Patent Description:
In most energy-based treatment systems, such as electromagnetic ablation systems using microwaves, radiation is delivered from a radiation generator, via a connecting cable, to a radiation delivering applicator placed in or on a tissue.

A microwave radiation delivery system <NUM> for treating biological tissue is shown in <FIG>. The system has a microwave generator <NUM> for generating microwave radiation, a flexible interconnecting cable <NUM> and a microwave applicator <NUM>.

Typically, the applicator <NUM> is inserted deep within the tissue when treating internal organs, for example hepatic tumour ablation. When treating the tissue on the surface such as skin tissue for a dermatological condition, the applicator is placed on the tissue externally and radiation is delivered to the surface.

Dermatological conditions such as small warts and papilloma exhibit an area of abnormal growth that is relatively small in size, for example a diameter of less than <NUM> or an active area of <NUM><NUM> or less. In the following, the term lesion is used to refer collectively to a surface area of biological tissue affected with an adverse biological condition. Treating these conditions with radiation devices is achievable with an applicator possessing a radiating or effective area identical in size or slightly bigger than the lesions. This helps deliver the radiation to the entire surface of the lesion in a single session.

Similarly, multiple smaller lesions can be treated individually by applying radiation with a variable magnitude usually depending upon the severity and requirement for treatment of the condition. However, the distribution of energy density may possibly be uneven on the surface of the lesion resulting in under and over treatment. It may also result in treating healthy tissue surrounding the lesion.

On the other hand, many biological conditions such as psoriasis, eczema, dermatitis are relatively larger in size and comprise a large surface area that requires treatment. To target these lesions with an applicator that is smaller in size than the lesion requires multiple treatments of the affected area to ensure sufficient coverage. A significant drawback of this approach may be over-treating certain areas resulting in undesirable events such as damage to the tissue, for example, this may lead to hematoma, blistering. Another drawback to multiple single treatments may be under-treatment of a certain area leaving behind the affected condition partially untreated. Performing multiple single treatments may also be time-consuming.

As an alternative, a smaller applicator may be moved continuously on the lesion surface with a simultaneous radiation of energy. This may be more efficient however, this may lead to an uneven treatment of the lesion. An uneven energy density in the region being treated may compromise the efficacy of the treatment.

One way to address the issue of using small applicators to treat a large lesion may be to utilise applicators of a larger size so as to cover the entire region of the affected area. However, considering the variations in the sizes of these biological conditions within a patient and across a spectrum of patients, it may be impractical to design and manufacture such bespoke applicators based upon the size and shape of a range of lesions. <CIT> describes an applicator which mechanically vibrates when RF power is applied. <CIT> describes a dynamic ablation device. <CIT> describes a movable microwaveable applicator. <CIT> describes using an ablation path. <CIT> describes a surgical instrument navigation system.

In accordance with a first aspect of the invention, there is provided a microwave system, comprising:.

The controller is configured to control one or more operational parameters of the microwave generator when the applicator is at a position based on the time elapsed since the applicator was previously at said position.

The controller may be configured to monitor sensor output from the one or more sensors, for example, as the applicator is moved relative to the surface.

The one or more sensors may be further configured for sensing at least one of a position, an orientation, an acceleration, a speed and/or a velocity of the surface.

The controller may be configured to control the one or more operational parameters thereby to maintain, increase and/or decrease a power or energy of the generated microwave radiation in response to the applicator being moved relative to the surface. The controller may be configured to deliver microwave radiation to the surface in accordance with a pre-determined dosage.

The controller may be configured to control the one or more operational parameters thereby to maintain, increase and/or decrease a power or energy of the generated microwave radiation in response to the applicator being moved relative to the surface thereby to provider microwave radiation to the surface in accordance with a pre-determined dose. The dose may comprise, for example, a distribution of energy in space, or a distribution of energy in time.

The controller may be configured to change the one or more operational parameters in response to a change in one or more of the position, orientation, velocity, or acceleration of the applicator.

The controller may be configured to control the one or more operational parameters of the microwave generator such that the microwave radiation delivered across the surface comprises a substantially constant energy density.

The controller may be configured to control the one or more operational parameters of the microwave generator based on the sensor output so that the delivered microwave radiation maintains a temperature of the surface within a pre-determined temperature window.

The controller may be further configured to cut-off the microwave radiation or at least reduce the amount of microwave radiation that is generated by the microwave generator in response to at least one of:.

The microwave applicator may be coupled to the microwave generator by a cable assembly.

The generated microwave radiation may comprise a series of pulsed microwave signals and the controller is configured to control the generation of microwave radiation by varying one or more pulse parameters. The one or more pulse parameters may comprise at least one of: a pulse width, a pulse frequency, a pulse height, a pulse duration.

The generated microwave radiation may comprise modulated microwave signals and the controller is configured to control the generation of microwave radiation by varying one or more modulation parameters.

The modulated microwave signals may be modulated in accordance with a modulation scheme to vary the average power delivered. The modulation scheme may comprise at least one of: amplitude modulation pulsing, pulse-width modulation and/or on off keying. The output may be modulated by control of linear gain to create a variable amplitude control of power.

The microwave applicator may be moveable by a user.

The controller may be further configured to control the microwave generator so that that the applicator delivers microwave radiation to a pre-determined treatment region of the tissue surface. The controller may be configured to reduce the microwave radiation generated when the applicator is outside the treatment region. The treatment region may be in two-dimensions or three dimensions. The treatment region may be a treatment area or a treatment volume. The treatment region may be a two-dimensional surface in three-dimensional space. The treatment area may have a height parameter.

The system may further comprise mapping circuitry configured to receive sensor output obtained during a mapping process and to determine said treatment region based at least on said sensor output. The treatment region may be a three dimensional volume. Determining the treatment region may comprise projecting three dimensional coordinates to a two dimensional surface. The treatment region may be represented by two-dimensional or three dimensional co-ordinates. The treatment region may be represented by one or more of height, width and/or length of the treatment region.

More than one treatment region may be determined. The generator may be controlled to generate microwave radiation comprising surface radiation densities for each respective treatment region.

The mapping process may comprise moving the applicator to trace a boundary of the treatment area in a two or three dimensional coordinate system.

The microwave generator may be configured to delivery microwave radiation comprising a frequency between <NUM> and <NUM>, optionally wherein the frequency is about <NUM>, about <NUM>, about <NUM>, about <NUM>, or about <NUM>.

The generated microwave power could range from <NUM>. 1W to 100W but preferentially between 1W to 20W. The treatment time may range from one thousandth of a second to <NUM> and <NUM> to <NUM> but preferably between <NUM>-<NUM>. Surface power density may range from 1mW/mm<NUM> to 20W/mm<NUM>. Surface energy density may range from 1mJ/mm<NUM> to 200J/mm<NUM>.

The microwave generator may be configured to deliver one of microwave radiation at a fixed frequency, microwave radiation at a variable frequency and/or modulated microwave radiation.

The microwave applicator may comprise a radiating antenna.

The system may further comprise an indicator for providing an indication in response to at least one of the one or more sensor outputs being above and/or below a threshold.

At least one of the controller and sensors may be provided as part of the applicator.

Wireless communication means may be provided for wirelessly communicating sensor data between the applicator and the controller.

The one or more sensors may be configured to sense data in <NUM> degrees of freedom.

The one or more sensors may comprise at least one of:
inertial measurement unit (IMU) sensors, Microelectromechanical systems (MEMS), accelerometer sensor, gyroscope sensor, an optical tracking system, an electromagnetic tracking system, a time of flight system (ToF), a Light Detection and Ranging system (Lidar system), a Doppler radar system.

The system may comprise marker detecting means for detecting the presence and/or position of one or more active or passive markers.

The system may further comprise a display for displaying a 2D or 3D map of the treatment area. The display may be updated based on sensor output to display treated and/or untreated areas. The map may be one of two dimensional, three dimensional or four dimensional.

In accordance with a second aspect of the invention, there is provided a method of controlling a microwave system comprising a microwave applicator configured to deliver microwave radiation generated by a microwave generator to a surface, wherein the microwave applicator is further configured to be moved relative to the surface, wherein the method further comprises:.

In accordance with a third aspect of the invention, there is provided a non-transitory computer readable medium comprising instructions operable by a processor to perform a method of controlling a microwave system, wherein the microwave system comprises a microwave applicator configured to deliver microwave radiation generated by a microwave generator to a surface and the microwave applicator is further configured to be moved relative to the surface, wherein the method comprises:.

Features in one aspect may be applied as features in any other aspect, in any appropriate combination. For example, system features may be provided as method features or vice versa.

Embodiments of the invention are described in relation to the following figures, in which:.

A method and system for treating biological tissue with a controlled energy density using one or more surface applicator types and a modulated power source is hereby described. A large or larger surface region of lesion hereon refers to the surface area of lesion larger than the surface area of an applicator. In the following, the term lesion is used to refer collectively to a surface area of biological tissue affected with an adverse biological condition.

In overview, a system of delivering controlled energy density using a single applicator over a large surface area of tissue is described. The system entails the use of sensors for obtaining position, acceleration and velocity of the applicator, for example, IMU (inertial measurement unit) and/or MEMS (Microelectromechanical systems) accelerometers and gyroscope. The microwave radiation applicator is moved along the surface of tissue continuously and the apparatus uses the motion of the applicator dataset to modify one or more operational parameters of the microwave generator, for example, to increase or decrease the amount of applied power in real time in a closed-loop system thereby to control the generated microwave radiation delivered to the region being treated.

By controlling the source of the microwave radiation, the microwave radiation delivered by the applicator to tissue is controlled and can be delivered in accordance with a pre-determined dose. The dose may include a spatial distribution of radiation or a temporal distribution of radiation. In accordance with embodiments, the energy dose is characterised by the energy density of the radiation delivered by the applicator and this may be, for example, uniform, non-uniform, optimum, or pre-set microwave energy density. The radiation is applied into tissues and/or onto tissue surface for medical applications. Uniform, non-uniform and optimum energy density may also be collectively referred to as a controlled energy density.

By controlling the applied microwave radiation, the over-treatment and/or under-treatment of an affected area may be reduced.

In the following, energy density may refer to the amount of energy in a given volume or area. The energy density can be, for example, a two dimensional or a three-dimensional energy density. The energy density may be have units, for example, of Joules/millimeter<NUM> (J/mm<NUM>) and or Joules/millimeter<NUM> (J/mm<NUM>).

In the following, microwave treatment refers collectively to applying microwave radiation, for example, for inducing therapeutically effective hyperthermia, ablation, sub-ablation, non-ablation, coagulation and non-coagulation in biological tissues.

A microwave radiation delivery system <NUM>, in accordance with embodiments, using closed loop feedback for treating a biological tissue, is illustrated in <FIG>. The system comprises of microwave generator <NUM> for generating microwave radiation, a flexible or rigid interconnecting cable <NUM> and microwave applicator assembly <NUM> for delivering microwave radiation to a biological tissue <NUM>. Microwave applicator assembly <NUM> is equipped with a sensor unit <NUM> which records at least one of position, acceleration, velocity and orientation of the said microwave applicator <NUM>. The microwave applicator assembly <NUM> may also be simply referred to as a microwave applicator. In the present embodiment, the sensor unit is an inertial measurement unit (IMU) and may be referred to as IMU sensor unit <NUM>.

Additionally, in the present embodiment, biological tissue <NUM> is equipped with a further sensor unit <NUM> which records at least one of position, acceleration, velocity and orientation of the biological tissue <NUM>.

A control system unit <NUM>, which may also be referred to simply as a controller, is also provided as part of the system <NUM>. The controller <NUM> is in communication with the sensor unit <NUM>, further sensor unit <NUM> and the microwave generator <NUM>. In the present embodiment, the communication is via wired connections. It will be understood that any suitable connection may be used. The controller <NUM> has monitoring circuitry for monitoring sensor output.

The control system unit <NUM> forms part of a feedback driven closed loop, indicated by <NUM>. The feedback driven closed loop <NUM> monitors and executes controlled radiation delivery from the microwave applicator <NUM> to the biological tissue <NUM> being treated.

Depending on the tissue and/or the condition that is being treated the radiation may be delivered on to a surface or into a surface.

The controller <NUM> has processing circuitry or other suitable processing resource for monitoring sensor output from sensor unit <NUM> and the further sensor unit <NUM>. The processing circuity is configured to process the sensor output and provide control signals to the microwave generator <NUM> based on the monitored sensor output.

In the present embodiment, the processing circuitry is configured to process sensor output from the sensor unit <NUM> and from the further sensor unit <NUM> and provide control signals to the microwave generator <NUM> based on the monitored sensor output.

In other embodiments the processing circuitry is configured to process sensor output from the sensor unit <NUM> and provide control signals to the microwave generator <NUM> based on the monitored sensor output from the sensor unit <NUM>.

The microwave generator <NUM> provides a source of microwave radiation that is provided to the applicator <NUM> via the cable <NUM>. The control signals from the controller <NUM> are representative of instructions to change the operational parameters of the microwave generator <NUM>. The microwave generator <NUM> is controlled by changing or selecting one or more operational parameters.

In some embodiments, the microwave generator <NUM> produces microwave radiation using a series of pulsed signals. The controller <NUM> can control the generation of microwave radiation by varying one or more properties of the pulsed signals, for example, pulse duration, pulse width, pulse frequency, pulse period.

Applied radiation may be in the form of a continuous oscillating electromagnetic wave (CW) at a fixed frequency or a modulated (variable frequency). Pulse regimes include amplitude control of signal energy (AM pulsing) and pulse width modulation control (PWM) and on/off keying (OOK). Modulation schemes include pulse modulation rates (<NUM>-<NUM>) or frequency modulation rate (<NUM>-<NUM>). The radiation generated by the microwave generator <NUM> can be controlled by providing control signals to the microwave generator <NUM> thereby to select or vary one or more parameters of the modulation scheme.

In some embodiments, the generated radiation is modulated by control of a linear gain thereby to control power via a variable amplitude.

The microwave generator <NUM> is configured to delivery microwave radiation comprising a frequency between <NUM> and <NUM>, optionally wherein the frequency is about <NUM>, about <NUM>, about <NUM>, about <NUM>, or about <NUM>.

In use, microwave radiation is generated by the microwave generator <NUM> in accordance with the operational parameters of the microwave generator <NUM> and supplied to the microwave applicator <NUM> via the cable <NUM>. The applicator <NUM> is then provided at a surface of a biological tissue <NUM> and microwave radiation is delivered to the surface by the applicator <NUM>.

The applicator <NUM> is then moved across the surface by the user. In the present embodiment, the applicator <NUM> is a hand-held applicator and is moved across the surface by hand. In the present embodiment, the sensor unit <NUM> senses position, velocity, acceleration, and orientation of the applicator <NUM> as it is moved across the surface. The controller <NUM> monitors the sensor output of the sensor unit <NUM> and provides control signals to the microwave generator <NUM> based on the monitored sensor output. In the present embodiment, as the applicator <NUM> is moved across the surface, the controller <NUM> monitors the sensor output to determine the position, velocity, acceleration and orientation of the applicator <NUM>. One or more of the position, velocity, acceleration and orientation may be measured relative to a reference frame. Position may be determined relative to a reference point and may be referred to as displacement.

Based on the position, velocity, acceleration and orientation of the applicator <NUM>, the controller <NUM> provides control signals to the microwave generator <NUM> to change or maintain one or more operational parameters of the microwave generator. In the present embodiment, the operational parameters are maintained and/or changed to maintain, increase or decrease the power of the generated microwave radiation by the generator <NUM>. By maintaining, increasing or decreasing the power of the generated microwave radiation the microwave radiation is delivered to the surface in accordance with a pre-determined dose.

In the present embodiment, the control system unit <NUM> also modifies one or more operational parameters of the generator to change the AM or PWM based on the acceleration, orientation, speed, velocity and position input of the biological tissue <NUM> being treated as determined using sensor output from the further sensor unit <NUM>.

The pre-determined energy dose is selected before the treatment starts. The selection is performed based on a number of factors, for example, the tissue type and/or condition to be treated. The energy dose may be, for example, an energy distribution that provides a controlled or constrained radiation delivery. For example, the energy distribution may be such that a uniform, non-uniform, optimum, or pre-set microwave energy density is delivered to the surface. In some embodiments, the energy dose is selected so that the heat treatment provided to the surface has a constant temperature or a temperature within a temperature window. In some embodiments, the energy dose is such that microwave radiation is provided inside a treatment area, for example, inside a pre-determined boundary.

For some treatment areas, different areas require different amounts of microwave radiation for treatment. Some conditions may require a more superficial treatment which would involve providing less power and a faster movement of the probe. Other conditions may require deeper heating and therefore slower movement of the probe to invoke radiating and conductive heating.

In some embodiments, it may be that the condition required different grades/levels of microwave treatment, and therefore more than one treatment region requiring different amounts of energy is provided. For example, the treatment area may have a sensitive area or a zone that is omitted (for example, a mole). As a further example, healthy tissue surface may be surrounded by a lesion to be treated.

<FIG> represents key phases of a process <NUM>, in accordance with embodiments, for delivering and controlling an energy density over the surface of the biological tissue being treated. The process flow has a localising stage <NUM>, in which a two dimensional map or 3D volume map of the treatment area is determined. 2D treatment areas and 3D treatment volumes may be referred to as a treatment region. The next stage <NUM> is an initialisation stage, in which one or more configuration parameters are selected. The next stage is the treatment stage <NUM>.

Localising stage <NUM> comprises of spatial registration <NUM> of microwave applicator <NUM> and biological tissue <NUM>. The spatial registration may occur in 2D or 3D space. This is followed by a mapping process <NUM> of the surface contour of the biological tissue <NUM> to acquire the boundary and surface geometry of the treatment area (the lesion) in 2D or 3D space. During the localising stage <NUM> no microwave power is supplied from the generator <NUM>. The mapping process <NUM> may be performed by mapping circuitry associated with the controller <NUM> that receives sensor output and is configured to produce a map of the treatment area. In some embodiments, the 3D contour mapping could also be performed using, for example, LIDAR (Light Detection and Ranging) or ToF (Time-of-Flight) cameras.

As part of the system initialisation stage <NUM>, one or more initialisation parameters are selected by a user. In particular, at treatment selection stage <NUM>, parameters related to the desired energy dose or parameters related to a specific treatment based on a particular condition are selected. For example, in the present embodiments, a desired energy density is selected by a user based on the type of treatment required.

As part of the treatment stage <NUM>, treatment is initiated at energy delivery step <NUM>. At the energy delivery step <NUM>, microwave power is generated from generator <NUM> through the microwave applicator assembly <NUM> on the biological tissue <NUM>. The treatment is then performed substantially as described with reference to <FIG>.

Further at step <NUM>, in the present embodiments, the control system unit <NUM> modifies one or more operational parameters of the generator to change the amplitude modulation (AM) or pulse-width modulation (PWM) of the generated microwaves. Step <NUM> may be referred to as operational parameter modifying stage <NUM>. The changes are based on the acceleration, orientation, speed, velocity and position input of microwave applicator assembly <NUM> from IMU sensors unit <NUM>. In the present embodiment, the control system unit <NUM> also modifies one or more operational parameters of the generator to change the AM or PWM based on the acceleration, orientation, speed, velocity and position input of biological tissue <NUM> being treated as determined using sensor output from further sensor unit <NUM>.

At step <NUM> (controlled delivery stage), the control system unit <NUM> continuously monitors and executes controlled delivery of microwave energy density (measured in J/mm<NUM>) over the entire surface area to be treated.

In the above described process, a localising stage <NUM> is described. However, it will be understood that, in some embodiments, a map is not used or a map is provided without performing a mapping process. In some embodiments, only some co-ordinates of the treatment area are used during the treatment process. For example, only extreme values of height, width and length may be used.

In some embodiments, the localising stage <NUM> includes receiving treatment region data from an external source, for example, MRI, ultrasound or CT scan data. Any other medical imaging modality may provide treatment region data. In these embodiments, the obtained dataset is registered with the treatment region using the applicator <NUM> using a marker or other geometrical or anatomical features.

<FIG> shows the microwave applicator assembly <NUM>, in accordance with embodiments. The microwave applicator assembly <NUM> has applicator housing <NUM>, microwave antenna <NUM> and sensor unit <NUM>. The sensor unit <NUM> is as described with reference to <FIG>. The applicator <NUM> is shown as being applied on a nonhomogenous surface <NUM> of the biological tissue <NUM>. The microwave applicator assembly <NUM> and sensor unit <NUM> are connected to the controller (not shown in <FIG>) by first cable <NUM> and second cable <NUM>, respectively. While shown as first cable <NUM> and second cable <NUM>, any wired or wireless connection suitable for carrying signals, for example, sensor data signals can be used in place of either first cable <NUM> or second cable <NUM>.

In the present embodiment, the sensor unit <NUM> is an IMU sensor unit <NUM> and is equipped with a <NUM>-axis accelerometer <NUM> and a gyroscope <NUM>. These sensors (accelerometer <NUM> and gyroscope <NUM>) can be used individually or in a combination with each other. In some embodiments, these sensors are combined in a single sensor and their location can be anywhere within the applicator housing <NUM>. In use, the microwave antenna <NUM> may or may not be positioned in contact with the surface <NUM>. Microwave antenna <NUM> is connected to the controller through the applicator housing <NUM> by means of the first cable <NUM>. Sensor unit <NUM> is connected to the controller <NUM> through applicator housing <NUM> by the second cable <NUM>.

Further sensor unit <NUM> is placed on the surface <NUM> of the tissue <NUM>. The surface <NUM> corresponds to the surface of the body part being treated. Similarly to the sensor unit <NUM>, the further sensor unit <NUM> consists of a <NUM>-axis accelerometer <NUM> and a gyroscope <NUM> which can be used individually or in combination with each other. In some embodiments, the sensors of the further sensor unit <NUM> (accelerometer <NUM> and gyroscope <NUM>) are combined in a single sensor and their location can be anywhere on the tissue <NUM>. Further sensor unit <NUM> is wired to the controller <NUM> by means of third cable <NUM>. In other embodiments, the further sensor unit <NUM> is connected to the controller <NUM> by a wireless connection and detects, for example, movements of the biological tissue.

In the above embodiment, a system for delivering radiation to a surface is described. In some embodiments, as described with reference to <FIG>, the system is configured to perform part of treatment area mapping process to determine the 2D or 3D position of the applicator and a surface contour of the tissue to be treated. The system is configured to determine a 2D or 3D map of the applicator displacement. The system is further configured to provide updates to the 2D or 3D map during treatment, for example, in real-time.

As an overview, initially a local 2D or 3D position of the applicator is registered spatially with a global co-ordinate system of the algorithm with the aid of IMU sensors such as accelerometer and gyroscope prior to the treatment. A boundary is then mapped manually using the applicator in "map mode". In some embodiments, the boundary is mapped by a user moving the applicator along the contour edge of the affected area on the surface of the tissue. In the "map mode" no microwave radiation is produced and data relevant for generating a map is collected. The applicator is moved along the said boundary in the 2D or 3D space generating 2D or 3D co-ordinate data representative of the surface of the tissue to be treated in the global co-ordinate system. The dataset can also include 4D generated time points with respect to each 3D co-ordinate being measured. The boundary coordinates of the area to be treated (the treatment area) are determined and hence provided in the control system.

While treating the tissue such that when the applicator <NUM> is moved beyond the extent of the coordinates of the lesion, the controller <NUM> ceases the power and thus radiation delivery. This may provide an automatic safety feature, further described with reference to <FIG>, that prevents radiation delivery when during the treatment, applicator is not on target tissue boundary or surface, for example when the applicator leaves the surface accidently during the treatment or the orientation deviates from the "normal" surface vector.

<FIG> shows a cross-sectional view of the microwave applicator assembly <NUM> as described with reference to <FIG>. <FIG> shows a first local co-ordinate system <NUM> having an origin <NUM> and three spatial axes (represented by X', Y' and Z'). The origin <NUM> of the local co-ordinate system <NUM> of the microwave applicator assembly <NUM> and thus of the microwave antenna <NUM> could be located anywhere on microwave applicator assembly <NUM>. In the present embodiment, the origin <NUM> is located at the centre of the IMU sensor unit <NUM>.

Similarly, a second local co-ordinate system <NUM> having an origin <NUM> and three spatial axes (represented by X", Y" and Z") represents spatial position of the further sensor unit <NUM>. The origin <NUM> of the second local co-ordinate system <NUM> of the biological tissue <NUM> being treated could be located anywhere on the biological tissue <NUM> but preferably on the tissue surface <NUM>. In the present embodiment, the origin <NUM> is located at the centre of the further sensor unit <NUM>. In the present embodiment, the co-ordinate systems <NUM> and <NUM> are Cartesian co-ordinate systems, but it will be understood that, in other embodiments, any suitable co-ordinate system may be used.

To enable real-time and continuous tracking of the microwave applicator assembly <NUM> in 3D space, the first local co-ordinate system <NUM> with axes X', Y', Z' is registered with a global co-ordinate system <NUM> with axes X, Y and Z. Further, to enable real-time and continuous tracking of the biological tissue <NUM> being treated in 3D space, local coordinate system <NUM> with axes X", Y", Z" is registered with the global co-ordinate system <NUM> with axes X, Y and Z.

As a final step of the registration, the applicator <NUM> is moved across various points on the surface <NUM> of the tissue <NUM> recording the relative position of the distal end <NUM> of the applicator <NUM> and surface <NUM> of the tissue <NUM> in 2D and 3D space. This enables registration of the co-ordinate system <NUM> of biological tissue with the co-ordinate system <NUM> of applicator assembly <NUM> which in turn allows real-time tracking of the applicator assembly <NUM> with respect to the biological tissue <NUM> being treated.

An algorithm is provided that includes developing a spatial relationship between the three co-ordinate systems (<NUM>, <NUM>, <NUM>). This helps generate a common reference frame and reference frame transform between the microwave applicator assembly <NUM>, IMU sensors unit <NUM>, biological tissue <NUM>, further sensor unit <NUM> and the global co-ordinate system <NUM> of the algorithm. Using this, the precise location of the sensors of sensor unit <NUM> and further sensor unit <NUM> (accelerometer <NUM>, gyroscope <NUM>, accelerometer <NUM>, gyroscope <NUM>), microwave applicator assembly <NUM>, microwave antenna <NUM>, distal end <NUM> of the microwave applicator assembly <NUM> and surface <NUM> of the biological tissue <NUM> can be all tracked in a singular global co-ordinate system <NUM> along X,Y,Z axes In addition, 2D and 3D position of the applicator <NUM> and tissue <NUM> can be tracked relative to each other. This feature may also provide a system suitable for treatments where keeping the tissue stationary for longer duration may not be possible. The transform may make processing easier and allows a re-mapping to be computed should the tissue move.

<FIG> illustrates a 2D mapping process of a surface contour of the biological tissue <NUM>. The map is generated along the X axis <NUM> and Y axis <NUM> of the global co-ordinate system <NUM> i.e. in the XY plane. The 3D data input from the sensors of sensor unit <NUM> and further sensor unit <NUM> (accelerometer <NUM>, gyroscope <NUM>, accelerometer <NUM>, gyroscope <NUM>) are processed to determine the position and orientation of the microwave applicator assembly <NUM> and biological tissue <NUM> in the 3D space.

The distal end <NUM> of the applicator assembly <NUM> may also be referred to as the treatment end of the applicator. In some embodiments, the distal end <NUM> has a diameter in the range of <NUM> to <NUM>. In some embodiments, the distal end <NUM> has a diameter substantially equal to <NUM>, <NUM>, <NUM> or <NUM>. In some embodiments, the diameter of the distal end <NUM> may be selected depending on the dielectric properties and/or frequency of operation of the probe.

In the following, a mapping process for obtaining data representing a treatment area is described, in accordance with embodiments. <FIG> shows a treatment area <NUM> (in this example, a lesion) of the biological tissue <NUM>.

At first, the microwave applicator assembly <NUM> is moved smoothly, by an operator, along a surface contour of the biological tissue <NUM> to map an outline of the lesion. During the mapping, a boundary <NUM> of the treatment area <NUM> on the surface of the biological tissue <NUM> in the XY plane of the global co-ordinate system <NUM> is determined.

<FIG> shows an alternative, cross sectional side view of the applicator assembly <NUM> applied to the surface <NUM>. The microwave applicator assembly <NUM> is moved smoothly along the surface contour <NUM> of the biological tissue <NUM> to map the outline of the lesion as well as to locate and determine the extremes of the surface of the biological tissue <NUM> in the direction of the Z axis (the height) <NUM> of the global co-ordinate system <NUM> i.e. locating the minimum value of Z (Zmin), for example <NUM> and the maximum value of Z (Zmax), for example <NUM>. The mapping process shown in the <FIG> and <FIG> is described for illustrative purposes and in real-time the X, Y, Z co-ordinates will be preferably recorded simultaneously.

In the present embodiment, values of the Z co-ordinate are used as a safety feature. It will be understood that these values may also ensure that the entire 3D surface is covered.

Although described as part of a process for mapping the outline, in some embodiments, determining the maximum and minimum height of the treatment area in the Z direction may include performing a second mapping stage. For example, the maximum value of Z may not lie on the boundary of the treatment area and may lie inside the treatment area therefore a user must move the applicator to cover the treatment area before commencing the treatment.

In further embodiments, the system is configured to evaluate required energy settings i.e. the microwave power and time input based on the type of condition being treated. The applicator when moved in the map mode calculates surface or lesion contour and surface area (mm<NUM> or cm<NUM>). The user then selects the desired energy density J/mm<NUM> or J/cm<NUM> depending on various factors such as but not limited to tissue type, lesion type and surface area to be treated. Using the applicator and user input, the algorithm determines the required power (mW or W) and time required (s, min) and hence energy (J) required to treat the condition.

Depending upon the determined energy (J) and treatment area, the algorithm establishes velocity envelope for the applicator <NUM> movement throughout the treatment duration. This aspect of the algorithm can alert the user when the speed of the applicator is greater than the velocity envelope that is needed to deliver the determined or selected energy density.

<FIG> shows the microwave treatment system in accordance with embodiments. <FIG> shows the system being used for treatment, with reference to the determined 2D/3D mapping of the biological tissue. <FIG> shows the treatment in in real-time.

<FIG> shows the microwave generator <NUM>, the cable <NUM> and applicator assembly <NUM> as described with reference to <FIG>. <FIG> also shows the biological tissue <NUM> that is being treated. <FIG> shows a display <NUM> for displaying the determined 2D or 3D map to a user. As described with reference to <FIG>, the microwave applicator assembly <NUM> is connected to the microwave generator <NUM> via the cable assembly <NUM>. The generator <NUM> has a port <NUM> to which the cable assembly <NUM> is connected.

A first wired connection <NUM> connects the sensor unit <NUM>, which is provided as part of the microwave applicator assembly <NUM>, to the controller <NUM>. A second wired connection <NUM> connects the further sensor unit <NUM>, which is provided at the biological tissue <NUM>, to the controller <NUM>. In the present embodiment, the controller <NUM> is provided as part of a computing resource <NUM>, together with other circuity, for example, display circuitry and mapping circuitry. The controller <NUM> is provided as part of a processing circuitry or other suitable processing resource of the computing resource <NUM>. The processing resource may also be referred to as an algorithm processing unit. Feedback data from the sensor unit <NUM> is communicated to the computing resource <NUM> via the first wired connection <NUM>. Feedback data from the further sensor unit <NUM> is communicated to the computing resource <NUM> via the second wired connection <NUM>. It will be understood that, in some embodiments, data from the sensor unit <NUM> and further sensor unit <NUM> may be communicated to the controller over a suitable wireless connection using wireless data transfer.

The computing resource <NUM> is connected to the microwave generator <NUM> via a further wired connection <NUM>.

Although shown separately in <FIG>, it will be understood that in some embodiments, one or more of components may be integrated into a single system or piece of hardware with internal connections. For example, the display <NUM> and computing resource <NUM> may be provided as a single system. In a further example, the algorithm processing unit <NUM> may be an external computer or an internal unit that can perform required tasks. In further embodiments, in addition to the sensor unit, the controller is provided as part of the applicator. A single probe may be provided that includes integrated controller, CPU/firmware and sensors.

Turning to display <NUM>, the display <NUM> and associated display circuitry of computer resource <NUM> are configured to display the determined map of the treatment area. The display circuitry is configured to update the display in real-time based on sensor output. In particular, the display is updated based on which parts of the treatment area have been treated.

In an embodiment, the display circuitry is configured to display the treatment area and graphical representation of where the applicator <NUM> has been moved i.e. the area that has been spanned by the movement of the applicator <NUM> during the treatment process. In the present embodiment, treated area <NUM> shown by a grid represents the displacement of the microwave applicator assembly <NUM> in the 2D/3D space hence providing 2D/3D footprints of the said applicator being moved continuously on the surface of the tissue being treated. The 2D/3D footprints of the applicator demonstrate the tissue surface that has already been treated. The display circuitry is also configured to display untreated area <NUM> representative of the area of the tissue that has not been treated.

The 2D or 3D displacement can be mapped in real-time by providing 2D or 3D footprints of the applicator <NUM> being moved continuously on the surface of the tissue being treated. As described above, the 2D or 3D footprints of the applicator can be used to differentiate between untreated tissue surface and the tissue surface that has already been treated. In some embodiments, the control system is configured to control the generator to cease or reduce the power delivery if the applicator is moved to an already treated tissue surface. For example, if the applicator <NUM> is moved to treated area <NUM>, the power delivery is ceased or reduced. In some embodiments, when the applicator is moved to a previously treated area, the delivered power is determined based on the time elapsed since the applicator was previously at that location. In some embodiments, the 3D displacement is mapped in real-time providing 3D (Z) relating information that can be used to detect when the applicator is removed away from the tissue surface or is oriented in such a way that the applicator <NUM> is no longer normal to the surface <NUM> of biological tissue <NUM>. As described in further detail with reference to <FIG>, this can form a safely mitigation and hence cease the delivery of power to the surface applicator.

The 2D/3D footprints of the applicator allow a user to see the size of treatment end of the applicator <NUM> in relation to the treatment area <NUM>. For example, the applicator may provide a small focus represented by a fine point, or, for example, a <NUM> diameter zone that can overlap by a particular fraction, for example, by <NUM>/<NUM>.

As described above, the power of generated microwave radiation and hence the energy density applied to a surface can be controlled by modulation. <FIG> illustrates pulse width modulation sequences regulated by the controller <NUM> for delivering a controlled microwave energy density.

As an illustrative example, <FIG> shows the case where a tissue treatment requires application of microwave radiation having a uniform energy density over the entire surface and treatment area of the lesion.

The control system is built in a closed-loop configuration where the control system modulates amplitude control of signal energy (AM pulsing) and/or PWM (pulse width modulation) duty cycle proportionally according the speed, velocity, orientation, displacement or acceleration of the microwave applicator delivering the energy thus keeping the delivered radiation density in the treated region uniform.

For example, as described in the following, a pre-determined velocity of <NUM> millimetres per second (referred to as Vbaseline) is assigned to the standard <NUM>% duty cycle. Selection of Vbaseline can be performed automatically by the algorithm based on the condition and area of the lesion being treated. Alternatively, the user can provide feedback to provide an accepted velocity envelope.

Based on the preselected value, increase in the Vbaseline elicits an increase in the PWM duty cycle (by making Ton greater Toff) which in turn increases the intensity or magnitude of the power delivered at the given instance of time. Alternatively and/or additionally, decrease in the Vbaseline of the applicator treating the area produces decrease of the PWM duty cycle (i.e. Ton less than Toff) resulting in the decreased power intensity over the region being treated. This ensures that, for example, the radiation being delivered is uniform over the treated surface across the whole region. A continuous dose of radiation is thus modulated using PWM duty cycle where the <NUM>% duty cycle relating to Vbaseline delivers power Pin. Pin refers to the actual power input specified that can be <NUM>. 1W to 100W but preferentially between <NUM>.

As described with reference to <FIG>, the control system can cease the power and hence the delivery if the velocity and acceleration of the applicator movement is outside a maximum specified value indicating the applicator is either being moved too fast or has been stationary for too long.

<FIG> show three pulse width modulation patterns for three different conditions.

The first pattern, of <FIG> represents a <NUM>% duty cycle where the period in which the signal is on (TON) is equal to the period in which the signal is off (TOFF). TON is represented by numeral <NUM> and TOFF is represented by numeral <NUM>. In the present embodiment, the first example represents a modulation pattern for a condition when sensor output indicates that the velocity (V) of the microwave applicator assembly <NUM> is equal to a baseline value (Vbaseline). The baseline value is a pre-determined value. As an illustrative example, Vbaseline could be, for example, <NUM>/sec or <NUM>/sec etc. The value could be selected by a user or determined by an algorithm based on the condition and type of treatment required (i.e. the condition and type of treatment required could be selected by a user and the value is determined by the processing resource). Vbaseline dictates the control system unit <NUM> to maintain the <NUM>% duty cycle of the PWM.

If the applicator <NUM> is moved such that the monitored sensor output indicates a velocity, V, of the microwave applicator assembly <NUM> to be less than Vbaseline (for example, in the event that the. operator slows down movement of the microwave applicator assembly <NUM> on the surface <NUM> of the biological tissue) then the controller provides control signals to the microwave generator to increase the PWM duty cycle. An example increased duty cycle is shown in <FIG>. TON (<NUM>) is greater than TOFF (<NUM>). The controller <NUM>, thus maintains the energy of the radiation being delivered to the surface to be substantially uniform in response to an increased velocity.

Furthermore, if the monitored sensor output indicates that the velocity, V of the microwave applicator assembly <NUM> has increased above Vbaseline (for example, if the microwave applicator assembly <NUM> is moved quicker than the Vbaseline across the surface <NUM> of the biological tissue) then the PWM duty cycle is decreased.

An example of a decreased duty cycle is shown in <FIG>. TON (<NUM>) is less than TOFF (<NUM>). The controller <NUM> thus maintains the energy of the radiation being delivered to the surface to be substantially uniform in response to a decreased velocity.

In some embodiments, the change in duty cycle or other modulation parameter is determined in proportion to the change in one or more of speed, orientation, velocity, position and acceleration.

Therefore, the present invention demonstrates uniform and optimum microwave radiation delivery on large surface area of biological tissue <NUM> by compensating for the non-uniform and changing movement and displacement of microwave applicator assembly <NUM>.

In some embodiments, the radiation delivery is controlled for microwave treatment which requires maintaining a precise temperature or a temperature within a temperature window over the entire duration of treatment. When the continuously tracked applicator returns back to a certain location to repeat the energy dose within a treatment, its current and previous time-points are known. Using this data, the time, location and evaluated temperature can be calculated and the radiation delivery can be modulated, for example by AM or PWM control, to maintain the temperature below a pre-set threshold. The determination of required microwave power may be determined in accordance with a mathematical relationship, for example, a bio-heat equation.

As an illustrative example, if the applicator is returned too quickly to a location that it has been previously visited, then for example PWM duty cycle is decreased (as illustrated in <FIG> to decrease the radiation delivered to that location.

When treating certain types of conditions, the treatment efficacy may be improved when the temperature of the tissue temperature is maintained to a certain value or range for a certain period of time. Similarly, the cumulative equivalent time (in minutes) at <NUM> also called as CEM43 model (Sapareto and Dewey, <NUM>), shows various temperature-time effects and is known to be used by thermal therapies to deliver specific thermal dose and to avoid thermal damage. (Rhoon, <NUM>; Mitra and Miller, <NUM>).

In the above describes embodiments, providing radiation for example, uniformly to a treatment area is described. The controller may be configured to monitor sensor output to maintain a required temperature window based on the condition to be treated by modulating radiation being delivered on the lesions surface. The temperature window could be in a range from <NUM>-<NUM>. The temperature may be substantially equal to precise values such as <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or a temperature window such as <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM>.

The temperatures are maintained for a pre-determined period of time, as a non-limiting example, this is between <NUM>-<NUM> seconds, in particular <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM>. The preselected Vbaseline based on the surface area of the lesion being treated and user feedback provides a known energy density being distributed on the tissue surface. Using fundamental properties such as blood perfusion rate of the tissue being treated and the Penne's Bioheat equation (Pennes HH (<NUM>)), the rate at which temperature of the tissue surface is increased or decreased is predicted by the algorithm for the preselected energy settings.

In some embodiments, the controller is configured to provide modulation of the energy density based on the calculated temperature decay of the surface. For example, for a condition such psoriasis and type of the treatment such as high dose of hyperthermia, the temperature window is selected to be <NUM>-<NUM> for a time period of <NUM>. Using the applicators map mode, the surface area of the tissue to be treated is recorded. During the treatment, the spatially tracked applicator is moved continuously on the surface being treated in a translation motion recording the timepoint and location of each 2D or 3D co-ordinate on the tissue surface that has been supplied with radiation. When the applicator returns to the already treated location, then the difference between the current spatial time point and the previous time point of radiation delivery provides temperature decay at that point. The energy density to the new time point at that location is then adjusted by the said control system by modulating the amplitude control of signal energy (AM pulsing) and/or PWM (pulse width modulation) duty cycle.

In further embodiments, the system also includes a failsafe mode, in which the microwave radiation being generated by the microwave generator is substantially reduced or switched off in response to a number of events. <FIG> shows six conditions <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> that correspond to six events, in response to which the controller controls the microwave generator to ceases power generation or turns the power to 0W (represented by step <NUM>).

The first condition <NUM> corresponds to the event when the monitored sensor output indicates that the applicator has reached or gone outside the boundary of the treatment area.

The second condition <NUM> corresponds to the event when the monitored sensor output indicates that the applicator <NUM> is moved back to an already treated position on the tissue surface. The second condition may only be implemented for certain radiation profiles, for example, only when a uniform energy density is required.

The third condition <NUM> corresponds to the event when the monitored sensor output is representative of the applicator <NUM> moving at a high velocity or acceleration. This may be determined by comparing the sensor output value to a threshold value.

The fourth condition <NUM> corresponds to the event when the monitored sensor output is representative of the application being stationary or static. This may be determined if the sensor output indicates that the applicator <NUM> is in substantially the same location for a period of time greater than a pre-determined threshold.

The fifth condition <NUM> corresponds to the event when the monitored sensor output is representative of the application being returns too soon or too quickly to a tissue surface during a treatment that is required to maintain a specific temperature as part of the treatment.

The sixth condition <NUM> corresponds to the event when the monitored sensor output is representative of the applicator <NUM> being orientated at an angle that is outside an angular range defined about the normal to (an axis perpendicular to) the treatment surface. It may be desirable to use the applicator <NUM> at an angle that is normal to the treatment surface and the sixth condition <NUM> corresponds to when the applicator is no longer at the desired, normal. In other embodiments, a different desired angle of application may be preferred and a condition may be such that that the monitored sensor output is representative of the applicator <NUM> being no longer oriented at the desired angle of application.

In response to any of these events, the controller controls the microwave generator to cut-out and cease generation of microwave radiation to prevent delivery of further microwave radiation from the applicator <NUM>.

In some embodiments, the system has an indicator. The indicator may be provided which indicate that one or more of the above events has occurred. The indicator may be a visual or audio indicator. In some embodiments, the indicator could be provided on the display or on the applicator.

In the above described embodiments, the energy applied using the system constitutes delivering specified microwave power over a specified time. The microwave power could range from <NUM>. 1W to 100W but preferentially between 1W to 20W. The treatment time may range from one thousandth of a second to <NUM> and <NUM> to <NUM> but preferably between <NUM>-<NUM>. Surface power density may range from 1mW/ mm<NUM> to 20W/mm<NUM>. The surface energy density may be in a range from 1mJ/mm<NUM> to 200J/mm<NUM>.

The radiation applied can be in the form of a continuous oscillating electromagnetic wave (CW) at a fixed frequency or modulated (variable frequency). The frequency could range from <NUM> to <NUM> but preferentially could be in the microwave range from <NUM> to <NUM>.

In the above describe embodiments an applicator with a radiating antenna surface of is described.

In the above described embodiments, the microwave applicator is moveable by a user. The applicator can be moved over the entire surface in any direction. In example embodiments, the applicator is sized and/or shaped to be moved across the surface by hand, for example, like a paintbrush on canvas or a pen on paper.

In the above described embodiments, the sensor unit <NUM> is an inertial measurement unit (IMU) sensor. The IMU includes, for example, an accelerometer to measure the acceleration (A) of the applicator. The accelerometer may also provide sensor output representative of the velocity and displacement of the applicator.

In the above described embodiment, sensor unit also has a gyroscope added to the distal end of the applicator. A combination of the IMU sensors of sensor unit <NUM> can provide <NUM> degrees of freedom (DOF) tracking i.e. X, Y, Z displacement as well as pitch, roll, yaw i.e. θ, ψ, φ respectively.

By sensing orientation, an angle of application may be determined. During use, the applicator may be touching the surface but only at a glancing angle thus imparting a fraction of the energy expected/designed at the normal of <NUM> degrees e.g. normal or perpendicular angle of application. By sensing the angle of application, the use of the applicator may be optimised to increase or decrease the fraction of energy provided from the applicator.

Industrial <NUM>-axis accelerometer and gyroscopes can be brought separately and embedded in one unit. Alternatively, <NUM>-axis accelerometer and gyroscope mounted on a same chip can serve as one unit, for example, the <NUM>-axis family devices package by InvenSense or the iNemo series by STMicroelectronics. The said accelerometer is used to detect magnitude and direction of the proper acceleration of the applicator. The acceleration and velocity of the applicator radiating energy in the tissue is continuously monitored over the given distance by the control system.

In the above described embodiments, pulse width modulation is described to control the power of the generated microwave radiation. It will be understood that other modulation schemes can be used, for example, pulse regimes including amplitude control of signal energy (AM pulsing) and pulse width modulation control (PWM) and on/off keying (OOK). Modulation schemes include pulse modulation rates (<NUM>-<NUM>) or frequency modulation rate (<NUM>-<NUM>).

A continuous dose may be a fixed level of radiation or a modulated level of radiation during a treatment session. This continuous radiation delivery could be pulsed modulated one or five or fifty times a second during the ongoing treatment session. Preferentially continuous radiation delivery could be pulsed five times per second (<NUM>).

The system described above provides inertial tracking of the biological tissue and the applicator assembly using IMU sensors providing <NUM> DOFs. It will be understood that other types of sensor may be used in combination or in place of the IMU sensors.

In a further embodiment, motion capture techniques such as optical tracking are employed. It is possible that sudden movement, for example, a sudden leg movement, could cause loss of registration, however by continuously tracking the biological tissue <NUM> and applicator assembly <NUM> using an optical tracking system this issue can be overcome thus allowing treatment of the correct areas. As described in further detail with reference to <FIG>, this alternate tracking is achieved by placing an active or passive set of markers on the biological tissue. One or more detecting cameras are then provided, externally or on the applicator assembly which would navigate the biological tissue and applicator assembly into a single co-ordinate system. In some embodiment, such a system is marker-less and can make use of anatomical features of the biological tissue being treated.

<FIG> shows the system provided together with an optical tracking system, in accordance with further embodiments. <FIG> shows part of microwave delivery system <NUM>, as described with reference to <FIG>. <FIG> shows applicator <NUM> and cable <NUM> of system <NUM>. Applicator <NUM> has a sensor unit <NUM> (not shown in <FIG>) with IMU sensors. As shown in <FIG>, applicator <NUM> is moveable by a hand <NUM>.

In <FIG>, a set of markers <NUM> is placed on the biological tissue <NUM>. In <FIG>, the biological tissue <NUM> is part of a foot. The markers are tracked by an external camera system <NUM> comprising two cameras 162a, 162b. The camera system is connected to controller <NUM> via wired connection <NUM>. In other embodiments, a wireless connection is provided.

In the embodiment of <FIG>, microwave applicator assembly <NUM> with IMU sensors is provided as described with reference to <FIG>. The camera <NUM> can visualise the set of markers <NUM> on the tissue <NUM> thus keeping the applicator assembly <NUM> and tissue <NUM> in a single co-ordinate system.

<FIG> shows a further embodiment, in which a set of markers are provided on the applicator assembly <NUM> which is tracked by the external camera system <NUM>, thus bringing tissue <NUM>, applicator assembly <NUM> into a single co-ordinate system.

<FIG>, <FIG> and <FIG> show further embodiments which are substantially the same as the embodiment of <FIG>, except: with camera system <NUM> replaced by camera system <NUM> provided on applicator <NUM> (shown in <FIG>); alternative position of camera system <NUM> (<FIG>, <FIG> and <FIG>) and with other possible configurations of markers <NUM> on tissue <NUM> (<FIG>, <FIG> and <FIG>). In particular, <FIG> shows markers provided on the tissue surface <NUM>.

As illustrated in <FIG>, the camera system <NUM> can be also be implemented externally on the body of applicator assembly <NUM>. Although shown as having two cameras, it may be that camera system (<NUM> or <NUM>) can have one, two or more cameras and can be placed anywhere on the applicator body. The camera system can visualise the set of markers <NUM> on the tissue <NUM> thus keeping the applicator assembly <NUM> and tissue <NUM> in single co-ordinate system.

The markers could be of any shape but preferably spherical. The markers may be active or passive. A passive marker can be covered with any material preferably any radiopaque material. An active marker comprises of an active source such as IRED (infrared emitting diodes) or LED (Light emitting diodes depending upon the detector camera type. Markers can be placed on prominent features of the tissue for example on the foot, on medial, lateral, dorsal or plantar side using bony palpations such as metarsal heads, metarsalphalangeal joint, cuboid etc or soft tissue palpations such as tibialis posterior tendon, or features such as transverse arch.

Although described as a camera detecting the position of the markers, in some embodiments, alternative marker detecting means for detecting the presence and/or position of one or more active or passive markers are provided. The alternative marker detecting means can be, for example, an electromagnetic system, a time of flight based system, a Lidar based system and/or a Doppler radar technique system. In some embodiments, the marker detecting means may use one or more sensors of the sensor <NUM> and/or further sensor <NUM>.

The system described relates to treating larger surfaces of various tissues such as, but not limited to, skin, liver, spleen, kidney, lung, muscle, cardiac tissue, venous or arterial structures etc. In particular, the said method and apparatus relates to treating any surface of the biological tissue by means of supplying microwave radiation for ablative, non-ablative and coagulative purposes. The system can be used to treat a variety of conditions in tissues and in particular surface based treatments for example but not limited to in treating dermatological conditions.

The system can be used to treat biological conditions affecting mucosal linings for example and not limited to mucosal linings of oral, gastrointestinal, cervical tissues. Oral lesions for example and not limited to leukoplakia, hairy leukoplakia, lichen planus, xerostomia, mucositis, pyogenic granuloma, angioma, nicotinic stomatitis, actinic cheilitis, keratoacantoma, epithelial dysplasia, hyperkeratosis, oral candidosis, erythema migrans, canker sores.

The microwave treatment system is intended for example, for tissue hyperthermia, ablative, sub-ablative, non-ablative, coagulative and non-coagulative purposes. In addition, a method of continuously tracking the microwave radiation applicator in 2D or 3D space to control the radiation delivery is described. Further, another feature is an algorithm to maintain a desired temperature range of a tissue based on the condition and type of microwave treatment.

Though not exclusively, the present disclosure relates to treating conditions affecting epithelial tissues or conditions affecting said epithelial tissues such as cervical neoplasia, gastrointestinal neoplasia, gastric antral vascular ectasia, ulcerative colitis. In particular, the present invention relates to treating human dermatological conditions covering lesions with larger surface area than the applicator on the skin surface, for example and not limited to psoriasis vulgaris (plaque psoriasis), Inverse psoriasis, Pustular psoriasis, Erythrodermic psoriasis, Dermatitis, Seborrheic dermatitis, Eczema, Pruritus, certain fungal infection, thick and large Actinic Keratoses, cellulitis, melanoma and non-melanoma skin cancer such as Basal Cell Carcinoma and Squamous Cell Carcinoma etc..

The present invention also includes treating dermatological conditions in animals especially ones covering larger surface area than the applicator on the skin surface, for example and not limited to granulomatous and pyogranulomatous skin lesions, Papillomatosis (Fibropapillomas), Cellulitis/subcutaneous abscesses, Pruritus Dermatitis, Eczema, certain fungal infections, melanoma and non-melanoma skin cancer such as Basal Cell Carcinoma, Squamous Cell Carcinoma, Histiocytoma, Mast cell tumors, Plasmacytoma, Soft tissue sarcomas, Hair follicle tumors such as trichoepithelioma and pilomatricoma and other abnormal masses such as Calcinosus circumscripta.

In the above described embodiments, the controller controls the power of the generated microwave radiation. However, it will be understood that one or more other given characteristics of the microwave radiation that is generated may be controlled, in accordance with other embodiments. For example, the one or more characteristics include at least one of the frequency, frequency spectrum, power, power density, energy, energy density, intensity, strength, amount, magnitude, exposure time, dose, pulse duration, and pulse repetition rate of the microwave radiation.

Claim 1:
A microwave system, comprising:
a microwave generator (<NUM>);
a microwave applicator (<NUM>) for delivering microwave radiation generated by the microwave generator (<NUM>) to a surface, wherein the microwave applicator (<NUM>) is moveable relative to the surface;
one or more sensors (<NUM>) for sensing at least one of a position, an orientation, an acceleration, a speed and/or a velocity of the microwave applicator (<NUM>), and
a controller (<NUM>) configured to monitor sensor output from the one or more sensors (<NUM>) and further configured to control one or more operational parameters of the microwave system based at least on the monitored sensor output,
characterized in that
the controller is configured to control one or more operational parameters of the microwave generator (<NUM>) when the applicator (<NUM>) is at a position based on the time elapsed since the applicator (<NUM>) was previously at said position.