 is proximal to the axis of rotation 220 of the surgical stapler 26, thereby positioning the instrument sensor 28 in a non-articulating portion of the stapler 26. See FIG. 53 . As a result, an instrument sensor 28 located on a non-articulating portion of the surgical stapler 26 does not capture articulation of the surgical stapler 26.

[0124] Accordingly, in another aspect of the present invention, a surgical stapler 26 is configured to measure the articulation angle of the stapler head. More specifically, an articulation sensor 225 is provided that preferably includes two portions. A first portion 230 of the articulation sensor 225 is disposed on the stapler shaft. A second portion 235 of the articulation sensor 225 is disposed on the articulating stapler head. The connection between the first portion 230 and the second portion 235 of the articulation sensor 225 is via a flexible encoder circuit that measures the angle of the articulating end of the stapler head. The encoder circuit is preferably a modified circular potentiometer for measuring the angle of the stapler head. See FIG. 54. A Wheatstone bridge circuit measures the variable resistance developed across the encoder circuit to estimate the stapler articulation angle. Additionally, the surgical stapler 26 may also include an LED indicator (not shown) on the stapler shaft to confirm the placement of the articulation sensor 225 on the surgical stapler 26. When articulation sensor 225 is positioned on surgical stapler 26, a circuit is completed causing the LED indicator to illuminate.

[0125] If desired, the articulation sensor 225 can measure stapler head articulation using a method other than electrical resistance, for example, an optical encoder or a magnetic encoder can be used to measure stapler head articulation. The articulation sensor 225 can also be internalized within a particular operation of the stapler device 26. Alternatively, a second sensor (not shown) can be located on a resilient extension that passes through the articulation from the sleeve toward the tip, allowing direct measurement of the stapler articulation angle. This extension can be secured with tape or other adhesive.

[0126] <Marking the borders of the resection margin and positioning the stapler> In one form of the invention, the lesion is segmented from diagnostic CT imaging to create a 3D model of the lesion 240 that is input into the navigation system. In another form of the invention, the lesion may be segmented based on the surgeon's direct visualization of the lesion, with or without input from radiological findings. The resection margin is determined based on input from the surgeon or a machine learning algorithm. A segmentation model for the resection margin 245 is generated by expanding the lesion label map by the desired resection margin. See Figures 55 and 56. Knowing the locations of the reference sensor (e.g., T-bar or J-bar assembly) and the lesion model 240, the position of the tracked surgical stapler can be accurately estimated relative to the lesion model 240 and the estimated resection margin model 245.

[0127] In addition to the above, in one form of the invention, the navigation software can guide the surgeon to accurately resect around the lesion based on the size of the tissue mass and the distance required to ensure a sufficient margin as defined by the surgeon based on the estimated diagnosis. See Figures 57-59. More specifically, in one form of the invention, and now turning to Figure 60, the navigation software calculates tangent lines 250 around the modeled resection margins 245 and then guides the surgeon to place staples 255 just outside of those tangent lines 250 so that the staples 255 follow a tangential path around the estimated resection margin model 245.

[0128] Although the above-described systems and methods for resecting tissue masses have been described for surgery involving the lung, they are also applicable to the resection of lesions in any other organ or structure of the body, such as resections for breast-conserving surgery, liver resection, sarcoma resection, partial nephrectomy, or pulmonary wedge resection. Furthermore, the above-described systems and methods for resecting tissue masses are not limited to VATS or minimally invasive surgery.

Claims

1. 1. A system for determining the position and orientation of an instrument relative to a tissue mass in or on an anatomical structure, comprising: a deployment assembly including a needle cannula having a first distal end, a first proximal end, and a lumen extending therebetween; a sensor assembly initially disposed within the lumen of the needle cannula and slidably disposed within the needle cannula, the sensor assembly including: a reference tracker having a second distal end and a second proximal end for providing a reference signal indicative of its position; and a conductor for powering the reference tracker, the conductor extending distally from the second distal end of the reference tracker toward the first distal end of the needle cannula; Equipment and an instrument tracking device carried by the instrument for providing an instrument signal indicative of a position and orientation of the instrument tracking device; a controller for determining the position and orientation of the tracked instrument relative to the reference tracker; wherein the sensor assembly is configured to slide into the lumen within the needle cannula to the first distal end, such that the reference tracking device, along with at least a portion of the lead, is exposed from the needle cannula and anchored within the anatomical structure near the tissue mass.

2. the system further includes an endoscope configured to carry the positioning assembly for advancement into the anatomical structure; The system of claim 1 , wherein the positioning assembly further comprises a pusher.

3. the needle cannula is configured to be slidably positioned in and out of the endoscope; 3. The system of claim 2, wherein the pusher is slidably disposed within the needle cannula such that, upon advancing the pusher within the needle cannula to engage the second proximal end of the reference tracker, the pusher is configured to position the reference tracker and at least a portion of the lead of the sensor assembly outside of the needle cannula.

4. 2. The system of claim 1, wherein the lead is sized to extend through the anatomical structure beyond the outer surface of the anatomical structure at a location on the outer surface of the anatomical structure when the fiducial tracker is positioned near the tissue mass.

5. The system of claim 4 , further comprising a surgical navigation system for determining the location at the exterior surface of the anatomical structure through which the electrical leads extend.

6. The system of claim 5 , wherein the surgical navigation system uses tracking of the fiducial tracker to determine the location at the exterior surface of the anatomy where the lead extends through the exterior surface of the anatomy.

7. The system of claim 1 , wherein the conductor comprises a hydrophobic braid.

8. The system of claim 1 , wherein the lead includes an atraumatic tip.

9. The system of claim 1 , wherein the lead includes at least one barb that limits proximal movement of the lead.

10. The system of claim 1 , wherein the fiducial tracker includes at least one barb that limits distal movement of the fiducial tracker.

11. the lead includes at least one barb that limits proximal movement of the lead; The system of claim 1 , wherein the fiducial tracker includes at least one barb that limits distal movement of the fiducial tracker.

12. the sensor assembly further includes a proximal conductor for providing power to the reference tracker; the proximal lead extends proximally away from the reference tracker; the proximal lead is detachable from the sensor assembly; The system of claim 1 , wherein the controller is configured to provide power to the reference tracker via the conductor extending distally through the reference tracker.

13. The system further comprising an endoscope configured to carry the positioning assembly for advancement into the anatomical structure; 13. The system of claim 12, wherein the controller is configured to track the fiducial tracker as the fiducial tracker is advanced through the endoscope into the anatomical structure and secured to the anatomical structure near the tissue mass.

14. The controller determines the position of the tracked instrument relative to the reference tracker by: determining the position and orientation of the reference tracker; determining the position and orientation of the instrument tracking device; The system of claim 1 , configured to determine by determining a difference between the position and orientation of the instrument tracker and the position and orientation of the reference tracker.

15. further comprising a user interface; the user interface is configured to communicate to a user a difference between the position and orientation of the instrument tracking device and the position and orientation of the reference tracking device; 15. The system of claim 14, wherein the user interface communicates with the user by using at least one from the group consisting of auditory cues, visual cues, quantitative cues, and tactile cues.

16. The system of claim 15 , wherein the visual cues include a virtual model of the reference tracker and a virtual model of the tracked instrument.

17. 17. The system of claim 16, wherein the spatial relationship between the virtual model of the reference tracker and the virtual model of the tracked instrument is the same as the spatial relationship between the reference tracker and the tracked instrument.

Images