Microwave generator with dynamic correction of temperature measurement

Abstract

A method for calculating a corrected temperature value (RTP corrected). The method includes determining a measured temperature value from a remote thermocouple probe (RTP measured), determining a temperature value of a remote thermocouple module (RTM), determining a temperature value of a system controller module (SCM), determining a temperature value of a microwave module (MWM), and calculating the corrected temperature value (RTP corrected). The corrected temperature value (RTP corrected) is based on at least one of the determined temperature value of the remote thermocouple probe (RTP measured), the determined temperature value of the system controller module (SCM), and the determined temperature value of the remote thermocouple module (RTM) or the determined temperature value of the microwave module (MWM).

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 065,555, filed on August 14, 2020. Technical Field

[0003] This disclosure relates to microwave generators, and more specifically, to a microwave generator that dynamically corrects temperature measurement errors (e.g., by compensating for inaccurate measurements caused by parasitic junctions and / or other factors). Background Technology

[0004] In microwave ablation, electromagnetic fields are used to heat and destroy tumor cells. The treatment may involve inserting an ablation probe into tissue where a cancerous tumor has been identified. Once the ablation probe is correctly positioned, it induces an electromagnetic field within the surrounding tissue to ablate the tissue.

[0005] Typically, systems used in microwave ablation surgery include a microwave generator and microwave instruments such as an ablation probe with an antenna assembly. The microwave generator and microwave instruments are operatively coupled to each other via a coaxial cable for transmitting microwave signals from the microwave generator to the microwave instruments. The microwave generator typically includes circuitry for generating microwave signals and a controller for controlling the operation of this circuitry and for controlling a user interface such as a display. The user interface includes user controls for setting characteristics of the microwave signals, such as controls for adjusting the power level and activation time of the microwave signals.

[0006] Microwave ablation systems can use thermocouples (TCs) to measure the temperature of tissue or the device. For example, needle-shaped remote thermocouple probes can be used to measure the temperature of tissue adjacent to or within the ablation zone to monitor the progress of treatment delivery. These systems can also use TCs to measure the internal temperature of the ablation probe antenna assembly to confirm that the probe is adequately cooled throughout the ablation procedure. Several factors can cause such temperature measurements to be inaccurate. Summary of the Invention

[0007] According to various aspects of this disclosure, a method for calculating a corrected temperature value (RTP correction) using a microwave generator is provided. The method includes: determining a measured temperature value from a remote thermocouple probe (RTP measurement), determining a temperature value of a remote thermocouple module (RTM), determining a temperature value of a system controller module (SCM), determining a temperature value of a microwave module (MWM), and calculating the corrected temperature value (RTP correction). The corrected temperature value (RTP correction) is calculated based on at least one of the determined temperature value of the remote thermocouple probe (RTP measurement), the determined temperature value of the system controller module (SCM), and the determined temperature value of the remote thermocouple module (RTM) or the determined temperature value of the microwave module (MWM).

[0008] On the one hand, the corrected temperature value (RTP correction) is calculated using the following formula:

[0009] RTP correction = RTP measurement - C1 * (RTM - SCM), where C1 = 0.3.

[0010] In one aspect, the method includes determining whether the microwave generator is in an idle or active state.

[0011] On the one hand, when it is determined that the microwave generator is in an idle state, the corrected temperature value (RTP correction) is calculated using the following formula:

[0012] RTP correction = RTP measurement - C1 * (RTM - SCM), where C1 = 0.3.

[0013] Alternatively, when it is determined that the microwave generator is active, the corrected temperature value (RTP correction) is calculated using the following formula:

[0014] RTP correction = RTP measurement - C2 * (MWM - SCM), where C1 = 0.13.

[0015] On the one hand, when it is determined that the microwave generator is in an idle state and not within the 120-second deactivation period, the corrected temperature value (RTP correction) is calculated using the following formula:

[0016] RTP correction = RTP measurement - C1 * (RTM - SCM), where C1 = 0.3.

[0017] Alternatively, when it is determined that the microwave generator is in an idle state and within 120 seconds of deactivation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0018] RTP correction = RTP measurement - C6 * (RTM - SCM), where C6 = 0.19.

[0019] On the one hand, when it is determined that the microwave generator is active and within 10 seconds of activation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0020] RTP correction = RTP measurement - C1*(RTM-SCM) - C2*(MWM-SCM), where C1 = 0.3 and C2 = 0.26.

[0021] On the one hand, when it is determined that the microwave generator is active and between 10 and 30 seconds of activation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0022] RTP correction = RTP measurement - C1*(RTM-SCM) - C3*(MWM-SCM), where C1 = 0.3 and C3 = 0.21.

[0023] On the one hand, when it is determined that the microwave generator is active and between 30 and 120 seconds of activation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0024] RTP correction = RTP measurement - C1*(RTM-SCM) - C4*(MWM-SCM), where C1 = 0.3 and C4 = 0.15.

[0025] On the one hand, once it is determined that the microwave generator is active and 120 seconds after activation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0026] RTP calibration = RTP measurement - C1*(RTM-SCM) - C5*(MWM-SCM), where C1 = 0.3 and C5 = 0.09.

[0027] In one aspect, the method includes determining the elapsed activation time (T) and output power level of the microwave generator (P), wherein a corrected temperature value (RTP correction) is calculated using the following formula:

[0028] RTP correction = RTP measurement - C1*(RTM-SCM) - P*1 / T*C2*(MWM-SCM), where C1 = 0.3 and C2 = 0.02.

[0029] According to another aspect of this disclosure, a microwave generator is provided. The microwave generator includes: a system controller module configured to control the microwave generator; a microwave module configured to generate microwave energy; and a remote thermocouple module configured to determine a temperature value of a remote thermocouple probe (RTP measurement). At least one of the system controller module or the remote thermocouple module is configured to determine a temperature value of the remote thermocouple module (RTM), a temperature value of the system controller module (SCM), a temperature value of the microwave module (MWM), and to calculate a corrected temperature value (RTP correction). At least one of the system controller module or the remote thermocouple module is configured to calculate the corrected temperature value (RTP correction) based on at least one of the determined temperature value of the remote thermocouple probe (RTP measurement), the determined temperature value of the system controller module (SCM), and the determined temperature value of the remote thermocouple module (RTM) or the determined temperature value of the microwave module (MWM).

[0030] On the one hand, the corrected temperature value (RTP correction) is calculated using the following formula:

[0031] RTP correction = RTP measurement - C1 * (RTM - SCM), where C1 = 0.3.

[0032] On one hand, at least one of the system controller module or the remote thermocouple module is configured to determine whether the microwave generator is in an idle or active state.

[0033] On the one hand, when it is determined that the microwave generator is in an idle state, the corrected temperature value (RTP correction) is calculated using the following formula:

[0034] RTP correction = RTP measurement - C1 * (RTM - SCM), where C1 = 0.3.

[0035] Alternatively, when it is determined that the microwave generator is active, the corrected temperature value (RTP correction) is calculated using the following formula:

[0036] RTP correction = RTP measurement - C2 * (MWM - SCM), where C1 = 0.13.

[0037] On the one hand, when it is determined that the microwave generator is in an idle state and not within the 120-second deactivation period, the corrected temperature value (RTP correction) is calculated using the following formula:

[0038] RTP correction = RTP measurement - C1 * (RTM - SCM), where C1 = 0.3.

[0039] Alternatively, when it is determined that the microwave generator is in an idle state and within 120 seconds of deactivation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0040] RTP correction = RTP measurement - C6 * (RTM - SCM), where C6 = 0.19.

[0041] On the one hand, when it is determined that the microwave generator is active and within 10 seconds of activation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0042] RTP correction = RTP measurement - C1*(RTM-SCM) - C2*(MWM-SCM), where C1 = 0.3 and C2 = 0.26.

[0043] On the one hand, when it is determined that the microwave generator is active and between 10 and 30 seconds of activation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0044] RTP correction = RTP measurement - C1*(RTM-SCM) - C3*(MWM-SCM), where C1 = 0.3 and C3 = 0.21.

[0045] On the one hand, when it is determined that the microwave generator is active and between 30 and 120 seconds of activation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0046] RTP correction = RTP measurement - C1*(RTM-SCM) - C4*(MWM-SCM), where C1 = 0.3 and C4 = 0.15.

[0047] Alternatively, when it is determined that the microwave generator is active and 120 seconds after activation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0048] RTP calibration = RTP measurement - C1*(RTM-SCM) - C5*(MWM-SCM), where C1 = 0.3 and C5 = 0.09.

[0049] In one aspect, at least one of the system controller module or remote thermocouple module is further configured to determine the elapsed activation time (T) and output power level of the microwave generator (P). The corrected temperature value (RTP correction) can be calculated using the following formula: RTP correction = RTP measurement - C1*(RTM-SCM) - P*1 / T*C2*(MWM-SCM), where C1 = 0.3 and C2 = 0.02.

[0050] According to another aspect of this disclosure, a non-transitory computer-readable storage medium is provided that stores instructions, when executed by a processor, causing the processor to perform a method for calculating a corrected temperature value. The method includes: determining a measured temperature value from a remote thermocouple probe (RTP measurement), determining a temperature value of a remote thermocouple module (RTM), determining a temperature value of a system controller module (SCM), determining a temperature value of a microwave module (MWM), and calculating the corrected temperature value (RTP correction). The corrected temperature value (RTP correction) is calculated based on at least one of the determined temperature value of the remote thermocouple probe (RTP measurement), the determined temperature value of the system controller module (SCM), and the determined temperature value of the remote thermocouple module (RTM) or the determined temperature value of the microwave module (MWM).

[0051] On the one hand, the corrected temperature value (RTP correction) is calculated using the following formula:

[0052] RTP correction = RTP measurement - C1 * (RTM - SCM), where C1 = 0.3.

[0053] In one aspect, the method includes determining whether the microwave generator is in an idle or active state.

[0054] On the one hand, when it is determined that the microwave generator is in an idle state, the corrected temperature value (RTP correction) is calculated using the following formula:

[0055] RTP correction = RTP measurement - C1 * (RTM - SCM), where C1 = 0.3.

[0056] Alternatively, when it is determined that the microwave generator is active, the corrected temperature value (RTP correction) is calculated using the following formula:

[0057] RTP correction = RTP measurement - C2 * (MWM - SCM), where C1 = 0.13.

[0058] On the one hand, when it is determined that the microwave generator is in an idle state and not within the 120-second deactivation period, the corrected temperature value (RTP correction) is calculated using the following formula:

[0059] RTP correction = RTP measurement - C1 * (RTM - SCM), where C1 = 0.3.

[0060] Alternatively, when it is determined that the microwave generator is in an idle state and within 120 seconds of deactivation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0061] RTP correction = RTP measurement - C6 * (RTM - SCM), where C6 = 0.19.

[0062] On the one hand, when it is determined that the microwave generator is active and within 10 seconds of activation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0063] RTP correction = RTP measurement - C1*(RTM-SCM) - C2*(MWM-SCM), where C1 = 0.3 and C2 = 0.26.

[0064] On the one hand, when it is determined that the microwave generator is active and between 10 and 30 seconds of activation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0065] RTP correction = RTP measurement - C1*(RTM-SCM) - C3*(MWM-SCM), where C1 = 0.3 and C3 = 0.21.

[0066] On the one hand, when it is determined that the microwave generator is active and between 30 and 120 seconds of activation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0067] RTP correction = RTP measurement - C1*(RTM-SCM) - C4*(MWM-SCM), where C1 = 0.3 and C4 = 0.15.

[0068] On the one hand, once it is determined that the microwave generator is active and 120 seconds after activation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0069] RTP calibration = RTP measurement - C1*(RTM-SCM) - C5*(MWM-SCM), where C1 = 0.3 and C5 = 0.09.

[0070] In one aspect, the method includes determining the elapsed activation time (T) and output power level of the microwave generator (P), wherein a corrected temperature value (RTP correction) is calculated using the following formula:

[0071] RTP correction = RTP measurement - C1*(RTM-SCM) - P*1 / T*C2*(MWM-SCM), where C1 = 0.3 and C2 = 0.02. Attached Figure Description

[0072] This document describes various embodiments of the disclosure with reference to the accompanying drawings, in which:

[0073] Figure 1 It is a block diagram of a microwave ablation system including a microwave generator;

[0074] Figure 2 yes Figure 1 Circuit isolation diagram of a microwave ablation system;

[0075] Figure 3 yes Figure 1 A block diagram of the power distribution module of a microwave generator;

[0076] Figure 4 yes Figure 1 A block diagram of the user interface module of a microwave generator;

[0077] Figure 5A yes Figure 1 A block diagram of the microwave module of a microwave generator;

[0078] Figure 5B yes Figure 5A Block diagram of the power amplifier of the microwave module;

[0079] Figure 6 yes Figure 1 A block diagram of the system controller module of the microwave generator;

[0080] Figure 7 yes Figure 1 A block diagram of the equipment monitoring module for a microwave generator;

[0081] Figure 8 yes Figure 1 A block diagram of the remote thermocouple module of the microwave generator;

[0082] Figure 9 It is a flowchart illustrating the method for calculating the corrected temperature according to this disclosure; and

[0083] Figure 10 It is a graph showing the experimental results of temperature measurement and calculation errors caused by parasitic conditions. Detailed Implementation

[0084] Specific embodiments of this disclosure are described below with reference to the accompanying drawings. Well-known functions or constructions are not described in detail in the following description to avoid unnecessary detail that could obscure the disclosure.

[0085] As used herein, the term "approximately" means that the numerical value is an approximation and that minor variations will not significantly affect the practice of the disclosed embodiments. When numerical limits are used, "approximately" means that the value may vary by ±10% and remain within the range of the disclosed embodiments, unless the context otherwise indicates.

[0086] In addition to its primary function of generating microwave signals for use by microwave instruments, a microwave generator can perform several functions related to this primary function. While these additional features increase the practicality of the microwave generator, they also require more power, consume more processing resources, and increase the overall cost of manufacturing. This disclosure relates to a modular microwave generator system comprising physical modules and components with distributed and isolated processing to perform auxiliary functions associated with the microwave generator. One such component is an improved remote thermocouple module that dynamically calculates and outputs corrected temperature measurements by compensating for inaccurate temperature measurements caused, for example, by parasitic junctions and other factors within the generator.

[0087] This disclosure relates to the compensation of parasitic thermocouple junctions in the thermocouple measurement circuitry of a microwave ablation generator using a digitally implemented algorithm in programmable logic (software and firmware). As described below, temperature measurements from a printed circuit board within the microwave generator, as well as the operating state of the microwave generator, are used as inputs to drive the calibration algorithm. In addition to integrated circuit compensation and remote thermocouple probe measurements, the calibration method utilizes two or more temperature measurements to reduce measurement errors to an acceptable specification range (e.g., + / - 0.5 dB).

[0088] Figure 1 This is a block diagram of a microwave ablation system according to an embodiment of this disclosure. Figure 1As shown, a microwave ablation system 100 typically includes a microwave generator 110, an energy applicator 120 (e.g., a microwave ablation device, such as a microwave antenna) connected to the microwave generator 110 via a reusable cable 115, a foot switch 130 for activating the output of the microwave generator 110, and remote thermocouple probes 140 that can be directly coupled to the microwave generator 110 or coupled to the microwave generator 110 via a multi-probe temperature display unit (not shown). The energy applicator 120 includes a device ID module 122 having a device unique identifier resistor (“DUIR”) 124 and a device ID memory 126. The DUIR 124 has a device unique identifier (“DUID”) resistor that can be measured by the microwave generator 110 and compared with a resistance value stored in the microwave generator 110's memory to identify the type of energy applicator 120. Based on the identified type of energy applicator 120, it can be determined whether the connected device is compatible with the microwave generator 110. The device ID module 122 can be incorporated into the power applicator 120 or into a separate connector or adapter configured to mate with the connector of the reusable cable 115. Thus, the reusable cable 115 can be connected to the DUIR 124 and the device ID memory 126 via a connection to the power applicator 120, or the reusable cable 115 can be connected to the DUIR 124 and the device ID memory 126, which in turn is connected to the power applicator 120. Similar memory and / or resistors for storing device-specific information may be included in the reusable cable 115.

[0089] Various subsystems can be employed during the use of the microwave ablation system 100. Typically, the operation of a subsystem is controlled by a microprocessor-driven control console (e.g., microwave generator 110). The microprocessor receives mechanical input from the operator or assistant of the microwave ablation system 100. Control input devices, such as foot switches 130, are used to accept mechanical input from the operator, allowing the operator to manage the operation of the subsystem within the microwave ablation system 100. When actuated by the operator, the control input device transmits an electrical signal to the microprocessor control system. The electrical signal is then used to control the operating characteristics of the subsystem within the microwave ablation system 100.

[0090] like Figure 1As shown, microwave generator 110 is connected to remote thermocouple probe 140. Remote thermocouple probe 140 may include a temperature sensor such as a thermocouple or a thermistor, and may include a memory storing a device ID or other information such as status information. Remote thermocouple probe 140 is operable for measuring tissue temperature at a surgical site. In one embodiment, remote thermocouple probe 140 is configured to continuously output a temperature signal to microwave generator 110, thereby allowing temperature observation and / or control of microwave generator 110 based on the temperature signal.

[0091] The microwave generator 110 may include any one, a subset, or all of the following: power supply module 200, power distribution module 300, user interface module 400, microwave module 500, patient isolator 550, system controller module 600, equipment monitoring module 700, and remote thermocouple module 800. Each module or subset of modules of the microwave generator 110 communicates via a bus.

[0092] Power module 200 converts AC to DC and outputs DC voltage (e.g., 34 volts DC) to power distribution module 300 and microwave module 500. Power distribution module distributes DC voltage (e.g., 12 volts DC) to power other modules of microwave generator 110, including user interface module 400, system controller module 600, device monitoring module 700, and remote thermocouple module 800.

[0093] Figure 2 It is a block diagram illustrating the isolation between each module of the microwave generator 110 and the isolation between the modules of the microwave generator 110 and the patient. Figures 3 to 8 Microwave generator 110 was shown respectively. Figure 1 ) power distribution module 300 ( Figure 3 ), User Interface Module 400 ( Figure 4 ), microwave module 500 ( Figure 5A ), System Controller Module 600 ( Figure 6 ), Equipment monitoring module 700 ( Figure 7 ) and remote thermocouple module 800 ( Figure 8 (A flowchart of a block diagram.)

[0094] Figure 5A A microwave module 500 and a patient isolator 550 of a microwave generator 110 according to an embodiment of this disclosure are shown. The microwave module 500 includes various components, including... Figure 5B The power amplifier 560 is shown in detail in the image. Figure 6 A system controller module 600 of a microwave generator 110 according to an embodiment of this disclosure is shown. Brief Reference Figure 2The system controller module 600 includes an isolator 601. The isolator 601 may include a transformer having a primary winding 601a and a secondary winding 601b. Other isolation techniques, such as optical isolation, are conceivable. For transformer isolation, power or signals received by the isolator 601 pass through the primary winding 601a of the transformer, which induces a current in the secondary winding 601b proportional to the current received by the isolator 601. The induced current supplies power or signals to / from components of the system controller module 600, such as the controller microprocessor 630. In an embodiment, the isolator 601 supplies power to an external system, for example, 5VDC, with a maximum power consumption of 5W. The isolator 601 may also isolate the operator from the internal electronics of the microwave generator 110 using an accessory (such as a foot switch) connected to the system controller module 600.

[0095] The controller microprocessor 630 is a programmable processor that can be configured, via flash memory programming or other suitable programming methods and languages, to digitally communicate with the microwave module 500, device monitoring module 700, remote thermocouple module 800, user interface module 400, foot switch 130, and other components of the microwave generator 110. The controller microprocessor 630 can be calibrated using software calibration methods (including cardinality-based digital self-calibration, background equivalent cardinality extraction, interference cancellation) or hardware calibration methods (including, for example, using a combination of comparator / digital-to-analog converter (DAC), a digitally controllable low-pass filter using a digital potentiometer, calibration multiplexer) or any hardware and / or software solution to improve the digital communication link. As part of the communication between the controller microprocessor and the microwave module 500, the device monitoring module 700, the remote thermocouple module 800, and the user interface module 400, the controller microprocessor 630 transmits information about itself (including, for example, status information, serial number, and firmware version) to each component, and simultaneously receives information about itself (including, for example, status information, serial number, and firmware version) from each component. The controller microprocessor 630 continuously processes and monitors this information.

[0096] The controller microprocessor 630 digitally communicates with the user interface module 400 to receive user input and send information that can be transmitted to the user by the user interface module 400. The controller microprocessor 630 can signal the user interface module 400 to prompt the user to input a microwave power level or treatment time. When the user makes a selection, the user interface module 400 sends a signal indicating the selection to the controller microprocessor 630, and the controller microprocessor 630 receives and processes the signal, then signals the microwave module 500 to set the power level or treatment time. Alternatively, the controller microprocessor 630 can delay sending the signal to the microwave module 500. For example, if the controller microprocessor 630 receives the treatment time, it only sends the signal to the microwave module 500 when the allocated time is over. When treatment occurs, the controller microprocessor 630 counts down the selected treatment time. In addition to sending an end signal to the microwave module 500, the controller microprocessor 630 also communicates with the user interface module 400 throughout the countdown to send information about the remaining treatment time for display, including the remaining treatment time to indicate to the user how much time is left.

[0097] At startup, or at any time requested by the system controller module 600 or the user, the system controller module 600 may instruct the device monitoring module 700 to measure the DUID resistance of the energy applicator 120 and transmit the measured DUID resistance value to the system controller module 600. If the energy applicator 120 is identified as a smart device based on the measured DUID resistance, the system controller module 600 may transmit / request data packets to the device ID memory 126 of the energy applicator 120 via a reusable cable 115. Upon receiving a requested data packet, the device ID memory 126 of the energy applicator 120 responds by transmitting the requested data packet.

[0098] Figure 7 It is coupled to the energy applicator 120 via a reusable cable 115. Figure 1 The circuit block diagram of the device monitoring module 700. During startup, and with the energy applicator 120 connected to the microwave generator 110 via a reusable cable 115, the microwave generator 110 supplies power to the DUIR 124 ( ) via the reusable cable 115. Figure 1 The device monitoring module 700 provides a precise current to generate the DUID resistance value. The device monitoring module 700 measures the DUID resistance value and transmits it to the system controller module 600. Figure 1To identify the type of energy applicator 120, system controller module 600 processes the DUID resistance value received from device monitoring module 700 and compares the processed DUID resistance value with multiple resistance value indices stored in the memory of system controller module 600, each corresponding to a specific device type. The identified type of energy applicator 120 can determine whether the connected device is compatible with microwave generator 110. The device type can correspond to a specific capability of the device, the device model, a specific series of the device model, a specific treatment mode type of the device, whether the device is a smart device, device compatibility with the microwave generator, or any combination thereof. Device-specific operating thresholds for configuring the operation of microwave generator 110 for use with energy applicator 120 can be determined based on the identified type of energy applicator 120.

[0099] Figure 8 Microwave generator 110 was demonstrated. Figure 1 The remote thermocouple module 800. The remote thermocouple module 800 and the remote thermocouple probe 140 ( Figure 1 The remote thermocouple probe 140 is used for communication to measure the temperature of a remote thermocouple probe 140. Specifically, the remote thermocouple probe 140 includes a thermocouple junction created by welding the ends of a constantan (copper-nickel alloy) wire and a copper wire together and placing the weld point at the desired measurement location. The junction of these dissimilar metals generates a voltage proportional to the junction temperature. The copper and constantan wires are insulated behind the junction to maintain the voltage difference between the two wires. The remote thermocouple module 800 monitors this voltage difference to measure the temperature.

[0100] Figure 9 A method for calculating a corrected temperature value is demonstrated, and this method is described below as method 900. Although method 900 is described as including specific steps, method 900 may include some or all of the described steps. Furthermore, although method 900 is described as being performed in a specific order, the steps of method 900 may be performed in any order.

[0101] On one hand, method 900 consists of remote thermocouple module 800 ( Figure 1 and Figure 8 Method 900 can be executed in part or in whole by microwave generator 110. Figure 1 Any component or module of the microwave ablation system 100 ( Figure 1 Any component of the method 900 may perform the steps. For example, the remote thermocouple module 800 may include firmware that performs some or all of the steps of the method 900.

[0102] Method 900 begins at step 901, whereby a remote thermocouple module 800 determines a measured temperature value (RTP measurement) of a remote thermocouple probe 140, which can be percutaneously inserted into the patient's skin adjacent to a target site. In step 903, the remote thermocouple module 800 determines its own (RTM) temperature value, for example, via a thermocouple attached to the remote thermocouple module 800. In step 905, the remote thermocouple module 800 determines the temperature value of the system controller module (SCM) 600, for example, via a thermocouple attached to the system controller module 600. In step 907, the remote thermocouple module 800 determines the temperature value of the microwave module 500 (MWM), for example, via a thermocouple attached to the microwave module 500. In one aspect, the temperature values ​​of each module described herein are delivered directly to the remote thermocouple module 800, but it is conceivable that the remote thermocouple module 800 may obtain temperature values ​​from a bus that delivers data between different modules of the microwave generator 110, or other values ​​that can be used to calculate or determine these temperature values.

[0103] In step 909, a correction temperature value is calculated. The correction temperature value (RTP correction) is calculated based on at least one of the determined temperature value of the remote thermocouple probe 140 (RTP measurement), the determined temperature value of the system controller module (SCM) 600, and the determined temperature value of the remote thermocouple module (RTM) 800 or the determined temperature value of the microwave module (MWM) 500.

[0104] In its simplest form, the corrected temperature value (RTP correction) is calculated in step 909 using the following formula:

[0105] RTP correction = RTP measurement - C1 * (RTM - SCM), where C1 = 0.3.

[0106] Accuracy can be further improved by considering the state of microwave generator 110 (e.g., active, idle, etc.) and taking into account four temperature variables. Therefore, in one aspect, method 900 includes the step of determining whether microwave generator 110 is in an idle or active state. When it is determined that microwave generator 110 is in an idle state, a corrected temperature value (RTP correction) is calculated using the following formula:

[0107] RTP correction = RTP measurement - C1 * (RTM - SCM), where C1 = 0.3.

[0108] Additionally, when it is determined that the microwave generator 110 is active, the corrected temperature value (RTP correction) is calculated using the following formula:

[0109] RTP correction = RTP measurement - C2 * (MWM - SCM), where C1 = 0.13.

[0110] Accuracy is further improved by considering both the activation and deactivation durations of the microwave generator 110. For example, more time-based correction algorithms with four temperature variables are envisioned to handle the transitional states of the microwave generator 110 during rapid heating or cooling. When it is determined that the microwave generator 110 is in an idle state and not within the 120-second deactivation period, the corrected temperature value (RTP correction) is calculated using the following formula:

[0111] RTP correction = RTP measurement - C1 * (RTM - SCM), where C1 = 0.3.

[0112] Additionally, when it is determined that the microwave generator 110 is in an idle state and within 120 seconds of deactivation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0113] RTP correction = RTP measurement - C6 * (RTM - SCM), where C6 = 0.19.

[0114] When it is determined that the microwave generator 110 is active and within 10 seconds of activation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0115] RTP correction = RTP measurement - C1*(RTM-SCM) - C2*(MWM-SCM), where C1 = 0.3 and C2 = 0.26.

[0116] When it is determined that the microwave generator 110 is active and between 10 and 30 seconds of activation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0117] RTP correction = RTP measurement - C1*(RTM-SCM) - C3*(MWM-SCM), where C1 = 0.3 and C3 = 0.21.

[0118] When it is determined that the microwave generator 110 is active and between 30 and 120 seconds of activation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0119] RTP correction = RTP measurement - C1*(RTM-SCM) - C4*(MWM-SCM), where C1 = 0.3 and C4 = 0.15.

[0120] Once it is determined that the microwave generator 110 is active and 120 seconds after activation, the corrected temperature value (RTP correction) is calculated using the following formula:

[0121] RTP calibration = RTP measurement - C1*(RTM-SCM) - C5*(MWM-SCM), where C1 = 0.3 and C5 = 0.09.

[0122] Further accuracy can be achieved by adjusting the correction factor by considering four temperature variables, as well as the output power level and the elapsed activation time. Therefore, in one aspect, the method includes determining the elapsed activation time (T) and output power level (P) of the microwave generator 110, and calculating the corrected temperature value (RTP correction) using the following formula:

[0123] RTP correction = RTP measurement - C1*(RTM-SCM) - P*1 / T*C2*(MWM-SCM), where C1 = 0.3 and C2 = 0.02.

[0124] Figure 10 It showcases microwave generator 110 ( Figure 1 A graph showing various temperature measurements of the modules during operation is provided, illustrating inaccurate temperature readings caused by parasitic junctions and other factors, for example, during the operation of microwave generator 110. The temperature of each module (PDM, SCM, DMM, UIM, MWM, RTM) is shown along with the RTP temperature measurement. The timeline begins with the startup of microwave generator 110, allows it to reach steady state, and then completes approximately 10 minutes of high-output-power (150W) microwave energy activation (easily represented by the rise in MWM temperature). From... Figure 10 As can be seen, the RTP temperature, which should remain constant during this test, is affected by both the microwave generator 110's cold start-up followed by reaching its steady-state temperature at startup, and the subsequent heating from the microwave amplifier during energy activation. The SCM, being adjacent to the housing cooling fan that draws air from the outside into the microwave generator 110, remains closest to ambient temperature. Its temperature rise is greatest due to the microwave power generated by the MWM. This indicates that the MWM and SCM can provide significant input to the calibration algorithm. The RTM temperature is also significant because it is closest to the parasitic thermocouple junction on the partition plastic connector within the front panel of the microwave generator 110. The calibration algorithm described above is able to correct for errors caused over time by the operation of the microwave generator 110 and the parasitic junction present within it.

[0125] Microwave generator 110 is designed to operate at room temperature of 10-30 dC, and the thermal environment within microwave generator 110 is dynamic due to heating from AC / DC, DC / DC, and DC / MW power supplies. When microwave generator 110 is powered on and idle, the AC / DC and DC / DC power supplies begin to slowly heat the housing, and when microwaves are generated, a dramatic temperature rise may occur inside the housing due to the DC / MW power supply (approximately half of the power consumed by the microwave amplifier is dissipated as heat within the amplifier itself). Various fans are used to cool microwave generator 110, and these fans can be dynamically controlled based on temperature (e.g., when microwave generator 110 is cooler, the fan speed may be lower to minimize fan noise, while when the module temperature inside the generator rises, the fan speed can be increased to deliver better cooling performance).

[0126] The formulas and methods described above are not limited to the scope of this disclosure. Algorithms using exponential or logarithmic functions and using more than four temperature variables from the microwave generator 110, as well as consideration of cooling fan speed, are also envisioned. Additionally, to obtain better ambient temperature readings, an embodiment is envisioned in which the user is instructed to place the tip of the remote thermocouple probe 140 on a metal plate or similar feature on the front panel of the microwave generator 110. This measurement can further improve the calibration algorithm with a higher confidence ambient temperature reading (instead of using SCM temperature).

[0127] While several embodiments of this disclosure are shown in the accompanying drawings and / or discussed herein, they are not intended to limit the disclosure thereto, as the aim is that the scope of the disclosure should be as broad as permitted by the art, and this specification should be read in the same manner. Therefore, the above description should not be construed as restrictive, but rather as exemplary of particular embodiments only. Other modifications within the scope and spirit of the appended claims will be contemplated by those skilled in the art.

Claims

1. A microwave generator, the microwave generator comprising: a system controller module configured to control the microwave generator; a microwave module configured to generate microwave energy; a remote thermocouple module configured to determine a temperature value of a remote thermocouple probe, RTP_meas; wherein at least one of the system controller module or the remote thermocouple module is configured to: determine a temperature value of the remote thermocouple module, RTM; determine a temperature value of the system controller module, SCM; determine a temperature value of the microwave module, MWM; and calculate a corrected temperature value, RTP_corrected, based on at least one of the determined temperature value of the remote thermocouple probe, RTP_meas, the determined temperature value of the system controller module, SCM, and the determined temperature value of the remote thermocouple module, RTM, or the determined temperature value of the microwave module, MWM.

2. The microwave generator of claim 1, wherein, The corrected temperature value, RTP_corrected, is calculated using the following equation: RTP_corrected = RTP_meas - C1 * (RTM - SCM), where C1 = 0.

3.

3. The microwave generator of claim 1, wherein, at least one of the system controller module or the remote thermocouple module is configured to determine whether the microwave generator is in an idle state or an active state.

4. The microwave generator of claim 3, wherein: when it is determined that the microwave generator is in the idle state, the corrected temperature value, RTP_corrected, is calculated using the following equation: RTP_corrected = RTP_meas - C1 * (RTM - SCM), where C1 = 0.3; and when it is determined that the microwave generator is in the active state, the corrected temperature value, RTP_corrected, is calculated using the following equation: RTP_corrected = RTP_meas - C2 * (MWM - SCM), where C1 = 0.

13.

5. The microwave generator of claim 3, wherein: when it is determined that the microwave generator is in the idle state and not within 120 seconds of deactivation, the corrected temperature value, RTP_corrected, is calculated using the following equation: RTP_corrected = RTP_meas - C1 * (RTM - SCM), where C1 = 0.3; and when it is determined that the microwave generator is in the idle state and within 120 seconds of deactivation, the corrected temperature value, RTP_corrected, is calculated using the following equation: RTP_corrected = RTP_meas - C6 * (RTM - SCM), where C6 = 0.

19.

6. The microwave generator of claim 3, wherein: when it is determined that the microwave generator is in the active state and within 10 seconds of activation, the corrected temperature value, RTP_corrected, is calculated using the following equation: RTP_corrected = RTP_measured - C1 * (RTM - SCM) - C2 * (MWM - SCM), where C1 = 0.3 and C2 = 0.

26.

7. The microwave generator of claim 3, wherein: when it is determined that the microwave generator is in the active state and between 10 and 30 seconds of activation, the corrected temperature value RTP_corrected is calculated using the following equation: RTP_corrected = RTP_measured - C1 * (RTM - SCM) - C3 * (MWM - SCM), where C1 = 0.3 and C3 = 0.

21.

8. The microwave generator of claim 3, wherein: when it is determined that the microwave generator is in the active state and between 30 and 120 seconds of activation, the corrected temperature value RTP_corrected is calculated using the following equation: RTP_corrected = RTP_measured - C1 * (RTM - SCM) - C4 * (MWM - SCM), where C1 = 0.3 and C4 = 0.15; and when it is determined that the microwave generator is in the active state and after 120 seconds of activation, the corrected temperature value RTP_corrected is calculated using the following equation: RTP_corrected = RTP_measured - C1 * (RTM - SCM) - C5 * (MWM - SCM), where C1 = 0.3 and C5 = 0.

09.

9. The microwave generator of claim 1, wherein, at least one of the system controller module or the remote thermocouple module is further configured to determine an elapsed activation time (T) and an output power level of the microwave generator (P), wherein the corrected temperature value RTP_corrected is calculated using the following equation: RTP_corrected = RTP_measured - C1 * (RTM - SCM) - P * 1 / T * C2 * (MWM - SCM), where C1 = 0.3 and C2 = 0.

02.

10. A non-transitory computer readable storage medium storing instructions that, when executed by a processor, cause the processor to perform a method for calculating a corrected temperature value, the method comprising: determining a measured temperature value RTP_measured from a remote thermocouple probe; determining a temperature value RTM of a remote thermocouple module; determining a temperature value SCM of a system controller module; determining a temperature value MWM of a microwave module; and calculating the corrected temperature value RTP_corrected based on at least one of the determined temperature value RTP_measured of the remote thermocouple probe, the determined temperature value SCM of the system controller module, and the determined temperature value RTM of the remote thermocouple module or the determined temperature value MWM of the microwave module.

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