Virtual ablation tool for interstitial trans-bronchial catheter therapy of lung tumors with circumferential ultrasound ablation

Abstract

A tool to create virtual lesions inside a 3D lung tumor image. The image can be an MRI or CT image of a patient's lung to be treated. This virtual pre procedural ablation allows the operator to identify optimal ablation sites and select the optimal ablation parameters for the given anatomy. Also, the actual procedure will be performed with the lung parenchyma surrounding the tumor preventing ultrasound to penetrate beyond the tumor walls. A diagnostic mode will guide the operator to optimize ablation parameters. This virtual pre ablation, the parenchymal ultrasound barrier and the diagnostic catheter operation should enable the operator to conduct the therapeutic procedure safe, fast and effective.

Description

[0001]

[0002] VIRTUAL ABLATION TOOL FOR INTERSTITIAL TRANS-BRONCHIAL

[0003] CATHETER THERAPY OF LUNG TUMORS WITH CIRCUMFERENTIAL

[0004] ULTRASOUND ABLATION

[0005] BACKGROUND OF THE INVENTION

[0006] Field of the Invention

[0007] The present invention relates to a pre-planned virtual method and system for catheter based treatments of lung tumors in mammalian subjects for the ablation of lung tumors as part of a transbronchial biopsy procedure with 3D navigation.

[0008] Background

[0009] Lung tumors represent a significant health issue with reduced quality of life due to prolonged and complicated treatment regiments. While procedures to successfully perform tumorbiopsies are established (Electromagnetic Navigation Bronchoscopy, ENB or shape sensing approaches), tumor removal or ablation is mostly performed in separate procedures putting the patient under enormous psychological stress.

[0010] US Patent No. 11,565,135, the entire contents of which are incorporated by reference herein, discloses catheter based treatments of lung tumors utilizing ultrasound. Lung tumor ablation with ultrasound has significant advantages over the currently used energy forms due to the total ultrasound reflection by air in the tumor surrounding parenchyma as explained below.

[0011] SUMMARY OF THE INVENTION

[0012] US Patent No. 11,565,135 discloses catheter based treatments of lung tumors utilizing ultrasound. The present invention provides enhancements for such procedures through its preplanning.

[0013] The catheter based treatment utilizes ultrasound for lung tumor ablation providing advantages over current treatment such as cryo, RF or microwave energy. It further utilizes application of circumferential or volumetric A-mode signals in lung tumor ablation methods for diagnostic assessment. To enhance the foregoing, the present invention provides a virtual plan system to guide and improve tumor ablation procedures and outcomes, discussed in detail below. In some embodiments, the present invention contemplates performing the lung tumor ablation as part of a 3D guided transbronchial biopsy procedure (ENB or shape sensing) with onsite pathological evaluation. This interstitial approach is currently performed with RF, Cryo or Microwave energy. Lung tumor ablation with ultrasound of the present invention has significant advantages over the currently used energy forms due to the total ultrasound reflection by air in the tumor surrounding parenchyma as explained below.

[0014] The present invention in some embodiments utilizes an OTW (over the wire) catheter with circumferential ultrasound.

[0015] The present invention provides a planning tool enabling virtual ablation in a 3D image, such as a CT or MRI 3D image, to allow optimization of treatment parameters. This provides graphic displays and representations of treatment virtually pre-procedure as a guide to the actual ablation procedure. This is described in detail below.

[0016] Also contemplated in some embodiments are graphic displays and representations during the actual procedure, which can utilize the pre-procedure displays and / or provide comparative visual graphics. This is also described in detail below.

[0017] In addition, the treatment catheter can, in some embodiments, be operated in a diagnostic mode monitoring the ablation progress, allowing the operator to adjust the ablation parameters, anatomical position, depth, and / or distance based on the volumetric A-mode diagnostic information. This involves receiving via the ultrasound transducer an ultrasound echo from organic tissues in particular the tumor / lung parenchyma interface of the mammalian subject in response to the short pulse, the ultrasound echo being a volume-integrated A-mode signal.

[0018] Alternatively, the OTW (over-the wire) therapy catheter can be exchanged for a diagnostic imaging catheter to monitor the ablation progress. The graphic displays, in relation to the 3D image, can also be utilized to monitor treatment.

[0019] In the virtual planning tool of the present invention, heat propagation calculations will give the operator feedback regarding collateral damage and ablation efficacy. With such feedback, anatomical variations can be addressed by for example varying ablation depth. Also, energy levels can likewise be addressed. By optimizing ablation parameters based on anatomic variations, a high degree of efficacy can be achieved. For example, varying tumor thickness require varying energy settings for the ablation to achieve lesions completely covering the tumor, but avoid collateral damage through significant over-ablation. One aspect of the present invention provides a tool to create virtual lesions inside a 3D lung image. The image can be an MRI or CT image of a patient’s lung in particular the tumor to be treated (see FIG 1 ). This virtual pre-procedural ablation allows the operator to identify optimal ablation sites and select the optimal ablation parameters for the given anatomy. Also, the safety margin with respect to collateral damage can be evaluated in the virtual model. This virtual ablation will enable the operator to conduct the subsequent actual procedure safer, faster and more effective. In the actual procedure the catheter is advanced into the lung tumor over the guidewire placed with Electromagnetic Navigation Bronchoscopy (ENB) or shape sensing technologies. The step of advancing the catheter may include advancing a dilator to create a pathway for the ultrasound catheter.

[0020] The above-described treatment energy delivery technique can be tested during the virtual pre-procedure through graphic overlays of the utilized devices.

[0021] The apparatus (treatment device / catheter) provides for a diagnostic mode operation of the catheter to sense an average diameter of the tumor (see FIG 4B). Due to the total reflection of ultrasound by the air-fdled parenchyma surrounding the solid tumor mass, the outer solid mass / parenchyma echo will be very strong and easy to detect. The width of the tumor / parenchyma echo represents a measure for the tumor eccentricity, while the middle of the echo represents the mean tumor diameter. Tumor size variations can be compensated for through output power, pulsed operation and application time adjustments. The ablation progress and the appropriate dosing of the energy can be monitored by switching the catheter into a circumferential diagnostic A mode detection. The ablated tumor tissue has a distinctly higher echo amplitude and frequency content compared to soft tissue. Also, gas bubbles will develop during ablation and change the tumor tissue signal. The diagnostic mode can be interleaved with the therapeutic ablation to enable a quasi-real time monitoring. Another option is to exchange the therapy for an imaging-catheter to obtain the diagnostic image (see FIG 4A).

[0022] The actuator or control unit can be configured to measure time delay of the volume integrated A-mode signal caused by total ultrasound reflection at a tumor / parenchyma interface and therewith determine the size of the tumor, the control unit being configured to control the ultrasound transducer to vary an amount of therapeutically effective ultrasound energy in accordance with a determined size of the tumor taking into account catheter efficiency variations. A preferred embodiment of the invention utilizes a guidewire positioned under ENB guidance or shape sensing guides into the tumor. The treatment catheter is advanced over this guidewire and the treatment performed through one or several additive ablations as indicated in FIG 2. Diagnostic mode measurements as shown in FIG 4B will allow monitoring of the ablation process by increased echo amplitudes, echo frequency and air bubble detection. Alternatively, the treatment catheter can be exchanged for an imaging catheter to monitor ablation progress, see FIG 4A.

[0023] In accordance with one aspect of the present invention, a method of virtually ablating a lung tumor of a mammalian subject is provided comprising the steps of (a) obtaining one or more three dimensional images, e.g., MR or CT images, of the lung to be treated and positioning a graphic display of an ablation device into the lung tumor to be treated; (b) positioning a graphical overlay of the energy distribution of the ablation device over the imaged lung tumor; and (c) repeatedly actuating the virtual energy emitter to apply energy throughout the tumor until a complete virtual circumferential lesion covering the tumor has been achieved.

[0024] In accordance with another aspect of the present invention, a method for performing tumor ablations in a mammalian subject after a pre-planned virtual ablation is provided comprising: a) subsequent to performing a virtual tumor ablation, operating an actuator or control unit, electrically connected to an ultrasound transducer, to energize the ultrasound transducer to emit a short pulse at a sub-therapeutic level; b) receiving via the ultrasound transducer an ultrasound echo from the tumor / lung parenchyma interface of the mammalian subject in response to the short pulse, the ultrasound echo being a volume-integrated A-mode signal; c) operating the actuator or control unit to process the volume integrated A-mode signal, which represents an accumulated intensity of the circumferential ultrasound echoes; d) analyzing the volume integrated A-mode signal to determine average tumor diameter; and e) activating the ultrasound transducer to transmit ultrasound therapeutic waveform energy optimized to create complete tumor ablation based on the A mode signal analysis.

[0025] In accordance with another aspect of the present invention, a system for performing tumor ablations in a mammalian subject after a pre-planned virtual ablation is provided, the system comprising an ablation device and an actuator or control unit electrically connected to an ultrasound transducer of the device to energize the ultrasound transducer to emit a short pulse at a sub-therapeutic level, the actuator or control unit a) processing a volume integrated A-mode signal generated by the transducer, which represents an accumulated intensity of circumferential ultrasound echoes; b) analyzing the volume integrated A-mode signal to determine average tumor diameter; and c) activating the ultrasound transducer to transmit ultrasound therapeutic waveform energy optimized to create complete tumor ablation based on the A mode signal analysis and based on the pre-planned virtual ablation.

[0026] In accordance with another aspect of the present invention, a graphic representation tracking a virtual lung tumor ablation procedure is provided comprising a graphic overlay positioned over an image of the lung tumor, the graphic representation visually depicting progress of lung tumor ablation upon application of virtual energy to the lung tumor and further depicting virtual temperature of the tissue during application of virtual energy, the graphic representation informing the clinician for subsequent lung tumor ablation procedure.

[0027] Further objects, features, and advantages of the present invention will be more readily apparent from the detailed described embodiments set forth below, taken in conjunction with the accompanying drawings.

[0028] BRIEF DESCRIPTION OF THE DRAWINGS

[0029] So that those having ordinary skill in the art to which the subject invention appertains will more readily understand how to make and use the apparatus (device) and method disclosed herein, preferred embodiments thereof will be described in detail hereinbelow with reference to the drawings, wherein:

[0030] FIG. 1 shows a lung tumor CT image.

[0031] FIG. 2 shows the interstitial trans bronchial tumor ablation approach.

[0032] FIG. 3 shows typical temperature distribution curves for continuous wave (CW) and pulsed operation.

[0033] FIG. 4A shows an ultrasound image of a lung tumor surrounded by lung parenchyma.

[0034] FIG. 4B indicates the diameter measurement and ablation progress monitoring of a lung tumor surrounded by lung parenchyma.

[0035] FIG. 5A shows non-coupled balloon with multiple reverberations.

[0036] FIG. 5B shows balloon coupled with tissue with no reverberations. DETAILED DESCRIPTION

[0037] Referring now to the drawings and particular embodiments of the present disclosure, wherein like reference numerals identify similar structural features of the apparatus throughout the several views, lung tumor ablation approaches and procedures are depicted.

[0038] The present invention provides a pre-planned virtual treatment for an apparatus for ablating lung tumors in a human or non-human mammalian subject. The apparatus preferably includes an ultrasound transducer adapted for insertion trans bronchially into the tumor of the subject. By ablating the tumor from the inside out, the impact volume or ablation zone is much better controlled than in extracorporeal or endo bronchial, side-firing, ultrasound applications. (As explained for example in Endobronchial High Intensity Ultrasound for Thermal Therapy of Pulmonary Malignancies, IntT J of Hyperthermia; Vol 36, Issue 1). The ultrasound transducer desirably is arranged to transmit a circumferential volume of ultrasound energy. The apparatus preferably also includes an actuator or control unit which is electrically connected to the transducer. The actuator / control unit preferably is adapted to control the ultrasound transducer to transmit ultrasound energy into an impact volume of at least approximately 1 cm3, surrounding the apparatus / catheter so that the circumferentially emitted ultrasound energy is applied at a therapeutic level sufficient to ablate tumor tissue. Further details of the catheter based system for lung tumor ablation is disclosed in commonly assigned U.S. Patent 11,565,135 (hereinafter the ‘ 135 patent), the entire contents of which are incorporated herein by reference.

[0039] Tumor dimensions are recorded during pre-procedural CT scans and determine the ultrasound settings (frequency, power and time) as well as the transducer length or focal depth (See FIG 2). Typical activation parameters are 1 to several MHz at 10 to 30 W for 0.5 to several minutes for tumor ablation. The transducer length is either adjusted electronically by selecting a certain number of cylindrical transducer subsegments or through catheter exchange. Further, the present invention contemplates use of a separate imaging catheter (for example a commercial IVUS catheter) advanced over the guide wire after the therapy catheter has been withdrawn to ensure complete tumor ablation (See FIG 4A). Catheter length markings may be provided on both the therapy catheter and the imaging or diagnostic catheter to enable a quick catheter exchange.

[0040] The treatment apparatus can include a catheter with a distal end and a proximal end, the transducer being mounted to the catheter adjacent the distal end. The transducer can be disposed inside a balloon which will make contact with the tumor tissue. This balloon can be filled with a circulating cooling fluid to conduct ultrasound energy from the transducer to the tumor tissue. This cooling fluid also transports excessive heat away from the transducer. About half of the electrical energy supplied to the transducer is converted into heat while the other half is converted to ultrasonic energy. To be enabled for clinical use, the energy levels and balloon diameters are adjusted in accordance with the tumor dimensions. If these parameters are not properly adjusted, e.g., if there is a constant energy setting for all tumor or bronchial diameters, there is a significant risk of either too much damage caused by the ultrasound ablation or not enough energy to properly ablate the tumor. Therefore, in order to work with a range of tumor volumes, the device advantageously is enabled to adjust ultrasound power settings based upon the diameter of the tumor, see FIG 4B.

[0041] The transducer may be configured to transmit the ultrasound energy in a 360° cylindrical pattern surrounding a longitudinal transducer axis. The transducer also can be subdivided into cylindrical sections / segment which allows for electronic near field (L L / lambda) adjustment by varying the overall transducer length L according to tumor dimensions.

[0042] The treatment catheter can in some embodiments be moved longitudinally to obtain complete tumor ablation under ENB, shape sensing or robotic guidance. That is, adjacent circular transducer segments can be activated longitudinally to obtain complete tumor ablation under ENB or robotic guidance.

[0043] The system circulating the coupling / cooling fluid may measure the fluid volume V and pressure P and therewith determine balloon contact with the tumor. Once the balloon is in circumferential contact with the tumor, the system will detect a pressure increase P without a significant volume increase V which corresponds with circumferential balloon / tissue contact. Alternatively, circumferential A-mode signal will show a change in the reverberation pattern once contact has been made.

[0044] FIG. 5A shows non-coupled balloon with multiple reverberations; FIG. 5B shows balloon coupled with tissue with no reverberations.

[0045] Because the impact volume is relatively large, and because the tissues throughout the impact volume preferably reach temperatures sufficient to necrose tissue, tumor dimensions need to be known from pre procedural CAT or MRI scans (see FIG 1) and or imaging catheters exchanged over the wire (OTW) for the therapeutic catheter (see FIG 4A) or through a diagnostic mode as shown in FIG 4B in order to adjust energy settings and transducer length L according to the treatment volume.

[0046] Alternatively, the treatment catheter represented through a graphic overlay can be positioned inside the virtual model (e.g., 3D CT or MRI) as shown in a 2D image in FIG 1, and the ablation process can be controlled through the temperature distribution simulation software calculation. During the simulated ablation process, the temperature distribution is represented through a graphic color overlay to allow the user to control and visualize the ablation process since ablated tissue has a certain color assigned and therefore can be observed during ablation simulation. Ablated tissue clearly shows a different color than non-ablated tissue so that the simulated ablation can be terminated when a complete tumor coverage has been obtained.

[0047] Consequently, the present invention provides a method of virtually ablating a lung tumor of a mammalian subject comprising the steps of a) obtaining one or more three dimensional images (e g., MR or CT 3D images) of the lung to be treated and positioning a graphic display of an ablation device into the imaged lung tumor to be treated; b) positioning another graphical overlay of the energy distribution of the ablation device over the lung tumor image; and (c) repeatedly actuating the virtual energy emitter to apply energy throughout the tumor until a complete virtual circumferential lesion covering the tumor has been achieved. The graphical overlay of energy distribution can be a color overlay representative of simulated temperature changes signifying ablated and non-ablated tissue differentiation. Other indicia for differentiation are also contemplated.

[0048] In the step of actuating the virtual energy, an ablation section is selected by an operator / user / clinician in the three dimensional MRI or CT or other image and the graphic overlay representing an energy field is brought into an overlapping position. Thus, the energy field display overlaps the treatment catheter display. With the virtual ablation section selected, it triggers a simulated calculation of temperature distribution which can be modified through dose, duration and pulsed mode for the therapeutic energy application. The temperature can be based on the energy level and volume of tissue in which the energy is applied. Thus, the user can determine the temperature changes and make in the simulation appropriate changes to the target area / volume of the tumor and / or energy level and / or duration of energy application, thereby providing an accurate and effective ablation treatment plan for the actual procedure. The present invention also provides a system for performing tumor ablations in a mammalian subject after a pre-planned virtual ablation is provided, the system comprising an ablation device and an actuator or control unit electrically connected to an ultrasound transducer of the device to energize the ultrasound transducer to emit a short pulse at a sub-therapeutic level, the actuator or control unit a) processing a volume integrated A-mode signal generated by the transducer, which represents an accumulated intensity of circumferential ultrasound echoes; b) analyzing the volume integrated A-mode signal to determine average tumor diameter; and c) activating the ultrasound transducer to transmit ultrasound therapeutic waveform energy optimized to create complete tumor ablation based on the A mode signal analysis and based on the preplanned virtual ablation.

[0049] The indicator of temperature distribution can be provided through an over-lay color map on the three dimensional image such as an MRI or CT 3D image. Other indicia, including for example numeric or graphic indicia, can alternatively or in addition be provided.

[0050] In some embodiments, the temperature distribution includes setting an alarm in the ablation simulation if a predetermined temperature is reached in the energy field during the simulation (virtual ablation). This can include for example automatic activation of an alarm if 70 degrees Centigrade is reached anywhere in the virtual energy field. Other predetermined temperatures are also contemplated. In some embodiments, temperature distribution includes setting an alarm in the ablation simulation if a predetermined temperature is reached outside the lung tumor. This can include for example activation of an alarm if 60 Centigrade is reached outside the lung tumor. Other temperatures are also contemplated.

[0051] It is also contemplated that in some embodiments, a graphical overlay is placed over the image of the lung tumor during actual application of energy to the tumor during the actual ablation procedure. This graphical overlay can provide visual representation of the lung tumor ablation during the procedure to provide a guide and feedback during the procedure. Thus, in this embodiment, a graphical overlay is used in the planning pre-procedure during virtual energy application and another graphical overlay is used during the procedure during actual energy application. It is also contemplated that the graphical overlay tracking the procedure is compared to the graphic overlay utilized during virtual energy for comparative analysis. In further alternate embodiments, a graphical overlay for a pre-planning virtual ablation is not utilized but only the graphical overlay during the ablation procedure is used. Thus, such embodiment does not provide virtual ablation but provides information to the user during the actual ablation procedure described herein using the ablation catheter described herein.

[0052] It is also contemplated that data regarding the energy level, temperature and other parameters, including adjustments made by the user during the pre-procedure virtual planning, can be stored in the device or a computing device connected either via wires / cable or wirelessly. Such data can be used to inform the user for future use. Such data can also be used by a health care practitioner to assess treatment efficacy. Machine learning is also contemplated to process the data and provide improved parameters and inputs for the particular user or overall for users of the technology. Data can also be collected during the procedure and compared to the data collected in the virtual procedure. Further, machine learning can alter the algorithms and user guidance to improve procedural parameters and outcomes.

[0053] Consequently, the invention provides a tool to create virtual lesions inside a 3D lung tumor image. The image can be an MRI or CT image of a patient’s lung to be treated. This virtual pre procedural ablation allows the operator to identify optimal ablation sites and select the optimal ablation parameters for the given anatomy. The actual procedure will be performed with the lung parenchyma surrounding the tumor preventing ultrasound penetrating beyond the tumor walls. A diagnostic mode will guide the operator to optimize ablation parameters. This virtual pre ablation, the parenchymal ultrasound barrier and the diagnostic catheter operation should enable the operator to conduct the therapeutic procedure safe, fast and effective.

[0054] Thus, the present invention provides a graphic representation tracking a virtual lung tumor ablation procedure comprising a graphic overlay positioned over an image of the lung tumor, the graphic representation visually depicting progress of lung tumor ablation upon application of virtual energy to the lung tumor and further depicting virtual temperature of the tissue during application of virtual energy, the graphic representation informing the clinician for subsequent lung tumor ablation procedure.

[0055] With the treatment catheter in the operative position, the energy excitation source is activated. Merely by way of example, the energy source is driven to emit, for example, about 10 watts to about 100 watts of acoustic power, most typically about 15 watts. The actuation in this example is continued for about 10 seconds to about a minute or more, most typically about 20 seconds to about 40 seconds per lesion. Optionally, based on the temperature distribution color map the actuation may be repeated several times or switched to pulsed mode operation to increase penetration as indicated in FIG 3. The power levels and actuation times may be varied from those given above.

[0056] The ultrasound field generated by the transducer propagates generally radially outwardly from the catheter shaft as indicated by a graphic overlay in the preprocedural simulation (see FIG 2). This graphic display will allow the user to avoid exposing collateral structures, e.g., the esophagus, to damaging energy exposures and therewith damaging temperatures. However, tumors surrounded by lung parenchyma which reflects ultrasound energy back into the tumor can be safely ablated without danger of impacting collateral structures as shown in Figs 4A and 4B. Provided the energy source is positioned optimally in the tumor (see FIG 1), the air filled alveoli in the surrounding lung parenchyma reflect sufficient energy so that temperatures in neighboring structures are harmless. This way the air filled lung parenchyma surrounding the tumor increases the safety of the actual procedure significantly.

[0057] In some embodiments, the actuator or control unit transmits ultrasound therapeutic energy based on the pre-planned virtual ablation which includes a graphical overlay of energy distribution of the ablation device positioned over the lung tumor and tracking virtual energy emitted to apply energy throughout the tumor until a complete virtual circumferential lesion covering the tumor has been achieved.

[0058] In some embodiments, the actuator or control unit is configured to analyze the volume integrated A-mode signal to facilitate complete tumor ablation by monitoring a speckle pattern (amplitude / frequency) and gas bubble reflections caused by tumor tissue necrosis, the speckle pattern effected by one or both of amplitude and frequency of the signal.

[0059] The energy applied by the ultrasound catheter is effective to heat and thus necrose (a section of) the tumor as shown in FIG 2. After several circular lesions have been formed, the tumor is completely ablated as shown in FIG 2. Through temperature distribution calculations also in the virtual procedure complete tumor ablation can be confirmed. The actual ablation progress is being monitored as indicated in FIG 4B through echo analysis (amplitude, frequency and air bubble reflections). Also, the color overlay in the pre procedural planning tool, very similar to anatomical mapping, will clearly show the ablation progress. The advantage of this approach is that all anatomical variations can be safely treated by moving the ablation plane to avoid ablating collateral structures and or by tilting the ablation plane by bending the distal catheter portion. In some embodiments, a 3D model is printed based on the CT or MR image wherein catheter manipulation can be performed.

[0060] With the present invention, tumors in general are selectively virtually ablated while minimizing impact on surrounding tissues by taking advantage of the ultrasound reflection back into the tumor by the tumor / parenchyma interface.

[0061] Numerous other variations and combinations of the features discussed above can be utilized without departing from the present invention as defined by the claims. The state of the lesion coagulation can be monitored by volumetric A mode ultrasound imaging during the treatment or therapeutic / diagnostic catheter exchanges. During treatment, the tissue changes its physical properties, and thus its ultrasound reflectivity when heated. These changes in tissue ultrasound reflectivity can be observed using ultrasonic volumetric A mode imaging to monitor the formation of the desired lesion in the lung tumor. Other imaging modalities which can detect heating can also be used to monitor the treatment. For example, magnetic resonance imaging can detect changes in temperature.

[0062] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.

[0063] Additionally, persons skilled in the art will understand that the elements and features shown or described in connection with one embodiment may be combined with those of another embodiment without departing from the scope of the present invention and will appreciate further features and advantages of the presently disclosed subject matter based on the description provided.

[0064] Throughout the present invention, terms such as “approximately,” “generally,” “substantially,” and the like should be understood to allow for variations in any numerical range or concept with which they are associated. For example, it is intended that the use of terms such as “approximately” and “generally” and “substantially” should be understood to encompass variations on the order of 25%, or to allow for manufacturing tolerances and / or deviations in design. Although terms such as “first,” “second,” “third,” etc., may be used herein to describe various operations, elements, components, regions, and / or sections, these operations, elements, components, regions, and / or sections should not be limited by the use of these terms in that these terms are used to distinguish one operation, element, component, region, or section from another. Thus, unless expressly stated otherwise, a first operation, element, component, region, or section could be termed a second operation, element, component, region, or section without departing from the scope of the present disclosure.

[0065] Each and every claim is incorporated as further disclosure into the specification and represents embodiments of the present disclosure. Also, the phrases “at least one of A, B, and C” and “A and / or B and / or C” should each be interpreted to include only A, only B, only C or any combination of A, B and C.

Claims

WHAT TS CLAIMED TS;1. A method of virtually ablating a lung tumor of a mammalian subject comprising the steps of:(a) obtaining one or more three dimensional images of the lung to be treated and positioning a graphic display of an ablation device into the lung tumor to be treated;(b) positioning a graphical overlay of the energy distribution of the ablation device over the imaged lung tumor; and(c) repeatedly actuating a virtual energy emitter to apply energy throughout the lung tumor until a complete virtual circumferential lesion covering the tumor has been achieved.

2. The method as claimed in claim 1, wherein the three dimensional image is a three dimensional MRI or CT image.

3. The method as claimed in claim 1, wherein the step of actuating the therapy is performed based on an ablation section selected by an operator in the three dimensional image and the graphic overlay representing an energy field brought into an overlapping position.

4. The method as claimed in claim 3, wherein the step of actuating the energy emitter based on the ablation section triggers a calculation of temperature distribution which can be modified through dose, duration and pulsed mode for a therapeutic energy application.

5. The method of claim 4, further comprising indicating the temperature distribution through an overlay color map on the three dimensional image.

6. The method of claim 5, wherein the temperature distribution includes setting an alarm if 70 degrees Centigrade is reached anywhere in the virtual energy field.

7. The method of claim 6, wherein the temperature distribution includes setting an alarm if 60 degrees Centigrade is reached outside the lung tumor.

8. The method of claim 7, wherein a graphical overlay is placed over the image of the lung tumor during application of energy to the tumor.

9. The method of claim 8, wherein the graphical overlay placed over the image of the lung tumor provides visual representation of the lung tumor ablation.

10. The method of claim 9, wherein the graphical overlay tracking the procedure is compared to the graphic energy emitter overlay utilized during the virtual procedure.

11. A method for performing tumor ablations in a mammalian subject after a preplanned virtual ablation, the method comprising:(a) subsequent to performing a virtual tumor ablation, operating an actuator or control unit, electrically connected to an ultrasound transducer, to energize the ultrasound transducer to emit a short pulse at a sub-therapeutic level;(b) receiving via the ultrasound transducer an ultrasound echo from a tumor / lung parenchyma interface of the mammalian subject in response to the short pulse, the ultrasound echo being a volume-integrated A-mode signal;(c) operating the control unit to process the volume integrated A-mode signal, which represents an accumulated intensity of the circumferential ultrasound echoes;(d) analyzing the volume integrated A-mode signal to determine average tumor diameter; and(e) activating the ultrasound transducer to transmit ultrasound therapeutic waveform energy optimized to create complete tumor ablation based on the A mode signal analysis.

12. The method of claim 11, further comprising moving the ultrasound transducer within a balloon to position the ultrasound transducer inside the tumor prior to activating the ultrasound transducer to transmit the ultrasound therapeutic waveform energy so that superimposed energy fields completely cover the tumor.

13. The method of claim 11 , wherein the ultrasound transducer is carried by a treatment catheter and the treatment catheter is moved longitudinally to obtain complete tumor ablation under ENB, shape sensing or robotic guidance.

14. The method of claim 11, where adjacent circular transducer segments are activated longitudinally to obtain complete tumor ablation under electronic navigation bronchoscopy or robotic guidance.

15. The method of claim 11 , wherein the ultrasound transducer is carried by a treatment catheter and the method further comprises obtaining the diagnostic information through an imaging catheter exchanged over the wire for the treatment catheter.

16. The method of claim 11 , wherein the ultrasound transducer is carried by a treatment catheter and the pre-planned virtual ablation includes positioning a graphical overlay of the energy distribution of the treatment catheter over the lung tumor, and repeatedly actuating a virtual energy emitter to apply energy throughout the tumor until a complete virtual circumferential lesion covering the tumor has been achieved.

17. A system for performing tumor ablations in a mammalian subject after a preplanned virtual ablation, the system comprising an ablation device and a control unit electrically connected to an ultrasound transducer of the device to energize the ultrasound transducer to emit a short pulse at a sub-therapeutic level, the actuator or control unit a) processing a volume integrated A-mode signal generated by the ultrasound transducer, which represents an accumulated intensity of circumferential ultrasound echoes; b) analyzing the volume integrated A-mode signal to determine average tumor diameter; and c) activating the ultrasound transducer to transmit ultrasound therapeutic waveform energy optimized to create complete tumor ablation based on the A mode signal analysis and based on the pre-planned virtual ablation.

18. The system of claim 17, wherein the virtual ablation includes a graphical overlay of energy distribution of the ablation device positioned over the lung tumor and tracking virtual energy emitted to apply energy throughout the tumor until a complete virtual circumferential lesion covering the tumor has been achieved.

19. The system of claim 17, wherein the control unit is configured to analyze the volume integrated A-mode signal to facilitate complete tumor ablation by monitoring a speckle pattern and gas bubble reflections caused by tumor tissue necrosis, the speckle pattern effected by one or both of amplitude and frequency of the signal.

20. The system of claim 17, wherein diagnostic information is obtained through an imaging catheter exchanged for the ablation device.

21. The system of claim 17, wherein the control unit is configured to measure time delay of the volume integrated A-mode signal caused by total ultrasound reflection at a tumor / parenchyma interface and therewith determine the size of the tumor, the control unit being configured to control the ultrasound transducer to vary an amount of therapeutically effective ultrasound energy in accordance with the determined size of the tumor taking into account catheter efficiency variations.

22. The system of claim 17, wherein the control unit is configured to control the transducer and cooling fluid circulation so as to avoid extreme temperatures in the near field while achieving a temperature about 60° Centigrade throughout the impact volume.

23. The system of claim 17, wherein the energy is applied in a pulsed mode to avoid near field over ablation and increased penetration.

24. A graphic representation tracking a virtual lung tumor ablation procedure comprising a graphic overlay positioned over an image of the lung tumor, the graphic representation visually depicting progress of lung tumor ablation upon application of virtual energy to the lung tumor and further depicting virtual temperature of the tissue during application of virtual energy, the graphic representation informing the clinician for a subsequent lung tumor ablation procedure.

25. The graphic representation as claimed in claim 24, wherein the energy emitter actuation triggers a calculation of temperature distribution which can be modified through dose, duration and pulsed mode for a therapeutic energy application.

26. The graphic representation of claim 25, wherein temperature distribution is indicated through an overlay color map on the three dimensional image.

27. The graphic representation of claim 26, wherein the temperature distribution includes an alarm if 70 degrees Centigrade is reached anywhere in the virtual energy field.

28. The graphic representation of claim 27, wherein the temperature distribution includes an alarm if 60 degrees Centigrade is reached outside the lung tumor.

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