Cycling of ablation device

Abstract

Various aspects of the present disclosure relate to devices, systems, and methods that can include a tissue ablation system. The tissue ablation system can include a plurality of ablation devices each configured to provide ablation energy, at least one ablation generator configured to provide ablation power to at least one of the plurality of ablation devices, and a controller configured to cause each of the plurality of ablation devices to selectively receive the ablation power and configured to cycle activation of a plurality of ablation states.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to provisional application No. 62 / 989,284, filed on March 13, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention generally relates to tissue ablation devices and methods of use. Background Technology

[0004] In the treatment of diseases such as cancer, it has been found that certain types of tissue denature at high temperatures. These types of treatments, often referred to as hyperthermia, typically utilize electromagnetic radiation to heat cancerous tissue to temperatures above 60°C while keeping healthy tissue at a lower temperature to prevent irreversible cell damage. Microwave ablation is one such treatment that uses electromagnetic radiation to heat tissue.

[0005] Microwave tissue ablation is a less invasive procedure than surgical resection and can be preferred in many situations where tumors are difficult to remove surgically, such as when the tumor is relatively small, located near a relatively small organ, or located near a major blood vessel. This method has been used in organs such as the prostate, heart, and liver, where surgical resection of tumors may be difficult.

[0006] To effectively plan and optimize procedures, it is desirable for ablation devices to produce ablation volumes of predictable size and shape. For this reason, regularly shaped, predictable ablation volumes are preferred, and particularly preferred those producing spherical or near-spherical ablation volumes. Ablation devices with predictable ablation volumes simplify surgical procedures and reduce adverse medical complications.

[0007] In some examples, multiple ablation devices can be used to ablate tissue. However, operating multiple ablation devices can require significant power, which may increase costs and / or reduce system portability. Furthermore, there may be negative interactions between the ablation energies emitted from multiple devices. For example, microwave radiation emitted from one microwave ablation device may interfere with microwave radiation emitted from another, leading to potential negative interference and incomplete ablation. Summary of the Invention

[0008] In Example 1, the tissue ablation system includes multiple ablation devices for placement at or near a target area of ​​a patient's anatomy, each ablation device being configured to provide ablation energy in an ablation zone adjacent to the ablation device when ablation power is provided to each ablation device; multiple ablation generators, each ablation generator being configured to provide ablation power to one of the multiple ablation devices; a controller communicating with the ablation generators, the controller being configured to cause each of the multiple ablation devices to selectively receive ablation power; a controller configured to cycle through activation of each of a multiple ablation states; and each ablation state corresponding to a unique subset of the multiple ablation devices, and activation of one of the ablation states including receiving ablation power at the ablation device in the corresponding subset of the multiple ablation devices.

[0009] In Example 2, the tissue ablation system of Example 1 activates the ablation state by not receiving ablation power for ablation devices that are not in the corresponding subset of multiple ablation devices.

[0010] In Example 3, the tissue ablation system of Example 1 or 2, activation of the ablation state includes the ablation device not in the corresponding subset of multiple ablation devices receiving less power than the ablation device receiving ablation power.

[0011] In Example 4, the tissue ablation system of Example 1 or 2, activation of the ablation state includes ablation devices that are not in the corresponding subset of multiple ablation devices not receiving power.

[0012] In Example 5, in any of the preceding examples of the tissue ablation system, the controller successively activates each of the multiple ablation states.

[0013] In Example 6, the tissue ablation system of any of the preceding examples, the controller repeatedly cycles through activation of each of the multiple ablation states.

[0014] In Example 7, the tissue ablation system of any of the preceding examples is cyclically configured to cause not all of the multiple ablation devices to receive ablation power simultaneously by activating each of the multiple ablation states.

[0015] In Example 8, the tissue ablation system of any of the preceding examples cyclically activates each of a plurality of ablation states, including activating each ablation state for the same duration.

[0016] In Example 9, the tissue ablation system of any of the preceding examples is activated for 100 to 300 ms for each ablation state.

[0017] In Example 10, the tissue ablation system of any of the preceding examples is cyclically activated by receiving ablation power at each ablation device according to its respective duty cycle through activation of each of the multiple ablation states.

[0018] In Example 11, the tissue ablation system of Example 10 has multiple devices with equal duty cycles.

[0019] In Example 12, the duty cycle of each of the multiple devices in the tissue ablation system of Example 10 is shifted over time.

[0020] In Example 13, the duty cycles of the tissue ablation systems of Example 10 are shifted over time, so that not all of the multiple ablation devices receive ablation power simultaneously.

[0021] In Example 14, the tissue ablation system of Example 10 has its duty cycle shifted in time, such that an alternating ablation device does not receive ablation power at all times as the controller cycles through activation of each of the multiple ablation states.

[0022] In Example 15, the tissue ablation system of any of the preceding examples, each of the plurality of ablation devices includes a microwave ablation needle.

[0023] In Example 16, the tissue ablation system includes a plurality of ablation devices for placement at or near a target region of a patient's anatomy, each ablation device being configured to provide ablation energy in an ablation zone adjacent to the ablation device when ablation power is received; a plurality of ablation generators, each ablation generator being configured to provide ablation power to one of the plurality of ablation devices; a controller communicating with the ablation generators, the controller being configured to cause each of the plurality of ablation devices to selectively receive ablation power; a controller configured to cycle through activation of each of a plurality of ablation states; and each ablation state corresponding to a respective unique subset of the plurality of ablation devices, and activating one of the ablation states includes receiving ablation power at an ablation device in the corresponding subset of the plurality of ablation devices, and activating an ablation state includes not receiving ablation power at an ablation device not in the corresponding subset of the plurality of ablation devices.

[0024] In Example 17, the tissue ablation system of Example 16, the activation of the ablation state includes the ablation device not in the corresponding subset of multiple ablation devices receiving less power than the ablation device receiving ablation power.

[0025] In Example 18, the tissue ablation system of Example 16, the activation of the ablation state includes ablation devices that are not in the corresponding subset of multiple ablation devices not receiving power.

[0026] In Example 19, the tissue ablation system of Example 16, the controller repeatedly cycles through activation of each of a plurality of ablation states.

[0027] In Example 20, the tissue ablation system of Example 16, the controller successively activates each of multiple ablation states.

[0028] In Example 21, the tissue ablation system of Example 16 is cyclically implemented by activating each of the multiple ablation states by receiving the ablation power at each of the multiple ablation devices with a duty cycle.

[0029] In Example 22, the tissue ablation system of Example 20 has multiple electrodes with equal duty cycles.

[0030] In Example 23, the tissue ablation system of Example 20 has a duty cycle shifted over time for each of the multiple electrodes.

[0031] In Example 24, the tissue ablation system of Example 16, each of the multiple ablation devices includes a microwave ablation needle.

[0032] In Example 25, a tissue ablation method includes providing a plurality of ablation devices for placement at or near a target region of a patient's anatomy, each ablation device being configured to provide ablation energy in an ablation zone adjacent to the ablation device when receiving ablation power; positioning two or more ablation devices sufficiently close to each other such that when the two or more ablation devices receive ablation power, the ablation zone of each of the two or more ablation devices at least partially overlaps with the ablation zone of another of the two or more ablation devices; and cyclically activating each of a plurality of ablation states via causing a particular ablation device to selectively receive and not receive ablation power, each ablation state corresponding to a respective unique subset of the plurality of ablation devices, and receiving ablation power when one of the plurality of ablation states is active.

[0033] In Example 26, the method of Example 25 activates the ablation state by having the ablation device in a corresponding subset of multiple ablation devices receive less power than the ablation device that receives the ablation power.

[0034] In Example 27, the method of Example 25, the activation of the ablation state includes ablation devices that are not in the corresponding subset of multiple ablation devices not receiving power.

[0035] In Example 28, the method of Example 25, which iterates through the activation of each of the multiple ablation states, includes repeatedly iterating through the activation of each of the multiple ablation states.

[0036] In Example 29, the method of Example 25 includes repeatedly switching each ablation device between an ON state and an OFF state by activating each of a plurality of ablation states, wherein ablation power is received in the ON state and not in the OFF state.

[0037] In Example 30, the method of Example 29 further includes measuring the reflected ablation power on each ablation device when it is in the OFF state, the reflected ablation power representing the ablation power from the ablation device in the ON state that is not absorbed in the target area.

[0038] In Example 31, the method of Example 25 states that one or more of the multiple ablation states correspond to a unique subset of multiple ablation devices that includes fewer ablation devices than the total number of ablation devices.

[0039] In Example 32, the method of Example 25 is implemented by cyclically activating each of the multiple ablation states by performing a duty cycle on the reception of ablation power at each of the multiple ablation devices.

[0040] In Example 33, a tissue ablation method includes providing a plurality of ablation devices for placement at or near a target region of a patient's anatomy, each ablation device being configured to provide ablation energy in an ablation zone adjacent to the ablation device when receiving ablation power; positioning two or more ablation devices sufficiently close to each other such that when the two or more ablation devices receive ablation power, the ablation zone of each of the two or more ablation devices at least partially overlaps with the ablation zone of another of the two or more ablation devices; and applying ablation power to the plurality of ablation devices according to their respective duty cycles, the duty cycles being equal and time-shifted such that an alternating one of the plurality of ablation devices does not receive ablation power.

[0041] In Example 34, the method of Example 33, two or more ablation devices are three or more ablation devices, and the three or more ablation devices are positioned equidistantly from each other.

[0042] In Example 35, the method of Example 34, the duty cycle of each of the plurality of ablation devices is arranged in time such that at any given time, two of the three or more ablation devices are in the ON state, and one of the three or more ablation devices is in the OFF state.

[0043] While several embodiments have been disclosed, other embodiments of the subject matter disclosed herein will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosed subject matter. Therefore, the accompanying drawings and detailed description should be considered illustrative rather than restrictive. Attached Figure Description

[0044] The advantages of the present invention will become apparent to those skilled in the art from the following detailed description and with reference to the accompanying drawings.

[0045] Figure 1A A block diagram showing components of a system for performing an ablation process according to an embodiment of the present disclosure is provided.

[0046] Figure 1B A block diagram illustrating the operation of an ablation device interface for interfacing with an ablation device for performing an ablation procedure, according to an embodiment of the present disclosure, is shown.

[0047] Figure 2 This is a simplified diagram of the cooling system according to the present disclosure.

[0048] Figure 3 This is a perspective view of a microwave tissue ablation device with a handle according to an embodiment of the present disclosure.

[0049] Figure 4A is a perspective view of a microwave tissue ablation apparatus 400 according to an embodiment of the present disclosure.

[0050] Figure 4B is a cross-sectional view through line XY to illustrate one embodiment of the cooling feature.

[0051] Figure 5 This is a side view of a microwave tissue ablation apparatus according to an embodiment of the present disclosure.

[0052] Figure 6A A plan view showing the configuration of multiple microwave ablation needles is displayed.

[0053] Figure 6B The image shows a front view of multiple ablation devices arranged at different depths.

[0054] Figure 7 The SAR field surrounding the two ablation devices is shown.

[0055] Figure 8 An exemplary embodiment of three ablation devices and their respective ablation zones is provided.

[0056] Figure 9A -C shows exemplary embodiments of three ablation devices in different ON / OFF states. Figure 9D Showing Figure 9A -C overlapping region.

[0057] Figure 10 Example sequences of duty cycle ablation devices are shown.

[0058] Figure 11 Example data of the received power signal from the first ablation device is shown.

[0059] Figure 12 Example data of the received power signal from the second ablation device is shown. Detailed Implementation

[0060] Among other factors, the size and dimensions of the ablation zone created by a microwave tissue ablation device depend on the type of microwave antenna. Clinicians can select a microwave antenna capable of generating an ablation zone larger than the target tissue and insert the antenna such that the ablation zone created by the antenna includes the target tissue. When the tissue to be ablated is larger than the ablation volume generated by the device, more than one device can be used, and the ablation volumes are combined to cover the tissue to be ablated. The embodiments of the microwave tissue ablation devices described herein can be used to create ablation zones of predictable shape with reduced tailing, which aids in ablation planning and prevents damage to tissue outside the volume to be treated.

[0061] In some embodiments, the ablation device disclosed herein is a microwave ablation device configured to induce ablation by emitting microwave energy to kill tissue by heating. Typically, the device is a microwave ablation needle with a microwave antenna, such as those described herein.

[0062] In another aspect, the present invention provides a system for microwave ablation of tissue, the system comprising one or more microwave ablation devices, such as probes or needles as described herein, the microwave ablation device including a microwave antenna configured to deliver microwave energy to the tissue, a microwave generator configured to provide microwave energy to the microwave antenna via a feed line, and one or more power cables configured to connect the microwave generator to the microwave antenna of the ablation device and deliver the microwave energy provided by the microwave generator to the antenna for tissue ablation.

[0063] Ablation devices such as those described herein can be configured to operate at up to 150 watts of power for up to 20 minutes or more. During use, the device heats up due to resistive heating of the antenna and energy reflected from tissue, and therefore typically at least the distal portion of the device (including the distal portion of the feed line and the antenna) requires cooling. Conveniently, in various embodiments, the entire feed line and antenna are cooled. Cooling the antenna prevents damage to the device itself and prevents overheating or charring of the tissue near the antenna. This alters the physical properties of the tissue, including its energy absorption and reflection characteristics, and thus reduces the efficiency of the antenna and may alter the ablation zone. In one embodiment, the aforementioned tissue ablation device may therefore additionally include a cooling system to cool the antenna and / or at least a portion of the feed line. Such a cooling system is typically configured to allow a coolant, such as a coolant (e.g., water), to pass through at least a portion of the feed line and antenna. Typically, such a system includes a coolant inlet and a coolant outlet, the coolant inlet cooperating with the coolant outlet to allow coolant to pass through the antenna and optionally at least a portion of the feed line to cool the antenna and optionally at least a portion of the feed line, preferably cooling the entire feed line. Antennas and feeders typically come into contact with coolant.

[0064] In one option, the cooling system includes a coolant chamber surrounding at least a distal portion of the antenna and feed line, and has: a coolant inlet conduit configured to supply coolant to the coolant chamber, and a coolant outlet conduit configured to remove coolant from the coolant chamber, the coolant inlet conduit and the coolant outlet conduit being configured to allow coolant to pass through at least a portion of the feed line and at least a portion of the antenna.

[0065] Figure 1A A block diagram showing components of a system for performing an ablation procedure according to one embodiment of the present disclosure is illustrated. The system includes a console 102, which includes a user interface 104, a controller 106, and an ablation device interface 108. In one embodiment, the user interface 104 includes a display for presenting information to a user and an input device for receiving input from the user, such as via one or more buttons, dial pads, switches, or other actuable elements. In another embodiment, the user interface 104 includes a touchscreen display serving as both the display and the input device.

[0066] According to one aspect of the invention, the ablation device interface 108 of the console 102 is arranged to interface with one or more ablation devices. Figure 1A In one embodiment, the ablation device interface 108 is connected to three ablation devices 120a, 120b, and 120c via pipelines 110a, 110b, and 110c, respectively. In one embodiment, the console 102 can connect to one, two, or all three ablation devices (120a, 120b, and 120c) individually or simultaneously. It should be understood that, although Figure 1AThe embodiments shown depict three ablation devices, but different aspects of the invention may include a console having an ablation device interface capable of interfacing with different numbers of ablation devices.

[0067] In one embodiment, the console includes an ablation device interface capable of interfacing with a single ablation device. In other embodiments, the console includes an ablation device interface capable of interfacing with two, three, four, or five ablation devices. In some examples, the ablation device interface can be configured to interfacing with any number of ablation devices.

[0068] According to certain aspects of the invention, the console can be used to operate any number of ablation devices, up to the number of ablation devices supported by the ablation device interface. For example, a console having an ablation device interface capable of receiving three ablation devices simultaneously can be configured to operate one, two, or three ablation devices.

[0069] In one embodiment, lines 110a, 110b, and 110c are configured to supply coolant (e.g., from coolant source 140) and ablation power (e.g., a microwave signal) to ablation devices 120a, 120b, and 120c, respectively. Lines 110a, 110b, and 110c may be configured to provide paths for supplying coolant to the respective ablation devices and return paths for receiving coolant from the respective ablation devices after passing through coolant flow paths within the ablation devices.

[0070] According to one aspect of the invention, controller 106 is configured to interface with user interface 104 and ablation device interface 108. In one embodiment, controller 106 may be configured to receive one or more inputs via user interface 104 and output one or more items via user interface 104.

[0071] Controller 106 can be configured to control the operation of one or more ablation devices (e.g., 120a, 120b, 120c) via ablation device interface 108. In one embodiment, controller 106 can cause coolant to be supplied to one or more ablation devices via ablation device interface 108. Controller 106 can also cause ablation power to be supplied to one or more ablation devices to enable them to perform an ablation process. In one embodiment, the ablation power supplied to the ablation devices causes the microwave ablation devices to emit microwave radiation. Power supply 130 can provide the electrical power used to generate the ablation power.

[0072] In one example, the controller includes one or more processors and memory, the memory including instructions that cause the one or more processors to execute via the controller. In various embodiments of the invention, the controller may be implemented as one or more processors, such as one or more microprocessors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), programmable logic circuits, etc. The controller may also include memory storing program instructions and associated data that, when executed, cause the controller to perform the functions attributed to it in this disclosure. The memory may include any fixed or removable magnetic, optical, or electrical medium, such as RAM, ROM, CD-ROM, flash memory, EEPROM, etc. The memory may also include a removable memory portion that can be used to provide memory updates or increase memory capacity. Removable memory may also allow image data to be easily transferred to another computing device. The controller may also be implemented as a system-on-a-chip, which integrates some or all components of a computer or other electronic system onto a single chip.

[0073] Figure 1B A block diagram illustrating the operation of an ablation device interface for interfacing with an ablation device for performing an ablation procedure, according to one embodiment of the present disclosure, is shown. In one example, the ablation device interface 108 includes one or more fluid pumps, each of which (148a, 148b, 148c) is configured to pump coolant to a corresponding ablation device. For example, as shown, pump 148a is in communication with a coolant source 140 and may be configured to supply coolant to an ablation device (e.g., 120a) via a coolant line 114a. Such a pump may be controlled by a controller. The controller may be configured to control the flow rate of fluid supplied from the pump (e.g., 148a) to the ablation device (e.g., 120a), including starting and stopping the pump supplying coolant to the ablation device.

[0074] exist Figure 1B In the example, the ablation device interface 108 includes three pumps 148a, 148b, and 148c for supplying coolant to the respective ablation devices via coolant lines 114a, 114b, and 114c, respectively. Coolant lines 114a, 114b, and 114c may be respectively included in... Figure 1A In the pipelines 110a, 110b, and 110c shown. In one embodiment, each pump is controlled by a controller and is independent of the other pumps; for example, any pump can operate independently of the operating state of the other pumps.

[0075] In another embodiment, each of pumps 148a, 148b, and 148c comprises a peristaltic pump driven by a single motor and controlled by a controller. In some such examples, each pump operates at the same rate defined by the motor, and coolant flows through coolant lines 114a, 114b, and 114c through any connected ablation device. The controller can regulate the flow rate of coolant through the ablation device by controlling the speed of the motor.

[0076] In some examples, the coolant supplied to the ablation devices is provided in a closed-loop recirculation system, wherein the coolant is received from the ablation devices and returned to the coolant source 140. In one embodiment, the coolant source 140 includes a reservoir of coolant (such as sterile water) from which coolant is extracted, directed via a coolant line to one or more ablation devices, and returned from one or more ablation devices to the reservoir via a coolant outlet line configured to remove coolant from the ablation devices. In some alternative examples, the coolant outlet line carries coolant from the ablation devices to a waste system (e.g., to a discharge line).

[0077] Figure 1B The ablation device interface includes a microwave generator 138 for generating microwave signals and providing them to a microwave antenna in the microwave ablation device, which is configured to deliver microwave energy to tissue. Providing microwave signals to the ablation device may include providing ablation power to the ablation device, causing the device to emit microwave radiation. The microwave generator 138 may provide microwave signals to the ablation device via a power cable. Figure 1B In one embodiment, the microwave generator 138 can provide microwave signals to up to three ablation devices via power cables 112a, 112b, and 112c, respectively.

[0078] The power cables 112a, 112b, and 112c are preferably coaxial cables, with a preferred rated power of at least 30 watts, more preferably at least 100 watts, and more preferably at least 150 watts. The cables may be cooling cables configured to be cooled by a coolant supply, preferably by circulating coolant along the cable between a coolant inlet and a coolant outlet. In some examples, coolant lines 114a-c supply coolant along the power cables 112a-c, respectively. In an example configuration, the system includes a cooling system configured to cool the cables and a microwave ablation device.

[0079] In some examples, the microwave generator is preferably configured to provide microwave energy to the antenna in one or more of the following frequency bands: 915 MHz (902 to 928 MHz), 2.45 GHz (2.402 to 2.483 GHz), or 5.8 GHz (5.725 to 5.875 GHz), preferably in the 2.45 GHz range, and most preferably in or around the 2.45 GHz band. The microwave generator can be configured to provide microwave energy to an antenna with up to five microwave ablation probes (preferably one, two, or three probes).

[0080] Microwave generator 138 can be configured to provide a microwave signal specified by controller 106. For example, in one example embodiment, controller 106 can instruct microwave generator 138 to provide a specific microwave signal to a specific ablation device. The controller can be configured to specify a specific ablation amplitude (e.g., the required microwave power and / or energy emitted from the ablation device), ablation duration, or other parameters such as duty cycle, phase shift, or other parameters associated with the microwave signal. In some examples, the microwave signal includes electrical power delivered to the ablation device (e.g., 90 W). The microwave signal can include an electrical signal containing attributes (e.g., electrical power, frequency, etc.) to cause the ablation device to emit microwave radiation with desired characteristics (e.g., microwave power radiated to surrounding tissue, etc.). The electrical signal can provide the required ablation power to the microwave ablation device.

[0081] In one embodiment, controller 106 may instruct microwave generator 138 to apply microwave signals to each of a plurality of ablation devices. For example, regarding Figure 1B The controller can instruct the microwave generator 138 to provide a first microwave signal to a first ablation device via power cable 112a, a second microwave signal to a second ablation device via power cable 112, and a third microwave signal to a third ablation device via power cable 112c. In some such examples, the microwave generator 138 can provide these first, second, and third microwave signals simultaneously. These signals can be the same or different signals. For example, in one embodiment, each of the first, second, and third microwave signals provides the same level of ablation power.

[0082] In some examples, the controller can be configured to control one or more of the following parameters: output wavelength, output power, the time period for delivering microwave energy to one or more antennas, and the time period for delivering energy at output power. Where the ablation device includes sensors (such as temperature sensors), the controller can be configured to control any one or more parameters in response to signals from the sensors (e.g., temperature measurements). For example, the controller can be configured to cut off power to one or more antennas in response to over-temperature conditions.

[0083] Although Figure 1B The diagram shows a single microwave generator 138 configured to provide microwave signals to multiple ablation devices. However, in some examples, the ablation device interface 108 may include multiple microwave generators, each corresponding to a specific ablation device. In one embodiment, the controller 106 communicates with multiple microwave generators and may be configured to cause the multiple microwave generators to apply microwave signals to corresponding power cables (e.g., 112a, 112b, 112c) to provide such microwave signals to the corresponding ablation devices.

[0084] Figure 1B An example embodiment is shown in which three lines 110a, 110b, and 110c can simultaneously provide microwave signals and coolant to three corresponding ablation devices. In some aspects of the invention, for example, if fewer than three ablation devices are connected to console 102, microwave signals and coolant can be provided to a subset of lines 110a, 110b, and 110c. Furthermore, in some aspects, even if three ablation devices are connected to console 102, microwave signals and coolant can be provided to a subset of lines 110a, 110b, and 110c. For example, one or more such connected ablation devices can remain unused.

[0085] In one embodiment, controller 106 controls which ablation devices (e.g., which lines of 110a, 110b, 110c) receive microwave signals and coolant. In one aspect of the invention, controller 106 may control aspects of the microwave signal, such as its amplitude, frequency, duty cycle, duration, etc. In another aspect of the invention, controller 106 may control aspects of the supply of coolant to the ablation devices, such as controlling the coolant flow rate, for example, by controlling the operation of the corresponding pumps. In one embodiment, for each ablation device, the controller controls both the microwave signal applied to the ablation device and the supply of coolant to the ablation device. During operation, different ablation devices may each receive microwave signals and cooling doses independently, independent of the signals and fluids received at other ablation devices, and may have the same or different amounts of microwave signals and fluids supplied to other ablation devices.

[0086] Although Figure 1B The diagram shows an ablation device interface for interfacing with three ablation devices, but it will be understood that the console, depending on the embodiment, may include an ablation device interface capable of interfacing with a different number of ablation devices.

[0087] It should be understood that, although Figure 1BThe block diagram shows an ablation device interface 108, which includes several components for interfacing with an ablation device. However, the components that are part of the ablation device interface 108 are not necessarily contained within a single module or housing. These components are grouped into the ablation device interface because they facilitate the controller 106 in controlling the connected ablation device.

[0088] In addition, although Figure 1B The ablation device interface for interfacing with microwave ablation equipment is shown, but it should be understood that similar ablation device interface concepts can be used to provide an interface between the controller and other ablation devices, such as RF ablation, cryoablation, etc.

[0089] In one embodiment, the ablation device interface includes one or more ports configured to receive a portion of the ablation device, such as a cartridge having a fluid interface for connection to a fluid line (e.g., 114a) and an electrical interface for connection to a power cable (e.g., 112a).

[0090] Figure 2 This is a simplified illustration of a cooling system according to the present disclosure. System 201 includes an ablation device 202. In this case, the microwave ablation device includes a microwave ablation needle configured to deliver microwave energy to a patient's tissue to ablate the tissue.

[0091] The microwave ablation device 202 may have a tip 203 configured to penetrate tissue and an elongated shaft having a proximal end 205 and a distal end 206. The shaft surrounds a coolant chamber 214 and a feed line 207, which may have an inner conductor, an outer conductor, and a dielectric material between them. Figure 2 (Not shown in the image) Coaxial cable. Figure 2 The feed line 207 includes a radiating region 208 at its distal end, which includes a microwave antenna 204. The proximal end of the feed line 207 can be attached to a cable 209 (typically a coaxial cable) that connects the microwave ablation device 202 to a microwave generator 210 for supplying microwave energy to the device. The cable can be releasably connected, or, as in this case, permanently attached to the device. In some embodiments, as per [reference to...] Figure 1A or Figure 1B As shown, the microwave generator 210 can be housed in a control console, such as control console 102.

[0092] The equipment is equipped with coolant via a coolant supply line 211, which may be permanently attached to a coolant inlet 212. Alternatively, in some embodiments, the coolant supply line may be releasably connected to the coolant inlet 212, such as via… Type connectors, etc. The equipment coolant inlet 212 is in fluid communication with the equipment coolant outlet 213 via a series of coolant channels 214, 215, and 216, which are configured to circulate coolant within the equipment. In this simplified representation, coolant enters the equipment through coolant inlet pipe 215, circulates through coolant chamber 214 to cool the equipment, and exits via coolant outlet pipe 216 and equipment coolant return line 217.

[0093] System 201 is equipped with a manifold 218 that receives coolant fluid from a coolant fluid source 219 via a coolant system supply line 220. The coolant system supply line 220 can be permanently connected to the manifold 218 at a manifold fluid supply inlet 250, or it can be releasably connected to the supply inlet 250, for example via... Connector. The coolant fluid source can be, for example, an IV bag. The incoming coolant can be distributed to one or more manifold outlet ports 21 via manifold inlet conduit 222. In an advantageous embodiment, and as... Figure 2 As shown, the coolant outflow from port 221 can be controlled by manifold outlet valve 223. This valve can normally be in the closed position. In some embodiments, as per [reference to...] Figure 1A or Figure 1B As shown, manifold 218 can be housed within a console, such as console 102.

[0094] Manifold 218 also includes a manifold coolant outlet conduit 224 that provides a fluid connection between one or more manifold fluid inlet ports 225 and a coolant system return line 226. The coolant system return line 226 may be permanently connected to manifold 218 at a manifold fluid return inlet 251, or it may be releasably connected to a supply inlet 250, for example via... Connector. In one aspect of the design, the manifold inlet valve 227 controls the flow through each inlet port and may also typically be in a closed state.

[0095] Supply connector 229 is configured to connect to manifold outlet port 221. The system may also include return connector 233, configured to connect to manifold inlet port. In one aspect, manifold outlet valve 223 may be configured to open when supply connector 299 is connected. In one method, the supply connector may include a protrusion 230 that opens the valve when connector 229 is connected to port 221; however, other arrangements as discussed elsewhere herein are also possible.

[0096] The coolant inlet 231 of the coolant circuit on the supply connector 229 is in fluid communication with the equipment coolant supply line 211, so the connection between the supply connector 299 and the outlet port 221 makes the cooling circuit 232 in fluid communication with the coolant source 219.

[0097] Return connector 233 may have a coolant loop outlet 234 in fluid communication with the equipment coolant return line 217. Supply connector 229 and return connector 233 may be arranged to be simultaneously connected to manifold outlet port 221 and inlet port 225, respectively.

[0098] The pumping section 235 can be arranged in the equipment cooling circuit 232, and for example, in the supply line 211, and is arranged to circulate the coolant through the microwave ablation device 202. Figure 2 In the system shown, the pump is a disposable pump head 236 with pump blades 237, permanently connected to the equipment coolant supply line 211, and adapted to be connected to a pump head driver (not shown). Alternative pumping sections may be used and are described elsewhere herein. In some embodiments, as per [reference to...] Figure 1A or Figure 1B As shown, the pumping section 235 can be housed within a control console, such as control console 102.

[0099] Figure 3 This is a perspective view of a microwave tissue ablation device 300 with a handle 305 according to an embodiment of the present disclosure.

[0100] The microwave tissue ablation device 300 includes a handle 305. The handle 305 is configured to provide a more secure grip for the surgeon to manipulate the tissue ablation device 300. The handle 305 is also configured to house a liquid manifold for coolant circulation and a coaxial connector for powering the feeder.

[0101] The microwave tissue ablation device 300 includes a probe 307. The probe 307 is configured to be inserted into a patient to heat target tissue. In one embodiment, the probe 307 includes various ablation device components described elsewhere herein, such as a feed line, an asymmetric dipole antenna, a cooling system with inlet and outlet tubes, etc. In one embodiment, the microwave antenna is configured to emit microwave radiation in a frequency band selected from the 915 MHz band (902 to 928 MHz), the 2.45 GHz band (2.402 to 2.483 GHz), and / or the 5.8 GHz band (5.725 to 5.875 GHz). Preferred wavelengths are within the 2.45 GHz band, and in particular, the antenna is preferably configured to emit microwave energy in the 2.45 GHz or approximately 2.45 GHz band. These devices are configured to operate at a power supply of up to 150 watts to the antenna.

[0102] The probe 307 includes a surface 315. Surface 315 is configured to contact human tissue and is made of a biocompatible material. The device shaft is at least partially metallic, such as stainless steel, and includes markings 311, such as laser markings. Markings 311 are configured to inform the surgeon of the depth to which the probe penetrates the body. It may include a smooth surface layer such as PTFE to aid insertion and prevent tissue from sticking to the needle shaft when the needle is inserted or withdrawn.

[0103] The shaft is typically cylindrical and is usually made of a biocompatible polymer, a biocompatible composite material (such as glass fiber reinforced polymer or carbon fiber reinforced polymer), ceramic, or metal (such as stainless steel). The shaft is preferably made of ceramic or metal, but in a preferred embodiment, the shaft includes both metallic and non-metallic portions. The non-metallic portion can be a biocompatible composite material, such as glass fiber reinforced polymer or carbon fiber reinforced polymer, or ceramic, but ceramic is preferred due to its improved properties and strength. The ceramic is preferably alumina or zirconia ceramic.

[0104] The shaft preferably terminates in a cap at its distal end. The shaft is preferably cylindrical. The feed line and antenna are preferably housed within the shaft. The shaft typically extends from a near-end hub and terminates in a far-end cap at its distal end. The hub includes electrical connections to electrical components of the shaft, such as the feed line, and may also include coolant inlet and outlet connections if necessary.

[0105] The diameter of the shaft is not limited and is generally suitable for the intended purpose, such as the same as the ablation needle. It is important to have a narrow needle to limit damage during insertion and to provide fine control of positioning. Therefore, the diameter of the needle shaft is between 1.4 and 3 mm, preferably between 1.5 and 2.5 mm, especially 2 to 2.5 mm.

[0106] Figure 3 The probe 307 includes an applicator cap 330. In one embodiment, the applicator cap 330 is made of a biocompatible metal or ceramic, preferably stainless steel or ceramic. The applicator cap 330 may include a circular base and a distal tip (e.g., a cannula tip). The tip of the applicator cap 330 may include a sharp end disposed at the distal end of the applicator cap 330 and configured for penetrating tissue. The circular base may be configured to be sealed with a sheath of the probe 307 such that the interior of the probe 307 is fluidly isolated from the exterior of the probe 307.

[0107] The axis may also include an echo region on its outer surface, configured to be visible under ultrasonic imaging. In one embodiment, the region includes a coating comprising acoustically reflective microspheres. The echo region extends at least to the radially outward region of the axis covering the antenna. Figure 3The probe 307 includes an echo region 325 configured to be visible under ultrasound imaging, and one embodiment includes a coating comprising acoustic reflective microspheres.

[0108] When the shaft comprises both metallic and non-metallic portions, the joint between the two adjacent portions can be a potential weak point, especially if the non-metallic portion is ceramic, as ceramic is generally less flexible and more brittle than metals such as stainless steel. Therefore, it is preferable that the shaft also include a resilient element between the non-metallic (e.g., ceramic) and metallic portions, configured to provide elasticity at the joint between the probe shaft and the non-metallic (e.g., ceramic) and metallic portions during use.

[0109] The probe 307 also includes a region 320 configured to mitigate strain on the probe during use, such as strain caused by axial bending. This strain-reducing region is particularly useful when the distal end of the probe sheath is ceramic. The strain-reducing region 320 is configured to provide additional flexibility to the probe 307 to prevent breakage during medical procedures.

[0110] While an elastic element can also exist between the non-metallic region and the cap, this is not necessary because the strain at that point on the shaft is low. For example, the elastic element could include an elastic annular gasket, which can be made of an elastic thermoplastic elastomer, such as polyether block amide (PEBA) – a trade name. or Evonik Industries or polyaryletherketone (PAEK), such as polyetheretherketone (PEEK). The gasket is preferably shaped and configured to space the proximal end of the non-metallic portion from the distal end of the metallic portion. The resilient element is preferably adjacent to the metallic portion on the proximal face and the non-metallic portion on the distal face. The resilient annular gasket typically extends radially outward to form a surface flush with the outer surface of the probe shaft. The radially inward portion of the annular gasket may extend proximally and / or distally to provide an annular step configured to support the inner surface of the proximal end of the non-metallic portion and / or the distal end of the metallic portion. In a preferred embodiment, the annular gasket extends proximally to provide an annular step configured to support the inner surface of the distal end of the metallic portion, but does not extend distally. The device shaft may also include an adapter sleeve to support the engagement between the non-metallic and metallic portions of the shaft. The adapter may be configured to accommodate any thickness differences between the non-metallic and metallic portions of the shaft to provide, for example, a smooth surface transition between the metallic and non-metallic portions. It can be metallic or non-metallic, such as thermoplastic elastomers, such as PEBA. or E or PAEK, such as PEEK. When the non-metallic part is ceramic, the adapter is particularly important due to the thickness required for the additional strength of the ceramic and the risk of cracking caused by shaft bending. Conveniently, the sleeve extends sufficiently to each side of the joint to provide support and is typically positioned radially inward of the shaft, usually between the feed line and the inner wall of the shaft. The adapter sleeve is preferably metallic.

[0111] The elastic element and the adapter sleeve together form the strain-relief zone. The elastic element and the adapter sleeve can be a single piece or separate pieces.

[0112] In a preferred embodiment, the strain relief region includes an elastic element as described above, comprising an elastic annular gasket shaped and configured to space the proximal end of a non-metallic portion from the distal end of a metallic portion. The gasket is configured such that the metallic portion on the proximal face abuts the non-metallic portion on the distal face. The gasket extends radially outward to form a surface flush with the outer surface of the probe shaft. The radially innermost portion of the gasket extends proximally to provide an annular step configured to support the inner surface of the distal end of the metallic portion. The strain relief region also includes an adapter sleeve extending on each side of the engagement and radially inward of the annular gasket. Preferably, the sleeve extends proximally to the annular gasket and is configured to contact and support the inner surface of the distal end of the metallic portion of the shaft; and preferably extends to the distal end of the gasket and is configured to contact and support the inner surface of the proximal end of the ceramic portion of the shaft.

[0113] The microwave tissue ablation device 300 includes a housing 310. The housing 310 houses coaxial cables, fluid lines, wires, etc.

[0114] Figure 4A is a perspective view of a microwave tissue ablation device 400 according to an embodiment of the present disclosure. Figure 4B is a cross-sectional view through lines X and Y to illustrate an embodiment of the cooling features.

[0115] The tissue ablation device 400 of Figure 4A has a shaft 401, which has a metal portion 445 and a ceramic portion 402. The ceramic portion 403 extends from the distal end 406 of the collar 405 to the base 441 of the cap 440. The ceramic portion 401 is shown separately from the shaft 401 to show the internal features of the device.

[0116] The tissue ablation device 400 includes an elastic element (e.g., a collar 405) and an adapter 410 to engage a metal portion 445 to a ceramic portion 402 of a shaft. In the device of the present invention, the adapter accommodates any difference in shaft thickness between the two portions and additionally reduces bending between the metal portion 445 and the ceramic portion 402. In the device of the present invention, an elastic annular gasket between the ceramic and metal portions of the shaft, as shown herein, provides elasticity to the area and reduces the risk of breakage at that point due to strain on the shaft during use.

[0117] For example, such as regarding Figure 1A or Figure 1B As shown, microwave energy generated by the microwave generator can be supplied to the antenna via a power cable that electrically connects the microwave generator to the feed line 432 of the antenna 452 within the device 400. The microwave ablation device also has a shaft that surrounds at least the distal portion of the microwave antenna and the feed line, and is typically coaxial with them. The shaft typically extends from the proximal hub to the distal cap.

[0118] The feeder preferably includes an inner conductor, an outer conductor, and a dielectric material disposed therebetween. The feeder may include an additional dielectric material or insulator that insulates the outer conductor from the rest of the device and acts as an outer insulator for the feeder, but this is not required in all embodiments. In some embodiments, there may be no additional dielectric material from the distal portion of the feeder at least up to the junction. Such an additional dielectric material may be absent within the device shaft, such as between the near-end feeder connector at the distal hub and the junction of the antenna. The feeder is typically a coaxial cable having a center conductor surrounded by a first dielectric material or insulator, which is then surrounded by a second conductor, which may be covered by an additional dielectric material or insulator as described above. The inner conductor is typically a power conductor.

[0119] In the example of Figure 4A, the tissue ablation device 400 has an antenna 452, which includes a helical arm 412 and a linear arm 420. The distal end 435 of the helical arm 412 forms an electrical connection at a junction 436 with the outer conductor 430 of the feed line 432. In some embodiments, the junction is conveniently oriented toward or located at the farthest end of the feed line. The feed line 432 may extend beyond the junction to provide suitable mechanical support for the electrical connection, but preferably, it extends no more than 5 mm beyond the junction, and especially no more than 1 mm.

[0120] Typically, the helical arm is a single conductor. The antenna's helical arm can be in the form of a wire or strip, but is usually a wire or strip with a circular cross-section. The helical arm is preferably in the form of a cylindrical conductor with a helical gap traveling from its proximal end to its distal end, providing a helical conductor with a planar conductor surface that bends around the feed line. Except at the junction, the helical arm makes no other contact with the inner or outer conductor.

[0121] In the example of Figure 4A, the spiral arm 412 extends proximally from the junction 436 in the form of a series of turns around the feed line 432, and is thus coaxially arranged around the feed line. Apart from the junction 436, the spiral arm 412 does not form any other electrical contact with the inner conductor 427 or the outer conductor 430. The spiral arm can be secured to its substrate with an adhesive to hold it in place and facilitate assembly. The spiral arm can be embedded in a matrix such as a polymer layer or coating to protect it, insulate it from other parts of the device, or provide a seal.

[0122] In some embodiments, the spiral arm is coiled without direct contact with the feed line. For example, it may form a turn at a location radially displaced from the feed line. The spiral arm is preferably coiled around a substrate supporting it. In cases where the feed line includes an outer insulator, the outer insulator may be a substrate for the spiral arm, around which a turn may be formed. Alternatively, for example, the spiral arm may coil around a tubular substrate, such as a cooling tube positioned around the feed line.

[0123] In some embodiments, the total number of turns (N) is in the range of 1-12, but is not limited to an integer. In a preferred embodiment, N is typically 4 to 8. For each complete spiral coil, the axial distance is the pitch (P), which ranges from 0.7 to 1.5 mm, preferably from 1 to 1.5 mm, and in a preferred embodiment, the pitch (P) of the spiral arm is 1.2 to 1.25 mm. The number of spiral coils (N) and the pitch (F) can affect the microwave energy output, the shape of the emission field, and the energy absorption spectrum. Wise selection of each variable in the combination can provide an ablation device with superior performance for tissue ablation.

[0124] In the example of Figure 4A, a helical arm is wound around a tube 426, which extends from a hub (not shown), passes through a metal portion 445 of the shaft, and reaches the tip 428 of the antenna 452. An electrical connection between the antenna's helical arm 412 and the outer conductor of the feed line 432 passes through the tube at a junction 436. In the illustrated example, the helical arm 412 has a length (Lha). In some examples, the total length (Lha) of the helical arm can range from 1 to 18 mm, preferably from 4 to 10 mm. In a preferred embodiment, the helical arm ranges from 4 to 7 mm.

[0125] Linear arm 420 is an extension of the inner conductor 427 of feed 432 and is surrounded by a dielectric layer 425, except for the second portion 423 which has no dielectric.

[0126] The linear arm of the antenna described herein is a conductor electrically connected to and extending distally from the inner conductor of a feed line, preferably on an axis coaxial with the helical arm and / or the feed line. The conductor is preferably in the form of a straight line. In a particularly preferred embodiment, the linear arm includes a first proximal insulating portion and a second distal non-insulated portion. Typically, the first portion is surrounded by a dielectric, and the second portion, i.e., the distal end of the first portion, is free of dielectric. The second portion extends to the tip of the arm. The dielectric surrounding the first portion of the linear arm preferably extends distally from the feed line. In its simplest form, the linear arm of the antenna may be an extension of the inner conductor of the feed line. Then, the dielectric may be an extension of the dielectric disposed between the center conductor and the outer conductor of the coaxial feed line.

[0127] Preferably, the linear arm and helical arm of the antenna are coaxial with the axis of the ablation device, and thus the linear arm is coaxial with the helical arm and extends distally from the helical arm. As shown, the linear arm 420 of the asymmetric dipole antenna of Figure 4A has a length L1a. The linear arm includes a first portion L1 421 coated with an insulator, which is an extension of the first dielectric layer of the feed line 432, disposed between the inner conductor 427 and the outer conductor 430, and is not visible in this view. The linear arm 420 also includes a second portion 423 having a length L2 422, and is not coated with an insulator. In one embodiment, the second portion L2 422 is exposed to circulating coolant.

[0128] In one aspect, the portion of the linear arm lacking the dielectric is partially or completely inserted into the metal cap, but without contacting the cap. This can be achieved by creating an open pocket at the base of the cap, into which this portion or a part of the antenna is inserted. The degree to which the exposed distal tip is inserted affects the shape of the distal portion of the energy field, thus influencing the shape of the ablation zone.

[0129] When the distance between the tip and the cap is greater than 3 mm, they are considered not sufficiently coupled for shape ablation, especially at 2.45 GHz.

[0130] The linear arm 420 preferably has a length of 4 mm to 14 mm (L1a), and more preferably 8 mm to 10 mm. The second exposed portion 423 preferably has a length of 0.1 mm to 2 mm (L2), and more preferably 0.3 mm to 0.5 mm.

[0131] Therefore, in a preferred embodiment, the spiral arm 412 of the antenna is in the form of a strip with a length (Lha) of 1 to 18 mm and includes 1 to 14 turns, the linear arm 420 of the antenna is 4 to 14 mm long and has a second distal portion 423 lacking dielectric for 0.1 to 3 mm, which is separated from the base of the cap by 0.2 to 3 mm.

[0132] In a more preferred embodiment, the antenna's spiral arm 412 is in the form of a strip with a length (Lha) of 4 to 10 mm and includes 4 to 8 turns, and the antenna's linear arm 420 is 7 to 10 mm long and has a second distal portion 423 lacking dielectric material, which is 0.3 to 0.5 mm long and is separated from the base of the cap by 1 to 2 mm.

[0133] In a more preferred embodiment, the spiral arm 412 of the antenna is in the form of a strip with a length (Lha) of 4 to 6 mm and includes 3 to 5 turns. The linear arm 420 is 7 to 10 mm long and has a second distal portion 423 lacking dielectric material, which is 0.3 to 0.5 mm long and is separated from the base of the cap by 1 to 2 mm, preferably 1.5 mm or about 1.5 mm.

[0134] When the shaft has a non-metallic portion (e.g., ceramic portion 402), the non-metallic portion preferably extends axially to cover the antenna and thus extends at least along with the radiating portion of the antenna. In one embodiment, the non-metallic portion extends at least from the nearest point of the helical arm to the distal end of the shaft (e.g., the attachment point of the tip of the device). The non-metallic portion extends both axially and circumferentially, such that the shaft is preferably non-metallic between the proximal and distal ends of the non-metallic portion.

[0135] The cap can be configured to seal the distal end of the device to prevent coolant leakage or tissue fluid seepage. The cap can be manufactured as a separate part and can be configured to be attached to a shaft. The cap is preferably configured to facilitate insertion into tissue and penetration of the patient's skin, and thus can, for example, reach the distal end, or be configured as a trocar. The cap 440 shown in Figure 4A includes a trocar tip. The trocar tip of the cap 440 can be made of stainless steel and / or ceramic.

[0136] In some examples, the cap can be made of any suitable biocompatible material, such as biocompatible polymers, composites, ceramics, or metals, such as stainless steel. When the cap is metallic, the cap and the distal end of the antenna (i.e., the distal end of the linear arm of the antenna) can be configured for electromagnetic coupling. This can be achieved by adjusting the distance between the distal tip of the antenna and the cap such that they are electromagnetically coupled at the frequency and power at which the antenna is expected to operate. This effect can be used to adjust the shape of the distal portion of the energy field generated by the antenna, thereby adjusting the shape of the ablation zone. However, the cap and antenna do not need to be coupled in this way; that is, the antenna can be electromagnetically decoupled from the cap. Preferably, the tip and cap do not contact each other. In practice, the gap between the tip and cap is 0.2 mm or greater, particularly 0.2 mm to 3 mm, and most preferably 1 to 2 mm. Most preferably, it is 1.5 mm or about 1.5 mm.

[0137] The shape of the energy field and therefore the ablation volume are also affected by the metal sheath concentric with the feed line. The sheath is preferably cylindrical and extends over at least a portion of the feed line near the antenna. The sheath may also extend over at least a portion of the antenna, but preferably it terminates near the farthest point of the spiral arm of the antenna and does not extend over the antenna. Preferably, the gap between the sheath and the farthest portion of the spiral arm is at least 0.1 mm. The gap may, for example, be between 0.1 and 2 mm or 0.1 and 1 mm, preferably 0.5 mm or about 0.5 mm. The sheath is preferably not placed on the outer surface of the shaft, but is preferably radially offset from the feed line and coaxial with it. Preferably, it is placed between the inner walls of the feed line and the shaft. In one arrangement, the metal sheath may be an adapter sleeve as described elsewhere herein.

[0138] Preferably, the coolant chamber is defined between the inner walls of the device shaft. The chamber may be defined at its distal end by a cap and at its proximal end by one or more proximal seals that close the coolant chamber proximally. The one or more seals are preferably formed at a point between the hub and the proximal portion of the helical arm of the antenna. The cooling system includes at least one coolant inlet conduit configured to deliver coolant to the coolant chamber and at least one coolant outlet conduit for removing coolant from the chamber. The coolant inlet and outlet conduits typically pass through the proximal seals. In one method, the coolant inlet conduit is a coolant inlet pipe configured to deliver coolant to a location adjacent to the antenna and / or feed line and radially outward from the antenna and / or feed line. In this case, the coolant inlet pipe is preferably disposed within the coolant chamber between the inner walls of the antenna and the shaft. It is preferably radially outward from the feed line.

[0139] In an alternative arrangement, the cooling system includes a coolant inlet conduit and a coolant outlet conduit, each conduit arranged around at least a portion of the feed line and a portion of the antenna. Each conduit is arranged in a helical configuration, with the coolant inlet and outlet conduits intersecting to form a double helix. In a preferred arrangement, the cooling system includes a pair of helical dividers arranged in a double helix around at least a portion of the feed line and antenna. Each divider extends radially outward toward the inner wall of the shaft and radially inward toward the antenna and / or feed line, such that the coolant inlet and outlet conduits are formed between the two dividers, and the coolant inlet and outlet conduits form a double helix. The dividers can be in the form of filaments or strips, or a combination of both. When the dividers include strips, the strips are preferably generally perpendicular to the inner shaft wall. The filaments can be formed of metal or an elastic polymer. The dividers preferably extend to seal the inner wall and at least a portion of the antenna and / or feed line.

[0140] The cooling system may further include a coolant mixing chamber in fluid communication with a coolant inlet conduit and a coolant outlet conduit, such that the coolant inlet and coolant outlet are in fluid communication via the coolant mixing chamber. The coolant mixing chamber is preferably configured to allow coolant to pass through at least a portion of the antenna, particularly at least a portion of the antenna's linear arm. The coolant mixing chamber is particularly configured to allow coolant to pass through at least a distal portion of the antenna's linear arm and at least a portion of the cap.

[0141] Alternatively and preferably, the cooling system includes a coolant chamber defined between the inner walls of the device shaft. As previously described, the chamber may be defined at its distal end by a cap and at its proximal end by a seal between the hub and the shaft, or at a point distal to the hub and between the antenna and the hub. The coolant chamber surrounds at least the distal portion of the antenna and feed line.

[0142] In one embodiment, the cooling system further includes a cooling tube disposed around the feed line, preferably extending distally around the feed line and preferably coaxial with it. The cooling tube preferably divides the coolant chamber into a first cooling conduit 448 and a second cooling conduit 460, the first cooling conduit being disposed between the feed line and the inner wall of the cooling tube, and the second cooling conduit being disposed between the outer wall of the cooling tube and the inner wall of the device shaft. The cooling tube preferably extends over the distal portion of the feed line and extends distally around at least a portion of the antenna, preferably extending at least to the tip of the linear arm of the antenna. A variety of materials are suitable for the cooling tube, but a non-metallic material is preferred. Conveniently, the cooling tube may be made of a thermosetting polymer (such as polyimide) or a thermoplastic polymer resin (such as polyethylene terephthalate (PET)) or a fluoropolymer (such as polytetrafluoroethylene (PTFE)) or PAEK (such as PEEK).

[0143] As described elsewhere in this document, in the example of Figure 4A, the helical arm is coiled around tube 426. In one embodiment, tube 426 defines a first cooling conduit 448 between the inner wall 454 of tube 426 and feeder 432, and a second cooling conduit 460 between the outer wall 455 of tube 426 and the inner wall of shaft 453. Coolant can be pumped through the space between tube 426 and feeder 432 to mixing chamber 429 between tube 426 and cap 440, and return to the space between the outside of tube 426 and ceramic portion 402 of shaft, through the space 411 between the inside of shaft and adapter 410, and return to hub along metal portion 445 of shaft.

[0144] The antenna's helical arm can be housed within a first cooling conduit. For example, the distal portion of the feed line may include the second insulator as described above, and the antenna's helical arm is directly wound around the feed line. The second insulator extends axially at least between the helical arm and the second conductor of the feed line. In this case, the cooling conduit may extend to cover a portion of the helical arm, but preferably covers a portion of both the helical arm and the linear arm. Most preferably, the cooling conduit extends at least to the distal end of the antenna, such that the first cooling conduit extends at least to the tip of the antenna.

[0145] Alternatively, the cooling pipe extends to cover the far end of the feed line and a portion of the linear arm, but most preferably, the cooling pipe extends at least to the far end of the antenna, such that the first cooling conduit extends at least to the tip of the antenna.

[0146] The cooling system may further include a coolant mixing chamber in fluid communication with both the first and second cooling conduits, such that the first and second cooling conduits are in fluid communication via the coolant mixing chamber. The coolant mixing chamber is preferably configured to allow coolant contact with a portion of the cap.

[0147] The first or second cooling conduit can serve as a coolant inlet conduit or a coolant outlet conduit. Both the first and second cooling conduits are open at their distal ends to allow coolant circulation through the coolant mixing chamber between the distal end of the cooling tube and the base of the applicator cap.

[0148] The cooling pipes preferably extend proximally toward the wheel hub. The first and second cooling conduits are in fluid communication with the coolant inlet and outlet connectors of the wheel hub for supplying and discharging coolant during use.

[0149] In a particularly preferred method, the spiral arm of the antenna is preferably wound around the cooling tube in the form of a strip. In this case, the spiral arm makes electrical contact with the outer conductor of the feed line at the junction and extends distally in a series of turns around the cooling tube as described above. In this case, the cooling tube preferably extends at least to the junction of the antenna and the feed line, preferably it extends to cover at least a portion of the linear arm, but most preferably, the cooling tube extends to the tip of the linear arm such that the first cooling conduit extends at least to the tip of the antenna. Preferably, the electrical contact between the distal end of the spiral arm and the outer conductor of the feed line passes through the cooling tube.

[0150] In this method, it is preferable that the outer insulator does not extend on the distal portion of the feed line. Preferably, it does not extend at least on the portion of the feed line from the point immediately adjacent to the near end of the antenna helical arm to the junction point. The outer insulator may not be present throughout the entire feed line within the shaft of the ablation device.

[0151] In embodiments where the cooling system includes the cooling pipes described above, the helical arm can be a wire or a strip, but is most preferably a strip. The helical arm is preferably in the form of a cylindrical conductor with a helical gap from its proximal end to its distal end to provide a helical conductor having a planar conductor surface disposed around and preferably coaxial with the feed line.

[0152] The cooling system described herein supplies coolant (e.g., water) through the feeder and at least a portion of the antenna, preferably the entire antenna. During normal operation, it is not necessary to isolate the antenna from the coolant. In some embodiments described herein, portions of the feeder lack external insulation surrounding the feeder. The feeder may lack insulation between the hub and the joint, or along its entire length within the device shaft. The antenna's spiral arm may also lack any insulation, particularly where it winds around the cooling pipes.

[0153] The ablation device described herein may additionally include one or more temperature sensors, such as thermocouples, to measure the temperature at various points along the axis. Typically, the thermocouple may be located within the cooling system and configured to measure the temperature of the coolant or other parts of the device (such as feeders or the device axis) during device operation. The tissue ablation device 400 of Figure 4A may include a temperature sensor 450 housed alongside an internal adapter 410 and having an electrical connection 451 via the hub to the control unit.

[0154] As described elsewhere in this document, ablation devices such as those described herein typically include a proximal hub as briefly discussed above. The hub typically includes connectors for connecting the feeder to the power supply line and for connecting electrical components within the device shaft to the control system. These connectors can be permanent or detachable. The hub may also include a coolant manifold with input and output connectors for connecting a coolant input to the coolant supply and a coolant output to a waste or recirculation system. The hub may also form part of a handle configured to provide the surgeon with a more secure grip for manipulating the tissue ablation device.

[0155] Figure 5 This is a side view of a microwave tissue ablation device according to an embodiment of the present disclosure. The ablation device 500 includes a handle 501. The handle 501 accommodates a manifold 505.

[0156] Manifold 505 is electrically connected to a power source (not shown) and tissue ablation probe 530 via coaxial cable connector 515. Tissue ablation probe 530 includes markings 535 configured to inform the surgeon of the depth of probe penetration during the procedure.

[0157] Manifold 505 is also fluidly connected to a coolant source (not shown) and a tissue ablation probe 530. Manifold 505 includes a coolant inlet 520 and a coolant outlet 525. Coolant inlet 520 is fluidly connected to a coolant inflow conduit, and coolant outlet 525 is fluidly connected to a coolant outflow conduit.

[0158] The tissue ablation device 500 also includes a tubular housing 540 that houses the wires and fluid lines.

[0159] As discussed elsewhere in this document, multiple ablation devices, such as tissue ablation device 300, can be used simultaneously to perform the ablation procedure. Such ablation devices can be arranged in a variety of ways. Figure 6A A plan view of a configuration of multiple microwave ablation needles is shown. In one example, the microwave ablation devices can be positioned equidistantly from each other, such as in an arrangement of 600. The needles can be arranged in regular polygons, such as in arrangements of 600, 610, and 620. Positioning the ablation devices equidistantly from each other can advantageously provide an approximately symmetrical net ablation volume formed by the multiple ablation devices. Furthermore, arranging the ablation devices in regular polygons can provide an approximately spherical net ablation volume formed by the multiple ablation devices. Alternatively, other arrangements may include multiple devices arranged in a line (such as arrangement 630) or in an irregular shape (such as arrangement 640). Multiple configurations of ablation devices can be arranged to provide the desired ablation volume suitable for a particular operation.

[0160] Furthermore, this device can be inserted at the same or different penetration depths. Figure 6B The diagram shows a front view of multiple ablation devices arranged at different depths. Ablation devices, such as microwave tissue ablation device 300, can be inserted to a specific depth, for example, as measured by mark 311. In some configurations, the devices are inserted to approximately the same depth, such as in arrangement 605. In other examples, the devices can be inserted to different depths, such as in arrangements 615, 625, and 635. Similar to different planar arrangements, ablation devices can be arranged in multiple configurations to provide the desired ablation volume suitable for a specific operation.

[0161] During operation involving one or more ablation devices, a control console (e.g., 102) may actuate a pump (e.g., 148a) to cause coolant to flow from a coolant source (e.g., 140) to each of the one or more ablation devices (e.g., 400). For each ablation device, coolant may flow through a coolant line (e.g., 114a), a coolant inlet (e.g., 520), a first cooling conduit (e.g., 448), a second cooling conduit (e.g., 460), and a coolant outlet (e.g., 525). In some examples, the coolant line (e.g., 114a) provides a return path to receive fluid from the coolant outlet (e.g., 525) in, for example, a recirculation system in which the coolant is recycled back to the coolant source. In one embodiment, coolant may flow through such a flow path to provide cooling to the ablation device.

[0162] As described herein, for example, a controller (e.g., 106) within a console (e.g., 102) of a receiving ablation device (e.g., 400) can be used to control the fluid flow through the ablation device and the microwave energy emitted from the ablation device.

[0163] When a microwave ablation device is inserted into a patient, the coolant can also act as a dielectric to couple microwave radiation emitted by the microwave antenna (e.g., 452) to surrounding tissue. In one embodiment, during therapeutic ablation, the coolant flows through the needle at a therapeutic ablation flow rate. Coolant flowing through the needle at a therapeutic ablation flow rate can couple microwave energy emitted from the needle to the tissue surrounding the needle and affect the penetration depth of the microwave energy into the tissue. Reducing the coolant flow rate can reduce the coupling of microwave energy to surrounding tissue, resulting in a smaller ablation zone. Additionally or alternatively, reducing the coolant flow rate can reduce the needle's ability to draw heat away from tissue near the needle, resulting in more localized heating of the tissue near the needle compared to a higher flow rate.

[0164] As discussed herein, multiple ablation devices, such as two or three, can be used during an ablation procedure. The use of multiple ablation devices can increase the size of the ablation zone. This increased ablation zone size allows the physician to successfully ablate the target area even when the ablation device placement is not precise. Similarly, the use of multiple needles allows the physician to more accurately cover the target area (e.g., infected tissue) with the ablation zone. For example, in embodiments where the target area is irregular or non-circular, multiple ablation devices can be positioned accordingly to completely ablate the target area and minimize the portion of the ablation zone that does not overlap with the target area (e.g., minimizing the ablation of healthy tissue). Additionally or alternatively, multiple needles can be provided to improve the efficiency of the generator used to power the ablation devices. In some examples, the generator used may be most efficient when providing a specific power range (e.g., 90W). Rather than having one ablation device receive 90W of power from the generator, it is advantageous to distribute the provided power among multiple ablation devices, such as allocating 45W of power separately to two ablation devices, 30W separately to three ablation devices, etc. In some examples, the power supplied to each individual ablation device may be different (e.g., a first ablation device receiving 70W and a second ablation device receiving 20W), and / or the power supplied to each ablation device may be adjusted throughout the procedure.

[0165] However, using multiple ablation devices can have adverse side effects, such as low energy points located between the devices. When waves from two or more sources interact, they may superimpose or partially or even completely cancel each other out, depending on how the waves are matched (e.g., the matching of wave amplitudes or crests and troughs). When wave crests or troughs interfere with each other, constructive interference may occur, resulting in a composite wave with an amplitude greater than either source wave. When crests and troughs interfere with each other, destructive interference may occur, resulting in a composite wave with an amplitude less than either source wave. Regarding the sources emitting microwave radiation, less microwave energy will appear at locations of destructive interference because the energy from the two sources can cancel each other out.

[0166] This effect can be achieved in Figure 7 I saw it in the middle. Figure 7 This is a simulated specific absorption rate (SAR) field representing the energy deposition in tissues from two ablation devices, 720a and 720b. From... Figure 7 As can be seen, the ablation energy is usually strongest around the two ablation devices and loses intensity further away from the devices.

[0167] exist Figure 7In the example, a low-energy point 735 appears between the ablation devices due to destructive interference. As shown, there is almost no microwave energy at point 735 due to the interference of microwaves emitted from devices 720a and 720b. The location and size of the low-energy point 735 can depend on a variety of factors, such as the frequency, amplitude, and phase of the microwave radiation emitted by the two ablation devices 720a and 720b, and the distance between the ablation devices. Furthermore, the electromagnetic and / or dielectric properties of the medium between the devices, and whether the medium is homogeneous, can also affect the location and size of the low-energy point 735.

[0168] The presence of a low-energy point (e.g., low-energy point 735) may require a longer ablation process and / or provide more ablation power to deliver the required amount of energy to the low-energy point. Additionally or alternatively, the presence of a low-energy point (e.g., low-energy point 735) may result in incorrect or incomplete ablation. For example, if ablation devices 720a and 720b are inserted into tissue, the tissue in low-energy point 735 may receive less microwave energy than expected, even if the surrounding tissue receives the expected or prescribed amount. Therefore, if the target area includes infected tissue, the infected tissue located within low-energy point 735 may not be completely treated during the ablation process.

[0169] One way to overcome the problem of the low energy point of 735 is to add additional ablation equipment, such as... Figure 8 As shown. Figure 8 The ablation zones associated with three microwave ablation devices are shown. As illustrated, ablation devices 820a, 820b, and 820c emit radiation, resulting in their respective ablation zones 825a, 825b, and 825c. However, in some cases, low-energy points may still occur when using three or more ablation devices, such as at locations between any two ablation devices and / or near the center of multiple ablation devices. Adding additional ablation devices or rearranging the ablation devices can adjust the location of potential low-energy points. For example, regarding... Figure 8 Even when ablation devices 820a, 820b, and 820c emit microwave energy simultaneously, low-energy points may still occur, such as near the center of the ablation devices. Similarly, adding additional ablation devices may still result in low-energy points located between the ablation devices, such as low-energy points 835a, 835b, and 835c.

[0170] To properly ablate low-energy points resulting from interference between two or more ablation devices, the ablation devices can operate in multiple ablation states to completely ablate potential low-energy points. When referring to a system comprising multiple ablation devices, the ablation states used herein correspond to combinations of the operating states (e.g., ON / OFF states) of each individual ablation device. In some embodiments, an ablation device in the ON state may represent an ablation device emitting ablation energy, while an ablation device in the OFF state may represent an ablation device that does not emit ablation energy from it. Alternatively, the ON state may represent an ablation device emitting ablation energy at a first energy level, and the OFF state may represent an ablation device emitting ablation energy at a second energy level below the first energy level. Additionally or alternatively, the operating states may include additional states with energy levels between the ON and OFF state energy levels, such as a 50% state, in which the ablation device emits 50% of the ablation energy emitted in the ON state. Advantageously, ablation devices that do not emit ablation energy can be used to determine reflected power or coupled power (e.g., power received from one or more ablation devices that is not delivered to the medium).

[0171] Different ablation states can correspond to different combinations of ablation devices receiving ablation power, such as a subset of the total number of ablation devices. For example, in a system including three ablation devices, a single ablation state could include providing ablation power to the first and second ablation devices, but not to the third ablation device. Another ablation state could include providing ablation power to both the second and third ablation devices, but not to the first ablation device.

[0172] Additionally or alternatively, in order to switch between ablation states (e.g., ON / OFF states), the phase difference between two or more ablation devices can be changed to remove, reduce, or adjust the location of any low-energy points (e.g., low-energy points 835a-c) appearing in the ablation zone. The phase difference between two or more ablation devices can be: the phase difference of the ablation energy emitted from the ablation device and / or the phase difference of the ablation power supplied to the ablation device.

[0173] Figures 9A-9C Showing the use Figure 8 Examples of various ablation states for the three ablation devices 820a, 820b, and 820c are shown. Figure 9A Each of the -D diagrams illustrates ablation devices 820a-c and respective ablation zones 825a-c generated by microwave energy emitted from the corresponding ablation device. Figures 9A-9C In the schematic diagram, the shadow ablation area (e.g., Figure 9A825a and 825b in the text represent the ablation zone associated with the ablation device in the ON state, while the shadowless ablation zone (e.g., Figure 9A 825c) in the figure represents the outline of the ablation zone corresponding to the ablation device in the OFF state. Figures 9A-9D Potential low-energy points 835a-c are also shown, which may be due to interference from microwave energies emitted from different ablation devices. In the example shown, potential low-energy points for a given ablation state are unshaded. Figure 9A 835c in the figure represents a lack of received microwave energy at such a location. Potentially low-energy points with shadows (e.g., Figure 9A 835a and 835b are shown in each ablation state for reference, but represent potential low-energy points from other ablation states (where such potential low-energy points are shown as unshaded).

[0174] exist Figure 9A In the ablation states shown, ablation devices 820a and 820b are in the ON state, as shown in the corresponding shaded ablation regions 825a and 825b, while ablation device 810c is in the OFF state, as shown in the unshaded ablation region 825c. As described elsewhere in this document, destructive interference between ablation devices 820a and 820b can result in one or more low-energy points, such as the unshaded low-energy point 835c.

[0175] Figure 9B The ablation states are depicted with ablation devices 820a and 820c in the ON state, as shown in the corresponding shaded ablation areas 825a and 825c, while ablation device 820b is in the OFF state, as shown in the unshaded ablation area 825b. Regarding... Figure 9B The destructive interference between ablation devices 820a and 820c can lead to Figure 9B The low-energy point 835b has no shadows. (See figure.) Figure 9A The low-energy point 835c, which is shown in the image as having no shadow and not receiving any ablation energy, is... Figure 9B The ablation state is shadowed, and the ablation energy is received from the ablation device 820a without interference from the operation of the ablation device 820c or with minimal interference.

[0176] Figure 9C The ablation states are depicted with ablation devices 820b and 820c in the ON state, as shown in the corresponding shaded ablation areas 825b and 825c, while ablation device 810a is in the OFF state, as shown in the unshaded ablation area 825a. Regarding... Figure 9C The destructive interference between ablation devices 820b and 820c can lead to Figure 9C The low-energy point 835a has no shadows. (See figure.) Figure 9AThe low-energy point 835c, which is shown in the image as having no shadow and not receiving any ablation energy, is also... Figure 9B The low-energy point 835b, which appears to be unshadowed and receives no ablation energy, is shown in the image. Figure 9C The ablation state is shadowed, and ablation energy is received from ablation devices 820b and 820c respectively without interference from other ablation devices or with minimal interference.

[0177] like Figure 9A As shown in -C, different low-energy points (e.g., low-energy points 835a-c) may occur depending on which ablation devices (e.g., ablation devices 820a-c) are in the ON state. By permute the ON and OFF states of the ablation devices over time, potential low-energy points caused by interference between ON devices cycle between low-energy points 835a, 835b, and 835c, as illustrated in the example. However, as... Figure 9A As shown in -C, the low-energy point caused by interference between the two devices (e.g., Figure 9A The low-energy point 835c between devices 820a and 820b receives ablation energy under other ablation conditions (e.g., Figure 9B and 9C ).

[0178] In embodiments where the ablation device 820a-c emits microwave energy and is inserted into the tissue, the tissue present at each low-energy point 835a-c may receive little to no microwave energy in each given ablation state (e.g., Figure 9A The low energy point 835c in the ablation state is shown. Figure 9B The low-energy point 835b in the ablation state shown, and Figure 9C The low-energy point 835a in the ablation state is shown. Advantageously, when the system operates in different ablation states, the potential low-energy point associated with a given ablation state can receive microwave energy. By making Figure 9A In each ablation state cycle shown in -C, each corresponding low-energy point can be successfully ablated, resulting in each region (e.g., ablation regions 825a-c) receiving the correct amount of microwave energy.

[0179] Cycling can be achieved by switching each ablation device between ON and OFF operating states. Figure 9A-C represents each ablation state. The cycle can be performed such that each ablation device has a first time amount in which the device is in the ON state and a second time amount in which the device is in the OFF state. The total time for a single ON state and a single OFF state can be defined as a cycle. In some embodiments, the cycling between ON and OFF states is accomplished by providing a duty cycle for each ablation device. In alternative embodiments, other methods can be used to cycle the ablation devices between ON and OFF states, such as those described herein.

[0180] Figure 10 The ablation power diagram provided to multiple ablation devices is displayed. Figure 10 Shown in Figure 8 Using duty cycle in ablation systems Figure 9A An exemplary embodiment of cycling between the ablation states shown in -C. Regarding Figure 10 The ablation signal provided to each ablation device 820a-c has the same period (P), first time duration (T1), and second time duration (T2). As shown in the figure, in the example illustrated, T2 is approximately twice the duration of T1. More specifically, in the illustrated example, T1 is approximately 200 ms, and T2 is approximately 400 ms. Furthermore, the first time duration of each ablation device is time-shifted relative to each other. More specifically, the first time duration for operation with a given ablation device is time-shifted by 200 ms compared to the first time duration for other ablation devices.

[0181] about Figure 10 The 200ms in the first diagram represents Figure 9A The ablation states are shown in the diagram, where ablation devices 820a and 820b are in the ON state and ablation device 810c is in the OFF state. Figure 10 The time range of 200-400ms represents Figure 9B The ablation state, wherein ablation devices 820a and 820b are in the ON state and ablation device 820b is in the OFF state. Figure 10 The time range of 400-600ms represents Figure 9C The ablation states are defined, with ablation devices 820b and 820c in the ON state and ablation device 820a in the OFF state. It can be seen that the mode is achieved through... Figure 10 The time returned is between 600-900ms. Figure 9A The ablation state repeats itself, and continues to repeat. For example... Figure 9A -C and Figure 10 As shown, the ablation process is cyclical by adjusting the duty cycle of each ablation device (820a, 820b, 820c). Figure 9AThe various ablation states shown in -C help to provide a uniform distribution of ablation energy throughout the ablation zone (e.g., ablation zone 825a-c), while taking into account the possibility of low-energy points due to interference between multiple devices. This distribution... Figure 9D The text indicates that, among other things, it will change over time. Figure 9A After combining the regions covered by each ablation state shown in -C, no potential low-energy point (e.g., 835a-c) remains unablated, as... Figure 10 As shown.

[0182] Figure 10 Three ablation devices (e.g., ablation devices 820a-c) are shown cycling between states every 600 ms. In some embodiments, the cycling time may be more or less than 600 ms. For example, ablation states may cycle faster, such that the cycling time between states is less than 600 ms (e.g., 200 ms to 600 ms). Alternatively, ablation states may cycle slower, such that the cycling time between states is more than 600 ms (e.g., 600 ms to 5 s). Furthermore, times faster than 200 ms and slower than 5 s have been considered.

[0183] like Figure 10 As shown, ablation power can be supplied to multiple ablation devices, which have duty cycles that are time-shifted relative to each other. As used herein, the time shift between duty cycles describes the time difference between the transitions between the ON and OFF states of the duty cycle. For example, as... Figure 10 As shown, the duty cycle associated with ablation device 820a is offset in time by approximately 200 ms from the duty cycle associated with ablation device 820b. In some embodiments, the time offset between duty cycles is between approximately 50 ms and approximately 500 ms. In some embodiments, the time offset between duty cycles is between approximately 100 ms and approximately 300 ms. In other examples, time offsets shorter than 50 ms and longer than 500 ms may be used.

[0184] In embodiments, the duty cycles associated with each ablation device have similar periods. In some such examples, the time offset between consecutive duty cycles can be approximately equal to the period divided by the number of ablation devices. For example, regarding Figure 10 The duty cycle associated with each of the three ablation devices (820a-c) is approximately 600 ms, and the duty cycle is offset in time by approximately 200 ms.

[0185] In some examples, the duty cycle itself can be implemented based on a variety of factors, including, for example, the number of ablation devices to be used, the maximum number of ablation devices that can be powered simultaneously, etc. For example, in an example using three ablation devices and being able to power two ablation devices simultaneously, a 2 / 3 duty cycle (two parts on, one part off) can be implemented. Each ablation device can be provided with a duty cycle ablation power, wherein the duty cycles of each ablation device are offset from each other in time.

[0186] Although Figure 10 Generally, each ablation device has an equal but time-shifted duty cycle; however, in alternative embodiments, the various duty cycles between ablation devices do not need to be similar. In some embodiments, one or more ablation devices may operate with different duty cycles, for example, having different amounts of time in the ON operating state (T1) or OFF operating state (T2). Ablation devices may also have the same or similar duty cycles but with different periods (P) associated with their duty cycles.

[0187] Additional or alternative land, although Figure 10 The diagram generally illustrates a cycle between various ablation states, but the pattern of change between ablation states does not necessarily have to be cyclical. For example, in some embodiments, a physician may manually switch between different ablation states in any order, for example via a user interface. Typically, for systems with one or more ablation devices, any ablation state or the order in which these ablation states are applied is possible.

[0188] In some examples, ablation states can be achieved by cycling different ablation devices between ON and OFF operating states, for example, via duty cycle. In some embodiments, different ablation states can be achieved by modulating the ablation power applied to different ablation devices with a non-square wave (such as a triangle wave, sawtooth wave, sine wave, etc.). In some such examples, the relative power applied to different ablation devices varies over time to eliminate or reduce the possibility of low energy points arising from the total power drawn from multiple ablation devices and / or due to interference between ablation energies emitted from the ablation devices.

[0189] In some embodiments, not all ablation devices can be configured to deliver the same ablation energy and / or average ablation energy to the ablation zone. For example, if an ablation device (e.g., ablation device 820a) is located near a critical component (e.g., an important blood vessel, organ, etc.), it may be advantageous for ablation device 820a to emit a lower ablation energy level and / or a lower average ablation energy level. A lower ablation energy level can be achieved by the ablation generator delivering less ablation power to ablation device 820a. A lower average ablation energy level can be achieved by operating ablation device 820a with different duty cycles (such as duty cycles that include more time spent in the OFF state compared to ablation devices 820b and / or 820c). Other methods for providing various ablation energy levels and / or average ablation energy levels known to those skilled in the art are also contemplated.

[0190] It is understood that the ablation power level can be controlled in at least two different ways: by controlling the amplitude or by using the duty cycle. For example, if an average power level of 40W is desired, it can be achieved by setting the power level to 40W, or by setting the power level to a higher value of 80W and implementing a 50% duty cycle. Both methods of controlling the power level have been considered.

[0191] In embodiments using multiple ablation devices, such as Figure 8-10 As illustrated in the example, the distance between ablation devices can affect ablation effectiveness. If the ablation devices are too far apart, there may be areas in the medium between the devices that cannot be successfully ablated, such as areas that are not reached by any ablation zone of each device (e.g., 824a-c). Alternatively, positioning the ablation devices too close to each other or too close to auxiliary devices may reduce the effectiveness of ablation and / or the reliability of any data collected during ablation.

[0192] In some embodiments, the ablation system can provide data to the user so that the ablation device is not placed too far or too close. In such embodiments, at least one of the ablation devices may include a directional coupler. The directional coupler can be used to measure the delivered and received power on the ablation device. Additionally or alternatively, other devices may be used to determine the delivered and / or received power, such as a directional coupler on an additional ablation device or an antenna configured to receive power.

[0193] When using a directional coupler or similar device, the received power (e.g., the S0 of the directional coupler) can be monitored. 11 To determine the reflected power. Figure 11 S provides the first ablation device using a directional coupler 11 Some example data for the signal. Figure 11In this process, the second ablation device was brought extremely close to the first ablation device. Initially, the distance between the second and first ablation devices was sufficient to allow for effective ablation of S... 11 Signal interference is minimal. Then, at time 1110 (approximately 55 seconds), the second ablation device is brought extremely close to the first ablation device. As shown in the figure, compared to when the second ablation device is moved further away, when the second ablation device is brought extremely close to the first ablation device, S... 11 The signal contains a lot of noise.

[0194] In some embodiments, when the first ablation needle is in the ON state and the second ablation needle is in the OFF state, S can be measured. 11 Signal. Alternatively, when both the first and second ablation needles are in the ON state, S can be measured. 11 Signal. In addition, S 11 Noise in the signal can represent the first ablation device being extremely close to multiple devices, such as two or more ablation devices, or an ablation device and an auxiliary measurement device.

[0195] As described in this article, a second directional coupler or similar device on the second device can also be used to determine whether the first ablation device is too close to the second ablation device. Figure 12 Provide S 21 Some example data for the signal. S 21 The signal can be a measurement of the signal received from the first ablation device on the second ablation device. Regarding... Figure 12 High S 21 The value may indicate that the second ablation device is extremely close to the first ablation device, and that the S value is low. 21 The value may indicate that the devices are sufficiently separated. As shown in the figure, during time zone 1210, S21 data shows high power, and time zone 1220 shows low power. As mentioned above, time zone 1210 depicts the time during which the ablation devices are extremely close to each other, and time zone 1220 depicts the time during which the ablation devices are sufficiently separated.

[0196] In some embodiments, when the first ablation needle is in the ON state and the second ablation needle is in the OFF state, S can be measured. 21 Signal. In a further embodiment, S 21 A signal can represent multiple ablation devices that are in the ON state. For example, refer to... Figure 8-10 An ablation device that is in the OFF state at a given time can be used to determine whether it is too close to one or more other ablation devices that are in the ON state.

[0197] In some embodiments, the user can use Figure 11 and Figure 12The data is used to correctly position the ablation needle, ensuring complete separation of the needle. In a particular embodiment, the user can receive data from one or more directional couplers, such as those similar to... Figure 11 and Figure 12 The data shown is for proper manipulation of the ablation device during the ablation procedure.

[0198] Alternatively, before initiating the ablation procedure, the ablation system may provide ablation power to the signal via a single ablation device to determine if it is too close to any additional ablation devices or auxiliary devices used during the ablation procedure.

[0199] Various non-limiting examples have been described. These and others are all within the scope of the following claims. Furthermore, while the invention is susceptible to various modifications and alternatives, some specific embodiments of the invention are illustrated by way of example in the accompanying drawings. The drawings may not be drawn to scale.

Claims

1. A tissue ablation system, comprising: a plurality of ablation devices for placement at or near a target region of a patient's anatomy, wherein each ablation device has a microwave antenna and each ablation device is configured to provide ablation energy in an ablation zone proximate to such ablation device when each ablation device is provided with ablation power; a plurality of ablation generators, each ablation generator configured to provide ablation power to one of the plurality of ablation devices; a controller in communication with the ablation generators, the controller configured to cause each of the plurality of ablation devices to selectively receive ablation power; the controller configured to repeatedly cycle through activation of each of a plurality of ablation states; and wherein each ablation state corresponds to a respective unique subset of the plurality of ablation devices, and wherein activation of one of the ablation states includes ablation devices in the corresponding subset of the plurality of ablation devices receiving ablation power; and wherein repeatedly cycling through activation of each of a plurality of ablation states ablates low energy points caused by interference between the plurality of ablation devices.

2. The tissue ablation system of claim 1, wherein, Activation of an ablation state includes ablation devices not in the corresponding subset of the plurality of ablation devices not receiving ablation power.

3. The tissue ablation system of claim 1 or 2, wherein, Activation of an ablation state includes ablation devices not in the corresponding subset of the plurality of ablation devices receiving less power than ablation devices receiving ablation power.

4. The tissue ablation system of claim 1 or 2, wherein, Activation of an ablation state includes ablation devices not in the corresponding subset of the plurality of ablation devices not receiving power.

5. The tissue ablation system of claim 1 or 2, wherein, The controller activates each of the plurality of ablation states in succession.

6. The tissue ablation system of claim 1 or 2, wherein, Cycling through activation of each of the plurality of ablation states is configured to cause not all of the plurality of ablation devices to simultaneously receive the ablation power.

7. The tissue ablation system of claim 1 or 2, wherein, Cycling through activation of each of the plurality of ablation states includes activating each ablation state for the same length of time.

8. The tissue ablation system of claim 1 or 2, wherein, Each ablation state is activated for 100 to 300 ms.

9. The tissue ablation system of claim 1 or 2, wherein, Cycling through activation of each of the plurality of ablation states is implemented by receiving the ablation power at each ablation device according to a respective duty cycle.

10. The tissue ablation system of claim 9, wherein, The duty cycles of the plurality of devices are equal.

11. The tissue ablation system of claim 9, wherein, The duty cycles of each of the plurality of devices are offset in time.

12. The tissue ablation system of claim 9, wherein, The respective duty cycles are offset in time such that not all of the plurality of ablation devices simultaneously receive the ablation power.

13. The tissue ablation system of claim 9, wherein, The respective duty cycles are offset in time such that alternating ones of the ablation devices do not receive the ablation power at all times when the controller cycles through activation of each of the plurality of ablation states.

14. The tissue ablation system of claim 1 or 2, wherein, Each of the plurality of ablation devices includes a microwave ablation needle.

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