System and method for a tissue resection margin measurement device

Embodiments of the invention provide a system and method 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 dimensioned to fit inside of or next to the tissue mass. The system also includes a second sensor attached to a surgical instrument configured to measure the position and orientation of the surgical instrument. A controller is in communication with the first sensor and the second sensor, and the controller executes a stored program to calculate a distance between the first sensor and the second sensor. Accordingly, visual, auditory, haptic or other feedback is provided to the clinician to guide the surgical instrument to the surgical margin.

FIELD OF THE INVENTION

This invention relates to surgery in general, and more particularly to computer-assisted surgery.

BACKGROUND OF THE INVENTION

Minimally invasive surgical resection of lesions involves the precise excision of the lesion while sparing surrounding healthy and critical tissue. Some examples include, but are not limited to, breast conserving surgery and Video-Assisted Thoracic Surgery (VATS). Surgical resection of the lesion requires the removal of a margin of tissue around the lesion to ensure complete removal of the lesion cells and improved long-term survival. The default margin is dependent on the type of lesion and micro-invasion of the lesion into the surrounding tissue. While this is particularly true in cancer, where the size of the original lesion and the margin of normal tissue resected with the lesion is associated with survival, this is also true for non-cancerous lesions. Significant deformation of the tissue due to high viscoelasticity, physiological motion (such as collapsing of the lung, breathing or beating motion), or tissue manipulation can lead to difficulty in localizing the lesion and precise removal of the lesion. As a result, this can lead to insufficient resection, lesion recurrence locally, or by metastasis (in cancer), and poorer long-term benefits compared with cases where a sufficient margin is obtained. Two surgical applications are listed below as an example. However, the disclosed system and method may be applied for resection or biopsy of other lesions through a minimally invasive or image-guided approach or open-surgery, or a combination of approaches.

Lung Lesion Surgery

Current clinical practice to remove lung tissue segments involves opening the chest by cutting the sternum or by spreading the ribs. Many times ribs are broken and often segments are surgically removed during these procedures. The orthopedic trauma alone presents considerable pain and it can complicate the recovery process with patients. Thoracic pain of this magnitude also complicates the task of recovering a patient from general anesthesia since the body acclimates to forced ventilation and the pain can interrupt natural chest rhythm. Patients benefit dramatically from procedures that are performed through small incisions or ports in the chest without causing this orthopedic trauma.

Even though minimally invasive or VATS techniques are well known to provide benefit to the patient by minimizing trauma and speeding recovery times compared to open chest procedures, a substantial number of open chest procedures are currently still performed. This is due, at least in part, to the fact that there are only a limited number of instruments designed specifically to facilitate thoracic procedures in this way.

Surgery for lung cancer, however, is moving to a minimally invasive approach using VATS and smaller anatomic or non-anatomic lung resection (e.g., a wedge resection or segmentectomy) particularly for small lesions. In the conventional method of performing VATS, however, the lung is collapsed during surgery, leading to difficulty in precisely locating the lesion and determining the resection margins. Additionally, palpation of lung tissue is not always possible (particularly in the case of smaller or early stage cancers) due to the minimally invasive approach to surgery. Imprecise surgical resection could lead to incomplete resection and subsequent lesion recurrence.

Breast Lesion Surgery

Breast conserving surgery (BCS) involves the removal of the lesion while sparing the healthy breast parenchyma around the lesion. Studies have shown that BCS combined with chemotherapy has similar long-term benefits as mastectomy with the additional cosmetic advantage. However, identifying and resecting the entire lesion is a challenging task due to the highly deformable nature of the breast. Achieving the negative surgical margin with minimal damage to the healthy parenchyma is non-trivial due to the soft-tissue nature of the breast. In fact, studies show that up to 25% of breast resections leave positive margins and require re-treatment.

Therefore, a tissue resection margin measuring device is needed that overcomes the above limitations by providing an improved approach for precisely locating a lesion and determining the resection margins.

SUMMARY OF THE INVENTION

The present invention relates to a system and method for resecting a tissue mass while compensating for tissue deformation due to its elastic nature and physiologically induced motion. In a non-limiting example, the invention enables minimally invasive surgical procedures by providing a device and method to perform tissue resection that discriminates against traumatizing critical tissue and precisely determines the resection margin. Additionally, auditory, visual and haptic cues may be provided to the surgeon to identify and more precisely measure the lesion margins and critical structures surrounding the lesions to ensure complete and safe resection of the lesion.

Some embodiments of the invention provide a system for resecting a tissue mass. The system includes a surgical instrument and a first sensor for measuring a first signal. The first sensor is dimensioned to fit inside of or next to (e.g., in close proximity to) the target lesion/tissue mass, usually at a location between the tissue mass and the ultimate cut area-margin. The system also includes a second sensor for measuring a second signal, and the second sensor is coupled to the surgical instrument. A controller is in communication with the first sensor and the second sensor, and the controller executes a stored program to calculate a distance between the first sensor and the second sensor based on the first signal and the second signal.

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

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

In one embodiment, the system may further include a third sensor for measuring a third signal. The third sensor may be dimensioned to fit next to the tissue mass at a position opposite the first sensor, such that the third signal received by the third sensor indicates a position and an orientation of the tissue mass relative to the first sensor.

In one embodiment, the first sensor may be embedded within a hook structure made of a superelastic material, e.g., Nitinol. The hook structure may be in the form of a T-bar or J-bar and dimensioned to fit inside a delivery needle and/or a sheath. The delivery needle and/or the sheath may be configured to guide the first sensor, and the hook structure may be configured to anchor the first sensor within the tissue mass. In one embodiment, the first sensor that is embedded within the hook structure may be inserted into the tissue mass under real-time image guidance.

In one embodiment, the first sensor is embedded within a hook structure that includes a plurality of prongs, and the first sensor may be dimensioned to fit inside a delivery needle and/or a sheath. The delivery needle and/or the sheath may be configured to guide the first sensor, and the plurality of prongs may be configured to anchor the first sensor within the tissue mass. The hook structure may further comprise a plurality of extensions extending from a tube portion of the hook structure, such that the plurality of extensions may be dimensioned to receive the first sensor.

The system may further include a display in communication with the controller. The display may be coupled to the surgical instrument 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, mid and tip of the surgical instrument (e.g., a cutting instrument such as a stapler) can 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 audible source for emitting an audible signal. The audible source may be in communication with the controller, which is configured to execute a stored program to alter 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.

The system may further include a piezoelectric actuator coupled to a handle of the surgical instrument. The piezoelectric actuator may be configured to emit a haptic signal. The piezoelectric actuator may be in communication with the controller, which is configured to execute a stored program to alter the haptic signal based on the distance between the first sensor and the second sensor.

The system may further include a monitor for emitting a visual signal in some embodiments. The monitor may be in communication with the controller, which is configured to execute a stored program to alter the visual signal based on the distance between the first sensor and the second sensor. Additionally or alternatively, the system may include a monitor for displaying a video overlay. The monitor may be in communication with the controller, which is configured to execute a stored program to fuse a laparoscopy, thoracoscopy or endoscopy image (i.e., a “scope image”) with a virtual model image (i.e., an image computer-generated from a virtual model of the anatomy), so as to create the video overlay of the scope image with the virtual model image. The video overlay may be configured to identify a position of the tissue mass and the first sensor.

In one embodiment, the invention provides a method for resection of a tissue mass inside a patient. The method includes inserting a first sensor inside of or next to the target tissue mass (e.g., in close proximity to the tissue mass) and capturing at least one image of the first sensor embedded within or next to (e.g., in close proximity to) the tissue mass. A resection margin is calculated around the tissue mass using the at least one image. A surgical instrument is inserted into the patient, and the surgical instrument is coupled to a second sensor. The second sensor is tracked relative to the resection margin, and the surgical instrument is used to cut on the resection margin. The surgeon will determine, based on the diagnosis and size of the mass, what might be the best margin to accomplish. This information may also be used to determine the exact operation required.

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

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

In one embodiment, the method may further include providing a third sensor for measuring a third signal. The third sensor may be dimensioned to fit next to the tissue mass at a position opposite the first sensor, such that the third signal received by the third sensor indicates a position and an orientation of the tissue mass relative to the first sensor.

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 dimensioned to fit inside a delivery needle and/or a sheath. The delivery needle and/or the sheath may be configured to guide the first sensor, and the hook structure may be configured to anchor the first sensor within the tissue mass. In one embodiment, the first sensor that is embedded within the hook structure may be inserted into the tissue mass under real-time image guidance or under direct visual guidance.

In one embodiment, the first sensor is embedded within a hook structure that includes a plurality of prongs, and the first sensor may be dimensioned to fit inside a delivery needle and/or a sheath. The delivery needle and/or the sheath may be configured to guide the first sensor, and the plurality of prongs may be configured to anchor the first sensor within the tissue mass. The hook structure may further comprise a plurality of extensions extending from a tube portion of the hook structure, such that the plurality of extensions may be dimensioned to receive the first sensor.

The method may further include providing a display in communication with a controller. The display may be coupled to the surgical instrument 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 as to the distances between various sensors, as well as to the quality of the measurements. In some embodiments, the method may include emitting an audible signal from an audible source. The audible source may be in communication with the controller, which is configured to execute a stored program to alter 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.

The method may further include emitting a haptic signal from a piezoelectric actuator coupled to a handle of the surgical instrument. The piezoelectric actuator may be in communication with the controller, which is configured to execute a stored program to alter the haptic signal based on the distance between the first sensor and the second sensor.

In some embodiments, the method may further include emitting a visual signal on a monitor. The monitor may be in communication with the controller, which is configured to execute a stored program to alter the visual signal based on the distance between the first sensor and the second sensor. Additionally or alternatively, the method may include displaying a video overlay on the monitor. The monitor may be in communication with the controller, which is configured to execute a stored program to fuse a laparoscopy/thoracoscopy/endoscopy scope image(s) to a virtual model image so as to create the video overlay. The video overlay may be configured to identify a position of the tissue mass and the first sensor.

In one form of the invention, the system may be used to identify the location of a particular airway. In this form of the invention, the system comprises means for bronchoscopic positioning of a sensor into an airway of the lung. This bronchoscopic positioning of the sensor in an airway of the lung (e.g., by positioning the sensor on a bronchoscope or on a catheter within the brochoscope and advancing the bronchoscope into the airway of interest) can be used to define the lobar, segmental or subsegmental bronchus for surgery such as segmentectomy, lobectomy or wedge resection during the actual operation. This function can be independent of the lesion margin measurement, and the position of the sensor identifying the bronchus can be correlated with the position of another device (e.g., a surgical instrument) carrying another sensor so that the surgeon can define the correct bronchus for surgery from the chest side of the operation. Thus, in this form of the invention, one sensor is positioned on a bronchoscope or on a catheter placed within the bronchoscope which is inserted into a specific airway so as to define the location of that specific airway, and another sensor is positioned on a surgical instrument which is advanced for surgery from the chest side of the operation, with the system continuously tracking the position of the sensor on the surgical instrument vis-à-vis the position of the sensor on the bronchoscope, so that the surgeon can continuously track the location of the surgical instrument relative to the airway of interest (identified by the sensor on the bronchoscope), e.g., to target the airway identified by the sensor on the bronchoscope, to avoid the airway identified by the sensor on the bronchoscope, etc.

In one form of the invention, the system comprises means for mapping and tracking airways surrounding a lesion.

In one form of the invention, the system comprises means for bronchoscopic deployment of the fiducial sensor or another sensor into tissue (e.g., bronchoscopic deployment of the fiducial sensor into the mass or adjacent to the mass).

In one form of the invention, the system comprises means for measuring the articulation of a surgical stapler.

In one form of the invention, the system comprises means for marking the boundary of a resection margin of a lesion and positioning a surgical stapler adjacent to the boundary of a resection margin of a lesion.

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, the method comprising:

positioning a tracked catheter in the selected lumen of the anatomical structure, wherein the tracked catheter is tracked relative to a given frame of reference; and

determining the position of a tracked instrument relative to the tracked catheter, wherein the tracked instrument is tracked relative to the given frame of reference, whereby to determine the position of the tracked instrument relative to the selected lumen of the anatomical structure.

In another form of the invention, there is provided a system for determining the position of an instrument relative to a selected lumen in an anatomical structure, the system comprising:a catheter sized to be disposable in the selected lumen of the anatomical structure;a catheter tracker for providing a catheter signal representative of the position of the catheter tracker relative to a given frame of reference, the catheter tracker being carried by the catheter;an instrument;an instrument tracker for providing an instrument signal representative of the position of the instrument tracker relative to the given frame of reference, the instrument tracker being carried by the instrument; anda controller for determining the position of the tracked instrument relative to the tracked catheter, whereby, when the tracked catheter is disposed in the selected lumen of the anatomical structure, the controller determines the position of the tracked instrument relative to the selected lumen in the anatomical structure.

In another form of the invention, there is provided a method for mapping and tracking a plurality of lumens in an anatomical structure, wherein the anatomical structure is deformable, the method comprising:

providing a virtual model of the anatomical structure while the anatomical structure is in a first configuration;

while the anatomical structure is in the first configuration, positioning a tracked catheter in one of the lumens in the anatomical structure which is to be mapped and tracked, and determining the position of the tracked catheter in that lumen so as to map the position of that lumen;

repeating the foregoing step for each of the lumens in the anatomical structure which is to be mapped and tracked so that those lumens are mapped;

supplementing the virtual model with the mapped lumens, whereby to provide a supplemented virtual model of the anatomical structure and the mapped lumens while the anatomical structure is in its first configuration;

maintaining the tracked catheter in one of the mapped lumens of the anatomical structure as the anatomical structure is deformed from its first configuration to a second configuration;

determining the position of the tracked catheter in the anatomical structure while the anatomical structure is in the second configuration; and

modifying the supplemented virtual model so as to represent the anatomical structure and the mapped lumens while the anatomical structure is in its second configuration, whereby to provide a modified supplemented virtual model, wherein modification is effected by:determining the spatial transformation of the tracked catheter as the anatomical structure deforms from its first configuration to its second configuration; andapplying the spatial transformation of the tracked catheter to the mapped lumens of the supplemented virtual model so as to provide the modified supplemented virtual model of the anatomical structure and the mapped lumens while the anatomical structure is in its second configuration.

In another form of the invention, there is provided a method for mapping and tracking a selected lumen in an anatomical structure, wherein the anatomical structure is deformable, the method comprising:

positioning a tracked catheter in the selected lumen of the anatomical structure while the anatomical structure is in a first configuration;

determining the position of the tracked catheter while the anatomical structure is in the first configuration;

scanning the anatomical structure and the tracked catheter positioned in the selected lumen of the anatomical structure while the anatomical structure is in the first configuration;

creating a virtual model of the scanned anatomical structure and the tracked catheter positioned in the selected lumen of the anatomical structure while the anatomical structure is in its first configuration;

maintaining the tracked catheter in position within the selected lumen of the anatomical structure while the anatomical structure deforms to a second configuration;

determining the position and orientation of the tracked catheter while the anatomical structures is in its second configuration, whereby to determine the position of the selected lumen of the anatomical structure while the anatomical structure is in the second configuration; and

adjusting the virtual model so as to represent the anatomical structure and the selected lumen while the anatomical structure is in its second configuration, whereby to provide an adjusted virtual model, wherein modification is effected by:determining the spatial transformation of the tracked catheter as the anatomical structure deforms from its first configuration to its second configuration; andapplying the spatial transformation of the tracked catheter to the selected lumen of the virtual model so as to provide the adjusted virtual model of the anatomical structure and the selected lumen while the anatomical structure is in its second configuration.

In another form of the invention, there is provided a system for mapping and tracking a plurality of lumens in an anatomical structure, wherein the anatomical structure is deformable, the system comprising:

a catheter sized to be disposed in the plurality of lumens of the anatomical structure which are to be mapped and tracked, and configured to remain in a selected lumen of the anatomical structure during deformation of the anatomical structure;

a catheter tracker for providing a catheter signal representative of the position of the catheter tracker, the catheter tracker being carried by the catheter;

a virtual model of the anatomical structure representing the anatomical structure while it is in a first configuration; and

a controller for:(i) determining the position of the tracked catheter as the tracked catheter is disposed within each of the plurality of lumens so as to map the plurality of lumens while the anatomical structure is in its first configuration; and(ii) supplementing the virtual model with the mapped lumens, whereby to provide a supplemented virtual model of the anatomical structure and the mapped lumens representing the anatomical structure while it is in its first configuration.

In another form of the invention, there is provided a system for mapping and tracking a selected lumen in an anatomical structure, wherein the anatomical structure is deformable, the system comprising:

a catheter sized to be disposed in the 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 tracker for providing a catheter signal representative of the position of the catheter tracker, the catheter tracker being carried by the catheter;

a virtual model of the anatomical structure and the tracked catheter positioned in the selected lumen of the anatomical structure, wherein the virtual model is created while the anatomical structure is in a first configuration; and

a controller for:(i) determining the position of the tracked catheter after the anatomical structure has assumed a second configuration; and(ii) adjusting the virtual model of the anatomical structure and the tracked catheter so that the virtual model conforms to the position of the tracked catheter when the anatomical structure is in its second configuration.

In another form of the invention, there is provided a method for tracking a tissue mass disposed in or on an anatomical structure, wherein the anatomical structure comprises at least one lumen, the method comprising:

advancing a scope along the at least one lumen until the distal end of the scope is disposed in the vicinity of the selected tissue mass;

advancing a fiducial sensor through the scope, into the anatomical structure, and securing the fiducial sensor to the anatomical structure in the vicinity of the tissue mass; and

detecting the position of the fiducial sensor within the anatomical structure.

In another form of the invention, there is provided a method for tracking a tissue mass disposed in or on an anatomical structure, wherein the anatomical structure comprises at least one lumen, the method comprising:

providing a sensor assembly comprising a fiducial sensor and an electrical lead extending distally from the fiducial sensor, and providing a deployment assembly comprising a needle cannula and a pusher, wherein the sensor assembly is slidably disposed in the needle cannula distal to the pusher;

advancing a scope along the at least one lumen until the distal end of the scope is disposed in the vicinity of the selected tissue mass;

advancing the needle cannula through the scope, into the anatomical structure, and through an outer surface of the anatomical structure;

retracting the needle cannula so as to expose a portion of the electrical lead extending through the outer surface of the anatomical structure;

supplying electrical power to the fiducial sensor via the electrical lead extending through the outer surface of the anatomical structure;

securing the fiducial sensor to the anatomical structure in the vicinity of the tissue mass by advancing the pusher relative to the needle cannula or by retracting the needle cannula relative to the pusher; and

detecting the position of the fiducial sensor within the anatomical structure.

In another form 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, the system comprising:

a wireless fiducial tracker for providing a fiducial signal representative of the position of the wireless fiducial tracker, the wireless fiducial tracker adapted to be secured in the anatomical structure in the vicinity of the tissue mass;

an instrument;

an instrument tracker for providing an instrument signal representative of the position of the instrument tracker, the instrument tracker being carried by the instrument; and

a controller for determining the position of the tracked instrument relative to the wireless fiducial tracker.

In another form 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, the system comprising:

a fiducial tracker for providing a fiducial signal representative of the position and orientation of the fiducial tracker, the fiducial tracker adapted to be secured in the anatomical structure in the vicinity of the tissue mass;

an electrical lead for providing electrical power to the fiducial tracker, the electrical lead being releasably connected to the fiducial tracker;

an instrument;

an instrument tracker for providing an instrument signal representative of the position of the instrument tracker, the instrument tracker being carried by the instrument; and

a controller for determining the position of the tracked instrument relative to the fiducial tracker.

In another form of the invention, there is provided a system for determining the position and orientation of an instrument relative to a tissue mass disposed in or on an anatomical structure, the system comprising:

a sensor assembly comprising:a fiducial tracker for providing a fiducial signal representative of the position of the fiducial tracker, the fiducial tracker adapted to be secured in the anatomical structure in the vicinity of the tissue mass; andan electrical lead for providing electrical power to the fiducial tracker, the electrical lead extending distally from the fiducial tracker;

an instrument;

an instrument tracker for providing an instrument signal representative of the position and orientation of the instrument tracker, the instrument tracker being carried by the instrument; and

a controller for determining the position and orientation of the tracked instrument relative to the fiducial tracker.

In another form of the invention, there is provided a system for determining the position and orientation of an instrument relative to a tissue mass disposed in or on an anatomical structure, the system comprising:

a sensor assembly comprising:a fiducial tracker for providing a fiducial signal representative of the position of the fiducial tracker, the fiducial tracker adapted to be secured in the anatomical structure in the vicinity of the tissue mass; andan electrical lead for providing electrical power to the fiducial tracker, the electrical lead extending distally from the fiducial tracker;

a deployment assembly comprising a needle cannula and a pusher, wherein the sensor assembly is slidably disposed within the needle cannula distal to the pusher;

an instrument;

an instrument tracker for providing an instrument signal representative of the position and orientation of the instrument tracker, the instrument tracker being carried by the instrument; and

a controller for determining the position and orientation of the tracked instrument relative to the fiducial tracker.

In another form 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, wherein the instrument comprises a shaft and the end effector, and wherein the disposition of the end effector relative to the shaft is adjustable, the method comprising:

tracking the position of the tissue mass;

tracking the shaft of the instrument;

determining the disposition of the end effector relative to the shaft; and

determining the disposition of the end effector relative to the tissue mass.

In another form of the invention, there is provided a system for determining the position of an end effector of instrument relative to a tissue mass carried by an anatomical structure, the system comprising:a wireless fiducial tracker for providing a fiducial signal representative of the position of the wireless fiducial tracker, the wireless fiducial tracker adapted to be secured in the anatomical structure in the vicinity of the tissue mass;an instrument comprising a shaft and an end effector, wherein the disposition of the end effector relative to the shaft is adjustable;an instrument tracker for providing an instrument signal representative of the position of the instrument tracker, the instrument tracker being carried by the shaft of the instrument;a sensor for detecting the disposition of the end effector relative to the shaft; anda controller for determining the position of the tracked instrument relative to the wireless fiducial tracker.

In another form of the invention, there is provided a method for directing the position of an instrument relative to a tissue mass carried by an anatomical structure, the method comprising:

determining the tangent lines of the tissue mass;

tracking the position of the tissue mass;

tracking the position of the instrument;

determining the disposition of the instrument relative to the tangent lines; and

directing movement of the instrument so that a portion of the instrument is aligned with the tangent lines.

In another form of the invention, there is provided a system for directing the position of an instrument relative to a tissue mass carried by an anatomical structure, the system comprising:a fiducial tracker for providing a fiducial signal representative of the position of the fiducial tracker, the fiducial tracker adapted to be secured in the anatomical structure in the vicinity of the tissue mass;an instrument;an instrument tracker for providing an instrument signal representative of the position of the instrument tracker, the instrument tracker being carried by the instrument; and

a controller for determining the tangent lines of the tissue mass and for directing the position of the tracked instrument relative to the tangent lines.

DETAILED DESCRIPTION OF THE INVENTION

Tracking The Location Of A Tissue Mass Using Fiducial Sensors

FIGS. 1-3illustrate an exemplary fiducial sensor10(also sometimes referred to as a fiducial marker or a fiducial tracker) being inserted through a delivery needle12. The fiducial sensor10may be, for example, a marker that includes a transmitter that measures position and orientation of a tissue mass18in real-time. The fiducial sensor10may be attached to a cable14, as shown inFIGS. 1-3, or the fiducial sensor10may be wireless. The fiducial sensor10may be embedded within a hook structure16, as shown inFIG. 1. The hook structure16of the fiducial sensor10can be made from a superelastic material, for example nitinol, or stainless steel, or any other suitable material. This will allow for the fiducial sensor10to be inserted through the delivery needle12and deployed through an opening22(i.e., the lumen) of the delivery needle12into the center of or at the periphery of the tissue mass18. The tissue mass18may be, for example, a lesion (e.g., a tumor, a nodule, etc.).

As shown inFIG. 4, a more detailed view of the fiducial sensor10and hook structure16is shown. The hook structure16may include a tube portion15having a plurality of extensions17extending from one end of the tube portion15and a plurality of prongs20extending from an opposing end of the tube portion15. The tube portion15may be, for example, a nitinol tube having an outer diameter D1between about 0.6 millimeters and about 0.8 millimeters, and the hook structure16may have an overall length L between about 8 millimeters and about 12 millimeters. The tube portion15may be laser micro-machined into a cylindrical shape having the plurality of extensions17extending therefrom to secure the fiducial sensor10in place. In some embodiments, the fiducial sensor10may be an electromagnetic sensor that is attached to the proximal end of the hook structure16using a medical grade epoxy adhesive, such as AA-Bond FDA22.

The plurality of prongs20, as shown inFIG. 4, may be configured to anchor the hook structure16, including the fiducial sensor10, into a tissue mass or at the periphery of a tissue mass, such as the tissue mass18ofFIG. 2. The plurality of prongs20may be constructed from a superelastic shape memory alloy, such as nitinol. The plurality of prongs20may be bent, for example, and extend outwardly from a central axis Y of the hook structure16. The plurality of prongs20may also be heat-treated to ensure that the prongs20retain the curved shape and the phase structure of the nitinol is in the Martensite phase, for example. In the embodiment shown inFIG. 4, the hook structure16includes three prongs20, however, any suitable number of prongs may be provided in order to anchor the hook structure16to the tissue mass or at the periphery of a tissue mass, such as the tissue mass18.

The fiducial sensor10along with the hook structure16may be inserted through a distal end of the delivery needle12, which may be an 18-gauge needle, for example. The plurality of prongs20of the hook structure16may be inserted into the lumen22of the delivery needle12first. Advantageously, due to the superelastic nature of nitinol, the hook structure16can be easily inserted into the lumen22of the delivery needle12. The hook structure16may be deployed using a metal stylet (not shown) that is inserted through the lumen22of the delivery needle12. Upon being completely deployed, the plurality of prongs20will regain their original curved shape and open up to firmly anchor the hook structure16into or at the periphery of the tissue mass18. The delivery needle12may then be removed after deployment of the hook structure16.

In some embodiments, the fiducial sensor10along with the hook structure16may be inserted through the delivery needle12under real-time image guidance (e.g., CT, C-arm CT, MRI, Ultrasound, etc.) and embedded within the tissue mass18, as shown inFIG. 5, or next to the tissue mass18(e.g., in close proximity to), as shown inFIG. 6. The fiducial sensor10may be embedded within or next to the tissue mass18before or during a surgical procedure. By using real-time image guidance, the spatial relationship (i.e., position and orientation) of the fiducial sensor10to the tissue mass18in three dimensions is known at all times. The hook structure16may be in the form of a T-bar or J-bar, for example, to anchor the fiducial sensor10within or next to the tissue mass18to inhibit migration. Advantageously, the force is at the center of the T-bar16due to the wire14, thereby facilitating anchoring the fiducial sensor10within or next to the tissue mass18. The fiducial sensor10embedded within or next to the tissue mass18will measure the position and orientation of the tissue mass18in real-time in spite of any deformation introduced due to soft tissue deformation or physiological motion such as collapsing of the lung or respiration, for example, thereby easily identifying the location of the tissue mass18that is often difficult to determine.

In an alternative embodiment, shown inFIG. 3, a second fiducial sensor11(in the form of a T-bar assembly, for example) may be put in a different location near the tissue mass18. The second fiducial sensor11may have a separate cable14from the first fiducial sensor10, as shown inFIG. 3, or the first fiducial sensor10and the second fiducial sensor11may share the same cable14. The second fiducial sensor11, or any other such device, can be used to improve the localization of the tissue mass18, even when there may be deformation. For example, the second fiducial sensor11can be placed on the opposite side of the tissue mass18from the first fiducial sensor10and be recognized by the first fiducial sensor10through distortions in the electromagnetic field. Therefore, by knowing that the tissue mass18is between these two sensors, the tissue mass18can be localized despite changes in the soft tissue.

Referring now toFIGS. 5 and 6, once the position and orientation of the tissue mass18is known, a resection margin24having a predetermined distance D2surrounding the tissue mass18is determined by creating a three dimensional envelope around the tissue mass18. The resection margin24may be manually set to the desired predetermined distance D2, for example, two centimeters, and is dependent on the surgeon's preference and the lesion type. The predetermined distance D2defines a threshold value so when a surgical device26(e.g., a surgical stapler), described in further detail below, is in a position less than the threshold value, auditory, visual and/or haptic cues may be provided to the surgeon or to the surgical device26to ensure precise and complete resection of the tissue mass18.

Tracking The Location Of A Surgical Device Using An Instrument Sensor

Referring now toFIG. 7, a conventional surgical device26, such as a surgical stapler, Bovi pencil, kitner, laparoscope and/or any suitable cutting, resecting or ablating device, is shown. The surgical device26may include a handle30coupled to a fastening assembly32at an opposite end of the surgical device26. The fastening assembly32may be a single-use component that is removably connected to the handle30, i.e., the fastening assembly32may be a cartridge that connects to the handle30and is removed after use. The fastening assembly32includes a housing34that contains a plurality of fasteners36that are secured to tissue during resection of the tissue mass18. The fastening assembly32may also include a blade slot38that accommodates a blade (not shown) for cutting along the resection margin24of the tissue mass18.

In a preferred embodiment, the surgical device26includes a sleeve40that is dimensioned to slide over the housing34, for example, as shown inFIG. 8. The sleeve40may be any commercially available sleeve, for example, that is configured to go over the housing34of the surgical device26. An instrument sensor28(sometimes referred to as an instrument tracker) may be attached, by stitching for example, to the sleeve40. Alternatively, the instrument sensor28may be attached directly to the housing34of the surgical device26via any suitable adhesive or integrated within the housing34itself. Regardless of where the instrument sensor28is attached, either the sleeve40or the housing34, the instrument sensor28can measure the position and orientation of the surgical device26in the same imaging reference frame as the fiducial sensor10embedded within or next to the tissue mass18. In other words, the position of the surgical device26may be precisely measured with respect to the fiducial sensor10which is within or next to the tissue mass18, as will be described in further detail below. Since both the fiducial sensor10and the instrument sensor28are measured in the same reference frame, errors introduced due to the registration and calibration steps, requiring a change of reference axis, can be minimized.

The sleeve40may also include a display42that shows the user a distance D3, shown inFIG. 9, of the surgical device26from the resection margin24, as will be described below. The display42may be attached to the handle30of the surgical device26and could be any commercially available organic light-emitting diode (OLED) display or liquid-crystal (LCD) display. In the case of an OLED display, a reformatted CT image of the tissue mass18located at the tip of the surgical device26, for example, may be displayed to the user.

Guiding The Surgical Device To The Tissue Mass

Referring now toFIG. 9, during operation, the fiducial sensor10is positioned next to or embedded within the tissue mass18using the plurality of prongs20of the hook structure16, as previously described. A CT/MRI/fluoroscopic/C-arm CT examination, for example, is performed to acquire images of the fiducial sensor10positioned next to or embedded within the tissue mass18. The tissue mass18is then segmented from the pre-operative diagnostic CT/MRI examination and a three dimensional model (not shown) of the tissue mass18is generated. The intra-operative images obtained during placement of the fiducial sensor10may be registered to the patient's diagnostic exam, and the location of the fiducial sensor10may be estimated. As previously discussed, the resection margin24having the predetermined distance D2surrounding the tissue mass18is displayed to the user on a monitor (not shown) as a three dimensional envelope or proximity sphere around the tissue mass18. The predetermined distance D2of the resection margin24may be determined based on the surgeon's preferences and the type of tissue mass18.

The surgical device26is then inserted into a body44(i.e., the patient), as shown inFIG. 9, to cut the tissue mass18along the resection margin24. The fiducial sensor10embedded within or close to the tissue mass18is in electrical or wireless communication with a controller48. The controller48may be a programmable logic controller (PLC) and is configured to interpret a signal generated by the fiducial sensor10. The fiducial sensor10may be an electromagnetic sensor, for example, that generates a signal indicative of the position and orientation (e.g., one or more spatial coordinates) of the fiducial sensor10. The signal generated by the fiducial sensor10may be, for example, an electrical signal and the controller48may interpret this signal via a stored program50. The stored program50may include, for example, a navigation system that is in communication with the fiducial sensor10and the instrument sensor28.

Similarly, the instrument sensor28may be an electromagnetic sensor, for example, that generates a signal indicative of the position and orientation (e.g., one or more spatial coordinates) of the instrument sensor28. The signal generated by the instrument sensor28may be, for example, an electrical signal and the controller48may interpret this signal via a stored program50. The fiducial sensor10and the instrument sensor28communicate with the controller48and relay the position and orientation of the tissue mass18and the surgical device26using the navigation system. In some embodiments, the stored program50may be configured to run calibration and/or registration algorithms to track the distal tip of the surgical device26and the normal vector to the surgical device26. Thereafter, the stored program50of the controller48calculates the distance D3, shown inFIG. 9, between the fiducial sensor10and the instrument sensor28such that when the surgical device26is below a threshold value of D3, an auditory, visual or haptic cue is generated for the user.

As the surgical device26is navigated towards the resection margin24of the tissue mass18, the surgical device26may excise the tissue mass18while minimizing damage to surrounding tissue due to both the fiducial sensor10and instrument sensor28being actively tracked. Minimal damage to the surrounding healthy tissue may also ensure normal physiological function, for example, lung function. Utilizing feedback from the fiducial sensor10and the instrument sensor28on the surgical device26, the distance D3from the tissue mass18and the surgical device26may be known to the user and visible on the display42at all times. As a result, the desired resection margin24may be maintained at all times, thereby ensuring complete resection of the tissue mass18. In one embodiment, the position and orientation data of the tissue mass18and the surgical device26may be used to lock or unlock the surgical device26to inhibit erroneous resection of the tissue mass18.

Tissue Deformation Algorithms

In some embodiments, the stored program50of the controller48may be configured to include one or more deformation algorithms that estimate or model changes that can occur to the resection margin24during a procedure, as a result of deformations of the tissue mass18and/or the surrounding tissue. The deformation algorithms attempt to account for any such changes to the resection margin24to provide more accurate resection margins to a user during a procedure, which aids in complete resection of the tissue mass18while limiting damage to, or removal of, healthy surrounding tissue.

In one non-limiting example, the stored program50includes a deformation algorithm that assumes that the tissue mass18(e.g., a breast lesion) is rigid and that the surrounding tissue (e.g., the parenchyma) deforms. The algorithm assumes every point on the tissue mass18moves along with the fiducial sensor10, which is anchored to the tissue mass18as described above. In another non-limiting example, the stored program50includes a deformation algorithm that assumes the tissue mass18is a rigid object moving through a viscoelastic or fluid medium. In yet another non-limiting example, patient-specific properties of the tissue mass18and the surrounding tissue can be measured, for example, via a CT/MRI/fluoroscopic examination, to predict deformations to tissue mass18or resection margin24that occur during an operation for that specific patient. It should be appreciated that the deformation algorithms of the stored program50may operate on a real-time basis with the navigation system of the stored program50.

More specifically, a tissue mass18(e.g., a lesion) can be segmented from volumetric images obtained, for example, from the CT/MRI/fluoroscopic examination, to create a surface model. Based upon a default resection margin inputted into the navigation system by a user, a segmented lesion label map can be dilated to the desired resection margin to create a surface model corresponding to the resection margin. Due to deformation of the lesion and the surrounding tissue, the resection margin can change, for example, due to movement of the patient. A linear elastic volumetric finite element model (“FEM”) mesh can therefore be created from the surface model of the lesion and the resection margin. Using the FEM model, an estimate of the displacement of the other nodes of tissue mass18and resection margin24can be made, given the real-time position measurement of the fiducial sensor10. Stiffness values may not be entirely accurate for the FEM model, and the FEM model may be constrained in one example to the tissue mass18and the surrounding tissue. Uncertainty measurements of the tissue mass18and the surrounding tissue deformation can therefore be provided to a user in real-time based upon the uncertainty in the estimated stiffness values of the FEM mesh.

As described above, auditory, visual and haptic cues may be provided to the surgeon and/or the surgical device26to identify the resection margin24to ensure precise and complete resection of the tissue mass18. For example, an audible source52may be configured to emit an audible signal. The audible source52may be in communication with the controller48that is configured to execute the stored program50to alter the audible signal based on the distance D3between the instrument sensor28and the fiducial sensor10. The instrument sensor28uses the signal generated by the fiducial sensor10to enable the controller48to execute the stored program50to calculate the distance D3, shown inFIG. 9, between the fiducial sensor10and the instrument sensor28such that when the surgical device26is below a threshold value of D3, the audible signal is generated. The audible signal may be, for example a tone, beep or alarm. The audible signal may also increase in frequency or duty cycle as the distance D3decreases, such that as the surgical device26is navigated too close to the resection margin24, the audible signal's frequency or duty cycle increases.

In addition to the auditory cues, visual cues may also be provided to the user on one or more displays54in communication with the controller48. The one or more displays54may include, for example, visual cues provided on an endoscopic display or a separate monitor. For example, the endoscopic display or the separate monitor may be configured to emit a visual signal. The endoscopic display or the separate monitor may be in communication with the controller48that is configured to execute a stored program50to alter the visible signal based on the distance D3between the instrument sensor28and the fiducial sensor10. The instrument sensor28uses the signal generated by the fiducial sensor10to enable the controller48to execute the stored program50to calculate the distance D3, shown inFIG. 9, between the fiducial sensor10and the instrument sensor28(e.g., near the tip of the surgical device26), and/or between the instrument sensor28(e.g., near the tip of the surgical device26) and a vector normal to the hook structure16, such that when the surgical device26is below a threshold value of D3, the visual signal is generated. The visual signal may be, for example, a solid or flashing light shown on the one or more displays54, such as the endoscopic display or the separate monitor. The visual signal may also increase in frequency or brightness, for example, as the distance D3decreases, such that as the surgical device26is navigated too close to the resection margin24, the visual signal's frequency and/or brightness increases. Further, the distances from the tip, mid or base of the cutting surface of the instrument can also be determined based on a stored program and displayed to the user. Such a display of distance numerics may sometimes be referred to herein as a so-called quantitative cue.

In one non-limiting example, the visual cue may be shown as a color changing sphere, for example, on one of the displays54. The color changing sphere may be representative of the tissue resection margin24, for example, such that the color changes based on the distance D3between the instrument sensor28and the fiducial sensor10. Thus, as the instrument sensor28approaches the fiducial sensor10, for example, the sphere may be shown in the display54in a first color. Likewise, as the instrument sensor28moves away from the fiducial sensor10, the sphere may be shown on the display54in a second color, for example, thereby allowing the surgeon to appreciate, visually, the distance D3between the instrument sensor28and the fiducial sensor10.

Although quantitative, visual, and auditory cues may be provided to the clinician to identify the distance of the resection margin24from the surgical instrument26, the visual cue may further include a video overlay provided to the user on one or more of the displays54in communication with the controller48. For example, a video overlay may be implemented to fuse the laparoscopy images and virtual endoscopy images to confirm the position of the fiducial sensor10and the tissue mass18, as shown on the display54ofFIG. 10. Based on the position of the laparoscope56, as shown on the display54ofFIG. 11, the virtual endoscopy video of the three dimensional anatomy can be generated. The focal length and field of view may be inputted to control the virtual endoscopy view generated using a visualization toolkit camera, for example, of the three dimensional view.

Haptic cues may also be provided to the user on the surgical device26. For example, a piezoelectric actuator46may be attached to the handle30of the surgical device26that is configured to emit a haptic signal. The piezoelectric actuator46may be in electrical communication with the controller that is configured to execute a stored program to alter the haptic signal based on the distance D3between the instrument sensor28and the fiducial sensor10. The instrument sensor28uses the signal generated by the fiducial sensor10to enable the controller to execute the stored program to calculate the distance D3, shown inFIG. 9, between the fiducial sensor10and the instrument sensor28such that when the surgical device26is below a threshold value of D3, the haptic signal is generated. The haptic signal may be, for example a vibration applied to the handle30of the surgical device26. The haptic signal may also increase in amplitude and/or frequency, for example, as the distance D3decreases, such that as the surgical device26is navigated too close to the resection margin24, the haptic signal's amplitude and/or frequency increases.

Application To Lung Cancer Surgery

Nearly 230,000 new cases of lung cancer are diagnosed each year in the United States, at an estimated cost of $12.1 billion to the healthcare system. Patients with lung cancer have 1-year and 5-year survival rates of 44% and 17%, respectively. For treatment of early stage small lesions, a parenchymal-sparing, minimally invasive Wedge Resection Surgery (WRS) or segmentectomy is becoming the preferred method of surgical resection over lobectomy. The preservation of healthy lung function becomes even more important when the lung physiology is compromised due to excessive smoking, old age, multiple lesions, previous lung surgery, cardiac comorbidity or Chronic Obstructive Pulmonary Disease (COPD). Although these approaches (i.e., WRS and segmentectomy) result in better lung function, the lesion recurrence rate is almost double that of a lobectomy, with significantly poorer 5-year survival rates. In addition, segmentectomy is associated with significant complications. The loco-regional recurrence and complications associated with segmentectomy may be attributed to the difficulty in accurately localizing and resecting the lesions in a deflated lung, and the difficulty in identifying the intersegmental plane. To avoid peri- and post-operative complications, precise anatomic landmarks (e.g., vascular and bronchial anatomic variations) need to be carefully identified and followed.

In the preceding sections, it is taught that a fiducial sensor10(e.g., a T-bar or J-bar assembly) is placed close to the lesion18in order to track the lesion in real-time. The surgical stapler (or other surgical device)26is also tracked in real-time using an instrument sensor28to precisely guide the resection of the lung lesion18. More particularly, navigation software computes the distance of the surgical stapler to the fiducial sensor (e.g., the T-bar or J-bar assembly),26and hence the distance of the surgical stapler26to the lesion18, and displays the distance measurement to the surgeon in real-time so as to ensure complete lesion resection. Further, the distances of the fiducial sensor10or the tumor surface to the tip, middle and base of the stapler cutting line (also sometimes referred to herein as a resection line) can also be computed and displayed in real-time.

Using The System To Identify A Specific Airway In The Lung So As To Assist A Surgeon In Identifying That Airway During Surgery From The Chest Side Of The Operation

The system can also be used to identify a specific airway in the lung so as to assist a surgeon in identifying that airway during surgery from the chest side of the operation.

More particularly, the airways of the lung have a complex tree-like structure. SeeFIG. 12.

When treating a lesion in the lung, and particularly where the treatment may involve a resection of the lung in order to remove the lesion, it can be important to plan the resection relative to specific airways, i.e., to remove a specific airway, to avoid a specific airway, etc. Therefore, it can be important to know the location of relevant airways when conducting the resection surgery.

During bronchoscopy, it is possible to identify the location of the bronchoscope relative to specific airways, since the bronchoscope follows a descending path characterized by specific branching as the bronchoscope proceeds down the tree-like structure of the airways. However, the bronchoscope can typically traverse only a limited distance down the airways of the lung given its size and the progressively decreasing size of the airways. Furthermore, during surgery from the chest side of the operation, the visualization provided to the surgeon from the chest side is limited to a direct field of view and it can be highly problematic to identify, from the chest side, a specific airway due to the limited view provided to the surgeon from the chest side.

The present invention can be used to identify a specific airway in the lung so as to assist a surgeon in identifying that airway during surgery from the chest side of the operation.

More particularly, and looking now atFIGS. 13, 13A and 13B, in this form of the invention, a bronchoscope60is used to position a catheter65carrying a sensor70(i.e., a “tracked catheter”75) into a relevant airway of the lung. More particularly, in one preferred form of the invention, the bronchoscope60can be advanced through the airways under bronchoscopic guidance or by some other form of guidance, e.g., CT imaging, C-arm imaging, etc. until the bronchoscope60is advanced as far as possible toward the relevant airway. SeeFIG. 13. Then a tracked catheter75(i.e., a catheter65carrying a sensor70) is advanced down the bronchoscope60and then out the end of the bronchoscope60into the relevant airway of the lung. SeeFIG. 13A. Note that, preferably, the tracked catheter75is not advanced through the bronchoscope60until after the bronchoscope60has been positioned in the lung in order to maintain maximum flexibility for the bronchoscope60. Once the tracked catheter75has been advanced out the bronchoscope60and into position in the relevant airway, the bronchoscope60can be withdrawn. SeeFIG. 13B. Withdrawal of the bronchoscope60is generally desirable at this point since it can impede ventilation.

The bronchoscopic positioning of a sensor in a relevant airway of the lung (i.e., by bronchoscopically positioning a tracked catheter in a relevant airway of the lung) can then be used to define the lobar, segmental or subsegmental bronchus for surgery such as segmentectomy, lobectomy or wedge resection during the actual operation. More particularly, the position of the sensor identifying the bronchus (i.e., the sensor70on the tracked catheter75) can be correlated with the position of another device (e.g., a surgical instrument)80carrying another sensor85(i.e., a tracked instrument90) so that the surgeon can use the system to identify the correct bronchus for surgery from the chest side of the operation (when direct visualization is limited and frequently ambiguous with respect to specific airways). Thus, in this form of the invention, one sensor70is positioned on a catheter65which is inserted into a specific airway so as to identify the location of that specific airway, and another sensor85is positioned on a surgical instrument80which is advanced for surgery from the chest side of the operation, and the system then tracks the position of the surgical instrument80vis-à-vis the tracked catheter75(and hence vis-à-vis the position of the airway in which the tracked catheter75is positioned). In this way, the surgeon can identify the location of the surgical instrument80relative to the airway of interest (which is identified by the sensor70on the tracked catheter75), even though direct visualization from the chest side of the operation may be limited and ambiguous with respect to specific airways. As a result, the surgeon can use the system to target the airway identified by the sensor70on the tracked catheter75, or to avoid the airway identified by the sensor70on the tracked catheter75, etc.

Significantly, the tracked catheter75may be inserted into a 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 transforms to a second configuration (e.g., a deflated configuration). This can be particularly advantageous when trying to identify a relevant airway of the lung during a limited access surgical procedure (e.g., where visualization is provided by a scope advanced into the chest) and the lung transforms between a first configuration and a second configuration.

Note that, if desired, the tracked catheter75may be inserted into the bronchoscope60before the bronchoscope60is advanced down the airways of the lung. However, as noted above, it is generally desirable to insert the tracked catheter75into the bronchoscope60after the bronchoscope60has been positioned in the lung since this provides maximum flexibility to the bronchoscope60.

Note also, if desired, the bronchoscope60may be left in position in the lung after the tracked catheter75has been advanced into the relevant airway. However, as noted above, in many cases it is desirable to remove the bronchoscope60after the tracked catheter75has been advanced into the relevant airway since this provides better ventilation of the lung.

In addition to the foregoing, it should also be appreciated that, if desired, the bronchoscope60itself can carry a sensor (not shown), such that the bronchoscope60itself can be tracked in the airways of the lung. This approach can be useful where the bronchoscope60is able to advance into the airway of interest, e.g., where the airway of interest is a relatively large airway which can be directly accessed by the bronchoscope60.

Note that, if desired, the tracked catheter75(and/or a tracked bronchoscope) may also be used to map a plurality of airways in the lung while the lung is in a given configuration (e.g., a first, inflated configuration).

In one form of the invention, a fiducial sensor10(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 catheter75is placed in a selected airway of the lung while the lung is in its first (e.g., inflated) configuration; the relative dispositions of the fiducial sensor10and the tracked catheter75are determined while the lung is in its first (e.g., inflated) configuration; the lung is transformed to a second (e.g., deflated) configuration; the relative dispositions of the fiducial sensor10and the tracked catheter75are determined while the lung is in its second (e.g., deflated) configuration; and the change in the relative dispositions of the fiducial sensor10and the tracked catheter75is determined after the lung transforms from its first (e.g., inflated) configuration to its second (e.g., deflated) configuration and used to estimate the extent of lung deformation and the location of lung structures when the lung is in its second (e.g., deflated) configuration.

Mapping And Tracking Of The Surrounding Airways

The foregoing system can be enhanced by mapping and tracking the surrounding airways (along with the lesion) so as to ensure that the correct segment of the lung is excised. This is because during deflation of the lung, the anatomy will shift and the tissue section to be excised may not be obvious to the surgeon.

The procedure for mapping and tracking the airways of the lung may be done as follows.

First, the patient is placed in the supine position. Then, bronchoscopically, a flexible catheter65having an on-board catheter sensor70is placed in the nearest/target bronchus of the lung segment containing the lesion18. This is done either by identifying the correct bronchus visually or by some form of guidance (e.g., CT imaging, C-arm imaging, etc.). The tracked catheter75is inserted into the targeted bronchus near to the mass of the lesion18, and as the catheter65is inserted, the trajectory of the catheter65is logged using the on-board catheter sensor70and an electromagnetic tracker system configured to identify the position and orientation of the catheter sensor70(and hence the position and orientation of the catheter65). This trajectory marks the position of the airway95in the coordinate space of the electromagnetic tracker system. SeeFIGS. 14-34. The successive detected locations of the catheter sensor70as the catheter65advances down the airway95can be concatenated so as to provide the centerline of the targeted airway. SeeFIG. 35.

Alternatively, the catheter65can comprise a plurality of catheter trackers70located along its length so that airway mapping can be conducted by simply logging the locations of the various catheter sensors70after the catheter65has been fully inserted in an airway. SeeFIGS. 36 and 37. Note that the catheter65can be advanced through the airways under bronchoscopic guidance or by some other form of guidance, e.g., CT imaging, C-arm imaging, etc.

The process can then be repeated with adjacent airways so as to map out the airways surrounding the lesion.

Once the mapping of the relevant airways has been completed, the position of the fiducial sensor10(e.g., the T-bar or J-bar assembly or similar tracker) and mapped airways are recorded in the inflated lung (and, ultimately, in the deflated lung).

Thereafter, with a fiducial sensor10next to the lesion18and the tracked catheter75disposed in a critical airway near the lesion, the lung is collapsed prior to the start of the surgery. The fiducial sensor10(e.g., the T-bar or J-bar assembly) and the tracked catheter75are tracked in real-time as the lung is collapsed. SeeFIG. 38. The position of the fiducial sensor10(e.g., the T-bar or J-bar assembly) and the critical airway (e.g., the airway containing the tracked catheter75) is recorded in the deflated lung. Using a finite element-based particle filter or FEM deformation algorithm, the spatial translation of the fiducial sensor10(e.g., the T-bar or J-bar assembly) and the critical airway from the inflated condition to the deflated condition is estimated. A smooth deformation field around the critical airway is estimated. The deformation field is then applied to the other airways mapped in the inflated lung so as to estimate the position of those other airways in the deflated lung. The “deformed” airways (i.e., the airways in the deflated lung) are displayed to the surgeon in the navigation system, along with the lesion, to precisely guide the surgical stapler26to the optimal resection margin while ensuring that critical anatomy is spared. This approach also, even without stapler navigation, helps define the correct segment for resection (as well as the correct bronchial segment to resect or not resect as part of the planned operation). Once the appropriate bronchial segment is identified in the thoracoscopic, or thoracic point of view, the catheter65may be removed prior to any surgical resection, by simply pulling it out of the airway from the mouth, nose or endotracheal tube.

In one aspect of the invention, a plurality of lumens in a deformable anatomical structure may be mapped and tracked by:

providing a virtual model of the anatomical structure while the anatomical structure is in a first configuration;

while the anatomical structure is in the first configuration, positioning a tracked catheter in one of the lumens in the anatomical structure which is to be mapped and tracked, and determining the position of the tracked catheter in that lumen so as to map the position of that lumen;

repeating the foregoing step for each of the lumens in the anatomical structure which is to be mapped and tracked so that those lumens are mapped;

supplementing the virtual model with the mapped lumens, whereby to provide a supplemented virtual model of the anatomical structure and the mapped lumens while the anatomical structure is in its first configuration;

maintaining the tracked catheter in one of the mapped lumens of the anatomical structure as the anatomical structure is deformed from its first configuration to a second configuration;

determining the position of the tracked catheter in the anatomical structure while the anatomical structure is in the second configuration; and

modifying the supplemented virtual model so as to represent the anatomical structure and the mapped lumens while the anatomical structure is in its second configuration, whereby to provide a modified supplemented virtual model, wherein modification is effected by:determining the spatial transformation of the tracked catheter as the anatomical structure deforms from its first configuration to its second configuration; andapplying the spatial transformation of the tracked catheter to the mapped lumens of the supplemented virtual model so as to provide the modified supplemented virtual model of the anatomical structure and the mapped lumens while the anatomical structure is in its second configuration.

In another aspect of the invention, a selected lumen in a deformable anatomical structure may be mapped and tracked by:

positioning a tracked catheter in the selected lumen of the anatomical structure while the anatomical structure is in a first configuration;

determining the position of the tracked catheter while the anatomical structure is in the first configuration;

scanning the anatomical structure and the tracked catheter positioned in the selected lumen of the anatomical structure while the anatomical structure is in the first configuration;

creating a virtual model of the scanned anatomical structure and the tracked catheter positioned in the selected lumen of the anatomical structure while the anatomical structure is in its first configuration;

maintaining the tracked catheter in position within the selected lumen of the anatomical structure while the anatomical structure deforms to a second configuration;

determining the position and orientation of the tracked catheter while the anatomical structures is in its second configuration, whereby to determine the position of the selected lumen of the anatomical structure while the anatomical structure is in the second configuration; and

adjusting the virtual model so as to represent the anatomical structure and the selected lumen while the anatomical structure is in its second configuration, whereby to provide an adjusted virtual model, wherein modification is effected by:determining the spatial transformation of the tracked catheter as the anatomical structure deforms from its first configuration to its second configuration; andapplying the spatial transformation of the tracked catheter to the selected lumen of the virtual model so as to provide the adjusted virtual model of the anatomical structure and the selected lumen while the anatomical structure is in its second configuration.

Bronchoscopic Deployment Of The Fiducial Sensor

In the system described above, the fiducial sensor10(e.g., the T-bar or J-bar assembly) is described as being deployed percutaneously. SeeFIG. 39. However, if desired, the fiducial sensor10(e.g., the T-bar or J-bar assembly) can be deployed via a bronchoscopic approach, or open chest approach or VATS approach.

More particularly, the fiducial sensor10(e.g., the T-bar or J-bar assembly) is a metal anchor with a wireless electromagnetic sensor embedded within a hook-like structure. The metal anchor could be made from superelastic material, for example nitinol, or it could be made from stainless steel. The fiducial sensor10(e.g., the T-bar or J-bar assembly) is placed within a long flexible hollow tube with a bevel tip at the end. This hollow tube is inserted through the working channel of the bronchoscope60. Under real-time image guidance using the navigation system, the wireless fiducial sensor10(e.g., the T-bar or J-bar assembly) is navigated through the airways using the bronchoscope60and placed close to the lesion. SeeFIG. 40. Once the fiducial sensor10(e.g., the T-bar or J-bar assembly) has been deployed close to the lesion18, the bronchoscope60(and the hollow tube extending through the working channel of the bronchoscope) is removed. SeeFIG. 41. Thereafter, the lung is collapsed and the lesion18is tracked in real-time using the fiducial sensor10(e.g., the T-bar or J-bar assembly). The surgical stapler (not shown) is also tracked in real-time using the instrument sensor attached to the surgical stapler. Note that the surgical stapler is tracked in the same reference frame as the fiducial sensor10(e.g., the T-bar or J-bar assembly). The surgical stapler can then be navigated to the optimal resection margin using the navigation system.

Alternatively, if desired, the fiducial sensor10(e.g., the T-bar or J-bar assembly) could carry a wire-based electromagnetic sensor. In this case, after the fiducial sensor10(e.g., the T-bar or J-bar assembly) has been deployed, the wire14of the fiducial sensor is then pushed bronchoscopically, under image guidance, through the lung parenchyma to the surface of the skin at the nearest spot to the lesion18so as to mark the lesion18. SeeFIG. 42.

In still another form of the invention, where the fiducial sensor10(e.g., the T-bar or J-bar assembly) carries a wire-based electromagnetic sensor, the wire14has a detachable connection to the electromagnetic sensor. Then, after the stapler has been used to establish the resection line, the wire14is detached from the electromagnetic sensor and pulled back up the airway. SeeFIG. 43.

In yet another form of the invention, and looking now atFIGS. 44-52, a bronchoscopic sensor unit100is provided for bronchoscopic deployment of fiducial sensor10into tissue mass18or adjacent to tissue mass18.

More particularly, and looking now atFIGS. 44-46, bronchoscopic sensor unit100(FIG. 44) generally comprises a J-bar and electrical lead assembly105(FIG. 45) and a deployment assembly110(FIG. 46).

J-bar and electrical lead assembly105generally comprises a J-bar assembly115and an electrical lead120. J-bar assembly115comprises the aforementioned hook structure16which carries the aforementioned fiducial sensor10and the aforementioned prongs20. One end125of electrical lead120is connected to fiducial sensor10such that electrical power delivered to electrical lead120can power fiducial sensor10. The other end130of electrical lead120comprises an atraumatic tip135. Electrical lead120may be covered with a hydrophobic braided wire to allow for easy insertion and retraction of J-bar and electrical lead assembly105through lumen150(see below) of deployment assembly110.

Alternatively, if desired, instead of an atraumatic tip135, the distal end of J-bar and electrical lead assembly105may comprise a second anchor that could prevent electrical lead120from re-entering the lung once the distal end of electrical lead120has emerged from the lung. In other words, this second anchor would prevent retrograde movement of the distal end of electrical lead120after deployment. Furthermore, in such a form of the invention, prongs120of J-bar assembly115could have a configuration which prevents antegrade movement of J-bar assembly115once it is released from deployment assembly110. See, for example,FIGS. 46A and 46B, which show prongs135A at the distal end of electrical lead120, and prongs20A at the distal end of J-bar assembly115, with prongs135A preventing post-deployment proximal movement of the distal end of electrical lead120and prongs20A preventing post-deployment distal movement of J-bar assembly115.

Deployment assembly110comprises a needle cannula140and a pusher145. Needle cannula140comprises a hollow lumen150and terminates in a sharp tip155. Pusher145comprises a shaft160. One end of shaft160ends in a blunt distal end165. The other end of shaft160terminates in a handle170. Shaft160of pusher145is sized to be slidably received in lumen150of needle cannula140. Note that needle cannula140of deployment assembly110is sized so that it can be inserted through the working channel of a bronchoscope.

As seen inFIG. 44, J-bar and electrical lead assembly105and shaft160of pusher145are initially disposed within lumen150of needle cannula140, with prongs20of J-bar assembly115being elastically deformed into a straighter configuration so as to be received within lumen150of needle cannula140, and with the proximal ends of the elastically deformed prongs20residing just distal to blunt end165of pusher145. Note also that when J-bar and electrical lead assembly105is disposed within lumen150of needle cannula140, atraumatic tip135of electrical lead120is elastically deformed so that it sits substantially straight within needle cannula140(note thatFIG. 44is intended to be schematic in nature, and in practice electrical lead120has a diameter which more closely fills lumen150of needle cannula140, such that atraumatic tip135of electrical lead120sits substantially straight when it is confined within needle cannula140, and returns to the coiled configuration shown inFIG. 45when atraumatic tip135is not confined within needle cannula140). In this way, needle cannula140can carry J-bar and electrical lead assembly105, with needle cannula140shielding J-bar and electrical lead assembly105from contact with surrounding structures (e.g., a bronchoscope, tissue, etc.). However, distal movement of pusher145can eject J-bar and electrical lead assembly105from lumen150of needle cannula140.

In a preferred method of use, the intended position of J-bar and electrical lead assembly105vis-à-vis the anatomy of the patient is planned prior to deployment in the lung using diagnostic or intraprocedural CT, C-arm CT, MRI or other imaging modalities, i.e., the intended position of J-bar assembly115, and the exit point of electrical lead120as it emerges from the lung surface, are planned in advance on diagnostic or intraprocedural CT, C-arm CT, MRI or other imaging modalities. The electromagnetic (EM) tracking coordinates are mapped to the diagnostic/intraprocedural imaging coordinates using image registration algorithms well known in the art to track the bronchoscope and J-bar and electrical lead assembly105in the imaging coordinates. The position of J-bar assembly115is chosen to be in the proximity of the tumor, preferably along the line joining the bronchoscope target position and the exit position of the electrical lead, while the exit point of electrical lead120from the lung is chosen to be (i) the shortest path from the J-bar location to the lung surface (or the fissure surface), or (ii) according to surgeon preference.

By way of example but not limitation, in a preferred method of use, and looking now atFIGS. 47-52, a bronchoscope60is advanced through the airways of the patient until the distal tip of bronchoscope60is disposed near the lesion (i.e., tissue mass)18. SeeFIG. 47. Note that bronchoscope60may be advanced under direct visualization and its position may be tracked using one or more sensors180carried by bronchoscope60. Alternatively, the position of bronchoscope60may be tracked using J-bar assembly115, provided that a temporary electrical connection is provided for J-bar assembly115(i.e., via an electrical connection extending through the interior of needle cannula140, such as by electrifying a portion of pusher145). The position of the tracked bronchoscope60can be mapped to the imaging coordinates (see above) using image registration algorithms of the sort well known in the art in order to guide the bronchoscope60to the lesion18.

Next, if it has not already been done, a target point185is identified on the outer surface of the lung as the point where it is desired that needle cannula140will emerge from the lung and enter the pleural space. SeeFIG. 48.

Then bronchoscopic sensor unit100(comprising deployment assembly110and its passenger J-bar and electrical lead assembly105) has its distal end advanced through bronchoscope60, through the lung, through target point185and into the pleural space. SeeFIG. 49. Note that the distal end of bronchoscopic sensor unit100can be guided visually via bronchoscope60, and/or via scanner visualization (e.g., CT imaging, C-arm imaging, ultrasound imaging, etc.), or by using the temporarily-electrically-connected J-bar assembly115, if a temporary electrical connection has been established through the interior of needle cannula140.

Next, pusher145of deployment assembly110may be used to push J-bar and electrical lead assembly105distally so that (i) atraumatic tip135and a portion of electrical lead120pass out of needle cannula140and into the pleural space, and (ii) J-bar assembly115is disposed adjacent to lesion18(note, however, that at this point J-bar assembly115and a portion of electrical lead120remain within needle cannula140). SeeFIG. 50.

Next, needle cannula140is retracted proximally while maintaining pusher145in position, thereby exposing (i) the portion of electrical lead120extending from target point185to J-bar assembly115, and (ii) J-bar assembly115. As needle cannula140retracts past prongs20of J-bar assembly115, prongs20are no longer constrained within lumen150of needle cannula140and are free to spring outboard and set into the tissue, whereby to anchor J-bar assembly115(and hence fiducial sensor10) adjacent to lesion18. SeeFIG. 51. At this point, if J-bar assembly115was temporarily connected to electrical power through the interior of needle cannula140, the wires of the J-bar are disconnected and retracted to within needle cannula140. Note that this disconnection and retraction of the electrical leads passing through needle cannula140is desirable, since it removes them from the intended resection line.

Then a power supply clamping tool190is advanced into the pleural space and clamped onto the portion of electrical lead120extending out of the lung, whereby to provide electrical power to electrical lead120and hence fiducial sensor10of J-bar assembly115. SeeFIG. 52. Note that by supplying electrical power to J-bar assembly115via a power supply clamping tool190advanced into the pleural space from a point outside the body (rather than through needle cannula140and bronchoscope60advanced through the bronchi), the electrical leads do not cross the intended resection line.

Power supply clamping tool190can take various forms. In essence, it is an elongated tool which is configured to extend from outside the body into the pleural space, and to make an electrical connection to the portion of electrical lead120extending out of the lung and into the pleural space, whereby to deliver power to J-bar assembly115. By way of example but not limitation, power supply clamping tool190may comprise a pair of electrically-connected jaws which can be closed about the portion of electrical lead120extending out of the lung and into the pleural space. Note that power supply clamping tool190can be deployed either through a needle extending through the skin or through a port created on the skin surface. The power supplied by power supply clamping tool190to electrical lead120enables J-bar assembly115to connect to the EM tracking system.

Once powered, fiducial sensor10communicates with the electromagnetic (EM) tracking system and the location of fiducial sensor10(and hence the location of lesion18) can be determined by controller48.

At this point, a surgical instrument80(carrying an instrument sensor85) can be used to effect the desired resection line in the lung, whereby to excise lesion18from the remainder of the lung. Note that J-bar and electrical lead assembly105extends from lesion18to the pleural space, and hence is contained within the tissue which is being excised, and does not cross the resection line. In other words, J-bar and electrical lead assembly105is always outboard of lesion18. As a result, fiducial sensor10of J-bar assembly115can remain powered throughout the resection procedure, does not interfere with the resection procedure, and J-bar and electrical lead assembly105is carried away with the resected tissue after resection has been completed.

As noted above, in one form of the invention, a bronchoscope60is advanced through the airways of the patient until the distal tip of bronchoscope60is disposed near the lesion (i.e., tissue mass)18. As also noted above, the bronchoscope60may be advanced under direct visualization and its position may be tracked using one or more sensors180carried by bronchoscope60. Alternatively, the position of bronchoscope60may be tracked using J-bar assembly115, provided that a temporary electrical connection is provided for J-bar assembly115(i.e., via an electrical connection extending through the interior of needle cannula140, such as by electrifying a portion of pusher145). Thus, it can be desirable to provide a temporary electrical connection for J-bar assembly115(i.e., via an electrical connection extending through the interior of needle cannula140, such as by electrifying a portion of pusher145) so that J-bar assembly115can be powered while the J-bar assembly is in needle cannula140.

It can also be desirable to provide a temporary electrical connection for J-bar assembly115(i.e., via an electrical connection extending through the interior of needle cannula140, such as by electrifying a portion of pusher145) so that J-bar assembly115can be powered prior to connecting power supply clamping tool190to the portion of the electrical lead120extending out of the lung.

In one preferred form of the invention, and looking now atFIG. 52A, a temporary electrical connection for J-bar assembly115can be provided as follows. Fiducial sensor10of J-bar assembly115comprises a proximal electrical connector200(as well as the electrical lead120, which extends distally from fiducial sensor10). Pusher145is cannulated and comprises a distal electrical connector205. Electrical power is provided to distal electrical connector205of pusher145by a wire210which extends through pusher145(and which connects to a power source, not shown). While J-bar assembly115is seated in needle cannula140, proximal electrical connector200of J-bar assembly115is connected to distal electrical connector205of pusher145, whereby to power fiducial sensor10. After J-bar assembly115has been deployed in the anatomy of a patient (and after prongs20have set in the tissue), pusher145is retracted, separating distal electrical connector205of pusher145from proximal electrical connector200of J-bar assembly115, thereby disconnecting J-bar assembly115from the power supplied by wire210extending through pusher145. However, it will be appreciated that power may still be delivered to J-bar assembly115via electrical lead120and power supply clamping tool190(connected to electrical lead120).

Stapler Articulation Measurement

Surgical stapler heads can be articulated about a pivot point220to provide the desired orientation while resecting the lesion. While the instrument sensor28may be placed on the articulating head of the surgical stapler26(e.g., such as is shown inFIGS. 8 and 9), this can cause interference from ferromagnetic material on the stapler head. Therefore, in practice, the instrument sensor28is typically positioned on the shaft of the surgical stapler26, just proximal to the articulation point, e.g., about 10 cm from the stapler tip, in order to avoid interference from ferromagnetic material on the stapler head. In this position, the instrument sensor28is proximal to the pivot point220on the surgical stapler26, so that the instrument sensor28sits on the non-articulating portion of the stapler26. SeeFIG. 53. As a result, the instrument sensor28placed on the non-articulating portion of the surgical stapler26does not capture the articulation motion of the surgical stapler26.

Therefore, in another form of the invention, the surgical stapler26is configured to measure the articulation angle of the stapler head. More particularly, an articulation sensor225is provided which preferably comprises two parts. The first part230of the articulation sensor225is placed on the stapler shaft. The second part235of the articulation sensor225is placed on the articulating stapler head. The connection between the first and second parts230,235of the articulation sensor225is through a flexible encoder circuit that measures the angulation of the articulating end of the stapler head. The encoder circuit is preferably a modified circular potentiometer to measure the angulation of the stapler head. SeeFIG. 54. A Wheatstone bridge circuit measures the variable resistance produced on the encoder circuit so as to estimate the stapler articulation angle. In addition, the surgical stapler26may also include an LED indicator (not shown) on the stapler shaft to confirm the placement of the articulation sensor225on the surgical stapler26. Once the articulation sensor225is placed on the surgical stapler26, the circuit is completed to light up the LED indicator.

If desired, the articulation sensor225may use schemes other than electrical resistance to measure stapler head articulation, e.g., an optical encoder may be used to measure stapler head articulation, or a magnetic encoder may be used to measure stapler head articulation, etc. The articulation sensor225can also be internalized to the specific working internal of the stapler device26. Alternatively, a second sensor (not shown) can be placed on an elastic extension from the sleeve towards the tip and past the articulation to allow direct measurement of the stapler articulation angle. This extension may be secured with tape or other adhesive.

Marking The Boundary Of A Resection Margin And Stapler Positioning

In one form of the invention, the lesion will be segmented from the diagnostic CT imaging so as to create a 3D model of the lesion240that will be inputted to the navigation system. In another form of the invention, the lesion may be segmented based on a direct visualization of the lesion by the surgeon, with or without input from radiologic findings. Based on input from the surgeon or a machine learning algorithm, the resection margin will be determined. A segmented model for the resection margin245is generated by expanding the lesion label map by the desired resection margin. SeeFIGS. 55 and 56. With knowledge of the position of the fiducial sensor (e.g., the T-bar or J-bar assembly) and the lesion model240, the position of the tracked surgical stapler can be precisely estimated with respect to the lesion model240and the estimated resection margin model245.

In addition to the foregoing, in one form of the invention, the navigation software can guide the surgeon to precisely resect around the lesion, based on a distance to secure a sufficient margin defined by the surgeon based on the mass size and presumed diagnosis. SeeFIGS. 57-59. More particularly, in one form of the invention, and looking now atFIG. 60, the navigation software computes the tangent lines250at the perimeter of the modeled resection margin245, and then guides the surgeon to place the staples255just outside those tangent lines250, so that the staples255follow a tangential path around the estimated resection margin model245.

Although the above described system and method for resecting a tissue mass was described for surgery involving the lung, it is also applicable to resection of lesions in any other organ or structure of the body, for example, resection for breast conserving surgery, liver resection, sarcoma resection, partial nephrectomy or lung wedge resection surgery. In addition, the above described system and method for resecting a tissue mass is not limited to VATS or minimally invasive surgery.