Patent Description:
Treatment of certain diseases requires the destruction of malignant tissue growths, e.g., tumors. Electromagnetic ("EM") radiation can be used to heat and destroy tumor cells. Treatment may involve inserting ablation probes into or adjacent to tissues where cancerous tumors have been identified. Once the probes are positioned, electromagnetic energy is passed through the probes into surrounding tissue to treat, e.g., heat, ablate and/or coagulate tissue.

EM ablation probes may require cooling to operate within desired parameters without damaging the ablation device or causing unintended tissue damage. Some probes implement cooling systems including a peristaltic pump that circulates a cooling fluid through a tubing system and the ablation probe, such that heat is drawn away from the ablation probe. Cooling the ablation probe may enhance the overall ablation pattern, prevent damage to the probe, and prevent harm to the clinician or patient.

However, during operation, if the flow of cooling fluid is interrupted or becomes irregular, the ablation probe may exhibit failure or reduced performance. In <CIT>, a surgical pump system arrangement receives an inflow cassette and provides fluid flow to a surgical site in a joint of a patient. In <CIT>, electrode assemblies actively cool mucosal surface tissue at or near a sphincter while applying energy through an electrode to heat tissue beneath the surface. In <CIT>, a heat exchanger catheter for controlling body temperature is described.

Disclosed is a method of determining the status of a fluid cooled microwave ablation system. The method includes providing an electrical current to a pump to pump fluid through an ablation system along a fluid path to cool the ablation system, measuring an electrical current drawn by the pump, and determining a status of the ablation system based on the measured electrical current.

Determining the status of the ablation system may include determining whether the measured electrical current is within a predetermined range.

If the measured electrical current is outside the predetermined range, operation of the ablation system may be adjusted.

Adjusting operation of the ablation system may include inhibiting the pumping of fluid through the ablation system.

Adjusting operation of the ablation system may include inhibiting supplying of energy to the ablation system.

If the measured electrical current is outside the predetermined range, an alert may be provided.

The alert may be displayed on a display screen.

The electrical current may be displayed on the display screen.

Determining the status may include determining whether the ablation system is functioning normally or abnormally.

Determining that the ablation system is functioning abnormally may indicate at least one of a blockage or a leakage in the ablation system.

Provided in accordance with an aspect of the present disclosure is an ablation system including an ablation probe defining a fluid path for circulation of fluid therethrough, a generator configured to supply energy to the ablation probe for treating tissue, a pump configured to pump fluid through the fluid path of the ablation probe to cool the ablation probe, a sensor configured to measure an electrical current drawn by the pump, and a computing device configured to determine a status of the ablation system based on the measured electrical current.

In another aspect of the present disclosure, the computing device is configured to determine the status of the ablation system by determining whether the measured electrical current is within a predetermined range.

In still another aspect of the present disclosure, the computing device is further configured, if the measured electrical current is outside the predetermined range, to inhibit the pump from pumping of fluid through the ablation probe.

In still yet another aspect of the present disclosure, the computing device is further configured, if the measured electrical current is outside the predetermined range, to inhibit the supply of energy from the generator to the ablation probe.

In another aspect of the present disclosure, the computing device is further configured, if the measured electrical current is outside the predetermined range, to provide an alert.

In yet another aspect of the present disclosure, a display screen is configured to display the alert.

In still another aspect of the present disclosure, the display screen is further configured to display the measured electrical current.

In still yet another aspect of the present disclosure, in determining the status, the computing device is configured to determine whether the ablation system is functioning normally or abnormally.

In another aspect of the present disclosure, a determination by the computing device that the ablation system is functioning abnormally indicates at least one of a blockage or a leakage in the ablation system.

Objects and features of the present disclosure will become apparent to those of ordinary skill in the art when descriptions of various embodiments thereof are read with reference to the accompanying drawings, of which:.

Measuring parameters of a pump used to circulate fluid through a fluid cooled microwave ablation assembly can be useful in determining the status of the cooling system. Specifically, the electrical current drawn by the pump can provide useful information, e.g., how much fluid is being used, the condition of components in the system, an assessment of energy being delivered by the fluid cooled microwave ablation antenna assembly, and/or whether or not the cooling system is operating within established parameters. These and other aspects and features of the present disclosure are detailed herein below.

Referring now to <FIG>, an exemplary fluid cooled microwave ablation system <NUM> of the present disclosure is depicted. The microwave ablation system <NUM> includes a computing device <NUM> storing one or more ablation planning and electromagnetic tracking applications, a touch display computer <NUM> which is an integrated computing device and display system controlling microwave ablation generator <NUM> via one or more user interfaces and a touch sensitive screen, an operating table <NUM>, including an electromagnetic (EM) field generator <NUM>, a second display <NUM>, an ultrasound imaging sensor <NUM>, an ultrasound workstation <NUM>, a fluid cooled microwave ablation antenna assembly <NUM>, and a base unit <NUM> configured to support computing device <NUM>, the microwave ablation generator <NUM> the touch display computer <NUM>, and the antenna assembly <NUM>. Computing devices described herein may be, for example, a laptop computer, desktop computer, tablet computer, or other similar device. Touch display computer <NUM> is configured to control microwave generator <NUM> (see <FIG>), pump <NUM> (see <FIG>) and other accessories and peripheral devices relating to, or forming part of, fluid cooled microwave ablation system <NUM>. Touch display computer <NUM> is configured to present a user interface enabling a clinician to input instructions and setting for the microwave ablation generator <NUM>, display images, and/or messages relating to the performance of the microwave ablation generator <NUM>, the progress of a procedure, and issue alarms or alerts related to the same.

Operating table <NUM> may be any table suitable for use during a surgical procedure, which in certain embodiments includes or is associated with an EM field generator <NUM>. EM field generator <NUM> is used to generate an EM field during the microwave ablation procedure and forms part of an EM tracking system, which is used to track the positions of surgical instruments, e.g., microwave ablation antenna assembly <NUM> and ultrasound sensor <NUM>, within the EM field around and within the body of a patient. Second display <NUM> (<FIG>), in association with computing device <NUM>, may be used for displaying ultrasound imaging and providing visualization of tissue to be treated as well as navigation of the fluid cooled microwave ablation antenna assembly <NUM>. However, it is envisioned that touch display computer <NUM> and computing device <NUM> may also be used for ultrasound imaging and navigation purposes in addition to its microwave ablation generator <NUM> control functions discussed above.

As will be described in more detail below (<FIG> and <FIG>), microwave ablation antenna assembly <NUM> is used to ablate tissue, e.g., a lesion or tumor (hereinafter referred to as a "target"), by using microwave energy to heat tissue in order to denature or kill cancerous cells. Further, although an exemplary microwave ablation antenna assembly <NUM> is detailed herein, it is contemplated that other suitable microwave ablation probes may be utilized in accordance with the present disclosure. For example, the ablation probes and systems described in <CIT>, International Application No. <CIT>, <CIT>, and <CIT>, the entire contents of each of which are incorporated herein by reference, may be used in conjunction with the aspects and features of the present disclosure.

In addition to the EM tracking system, the surgical instruments, e.g., microwave ablation antenna assembly <NUM>, may also be visualized by using ultrasound imaging work station <NUM>. Ultrasound sensor <NUM>, such as an ultrasound wand, may be used to image the patient's body during the microwave ablation procedure to visualize the location of microwave ablation antenna assembly <NUM> inside the patient's body. Ultrasound sensor <NUM> may have an EM tracking sensor embedded within or attached to the ultrasound wand, for example, a clip-on sensor or a sticker sensor. Ultrasound sensor <NUM> may be positioned in relation to microwave ablation antenna assembly <NUM> such that microwave ablation antenna assembly <NUM> is at an angle to the ultrasound image plane, thereby enabling the clinician to visualize the spatial relationship of microwave ablation antenna assembly <NUM> with the ultrasound image plane and with objects being imaged. Further, the EM tracking system may also track the location of ultrasound sensor <NUM>. This spatial depiction of the ultrasound sensor <NUM> and the microwave ablation antenna assembly <NUM> is described in greater detail in <CIT> which is incorporated herein by reference. During surgery, one or more ultrasound sensors <NUM> may be placed on or inside the body of the patient. EM tracking system may then track the location of such ultrasound sensors <NUM> and microwave ablation antenna assembly <NUM> as they are moved relative to each other.

Turning now to <FIG>, a system diagram of computing device <NUM> and touch display computer <NUM> of system <NUM> are generally depicted. Computing device <NUM> and touch display computer <NUM> may include memory <NUM>, processor <NUM>, display <NUM> or <NUM>, network interface <NUM>, input device <NUM>, and/or output module <NUM>. Memory <NUM> includes any non-transitory computer-readable storage media for storing data and/or software that is executable by processor <NUM> and which controls the operation of computing device <NUM>. Processor <NUM> may be a general purpose processor, a specialized graphics processing unit (GPU) configured to perform specific graphics processing tasks while freeing up the general purpose processor to perform other tasks, and/or any number or combination of such processors. As noted above with respect to touch display computer <NUM>, display <NUM> may be touch sensitive and/or voice activated, enabling display <NUM> or <NUM> to serve as both an input and output device. Alternatively, a keyboard (not shown), mouse (not shown), or other data input devices may be employed.

Network interface <NUM> may be configured to connect to a network such as a local area network (LAN) consisting of a wired network and/or a wireless network, a wide area network (WAN), a wireless mobile network, a Bluetooth network, and/or the internet. For example, computing device <NUM> or and touch display computer <NUM> may receive computed tomographic (CT) image data of a patient from a server, for example, a hospital server, internet server, or other similar servers, for use during surgical ablation planning. Patient CT image data <NUM> may also be provided to computing device <NUM> and touch display computer <NUM> via memory <NUM>. Computing device <NUM> may receive updates to its software, for example, application <NUM>, via network interface <NUM>. Computing device <NUM> may also display notifications on display <NUM> or <NUM> that a software update is available. Input device <NUM> may be any device by means of which a user may interact with computing device <NUM> or and touch display computer <NUM>, such as, for example, a mouse, keyboard, foot pedal, touch screen, and/or voice interface. Output module <NUM> may include any connectivity port or bus, such as, for example, parallel ports, serial ports, universal serial busses (USB), or any other similar connectivity port known to those skilled in the art.

Application <NUM> may be one or more software programs stored in memory <NUM> and executed by processor <NUM> of computing device <NUM> or touch display computer <NUM>. Referring also to <FIG>, computing device <NUM> may be linked to touch display computer <NUM>, thus enabling computing device <NUM> to control the output on and touch display computer <NUM> along with the output on second display <NUM>. Computing device <NUM> may control touch display computer <NUM> to display output which is the same as or similar to the output displayed on second display <NUM>. For example, the output on display <NUM> may be mirrored on touch display computer <NUM>. Alternatively, as described above computing device <NUM> may control second display <NUM> to display different output from that displayed on touch display computer <NUM>. For example, second display <NUM> may be controlled to display guidance images and information during the microwave ablation procedure, while touch display computer may display other output, such as configuration or status information see (<FIG>).

Referring now to <FIG>, microwave ablation antenna assembly <NUM>, microwave ablation generator <NUM>, touch display computer <NUM>, and peristaltic pump <NUM> are depicted schematically as housed on base unit <NUM> of system <NUM> (<FIG>) are illustrated. Microwave ablation antenna assembly <NUM> is coupled to a microwave generator <NUM> via a flexible coaxial cable <NUM>. Microwave generator <NUM> is configured to provide microwave energy at an operational frequency from about <NUM> to about <NUM>, although other suitable frequencies are also contemplated. Microwave ablation antenna assembly <NUM> may include a connection hub <NUM> for connection of coaxial cable <NUM>, as well as the connection of a fluid inlet port <NUM> and a fluid outlet port <NUM>. Fluid inlet port <NUM> permits the ingress of fluid into the microwave ablation antenna assembly <NUM> for cooling of components housed therein and control of the energy dissipation of microwave energy. Fluid outlet port <NUM> permits the egress of the fluid following circulation of the fluid through the microwave ablation antenna assembly <NUM>.

The ports <NUM> and <NUM> are also coupled to a pump <NUM> that is, in turn, coupled to a supply tank <NUM> via a connection line 119a. Supply tank <NUM> may be a fluid filled bag (e.g., saline), as depicted in <FIG>, or any other type of storage unit for any type of fluid. Pump <NUM> may be a positive displacement pump, such as a peristaltic pump. The supply tank <NUM> stores the fluid and may maintain the fluid at a predetermined temperature. The supply tank <NUM> may include a coolant unit (not explicitly shown) that cools returning liquid from the microwave ablation antenna assembly <NUM>. In another embodiment, the fluid may be a gas and/or a mixture of liquid and gas. Pump <NUM> forces fluid from supply tank <NUM> through a supply line 119b into microwave ablation antenna assembly <NUM>, such that heat is drawn away from the microwave ablation antenna assembly <NUM>, which may enhance the overall ablation pattern, prevent damage to microwave ablation antenna assembly <NUM>, and prevent harm to the clinician or patient. The fluid is returned to pump <NUM> and, ultimately, supply tank <NUM>, via return line 119c and pump return line 119d.

<FIG> illustrates the distal portion <NUM> of the microwave ablation antenna assembly <NUM>. Distal portion <NUM> of microwave ablation antenna assembly includes a proximal radiation portion <NUM> having a length "L1," and a distal radiation portion <NUM> having a length "L2," including an electrically-conductive radiator <NUM> and a feed point <NUM> disposed between the proximal and distal radiating portions <NUM> and <NUM>. A feedline <NUM> is formed of a coaxial cable having an inner conductor <NUM>, and outer conductor <NUM>, and a dielectric <NUM> separating the two. The feedline <NUM> is connected at its proximal end to flexible cable <NUM> (<FIG>). The distal radiating portion <NUM> and the proximal radiation portion <NUM> may be either balanced (e.g., of equal lengths) or unbalanced (e.g., of unequal lengths). The proximal radiating portion <NUM> may be formed of a portion of the feedline <NUM>, and particularly the outer conductor <NUM> extending between a balun <NUM> and the feedgap <NUM>.

Referring still to <FIG>, microwave ablation antenna assembly <NUM> also includes a balun (also called a choke) <NUM> disposed around the feedline <NUM>. The balun <NUM> may be a quarter-wavelength balun formed of at least a dielectric layer <NUM> and a conductive layer <NUM>. The conductive layer <NUM> may be shorted to the feedline <NUM> at the proximal end of the balun <NUM> by soldering or other suitable methods, or may be in electrical contact with a balun short <NUM> which itself is in electrical contact with the outer conductor <NUM> of the feedline <NUM>. Microwave ablation antenna assembly <NUM> also includes a tip <NUM> having a tapered end <NUM> that terminates, in one embodiment, at a pointed end <NUM> to allow for insertion into tissue with minimal resistance. In cases where the microwave ablation assembly <NUM> is inserted into a pre-existing opening, tip <NUM> may be rounded or flat. The tip <NUM> may be formed from a variety of heat-resistant materials suitable for penetrating tissue, such as metals (e.g., stainless steel) and various thermoplastic materials, such as poletherimide, and polyamide thermoplastic resins.

The microwave ablation antenna assembly <NUM> includes fluid channels <NUM> and <NUM>. Fluid channel <NUM> is spaced between the feedline <NUM> (including its electrically connected components balun <NUM> and proximal and distal radiating portions <NUM> and <NUM>) and an inner tube <NUM>. Fluid channel <NUM> is formed between the inner tube <NUM> and an outer cannula <NUM> of the microwave ablation antenna assembly <NUM>. Fluid channel <NUM> connects to fluid inlet port <NUM> and fluid channel <NUM> connects to fluid outlet port <NUM>, thereby completing a fluid circuit from the fluid tank <NUM>, through the pump <NUM> and through the microwave antenna ablation assembly <NUM>.

Referring back to <FIG>, a power source provides power to base unit <NUM>, while computing device <NUM> controls the operation of microwave generator <NUM> and peristaltic pump <NUM> of base unit <NUM>. A current sensor <NUM> operably connected with computing device <NUM> measures the electrical current drawn by peristaltic pump <NUM> during operation thereof. Computing device <NUM> may then adjust energy output from generator <NUM> (or to microwave ablation antenna assembly <NUM>) and/or the power supplied to peristaltic pump <NUM> (to thereby vary the rate at which pump <NUM> operates) based on the sensed electrical current drawn by peristaltic pump <NUM>, as will be described in more detail below.

Referring now to <FIG>, in conjunction with <FIG>, a method <NUM> of determining the status of a fluid cooled treatment system is provided in accordance with the present disclosure. Although detailed with respect to fluid cooled microwave ablation system <NUM> (<FIG>), method <NUM> may be used in conjunction with any other suitable fluid cooled treatment system. Method <NUM> may be implemented by a software program(s) or sub-program(s) loaded onto and/or integrated into application <NUM> of computing device <NUM>.

Method <NUM> initially includes powering on the system <NUM> at S510. Powering on the system may include, for example, turning on computing device <NUM>, base unit <NUM>, and/or pump <NUM>, selecting an application <NUM>, using ultrasound workstation <NUM> to properly place microwave ablation antenna assembly <NUM> in the appropriate surgical site, and energizing microwave ablation antenna assembly <NUM> to emit microwave radiation therefrom for treating tissue therewith. Method <NUM> further includes, at S520, supplying fluid from a fluid supply to cool the system. More specifically, at S520, power from the power supply is drawn by pump <NUM> to pump fluid from fluid supply <NUM> to microwave ablation antenna assembly <NUM> via supply line 119b, and to return the fluid from microwave ablation antenna assembly <NUM> to fluid supply <NUM> via return line 119c. In embodiments, supplying fluid (S520) may alternatively be performed before or simultaneously with powering on the system (S510).

At S530, the electrical current drawn by pump <NUM> is measured. More specifically, current sensor <NUM> is utilized to measure the electrical current drawn by pump <NUM> from the power supply and to relay the same to computing device <NUM>. Measuring the electrical current at S530 may be performed continuously or periodically, and may begin upon initiation of the supply of fluid (S520) or at any other suitable point during use.

Based upon the sensed electrical current (S530), the status of fluid cooled microwave ablation system <NUM> is determined at S540. Determining the status may include determining whether pump <NUM> is operating within established parameters (based upon the currently drawn by pump <NUM>), which, in turn, may indicate whether system <NUM> is operating normally. If the electrical current drawn by pump <NUM> is outside normal operating parameters, computing device <NUM> may inhibit further operation of system <NUM>, or provide an alert to a user, as such may indicate a problem, e.g., that there is an improper connection in supply line 119b or return line 119c, and/or that there is a blockage or leakage in the system <NUM>.

Method <NUM>, as detailed above, is utilized to determine the status of system <NUM> based upon the current drawn by the pump <NUM> thereof. This is based upon the fact that the current drawn by the pump <NUM> is indicative of the pressure and flow rate of the fluid being pumped through the system <NUM>. More specifically, a greater electrical current draw by pump <NUM> is required to pump the fluid at an increased pressure and/or flow rate. Likewise, less electrical current drawn by pump <NUM> is needed to pump the fluid at a reduced pressure and/or flow rate. As such, electrical current drawn by pump <NUM> may be correlated to fluid flow rate and/or pressure, and, thus, may be a useful in determining the status of system <NUM>.

For example, an increased current draw may indicate increased pressure, which may be the result of a blockage (or partial blockage) within the system <NUM>. The blockage may be the result of a person (e.g., clinician) unintentionally standing and/or sitting on supply line 119b or return line 119c or an object being disposed within, on, or over supply line 119b or return line 119c thereby inhibiting flow therethrough. A decreased current draw may indicate reduced pressure, which may be the result of a faulty connection, leakage, or lack of fluid within the system <NUM>. As can be appreciated in view of the above, by monitoring the electrical current drawn by pump <NUM>, damage to the system <NUM> as well as harm to the clinician or patient may be prevented. Monitoring the electrical current drawn by pump <NUM> may be more advantageous than, for example, monitoring temperature from a temperature sensor on microwave ablation antenna assembly <NUM>, because, while useful, temperature may be a lagging indicator of a problem whereas pump current draw is a leading indicator that there may be an immediate issue within system <NUM>.

Computing device <NUM> may continually monitor, record, measure, determine and/or display the electrical current drawn by pump <NUM> at any and all times before and/or during a procedure. Upon determining that the electrical current drawn by pump <NUM> is outside normal operating parameters, computing device <NUM> may inhibit further operation of system <NUM> or provide an alert to a user, warning of a potentially unsafe condition. The alert may be in the form of visual, audible, and/or tactile feedback (<FIG>, described in more detail below).

Referring still to <FIG> and <FIG>, computing device <NUM> may store normal operating range data of the current drawn by the pump <NUM> when used with system <NUM> and, during use, compare this range to the sensed data from current sensor <NUM> to determine if system <NUM> is operating normally. This data may be determined experimentally, empirically based upon the components utilized, or in any other suitable manner. In embodiments, manufacturer performance data for pump <NUM> (e.g., performance curves) and any or all of the other components of system <NUM>, e.g., microwave ablation antenna assembly <NUM>, the tubing (lines 119b, 119c), the fluid supply <NUM>, the particular fluid, etc., may be input into computing device <NUM> and/or application <NUM>. Such data may be used to calculate the normal operating range data for that particular system <NUM> set-up. Computing device <NUM> may compare this normal operating range data to real time data (determined by computing device <NUM> using current sensor <NUM>) to determine if the real-time data falls within, above, or below the normal operating range. Should the real time data fall outside the acceptable ranges, a blockage, leakage, or other problem (e.g., tubing not properly placed in pump head, pump head door not closed, incompatible pump tubing used with system, defective pump tubing used with system, etc.) in the system <NUM> may be present which causes the pump <NUM> to need to work harder or not as hard (as reflected by the current drawn by the pump <NUM>).

Computing device <NUM> may also make calculations and/or determinations based on the specifications of the pump <NUM> used in fluid cooled treatment system <NUM>. For example, if pump <NUM> is a peristaltic pump, then computing device may calculate flow rate based on peristaltic pump's <NUM> tube inner diameter(s), outer diameter(s), pump head RPM, or occlusion, which computing device <NUM> may then compare to the electrical current data from pump <NUM>, such that the status of fluid cooled treatment system <NUM> may be determined.

In an embodiment, computing device <NUM> may be able to determine and display (<FIG>) the type of ablation probe being used during the procedure. Since each type of ablation probe is rated for a specific electrical current usage (e.g., watts), computing device <NUM> may determine the type of device that is connected to fluid cooled treatment system <NUM> by using the electrical current profile of microwave ablation antenna assembly <NUM> as a metric. For example, touch display computer <NUM> (<FIG>) may indicate whether the microwave ablation antenna assembly <NUM> connected to fluid cooled treatment system <NUM> is a short length (<NUM>), standard length (<NUM>), or long length (<NUM>), each of which have unique electrical current profiles e.g., that are specific to the length of their respective probes.

With continued reference to <FIG>, a safety protocol SP550 may be implemented with method <NUM> to prevent an unsafe condition to the clinician or patient. Safety protocol SP550 of computing device <NUM> may compare the electrical current drawn by pump <NUM> to a known, safe range. With safety protocol SP550 in use, electrical current data by pump <NUM> is provided to computing device <NUM>, which may represent a real-time measurement. If the electrical current drawn by pump <NUM> is within a predetermined range (normal operating range), computing device <NUM> may control the fluid cooled treatment <NUM> to continue with the ablation procedure. If the electrical current is outside the predetermined range, safety protocol SP550 of computing device <NUM> may implement an interlock to cease the ablation procedure, provide an alert, and/or modify the operation of microwave generator <NUM> and/or pump <NUM>.

Moreover, if the temperature of microwave antenna assembly <NUM> is out of a normal range, fluid cooled treatment system <NUM> and/or computing device <NUM> may adjust the electrical current to pump <NUM> to maintain the temperature within a normal range. As such, the current of pump <NUM> and temperature feedback of microwave ablation antenna assembly <NUM> may be used to avoid an overshoot and/or undershoot of both flow rate and device temperature. The power level of microwave generator <NUM> may also be automatically adjusted based on the temperature of microwave ablation antenna assembly <NUM> and electrical current drawn from pump <NUM>. All of the aforementioned systems may be interdependent and managed to maintain a desirable system state. In addition, the supplying of energy to microwave ablation antenna assembly <NUM> may be delayed until coolant from fluid cooled treatment system <NUM> has been primed, such that an unsafe condition may be avoided. The predetermined range of electrical current drawn by pump <NUM> may correspond to a normal range of fluid flow rates and/or pressures through supply line 119b (<FIG>), return line 119c (<FIG>) provided in application <NUM> of computing device <NUM>.

Referring now to <FIG>, an example screen <NUM>, which may be displayed on touch display computer <NUM> or display <NUM> during a microwave ablation procedure, is shown. Screen <NUM> includes a view <NUM> of the live 2D ultrasound images captured during the procedure. Screen <NUM> further includes a view <NUM> for showing transient messages relating to the ablation procedure. Screen <NUM> may include a view <NUM> for displaying status messages relating to electrical current drawn by pump <NUM>, which, as detailed above, may be indicative of leakages, blockages, or other system problems. By way of another example, view <NUM> may indicate whether fluid cooled treatment system <NUM> is operating normally. View <NUM> may also display other useful information, such as the temperature, elapsed time of the procedure, and the output from the electrosurgical generator (indicated here in watts),.

Claim 1:
An ablation system (<NUM>), comprising:
an ablation probe (<NUM>) defining a fluid path for circulation of fluid therethrough;
a generator (<NUM>) configured to supply energy to the ablation probe for treating tissue;
a pump (<NUM>) configured to pump fluid through the fluid path of the ablation probe to cool the ablation probe; characterised in that the system further comprises:
a sensor (<NUM>) configured to measure an electrical current drawn by the pump; and
a computing device (<NUM>) configured to determine a status of the ablation system based on the measured electrical current.