CN109276811A - The setting device and setting method in zero magnetic field point position - Google Patents
The setting device and setting method in zero magnetic field point position Download PDFInfo
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- CN109276811A CN109276811A CN201811170387.XA CN201811170387A CN109276811A CN 109276811 A CN109276811 A CN 109276811A CN 201811170387 A CN201811170387 A CN 201811170387A CN 109276811 A CN109276811 A CN 109276811A
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
- A61N2/00—Magnetotherapy
- A61N2/02—Magnetotherapy using magnetic fields produced by coils, including single turn loops or electromagnets
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
- A61N2/00—Magnetotherapy
- A61N2/004—Magnetotherapy specially adapted for a specific therapy
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06N—COMPUTING ARRANGEMENTS BASED ON SPECIFIC COMPUTATIONAL MODELS
- G06N3/00—Computing arrangements based on biological models
- G06N3/004—Artificial life, i.e. computing arrangements simulating life
- G06N3/006—Artificial life, i.e. computing arrangements simulating life based on simulated virtual individual or collective life forms, e.g. social simulations or particle swarm optimisation [PSO]
Abstract
The present invention provides the setting devices and setting method of a kind of zero magnetic field point position, wherein, the setting device in zero magnetic field point position includes: 6 groups of coil blocks, coil block described in 6 groups surrounds a center circle, coil block described in every group includes 3 coils, the center of circle of each coil is uniformly distributed in the center circle according to every 120 degree, the center circle is marked off 18 regions clockwise by clock and watch to the line between the center of circle of each coil by the center of circle of the center circle, wherein, corresponding current value is loaded in each coil, current value in each coil is determined according to location information of the tumour in the setting device, to control the magnetic field strength of tumour position as zero or near zero.According to the technical solution of the present invention, rationally, can accurately control in device magnetic field at tumour present position is zero or near zero to whole device construction, it is ensured that other organs and cell of non-focal area, with higher practical and researching value.
Description
Technical field
The present invention relates to technical field of medical equipment, a kind of setting device in particular to zero magnetic field point position and
A kind of setting method of zero magnetic field point position.
Background technique
Tumor thermotherapy is using cancer cell compared with the heat labile physiological phenomenon of normal cell, and kill tumour is thin after tissue is heated
Born of the same parents are a kind of thermotherapy methods for being referred to as Microwave, are " green remedies " after operation, radiation and chemotherapy.Currently, hot
Microwave radiation, radio-frequency radiation, focusing ultrasonic wave, resistance heating, alternating magnetic field can be divided into according to heating method by, which treating, heats magnetic grain
The methods of son.
It is a kind of thermotherapy mode emerging in recent years that alternating magnetic field, which heats magnetic particle, and magnetic particle material is injected lesion group
It knits, applies alternating magnetic field in outside, since the presence of magnetic hystersis loss makes magnetic material generate heat.During thermotherapy, by
In the mobility of magnetic particle, it will be inevitably diffused into normal tissue, therefore normal tissue also will receive heating or even be damaged
Wound.In order to protect normal tissue, while normal organ around static magnetic field protection focal area and thin is established on tumour periphery
Born of the same parents.It is required that the magnetostatic field of tumour region is zero as far as possible, the magnetic nano-particle for ensuring to inject in this way utilizes carrier
Drug directly reaches tumor region, and other organs and cell of non-focal area are protected by static magnetic field, therefore, how
So that specific tumor location magnetic field is close to zero as technical problem urgently to be resolved in constructed thermotherapeutic apparatus.
Summary of the invention
The present invention is based at least one above-mentioned technical problem, proposes a kind of setting side of zero new magnetic field point position
Case, rationally, can accurately control in device magnetic field at tumour present position is zero or near zero to whole device construction, effectively really
Other organs and cell of non-focal area, with higher practical and researching value are protected.
In view of this, proposing a kind of setting device of zero magnetic field point position according to the present invention, comprising: 6 groups of coil blocks,
Coil block described in 6 groups surrounds a center circle, and coil block described in every group includes 3 coils, and the center of circle of each coil is pressed
It is uniformly distributed in the center circle according to every 120 degree, the center of circle of the center circle to the company between the center of circle of each coil
The center circle is marked off 18 regions clockwise by clock and watch by line, wherein is loaded in each coil corresponding
Current value, the current value in each coil is determined according to location information of the tumour in the setting device, swollen to control
The magnetic field strength of tumor position is zero or near zero.
In the technical scheme, the center of circle for all coils being arranged in device is on same plane, on this plane,
Magnetic field strength can cancel out each other in its vertical direction, and for subsequent process when knub position is located in the plane, calculation amount will
It greatly reduces, the current value determined according to location information of the tumour in setting device is in addition loaded in each coil, entirely
It is zero or near zero that device, which is arranged, to can control the magnetic field strength of tumour position, effectively ensures other of non-focal area
Organ and cell, and whole device construction is rationally, with higher practical and researching value.
In the above-mentioned technical solutions, it is preferable that the diameter of each coil is 80mm, and the center diameter of a circle is
800mm。
In the technical scheme, by the diameter of coil be set as 80mm and set 800mm for center diameter of a circle can
The universality for increasing entire setting device, meets the actual needs.
According to the second aspect of the invention, a kind of setting method of zero magnetic field point position is proposed, above-mentioned technical side is based on
The method of the setting device of zero magnetic field point position described in case, comprising: obtain position of the tumour in the setting device and believe
Breath；The location information that will acquire is brought into default solving model, and carries out solution analysis based on improved bat algorithm,
To obtain 18 current values；18 obtained current values will be solved to be loaded into respectively in the setting device in corresponding coil,
To control the magnetic field strength of tumour position as zero or near zero.
In the technical scheme, modeling processing and bat algorithm are carried out by the location information to tumour to solve to 18
A current value can effectively reduce the error in calculating process and improve computational efficiency, it is ensured that the accuracy of calculated result,
After the accurate current value acquired is loaded into respectively in corresponding electric current circle, it can be ensured that the magnetic field strength of tumour position
For zero or near zero.
In the above-mentioned technical solutions, it is preferable that the default solving model is using the geometry based on the setting device
The mathematical model of shape building.
In any of the above-described technical solution, it is preferable that the improved bat algorithm are as follows:
Wherein,It is spatial position of the bat individual i in the t+1 times search；x*It is current global optimum position；
Levy (λ) is the random perturbation vector that step size mu obeys Levy distribution, and λ=3/2 is scale parameter；Indicate vector calculus；Tmax
It is maximum number of iterations, t is current the number of iterations.
In the technical scheme, Levy disturbance quantity is gradually reduced while the number of iterations increases, uses Levy perturbation strategy
Multiple microvariations and large disturbances once in a while in the location updating of bat, will increase the diversity of population, expand searching for bat individual
Rope space promotes bat algorithm in the optimizing ability of higher dimensional space, bat individual is avoided to fall into local optimum.
By above technical scheme, whole device construction rationally, can be accurately controlled in device at tumour present position
Magnetic field is zero or near zero, effectively ensures other organs and cell of non-focal area, with higher practical and research valence
Value.
Detailed description of the invention
Fig. 1 shows the three dimensional structure diagram of the setting device of zero magnetic field point position of embodiment according to the present invention；
Fig. 2 shows the top views of the setting device of zero magnetic field point position of embodiment according to the present invention；
Fig. 3 shows the flow diagram of the setting method of zero magnetic field point position of embodiment according to the present invention；
Fig. 4 shows the flow diagram of the improved bat algorithm of embodiment according to the present invention；
The knub position that Fig. 5 A shows embodiment according to the present invention is located at the simulated effect figure of (0,0,0)；
The knub position that Fig. 5 B shows embodiment according to the present invention is located at the simulated effect figure of (0,100,0)；
The knub position that Fig. 5 C shows embodiment according to the present invention is located at the simulated effect figure of (200,100,0).
Specific embodiment
To better understand the objects, features and advantages of the present invention, being not conflict below with reference to attached
In the case where, the feature in embodiments herein and embodiment can be combined with each other.
Below in conjunction with Fig. 1 to Fig. 5 C, technical scheme is described further:
As shown in Figure 1, the setting device of zero magnetic field point position includes: that 6 groups of coil blocks and 6 groups of coil blocks surround one
Center circle, wherein every group of coil block includes 3 coils, as shown in Fig. 2, the center of circle of each coil is uniformly divided according to every 120 degree
It is distributed in center circle, center circle is clockwise drawn by clock and watch to the line between the center of circle of each coil in the center of circle of center circle
18 regions are separated, in the case where not being grouped, the angle between every two adjacent windings is 20 degree, in order to increase entire setting
It the universality of device and meets the actual needs, the diameter of each coil can be set to 80mm, center diameter of a circle is set
It is set to 800mm, in addition, being loaded with corresponding current value in each coil, the current value in each coil is being arranged according to tumour
Location information in device determines, to control the magnetic field strength of tumour position as zero or near zero.
Specifically, the magnetic field strength for controlling tumour position is the method for zero or near zero, it is specific as shown in figure 3,
The following steps are included:
Step 302, location information of the tumour in the setting device is obtained.
Specifically, thermotherapy object is placed in the circle that 18 coils surround in device (i.e. in center circle), is establishing such as Fig. 2
Shown under coordinate system, obtain the location information of tumour.
Step 304, the location information that will acquire is brought into default solving model, and is carried out based on improved bat algorithm
Analysis is solved, to obtain 18 current values.
In the predetermined solving model (mathematical modulo that predetermined solving model constructs for the geometry based on setting device of foundation
Type) in, it is approximately circular electric current by coil.It can be obtained according to Biot-Savart law using the center of circle of circular electric current as origin, center
Axis is under the rectangular coordinate system that z-axis is established, and circular electric current is respectively as follows: in the magnetic-field component expression formula that spatial point excites
Wherein, μ0For space permeability, R is coil radius, and I is coil current.By mathematical software, Simpson's product is utilized
Point-score is calculated, and can obtain circular electric current magnetic field in the distribution of the magnetic induction intensity of entire three-dimensional space.When tumour is located at XY
Plane, it is zero that the magnetic induction intensity of Z axis, which is cancelled out each other,.According to formula above, each coil can be calculated and produced in specific tumor location
Raw magnetic field strength, by vector addition, the mould of the magnetic field strength of available specific tumor location.Wherein, vector addition formula
It is as follows:
Wherein, BXiFor the magnetic induction intensity that coil i is generated in specific tumor location X-direction, BYiIt is coil i in tumour
The magnetic induction intensity generated in Y direction at position, BZiThe magnetic induction generated in specific tumor location Z-direction for coil i is strong
Degree, B be specific tumor location magnetic induction intensity, for reach the magnetic field strength of specific tumor location be zero close to zero requirement, then want
The mould for seeking B is zero or near zero.
It is specifically as shown in Figure 4 that solution analytic process is carried out based on improved bat algorithm (wLevyOLBA), comprising:
Before algorithm starts iteration, backward learning first is carried out by following formula to every bat, acquisition one is more outstanding
Initial population.
x’i=xmax+xmin-xi
In formula: xmaxAnd xminIt is location information when fitness function obtains maximum and minimum value, x respectivelyiFor current grain
The location information of son, xi' it is its reversed location information.
The update of position is carried out by following formula in iterative process, and bat is made to realize that Levy is disturbed in location updating.
Wherein,It is spatial position of the bat individual i in the t+1 times search；x*It is current global optimum position；
Levy (λ) is the random perturbation vector that step size mu obeys Levy distribution, and λ=3/2 is scale parameter；Indicate vector calculus；Tmax
It is maximum number of iterations, t is current the number of iterations, and the number of iterations gradually reduces Levy disturbance quantity while increase, is used
Levy perturbation strategy multiple microvariations and large disturbances once in a while in the location updating of bat, will increase the diversity of population, expand
The search space of bat individual promotes bat algorithm in the optimizing ability of higher dimensional space, bat individual is avoided to fall into local optimum.
Wherein, Levy process is a kind of Markov process, and functional value meets heavy-tailed (Heavy-tailed) distribution, function
Formula and the calculation formula difference of the probability of occurrence P (μ) of value μ is as follows:
U=rand (n, 1) × σ
V=rand (n, 1)
Wherein n is the dimension of solution, and gamma function isα is step factor.
Step 306,18 obtained current values will be solved to be loaded into respectively in the setting device in corresponding coil, with
The magnetic field strength for controlling tumour position is zero or near zero.
Specifically, 18, periphery coil current is calculated according to algorithm, current value input coil goes to determine tumor region
Range, make the magnetostatic field of tumour region is zero as far as possible.
In above-described embodiment, the center of circle for all coils being arranged in device is on same plane, on this plane,
Magnetic field strength can cancel out each other in vertical direction, and for subsequent process when knub position is located in the plane, calculation amount will be big
It is big to reduce, it carries out modeling processing and bat algorithm additionally by the location information to tumour to solve to 18 current values, it can
The error in calculating process is effectively reduced and improves computational efficiency, it is ensured that the accuracy of calculated result, in the essence that will be acquired
After true current value is loaded into respectively in corresponding electric current circle, so that the magnetic field strength of tumour position is zero or approaches
Zero, effectively ensure other organs and cell of non-focal area, and whole device construction is rationally, it is with higher practical and grind
Study carefully value.
Emulation experiment is additionally carried out by comsol simulation software.Specifically, it is assumed that tumor center location is flat positioned at XY
Face, respectively (0,0,0), (0,100,0), (200,200,0).Wherein, the number of turns of coil takes 1000 circles, and wLevyOLBA is calculated
Method carries out solution calculating to predetermined solving model according to knub position, and it is soft that 18 current values of solution are updated to comsol emulation
In the simulation model of part, required current value is as shown in Table 1 to Table 3, wherein table 1 is 18 lines at knub position (0,0,0)
The electric current of circle；Table 2 is the electric current of 18 coils at knub position (0,100,0)；18 at 3 knub position of table (200,200,0)
The electric current of coil:
Table 1
Table 2
Table 3
18 current values that table 1 is solved into table 3 are updated to respectively in the simulation model of comsol simulation software, are obtained
Such as Fig. 5 A, such as Fig. 5 B and as shown in Figure 5 C prevent that true effect picture, Fig. 5 A are that tumor center is located at the simulated effect at (0,0,0)
Figure, Fig. 5 B are that tumor center is located at the simulated effect figure at (0,100,0), and Fig. 5 C is that tumor center is located at (200,200,0)
Simulated effect figure, from simulated effect figure, knub position region is compared to peripheral region, magnetic field strength very little, in tumour
Zero magnetic field or the region close to zero magnetic field are formd at place-centric, tumour is heated in specific tumor location, around tumour
Tissue is protected, to demonstrate the validity that device and setting method are arranged in above-described embodiment.
The technical scheme of the present invention has been explained in detail above with reference to the attached drawings, and technical solution of the present invention proposes a kind of new
The plan of establishment in zero magnetic field point position, whole device construction rationally, can accurately control in device magnetic at tumour present position
Field is zero or near zero, effectively ensures other organs and cell of non-focal area, with higher practical and researching value.
The foregoing is only a preferred embodiment of the present invention, is not intended to restrict the invention, for the skill of this field
For art personnel, the invention may be variously modified and varied.All within the spirits and principles of the present invention, made any to repair
Change, equivalent replacement, improvement etc., should all be included in the protection scope of the present invention.
Claims (5)
1. a kind of setting device of zero magnetic field point position characterized by comprising
6 groups of coil blocks, coil block described in 6 groups surround a center circle, and coil block described in every group includes 3 coils, each
The center of circle of the coil is uniformly distributed in the center circle according to every 120 degree, the center of circle of the center circle to each line
The center circle is marked off 18 regions clockwise by clock and watch by the line between the center of circle of circle, wherein each line
Corresponding current value is loaded in circle, the current value in each coil is believed according to position of the tumour in the setting device
Breath determines, to control the magnetic field strength of tumour position as zero or near zero.
2. the setting device of zero magnetic field point according to claim 1 position, which is characterized in that the diameter of each coil
For 80mm, the center diameter of a circle is 800mm.
3. a kind of setting method of zero magnetic field point position, the setting device based on zero magnetic field point of any of claims 1 or 2 position
Method characterized by comprising
Obtain location information of the tumour in the setting device；
The location information that will acquire is brought into default solving model, and solve based on improved bat algorithm and be divided
Analysis, to obtain 18 current values；
18 obtained current values will be solved to be loaded into respectively in the setting device in corresponding coil, to control tumour place
Magnetic field strength at position is zero or near zero.
4. the setting method of zero magnetic field point according to claim 3 position, which is characterized in that the default solving model is
Using the mathematical model of the geometry building based on the setting device.
5. the setting method of zero magnetic field point according to claim 3 or 4 position, which is characterized in that the improved bat
Algorithm are as follows:
Wherein,It is spatial position of the bat individual i in the t+1 times search；x*It is current global optimum position；Levy(λ)
It is the random perturbation vector that step size mu obeys Levy distribution, λ=3/2 is scale parameter；Indicate vector calculus；TmaxIt is that maximum changes
Generation number, t are current the number of iterations.
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