Patent ID: 12257105

DETAILED DESCRIPTION

The present disclosure provides a system for tracking a treatment probe and imaging both the treatment probe and a region of interest in a patient. While performing a surgical treatment, it is important to know exactly where a treatment probe is located within the patient's body, and the location with respect to a target for treatment. In addition, it is beneficial to see an actual image of the treatment probe as it is traversing tissue or entering the target. In this regard, the present disclosure describes location tracking features with which the spatial relationship between the treatment probe and the imaging device can be identified and presented as the treatment probe is navigated to a location within the patient in combination with real-time images of the treatment probe and the target as well as surrounding tissue.

A treatment plan may be used as a guide during the performance of the surgical procedure, where the system is configured to track the position of treatment probe inside the patient and give the clinician a real-time indication of the position of the treatment probe in relation to the target and the pre-planned pathway toward the target. The system also presents a clinician with the capability to compare and contrast pre-operative and post-operative CT image data to assess the outcome of a surgical treatment procedure that has been performed.

Although the present disclosure will be described in terms of specific illustrative embodiments, it will be readily apparent to those skilled in this art that various modifications, rearrangements and substitutions may be made without departing from the spirit of the present disclosure. The scope of the present disclosure is defined by the claims appended hereto.

A procedure according to the present disclosure, such as a microwave ablation procedure is generally divided into two phases: (1) a planning phase, and (2) a treatment phase. The planning phase of a procedure, such as microwave ablation treatment, is more fully described in provisional patent application No. 62/035,851 entitled TREATMENT PROCEDURE PLANNING SYSTEM AND METHOD, filed on Aug. 11, 2014 by Bharadwaj et al., the contents of which is hereby incorporated by reference in its entirety. An alternative planning or additional planning phase as well as a treatment phase is more fully described below.

A tracking and treatment system according to the present disclosure may be a unitary system configured to perform both the planning phase and the treatment phase, or the system may include separate devices and software programs for the various phases. An example of the latter may be a system wherein a first computing device with one or more specialized software programs is used during the planning phase, and a second computing device with one or more specialized software programs may import data from the first computing device to be used during the treatment phase.

Referring now toFIG.1, the present disclosure is generally directed to a treatment system10, which includes an EM tracking system100, an electrosurgical generator101, a workstation102, a display110, a table120, a treatment probe130, an ultrasound imager140, and an ultrasound workstation150. The EM tracking system100may be, for example, a laptop computer, desktop computer, tablet computer, or other similar device. The workstation102may also be used to control a cooling pump or other peripheral devices not expressly shown inFIG.1. The EM tracking system100may interact with an EM field generator121, one or more tracking sensors137and141(e.g., an EM sensor, though others could be used), and a display110on which a user interface presents the location of the tracking sensors137in the EM field in combination with one or more imaging modalities, as will be described in greater detail below. The workstation102includes software which converts signals received from the EM sensors137and141and performs necessary calculations to track the location of the EM sensors in an EM field. In addition to tracking information, the display110presents to a user the results of the software processing including instructions, images, and messages relating to the performance of the procedure. The EM field generator121rests on or may be built into a table120and is located under a patient thus generating an EM field around a portion of the patient through which navigation to a target is desired. Typically this will be the patient's torso which enables navigation to and treatment of all the major organs of the body. However, the same system could be used to treat other locations on the patient. An example of such an EM field generator121is the AURORA™ system sold by Northern Digital Inc.

The electrosurgical generator101generates electrosurgical energy (e.g., RF or microwave) and provides the generated energy to the treatment probe130. The treatment probe130is a surgical instrument, for example, a microwave ablation antenna used to ablate and treat tissue. Various other surgical instruments or surgical tools, such as electrosurgical pencils, vessel sealers, staplers, resection devices and others, may also be used with EM tracking system100either with or without an EM sensor137. In one embodiment, located on the treatment probe130is the tracking sensor137as will be described in detail below, allowing for the tracking of the location of the treatment probe130in the EM field. While the present disclosure describes the use of the system10in a surgical environment, it is also envisioned that some or all of the components of system10may be used in alternative settings, for example, at a treatment review board or other office setting such as during a post treatment review of the procedure or assessment of progress of the patient.

In addition to the EM tracking system100, the system10includes the capabilities for patient, target, and treatment probe130visualization using ultrasonic imaging. The ultrasound imager140, such as an ultrasonic wand, may be used to image the patient's body during the procedure to visualize the location of the surgical instruments, such as the treatment probe130, inside the patient's body. The ultrasound imager140may also have an EM tracking sensor141embedded within or attached to the ultrasonic wand, for example, a clip-on sensor or a sticker sensor. As described further below, the ultrasound imager140may be positioned in relation to the treatment probe130such that the treatment probe130is at an angle to the ultrasound image plane, thereby enabling the clinician to visualize the spatial relationship of the treatment probe130with the ultrasound image plane and with objects being imaged. Further, the EM tracking system100may also track the location of ultrasound imager140using the EM sensor141placed thereon.

The ultrasound imager140includes an ultrasound transducer (140ainFIG.4A) which emits ultrasound energy receives reflected ultrasound energy. The ultrasound imager140then transmits reflected ultrasound waves to the ultrasound workstation150, which processes the reflected ultrasound waves and generates ultrasound images.

The treatment probe130may be an ablation probe used to ablate a lesion or tumor (hereinafter referred to as a “target”) by using electromagnetic radiation or microwave energy to heat tissue in order to denature or kill cancerous cells. The construction and use of a system including such an ablation probe is more fully described in provisional patent application No. 62/041,773 entitled MICROWAVE ABLATION SYSTEM, filed on Aug. 26, 2014, by Dickhans, co-pending patent application Ser. No. 13/836,203 entitled MICROWAVE ABLATION CATHETER AND METHOD OF UTILIZING THE SAME, filed on Mar. 15, 2013, by Ladtkow et al., and co-pending patent application Ser. No. 13/834,581 entitled MICROWAVE ENERGY-DELIVERY DEVICE AND SYSTEM, filed on Mar. 15, 2013, by Brannan et al., the contents of all of which are hereby incorporated by reference in its entirety.

As described above, the location of the treatment probe130within the body of the patient may be tracked during the surgical procedure using the EM tracking system101and the EM sensor137located on the treatment probe130. Various types of sensors may be used, such as a printed sensor, the construction and use of which is more fully described in provision patent application No. 62/095,563 entitled MEDICAL INSTRUMENT WITH SENSOR FOR USE IN A SYSTEM AND METHOD FOR ELECTROMAGNETIC NAVIGATION, filed Dec. 22, 2014, the entire contents of which is incorporated herein by reference. Prior to starting the procedure, the clinician is able to verify the accuracy of the tracking system.

The workstation102may combine the ultrasound images from the ultrasound workstation150and EM data from the EM tracking system100. The EM data may include spatial relationship between the location of the ultrasound imager140and the location of the treatment probe130in the EM field. Based on the spatial relationship, the workstation102generates images depicting the location of the treatment probe130with respect to pre-stored images illustrating the treatment probe130on display110. In addition the workstation102generates a representation of the location of the treatment probe in relation to the ultrasound images such that the treatment probe130is depicted with respect to the ultrasound image and any pre-planned pathway to a target in the ultrasound image is also displayed allowing the clinician to follow the pathway and achieve the target.

Turning now toFIG.2, there is shown a system diagram of a computing device, which can be the EM tracking system100, the workstation102, or the ultrasound workstation150. The computing device200may include memory202, processor204, the display206, network interface208, input device210, and/or output module212.

Memory202includes any non-transitory computer-readable storage media for storing data and/or software that is executable by processor204and which controls the operation of the computing device200. In an embodiment, memory202may include one or more solid-state storage devices such as flash memory chips. Alternatively or in addition to the one or more solid-state storage devices, memory202may include one or more mass storage devices connected to the processor204through a mass storage controller (not shown) and a communications bus (not shown). Although the description of computer-readable media contained herein refers to a solid-state storage, it should be appreciated by those skilled in the art that computer-readable storage media can be any available media that can be accessed by the processor204. That is, computer readable storage media includes non-transitory, volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules or other data. For example, computer-readable storage media includes RAM, ROM, EPROM, EEPROM, flash memory or other solid state memory technology, CD-ROM, DVD, Blu-Ray or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by the computing device200.

Memory202may store application216and/or CT data214. Application216may, when executed by processor204, cause the display206to present user interface218.

Processor204may be a general purpose processor, a specialized graphics processing unit (GPU) configured to perform specific graphics processing tasks while freeing up the general purpose processor to perform other tasks, and/or any number or combination of such processors.

The display206may be touch-sensitive and/or voice-activated, enabling the display206to serve as both an input and output device. Alternatively, a keyboard (not shown), mouse (not shown), or other data input devices may be employed.

Network interface208may be configured to connect to a network such as a local area network (LAN) consisting of a wired network and/or a wireless network, a wide area network (WAN), a wireless mobile network, a Bluetooth network, and/or the internet. For example, the computing device200may receive computed tomographic (CT) image data of a patient from a server, for example, a hospital server, internet server, or other similar servers, for use during surgical ablation planning. Patient CT image data may also be provided to the computing device200via a removable memory202. The computing device200may receive updates to its software, for example, application216, via network interface208. The computing device200may also display notifications on the display206that a software update is available.

Input device210may be any device by means of which a user may interact with the computing device200, such as, for example, a mouse, keyboard, foot pedal, touch screen, and/or voice interface.

Output module212may include any connectivity port or bus, such as, for example, parallel ports, serial ports, universal serial busses (USB), or any other similar connectivity port known to those skilled in the art.

Application216may be one or more software programs stored in memory202and executed by processor204of the computing device200. During a planning phase, application216guides a clinician through a series of steps to identify a target, size the target, size a treatment zone, and/or determine an access route to the target for later use during the procedure phase. In some embodiments, application216is loaded on computing devices in an operating room or other facility where surgical procedures are performed, and is used as a plan or map to guide a clinician performing a surgical procedure, but without any feedback from the treatment probe130used in the procedure to indicate where the treatment probe130is located in relation to the plan

Application216may be installed directly on the computing device200, or may be installed on another computer, for example a central server, and opened on the computing device200via network interface208. Application216may run natively on the computing device200, as a web-based application, or any other format known to those skilled in the art. In some embodiments, application216will be a single software program having all of the features and functionality described in the present disclosure. In other embodiments, application216may be two or more distinct software programs providing various parts of these features and functionality. For example, application216may include one software program for use during the planning phase, and a second software program for use during the treatment phase. In such instances, the various software programs forming part of application216may be enabled to communicate with each other and/or import and export various settings and parameters relating to the navigation and treatment and/or the patient to share information. For example, a treatment plan and any of its components generated by one software program during the planning phase may be stored and exported to be used by a second software program during the procedure phase.

Application216communicates with a user interface218which generates a user interface for presenting visual interactive features to a clinician, for example, on the display206and for receiving clinician input, for example, via a user input device. For example, user interface218may generate a graphical user interface (GUI) and output the GUI to the display206for viewing by a clinician.

The computing device200may be linked to the display110, thus enabling the computing device200to control the output on the display110along with the output on the display206. The computing device200may control the display110to display output which is the same as or similar to the output displayed on the display206. For example, the output on the display206may be mirrored on the display110. Alternatively, the computing device200may control the display110to display different output from that displayed on the display206. For example, the display110may be controlled to display guidance images and information during the surgical procedure, while the display206is controlled to display other output, such as configuration or status information of an electrosurgical generator101as shown inFIG.1.

As used herein, the term “clinician” refers to any medical professional (i.e., doctor, surgeon, nurse, or the like) or other user of the system10involved in performing, monitoring, and/or supervising a medical procedure involving the use of the embodiments described herein.

Due to potential interferences both electrical and mechanical, it is not always desirable or possible to place the EM tracking sensor137on the distal tip of a treatment probe130. Thus, for example in the case of a microwave ablation probe, it is necessary to place the EM tracking sensor137some distance proximal the distal end of the microwave ablation probe. However because treatment occurs at and near the distal end of a microwave ablation probe it is important to know its location in space and more particularly the patient. When the spatial relationship between the EM tracking sensor137and the tip of the shaft133is known, the location of the tip of the shaft133can be identified based on the spatial relationship.FIGS.3A and3Bprovide one solution for addressing this issue without the need to alter an existing treatment probe130.

FIG.3Adepicts a hub131which can be placed around existing treatment probes, such as the Emprint™ ablation probe currently sold by Medtronic PLC, in order to secure the EM tracking sensors137and to enable the use of such a device in an EM field of the system10. The hub131includes a cannula132and first and second locking member134and135, respectively. As shown inFIG.3A, a portion of the shaft133of the treatment probe130extends beyond the distal end of the hub131allowing for effective use of the treatment probe130. The treatment probe130is secured in the hub131by the cannula132, the first locking member134, which prevents the axial movements of the treatment probe130, and the second locking member135prevents rotational movement of the treatment probe130, relative to the hub131. The first and second locking members134and135may be clip-type locks or any locking devices suitable to lock movements of the treatment probe130relative to the hub131.

Turning now toFIG.3B, there is shown an expanded view of the cannula132of the hub131with the shaft133of the treatment probe130extending therefrom. As depicted inFIG.3B, the cannula132has three parts, a proximal part132a, a middle part132b, and a distal part132c. In one embodiment the proximal part132aand the distal part132care rigid and the middle part132bis flexible. The flexible middle part132bhelps eliminate any stress that the hub131might place on the shaft133of the treatment probe130. As an example, the hub131may be made of a less flexible material than the shaft133of the treatment probe, thus when placed in the hub131normal operation of the treatment probe130might induce stresses in the shaft133at the locations identified as136inFIG.3B. By adding the flexible middle part132b, these stresses are reduced and the potential for damaging the treatment probe130is also reduced.

As shown inFIG.3B, an EM tracking sensor137is affixed at the distal part132cof the cannula132. In one embodiment, by being placed in the EM field, the EM tracking sensor137outputs a voltage (or multiple voltages) that can be sensed by the EM tracking system100and converted into location information of the EM tracking sensor137in the EM field generated by the EM field generator121to identify the location of the EM tracking sensor137or the distal part132cwithin an EM field, and therewith the location of the EM tracking sensor137with respect to the patient. By knowing the distance from the EM tracking sensor137to the distal end of the treatment probe130, one or more of the software applications running on the EM tracking system100determine the location of the distal end of the treatment probe130, and generate a representation of its location on the display based on the sensed location of the EM tracking sensor137. This representation can be used to assist in navigating to a desired point in the patient as depicted in either two-dimensional images or a three-dimensional model of a desired portion of the patient. For example, the system10may display a virtual image of the shaft133overlaid over an ultrasound image on the display110.

Since the only middle part132bof the cannula132is flexible, when the shaft133navigates within a patient's body, the distal part132cincluding the EM tracking sensor137moves along with the navigation of the shaft133. Thus, flexibility of the middle part132balso increases detection accuracy of the current location of the shaft133and prevent the shaft133from breaking due to the stress. The EM tracking sensor137may be rigidly affixed by an adhesive or by other suitable means which do not interfere with the EM field and the frequency employed by the treatment probe130, may be used. Alternatively, the EM tracking sensor137may be printed on the cannula132at a predetermined position.

Now turning toFIGS.4A-4G, there are shown various sensor mounts for the ultrasound imager140to provide location information about the ultrasound imager140to the EM tracking system100to provide real time images of the patient while the clinician navigates the treatment probe130to a desired location. These sensor mounts are to enable the use of off the shelf ultrasound probes with the system10, thus enabling clinicians to utilize their preferred imaging systems and probes and integrate them into system10. In particular,FIG.4Ashows the ultrasound imager140, an EM tracking sensor141, and a sensor mount142. The ultrasound imager140includes an ultrasound transducer140awhich emits ultrasound energy and receives reflected ultrasound energy. The received ultrasound energy is then transmitted to an image processing device such as the ultrasound workstation150, which calculates and processes the reflected ultrasound energy to generate real-time ultrasound images and transmits to the workstation102. When the ultrasound imager140is proximate the treatment probe130the images may include the shaft133, a target region for treatment, and other internal organs. The processed real-time images are displayed on the display110.

The ultrasound imager140may include a smooth round-shape at its distal tip140band/or a cut-out portion140cin the middle thereof. The cut-out portion140cmay have an inclination from the top surface toward the center. The inclination has an angle θ with respect to the longitudinal axis, which is greater than zero degrees and less than 90 degrees.

The EM tracking sensor141is mounted inside of a sensor mount142which may slidably and releasably engage with the distal tip140b. The sensor mount142includes a locking mechanism, which will be described below inFIGS.4E-4H. The locking mechanism makes a locking engagement sufficiently strong enough so that the ultrasound imager140can navigate inside of the patient's body without risks of removal of the sensor mount142. The material of the sensor mount142should not hinder propagation and reception of the ultrasound energy by the ultrasound transducer140a.

The position of the EM tracking sensor141may be predetermined to have a spatial relationship between the EM tracking sensor141and the distal tip140bof the ultrasound imager140. As with the treatment probe130, described above the EM tracking system100is able to identify the location of the distal tip140bbased on the spatial relationship and the detected location of the EM tracking sensor141. In this manner, the location of the ultrasound imager140in space, and more particularly within or over the patient, can be determined such that the ultrasound image plane generated by the ultrasound imager140can be determined, compared, and correlated to the location of the treatment probe130.

In another aspect, the material of the sensor mount142may not hinder propagation and reception of the ultrasonic waves by the ultrasound transducer140a.

InFIG.4B, there is shown a sensor mount143, which is a top cap version. The sensor mount143engages with the ultrasound imager140from the top or at the inclination of the ultrasound imager140. Since the inclination has the angle θ, the top portion of the sensor mount143also has an inclination having the angle θ with respect to the longitudinal axis of the ultrasound transducer140a, they fit to each other. Also, the inclinations of the sensor mount143and the cut-out portion140cmake possible to align the EM tracking sensor141with an angle with which the ultrasound imager140transmits ultrasonic waves. In an aspect, the position in the sensor mount143, to which the EM tracking sensor141is fixed, may be predetermined to set a spatial relationship between the EM tracking sensor141and the ultrasound transducer140a. It will be appreciated by those of skill in the art that extending from the sensor mounts142and143are wires which are used to connect the EM tracking sensor141to the EM tracking system100such that the location of the EM tracking sensor141in the EM field can be determined.

Turning now toFIGS.4C and4D, there are shown sensor mounts, which are hypotubes. InFIG.4C, the hypotube146as a sensor mount may have four fingers that grab the cut-out portion140c(FIG.4A) of the ultrasound imager140and may cover a portion of the bottom and the side of the ultrasound imager140. The EM tracking sensor141may be between the hypotube146and the ultrasound imager140, or may be affixed at a predetermined position on the outside surface of the hypotube146. The hypotube146is made of materials, which decreases neither the sensitivity of the EM tracking sensor141in the EM field nor the quality of ultrasound images obtained by the ultrasound transducer140a.

The hypotube147ofFIG.4Dincludes all the features of the hypotube146ofFIG.4Cand further includes a distal cap147acovering a portion of the distal tip140bof the ultrasound imager140.

Turning now toFIGS.4E-4G, there are shown sensor mounts, which are hypotube clips.FIG.4Eshows a perspective view andFIG.4Fshows a transverse view of the ultrasound imager140. The hypotube clip148may be connected with the ultrasound imager140from the side of the ultrasound transducer140a. The hypotube clip148may include two clip tabs, which are bent flat to match the profile of the ultrasound transducer140a. The EM tracking sensor141may be affixed at a predetermined position on the hypotube clip148. In an aspect, the clip tabs148amay lock the EM tracking sensor141in the circumferential direction.

The hypotube clip149ofFIG.4Gincludes only one clip tab149aat the proximal end of the ultrasound transducer140aand a cap149bat the distal end of the ultrasound transducer140awhich covers the distal tip140b. In an aspect, the cap149bmay embed the EM tracking sensor141. The clip tab194aand the cap149btogether may prevent a shift movement along the longitudinal direction so that the position of the EM tracking sensor141can be consistent with respect to the distal tip of the ultrasound imager140.

As will be appreciated, one of the issues with connecting the EM tracking sensor141to the ultrasound imager140is to ensure that the EM tracking sensor141does not interfere with the ultrasound transducer140a. Accordingly, all the preceding embodiments focused on placing the EM tracking sensor141near the ultrasound transducer140abut not on the ultrasound transducer140a. An alternative approach would be to adhere the EM tracking sensor141to the ultrasound transducer140ausing a phantom material, which does not interfere with the transducer's imaging capabilities.

A further approach, much like discussed above, with respect to the treatment probe130, is to insert the ultrasound imager140into a cannula170which includes the EM tracking sensor141. By fixing the orientation of the cannula170to the ultrasound imager140, the effect is similar to that of affixing the EM tracking sensor141directly to the ultrasound imager140. InFIG.5A, there is shown a locking mechanism for connecting the ultrasound imager140to a cannula170. The shaft of an ultrasound imager140can be locked into the cannula170using a collet, for example a John Guest® collet, which includes an inner tube171and an outer tube172. When the ultrasound imager140is inserted into the cannula170, the outer tube172compresses the inner tube171. As a result, the teeth of the inner tube171grab the ultrasound imager140holding it in place with respect to the cannula170.

An alternative approach is shown inFIG.5B, there is shown a Tuohy-Borst type locking mechanism180which can be used to lock a cannula170to the ultrasound imager140using an O-ring. The locking mechanism180includes a front end180aand an O-ring180b. In operation the locking mechanism is locate on a proximal end of a cannula170and the ultrasound imager is inserted into the cannula and locked into place by rotating the front end180asuch that the O-ring type is compressed locking the cannula170to the ultrasound imager140. Rotation of the front end180ain the opposite direction releases the pressure applied by the O-ring to the ultrasound imager140and allows for its removal from the cannula170.

Now turning toFIG.5C, there is shown a cannula190into which the ultrasound imager140may be inserted. The cannula190may include a flexible middle portion190a, which in combination with a D-shape190bat the distal end allows for the ultrasound imager140to self-align in the cannula190and have flexibility of motion. In addition, the D-shape190ballows for the accommodation of a 4-way ultrasound transducer. The EM sensor137may be formed directly on the cannula190. As a result of the self-alignment enabled by the D-shape, the orientation of the EM sensor137and the ultrasound imager140placed therein (and not shown inFIG.5C) is fixed, even in instances where the ultrasound imager flexes or bends, such as when the ultrasound imager140is a 4-way ultrasound imager. The EM sensor137may be connected via a wire to the EM tracking system100as shown inFIG.1. The wire may run internally or externally of the cannula190, and may be modified to accommodate the flexure of the cannula190.

In addition to the foregoing, methods for performing a treatment (e.g., microwave ablation) procedure using the EM tracking sensor137of the treatment probe130and ultrasound imager140are further described in provisional patent application No. 62/154,958 entitled SYSTEMS AND METHODS FOR CONTROLLING AN ELECTROSURGICAL GENERATOR DURING A MICROWAVE ABLATION PROCEDURE, filed on Apr. 30, 2015, by Covidien LP, the contents of which is hereby incorporated by reference in its entirety.

FIG.6shows a graphical interface600displayed on the display110ofFIG.1. The display110displays an ultrasound image602, the left side image, received from the ultrasound workstation150and also shows two indications604and606informing that an antenna tracker and an ultrasound tracker are activated and being tracked. Right side image612is a composite of image600illustrating the progression of a treatment, here microwave ablation. Indication610may shows that an ablation treatment has started. The treatment probe130is displayed as generated image614, its location and orientation on the image having been determined by the special relationship between the treatment probe130and the ultrasound probe140, as described above. A treatment region618shows the tissue which has been treated, while target region620depicts the entire region to be treated. The tip614aof the treatment probe130is displayed being inserted to the target region. Other textual information616and608may be displayed to show power being applied to the treatment probe130and the temperature of the treatment probe130or tissue proximate the treatment probe130.

Although embodiments have been described in detail with reference to the accompanying drawings for the purpose of illustration and description, it is to be understood that the inventive processes and apparatus are not to be construed as limited thereby. It will be apparent to those of ordinary skill in the art that various modifications to the foregoing embodiments may be made without departing from the scope of the disclosure.