Patent Application
20180153618
The invention relates to an estimation technique, and more particularly, to an electromagnetic thermotherapy estimation system and an electromagnetic thermotherapy estimation method.
Cancer (also known as tumor) is one of major human diseases ranked as the top three of statistical death factors in many countries. Thus, not only is cancer treatment an urgent medical need in those countries, research and development on various medical equipments for cancer-related treatment has also becomes very important in the related field. In particular, a thermotherapy surgery on tumor is currently one of main cancer treatment techniques. For example, the main cancer treatment techniques, such as RFA (Radio Frequency Ablation) or MWA (Microwave Ablation) in tumor ablation surgery, are now applicable in local tumor treatment.
On the other hand, a thermotherapy system based on EMA (Electromagnetic Ablation) is also available. However, because the current electromagnetic thermotherapy system is still lack of an estimation technique for post-ablation temperature area range, medical professionals are unable to clearly learn about ablation conditions at the site of treatment for patients so proper commands or operations cannot be promptly given to the thermotherapy system. For instance, said ablation conditions can involve an amount of current to go through a magnetic field generator, a length of an ablation time, a needle tip depth for inserting a needle, whether an ablation range on a biological tissue to be ablated meets the criteria, and the like. In other words, if physical characteristics of the biological tissue an operation time on which cannot be precisely handled in the practice, a normal tissue may be inadvertently removed since a diameter of high temperature area generated by energy-based surgical instruments may become overly large. Alternatively, a complete ablation result cannot be effectively achieved if the diameter of the high temperature area is overly small.
Accordingly, it is required to ensure that the electromagnetic ablation can provide a safe treatment range in order to improve a treatment quality as well as surgical safety and accuracy for patients. Therefore, finding a way to effectively estimate a temperature area range and a temperature variation of the needle over time during the electromagnetic ablation is one of important issues to be addressed. In view of the above, several embodiments of the invention are provided as follows.
The invention is directed to an electromagnetic thermotherapy estimation system and an electromagnetic thermotherapy estimation method, which are capable of correspondingly calculating ablation range data and temperature envelope data according to inputted setting parameters in order to effectively estimate preoperative estimation information regarding ablation range and temperature envelope.
The electromagnetic thermotherapy estimation system of the invention is adapted to estimate an ablation result of a biological tissue ablated by a needle induced by an electromagnetic coil. The electromagnetic thermotherapy estimation system includes an input device and a processing device. The input device is configured to receive a plurality of setting parameters. The setting parameters include a needle tip depth and a current magnitude. The processing device is electrically connected to the input device, and has a database configured to store an ablation range estimation model and a temperature envelope estimation model. The processing device is configured to calculate ablation range data and temperature envelope data corresponding to the setting parameters according to the ablation range estimation model, the temperature envelope estimation model, and the setting parameters.
In one embodiment of the invention, the database is further configured to store a plurality of first thermal physical parameters of the biological tissue and store a plurality of second thermal physical parameters of the needle and the electromagnetic coil. The processing device is configured to perform an electromagnetic simulation analysis and a heat transfer simulation analysis according to the first thermal physical parameters and the second thermal physical parameters so as to create the ablation range estimation model and the temperature envelope estimation model.
In one embodiment of the invention, the first thermal physical parameters include a density, a specific heat capacity value, a thermal conductivity and an electrical conductivity of the biological tissue.
In one embodiment of the invention, the second thermal physical parameters include a density, a specific heat capacity value, a thermal conductivity and an electrical conductivity of the needle and a surface current density, a radiant flux and an electrical conductivity of the electromagnetic coil.
In one embodiment of the invention, the setting parameters further include an ablation time. The processing device calculates temperature variation data of the needle according to a temperature characteristic equation and the setting parameters.
In one embodiment of the invention, the temperature characteristic equation further includes a plurality of parameter values. The parameter values include a needle tip temperature, a needle tail temperature, a nonlinear regression parameter value, a thermotherapy execution time and a time-varying parameter value of a temperature index.
In one embodiment of the invention, the processing device performs a plurality of sampling ablation operations having different ablation times, different needle tip depths and different current magnitudes on another biological tissue in advance by the needle, and analyzes a needle tip temperature and a needle tail temperature of the needle in each of the sampling ablation operations through a nonlinear regression analysis so as to create the temperature characteristic equation.
In one embodiment of the invention, the electromagnetic thermotherapy estimation system further includes a driving circuit, a current sensor and a temperature sensor. The driving circuit is electrically connected to the electromagnetic coil. The driving circuit is configured to generate an alternating magnetic field through the electromagnetic coil so as to induce the needle. The current sensor is electrically connected to the driving circuit. The current sensor is configured to sense a plurality of current values provided by the driving circuit respectively corresponding to a plurality of sampling ablation results. The temperature sensor is electrically connected to the needle. The temperature sensor is configured to sense a plurality of temperature values of the needle respectively corresponding to the sampling ablation results. The processing device creates the temperature characteristic equation through the nonlinear regression analysis according to the current values and the temperature values corresponding to the different ablation times and the different needle tip depths.
In one embodiment of the invention, the display device is electrically connected to the processing device. The display device is configured to display an ablation range image and at least one temperature envelope corresponding to the setting parameters according to the ablation range data and the temperature envelope data. The ablation range image comprises marking a maximum ablation width.
In one embodiment of the invention, the display device is further configured to display a temperature variation curve of the needle according to the temperature variation data.
The electromagnetic thermotherapy estimation method of the invention is adapted to estimate an ablation result of a biological tissue ablated by a needle induced by an electromagnetic coil. The electromagnetic thermotherapy estimation method includes the following step. A plurality of setting parameters is received, where the setting parameters include a needle tip depth and a current magnitude. Ablation range data and temperature envelope data corresponding to the needle tip depth and the current magnitude are calculated according to an ablation range estimation model, a temperature envelope estimation model and the setting parameters.
In one embodiment of the invention, the electromagnetic thermotherapy estimation method further includes the following step. An electromagnetic simulation analysis and a heat transfer simulation analysis are performed according to a plurality of first thermal physical parameters of the biological tissue and a plurality of second thermal physical parameters of the needle and the electromagnetic coil so as to create the ablation range estimation model and the temperature envelope estimation model.
In one embodiment of the invention, the first thermal physical parameters include a density, a specific heat capacity value, a thermal conductivity and an electrical conductivity of the biological tissue.
In one embodiment of the invention, the second thermal physical parameters include a density, a specific heat capacity value, a thermal conductivity and an electrical conductivity of the needle and a surface current density, a radiant flux and an electrical conductivity of the electromagnetic coil.
In one embodiment of the invention, the setting parameters further include an ablation time. The electromagnetic thermotherapy estimation method further includes the following step. Temperature variation data of the needle is calculated according to a temperature characteristic equation and the setting parameters.
In one embodiment of the invention, the electromagnetic thermotherapy estimation method further includes the following step. A plurality of sampling ablation operations having different ablation times, different needle tip depths and different current magnitudes are performed on another biological tissue in advance by the needle. A needle tip temperature and a needle tail temperature of the needle in each of the sampling ablation operations are analyzed through a nonlinear regression analysis so as to create the temperature characteristic equation.
In one embodiment of the invention, the step of creating the temperature characteristic equation includes the following step. An alternating magnetic field is generated by driving the electromagnetic coil through a driving circuit so as to induce the needle. A plurality of current values provided by the driving circuit respectively corresponding to a plurality of sampling ablation results are sensed through a current sensor. A plurality of temperature values of the needle respectively corresponding to the sampling ablation results are sensed through a temperature sensor. The temperature characteristic equation is created through the nonlinear regression analysis according to the current values and the temperature values corresponding to the different ablation times and the different needle tip depths.
In one embodiment of the invention, the electromagnetic thermotherapy estimation method further includes the following step. An ablation range image and at least one temperature envelope corresponding to the setting parameters are displayed through a display device according to the ablation range data and the temperature envelope data. The ablation range image comprises marking a maximum ablation width.
In one embodiment of the invention, the electromagnetic thermotherapy estimation method further includes the following step. A temperature variation curve corresponding to the setting parameters is displayed through the display device according to the temperature variation data.
Based on the above, the electromagnetic thermotherapy estimation system and the electromagnetic thermotherapy estimation method according to the embodiments of the invention can be used to calculate the ablation range data and the temperature envelope data corresponding to the setting parameters according to the ablation range estimation model and the temperature envelope estimation model created in advance in the database and the inputted setting parameters. In this way, the electromagnetic thermotherapy estimation system according to the embodiments of the invention can effectively estimate the ablation range and the temperature envelope caused by ablating the biological tissue by the needle induced by the electromagnetic coil according to the setting parameters provided by medical professionals. As a result, the electromagnetic thermotherapy estimation system according to the embodiments of the invention can effectively improve ablation safety and thermotherapy quality by effectively providing accurate preoperative estimation information.
To make the above features and advantages of the invention more comprehensible, several embodiments accompanied with drawings are described in detail as follows.
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
Embodiments are provided below to describe the invention in detail, though the invention is not limited to the provided embodiments, and the provided embodiments can be suitably combined. The term “electrically connected” used in this specification (including claims) of the present application may refer to any direct or indirect connection means. For example, “a first device is electrically connected to a second device” should be interpreted as “the first device is directly connected to the second device” or “the first device is indirectly connected to the second device through other devices or connection means”.
In the present embodiment, the input device 110 may be, for example, a physical component, such as physical keyboard, mouse, button or touchpad, and the like. Alternatively, the input device 110 may also be, for example, a software component such as an input interface. For instance, the display device 130 may be, for example, a display with touch functions. The display device 130 can display image information of the input interface so medical professionals can input the setting parameters by touching on the display device 130. Alternatively, medical professionals may also input the setting parameters by using an additional physical keyboard, but the invention is not limited to the above. In this regard, enough teaching, suggestions and implementations for the input device 110 and the display device 130 of the present embodiment may be obtained according to the common knowledge in the field, which are not repeated hereinafter.
In the present embodiment, the processing device 120 may be, for example, a central processing unit (CPU) composed of single-core or multi-core, a microprocessor for general purpose or special purpose, a digital signal processor (DSP), a programmable controller, an application specific integrated circuits (ASIC), a programmable logic device (PLD) or other similar devices, or a combination of the above devices, which are capable of the electromagnetic thermotherapy estimation method in each embodiment of the invention. Also, the processing device 120 may further include a memory component. The memory component may be, for example, a random access memory (RAM), a read-only memory (ROM) or a flash memory and the like, which may be at least used to store the database described in each embodiment of the invention. Further, the database can store various parameter data and the estimation models described in each embodiment of the invention.
Specifically, the electromagnetic thermotherapy estimation system 100 of the present embodiment is used to estimate an ablation result of a biological tissue ablated by a needle induced by an electromagnetic coil. In the present embodiment, the processing device 120 can store an ablation range estimation model and a temperature envelope estimation model in advance. Medical professionals can input the setting parameters through the input device 110, where the setting parameters can include a needle tip depth and a current magnitude. By doing so, the processing device 120 can calculate ablation range data and temperature envelope data corresponding to the setting parameters according to the ablation range estimation model, the temperature envelope estimation model, and the setting parameters. Further, the display device 130 can display an image frame having the ablation range and a temperature envelope corresponding to the setting parameters according to the ablation range data and the temperature envelope data. It should be noted that, in the present embodiment, the needle tip depth refers to a distance from the electromagnetic coil to a needle tip of the needle. The current magnitude refers to a current value for driving the electromagnetic coil so the electromagnetic coil can generate an alternating magnetic field to induce the needle.
In the present embodiment, the database 121 of the processor 120 can be used to store a plurality of first thermal physical parameters of the biological tissue and store a plurality of second thermal physical parameters of the needle and the electromagnetic coil. In the present embodiment, the biological tissue may be, for example, in vitro tissue or living tissue. Further, the biological tissue may be, for example, tissue parts of various organs in human or animal body, such as thyroid or liver tissue, which are not particularly limited by the invention. The first thermal physical parameters and the second thermal physical parameters may be obtained in advance from medical journal literatures or clinical trials, and built into the database 121. In the present embodiment, the first thermal physical parameters include, for example, a density, a specific heat capacity value, a thermal conductivity and an electrical conductivity of the biological tissue. The second thermal physical parameters include, for example, a density, a specific heat capacity value, a thermal conductivity and an electrical conductivity of the needle and a surface current density, a radiant flux and an electrical conductivity of the electromagnetic coil, but the invention is not limited to the above.
In the present embodiment, the processing device 120 can create geometric structure models of the electromagnetic coil, the needle and the biological tissue, and perform a composite physical quantity analysis with a finite element method to create modules for an electromagnetic analysis and a heat transfer analysis separately according to the first thermal physical parameters and the second thermal physical parameters. In other words, before the estimation operation is performed by the electromagnetic thermotherapy estimation system 100, the processing device 120 can create the ablation range estimation model and the temperature envelope estimation model in advance according to the first thermal physical parameters and the second thermal physical parameters. In this way, during the estimation operation performed by the electromagnetic thermotherapy estimation system 100, the processing device 120 can directly use the ablation range estimation model, the temperature envelope estimation model and the setting parameters pre-stored in the database 121 to obtain the corresponding ablation range data and the temperature envelope data so the image information having the ablation range and the temperature envelope may be displayed by the display device 130. In addition, enough teaching, suggestions and implementations related to actual calculation of the finite element method described above may be obtained according to the common knowledge in the field, which are not repeated hereinafter.
As shown in
Incidentally, the temperature envelopes presented in
The following refers to
Specifically,
In the present embodiment, the processing device 120 can obtain a plurality of sampling ablation results through a plurality of sampling ablation operations so as to create the temperature characteristic equation in advance. Specifically, medical professionals can perform ablation experiments (e.g., the ablation operation described in embodiments of
In the present embodiment, the temperature characteristic equation may be expressed by Equation (1) below.
(T1−T2)=K1*(tK
In Equation (1), T1 is the needle tip temperature of the magnetic induction area, T2 is the needle tail of the magnetic induction area, K1 is a nonlinear regression parameter value for the specific current value and the needle top depth, K2 is a time-varying parameter of a temperature index and t is a thermotherapy execution time. For instance, after going through the calculation with the nonlinear regression analysis, the nonlinear regression parameter value K1 may, for example, fall between 1 and 100 and the time-varying parameter value K2 may, for example, fall between 0.1 and 0.5, but the invention is not limited thereto. Ranges of the nonlinear regression parameter value K1 and the time-varying parameter value K2 may be correspondingly adjusted based on different needle specifications, different electromagnetic coil specifications or different biological tissue characteristics.
In other words, in addition to the estimation on the ablation range and the range of the temperature envelopes caused by ablating the biological tissue by the needle, the electromagnetic thermotherapy estimation system 100 of the present embodiment can also estimate the temperature variation on the needle heated by the electromagnetic coil. In this way, when medical professionals use the electromagnetic thermotherapy estimation system 100 to estimate the ablation operation, medical professionals can learn about the temperature variation curve through the display device 130. Accordingly, medical professionals can take into consideration of how to adjust the length the ablation time in the actual ablation operation so as to prevent excessive ablation or insufficient ablation from happening.
In addition, the ablation range data and the temperature envelope data obtained by using the electromagnetic thermotherapy estimation method of the present embodiment may be presented by the display device 130, but the invention is not limited thereto. In one embodiment, the electromagnetic thermotherapy estimation system 100 may also output the estimated data in each of the foregoing embodiments by other means, which are not particularly limited in the invention. In addition, sufficient teaching, suggestion, and implementation illustration regarding the electromagnetic thermotherapy estimation method of the present embodiment may be obtained from the foregoing embodiments depicted in
In summary, the electromagnetic thermotherapy estimation system and the electromagnetic thermotherapy estimation method according to the embodiments of the invention can be used to calculate the corresponding ablation range data and the temperature envelope data according to the ablation range estimation model and the temperature envelope estimation model created in advance in the database together with the inputted needle tip depth and the current magnitude. Further, the corresponding temperature variation data may also be calculated according to the temperature characteristic equation created in advance in the database and the inputted ablation time. In this way, the electromagnetic thermotherapy estimation system can display the ablation range, the temperature envelope and the temperature variation curve related to the ablated biological tissue according to the ablation range data, the temperature envelope data and the temperature variation data through the display device. As a result, the electromagnetic thermotherapy estimation system and the electromagnetic thermotherapy estimation method according to the embodiments of the invention can effectively provide accurate preoperative estimation information for medical professionals so as to effectively improve the ablation safety and the thermotherapy quality.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.
