JP3425640B2 - Heat treatment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermotherapy device.
In particular, impedance matching is automatically controlled.
The present invention relates to a high-frequency thermotherapy device to be performed. [0002] 2. Description of the Related Art A high-frequency thermotherapy device is suitable for affected areas such as neuralgia.
A pair of conductors is sandwiched, and the frequency between the pair of conductors is several MHz to
A high-frequency electromagnetic wave of several tens of MHz is generated to heat the affected area.
Heat treatment. Using such high-frequency electromagnetic waves
To perform treatment efficiently, the output of a high-frequency
Match the impedance to the impedance of the load
Need to be done. Therefore, the high frequency generator body and the conductor
A matching circuit is interposed therebetween, and further flows through the matching circuit.
Control unit that performs matching control by detecting load current
Are provided. The control unit outputs the matching circuit.
While increasing or decreasing the force impedance,
If the load current increases in accordance with the
Increase or decrease as it is,
Output impedance if the load current decreases accordingly
Is reversed. Thus, the load current always increases.
Since the load current is controlled to increase, the load current reaches the maximum point.
Becomes stable when it reaches. Also, the patient changes posture.
Load impedance of the affected area
When the load changes, the load current also deviates from the maximum point and decreases.
However, in such a case, the control operation as described above is performed again.
And return to the maximum point. Thus, the load current
High-frequency thermal treatment device by always being held at the maximum point
Is automatically controlled. [0003] SUMMARY OF THE INVENTION
If there is only one maximum point for the load current,
Output impedance can be increased or decreased in the direction of load current increase.
If the maximum point finally reached is the matching point (maximum
Point), ensure that impedance matching is performed
Can be. However, there may be more than one maximum point.
You. In such a case, the load current is adjusted among the plurality of maximum points.
Undulating hillside with a peak not at the junction (maximum point)
If it was located in the part, the conventional high-frequency heat treatment device
Is controlled to reach a maximum point that is not the matching point (maximum point).
Will be done. Therefore, impedance matching
Cannot be executed reliably. Therefore, the load on the output impedance
Even if there are multiple current maxima,
Force impedance is located at the matching point (maximum point) of the load current
To determine the accuracy of impedance matching
There are technical issues that need to be resolved to improve
Therefore, the present invention aims to solve the problem.
You. [0005] The present invention solves the above-mentioned problems.
The load current of the matching circuit.
And the output impedance of the matching circuit
Is increased or decreased in the load current increasing direction, and the load current reaches the maximum point.
(Impedance matching point)Control to be kept in
In a thermotherapy device provided with control means, the control meansPrevious
Over the entire variable range of the impedance of the matching circuit
OverThe output impedanceIntermittent at minute time intervals
To detect the maximum point of the load current, andThe maximum point
ButMaximum point of load current before scanning(Impedance adjustment
Meeting point)If different from the output impedance,
The maximum point of(Impedance matching point) as much as possible
To be able to be transferred to a new position
A hyperthermia treatment device is provided. [0006] The control means of the high-frequency thermotherapy device according to the present invention
Increases or decreases the output impedance in the direction of increasing load current.
Control to keep the load current at the maximum point.
In addition,Very smallEvery time intervalIntermittentlyOutput impedance
Scan the load to detect the matching point (maximum point) of the load current.
You. If there is only one maximum point of the load current, the matching point
(Maximum point) is the maximum point that was the target of control before the scan
Is inevitably equal to the maximum point, that is,
If control is continued so that the load current is maintained at the matching point,
good. On the other hand, there are a plurality of maximum points of the load current.
If there is, the matching point (maximum point) is not always
However, it is not always the maximum point that was the target of control. Both
If there is only one, there is only one maximum point
In the same way as before,
The maximum point can be maintained at the matching point (the maximum point).
If it is different from the main point, the control
Can't match the speed. Thus, it takes
The maximum point targeted before scanning is different from the matching point (maximum point).
The control means sets the output impedance to
Transfer to the undulating part with the matching point (maximum point) at the top,
After that, the output impedance becomes
Normal control is performed so as to increase or decrease in the flow increasing direction. Thus
Output even if there are multiple
Ensure that the impedance is at the matching point (maximum point) of the load current
It will be controlled to be positioned. [0008] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will now be described with reference to FIGS.
Will be described in detail. FIG. 1 shows a configuration diagram of a high-frequency thermotherapy device 1.
The high frequency generator 2 includes a high frequency oscillation circuit, a resonance circuit,
And a high-frequency generator.
The output of unit 2 is output through balun 3 and matching circuit 4
Are transmitted to the connectors 5 and 5. Output connectors 5 and 5
The plastic conductors 6, 6 each covered with a copper mesh covered with an insulating cloth,
It has been extended. When the guides 6, 6 are pinched to the affected part of the human body
If frequency, several MH_Z~ Several tens of MH_ZHigh frequency band electromagnetic waves
Dielectric heating of the affected area generated between the two conductors 6, 6
And heal by healing. Thus, the output input of the high-frequency thermotherapy device 1
Peedance Z_OAnd the patient pinched by the conductors 6,6
Load impedance Z_LBefore to do the matching
The matching circuit 4 has a variable capacitor with a built-in rotating movable electrode.
The variable capacitor 7 is automatically controlled.
A control unit 8 for controlling the operation is extended. The control unit 8 first
Load current flowing through the matching circuit 4 by the current detector 9
I is detected. The load current I is rectified by the rectifier 10.
And smoothed by the capacitor 11. Soshi
Further, after the value is adjusted by the variable resistor 12, A /
Digitally converted via the D converter 13
The data is input to the CPU 14 which is the main body of the unit 8. Such load
The detection of the current I is performed intermittently at minute time intervals. The CPU 14 intermittently operates
Once the detected load current I is stored in the memory 15,
In both cases, the motor 17 is controlled via the motor rotation control circuit 16.
Activates the movable electrode of the variable capacitor 7 in a certain direction.
By rotating the output impedance Z_OTo
Increase or decrease. As a result, the load current I
If it is increasing occasionally, the variable capacitor
7 is rotated in the same direction, and the
If the flow I decreases over time, the variable
The rotating direction of the movable electrode of the capacitor 7 is reversed and the load current I
Is operated to increase. [0011] Further, the CPU 14 sets the above-mentioned
By operating the motor rotation control circuit 16 and the motor 17,
The movable electrode of the variable capacitor 7 makes one turn (360 °)
Output impedance of the matching circuit 4
Z_OOutput impedance over the entire variable range of
SUZ_OAnd outputs each output impedance to the memory 15.
SUZ_OIs recorded. FIGS. 2 and 3 show the output recorded during the scanning.
Impedance Z_OOf load current I for
It is. As shown in FIG. 2, the maximum point P of the load current I₀
If there is only one, the maximum point P₀≡ alignment
Point P_mTherefore, the load current I
Force impedance Z_OIf you increase or decrease
Can be combined. That is, the output impedance Z_O
Is the maximum point P₀A of the left rising part of the undulation with the peak
, The output impedance Z_OIncrease
Output impedance Z_OIs the right fall of the undulation
When the output impedance is located at the value B,
Z_OIs controlled by the control unit 8 so as to reduce
And finally the output impedance Z_OIs the maximum point P₀
≡ Matching point P_mIt is positioned at. On the other hand, as shown in FIG.
When there are two or more maximum points of the load current I,
Is the largest of those maximal points (point
P₁) Is the matching point P_mAnd other maximum points (in the figure,
Point P_TwoLarge power loss even if positioned at)
No effect. That is, the output impedance
Z_OIs the other maximum point P_TwoTo the left of the undulation
It is located at the value C of the rising part and the value D of the right falling part.
The output impedance simply increases in the direction of load current I
Dance Z_OBy simply performing control to increase or decrease
Output impedance Z _OIs the other maximum point P_TwoCollected in
It is necessary to make accurate impedance matching
And cannot be done. Thus, the output impedance Z_OIs
If located at point C or D,
On the floor, the control unit 8 controls the output impedance Z._O
To the other maximum point P_TwoControl to reach
ing. However, the distribution of the load current I is changed by scanning.
Knowing that, the current maximum point P_TwoIs in order
Joint point P_mIt turns out that it is not. Ma
At the same time, the matching point P_m≡P₁(The load current I is the maximum value I
_maxOutput impedance Z when_OmKnow the value of
Can be. Based on the result, the CPU 14 sets the mode.
Operating the motor rotation control circuit 16 and the motor 17
By rotating the movable electrode of the variable capacitor 7, the output impedance is
Dance Z_OFrom the point C or D before scanning to the matching point P_m
≡P₁To point E or F, which is as equal to
is there. Thus, the output impedance Z_OIs the matching point P _m
Into the undulating area where the top is
Output impedance Z in the direction of increasing load current I_OIncrease
If it is reduced, accurate impedance matching can be performed
Will be. Further, the patient performs an operation such as changing the posture.
And the load impedance Z of the affected part_LFluctuates
And the output impedance Z shown in FIG. 2 or FIG._O
Of the load current I with respect to
Or deform. Therefore, impedance matching before operation
Is out of alignment due to patient movement
Will be. In such a case, return to the matching state again.
Then, the control unit 8 operates. For example, FIG.
Before patient movement, as shown by the dashed line
Point P_mOutput impedance Z located at_O= Z_OmBut
The other maximum point P depending on the patient's operation_TwoHas moved
Point P_ThreeSo that it is located at point G on the undulating part with
In the normal control, the output impedance Z
_OIs a point P that is not a matching point_ThreeWill be positioned at
You. However, the aforementioned output impedance Z_OScanning is 1
Performed every minute, so it is performed immediately after the patient's movement
Output impedance Z based on the result of scanning_OIs new
Matching point P_FourIt will be transferred to the vicinity. Thus,
The load impedance Z depends on the operation of the patient._LFluctuates
Can always perform accurate impedance matching
Will be. In this embodiment, the variable co
Impedance by changing the rotation angle of the capacitor 7
Alignment is performed, but as shown in FIG.
Are connected to switches 19, 19, such as relays.
Perform impedance matching by switching with…
May be. The present invention does not depart from the spirit of the present invention.
Various modifications can be made as long as the present invention
It goes without saying that it extends to modified ones. [0018] The present invention has been described in detail in the above embodiment.
AndVery smallEvery time intervalIntermittentlyOutput impedance
By scanning, the local maximum point before scanning becomes the matching point (maximum point).
If not, set the output impedance near the matching point.
It is configured to transfer to the side. Therefore, the maximum point
Even if there are multiple
Impedance is positioned at the matching point and impedance matching
Accuracy is improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram showing one embodiment of the present invention. FIG. 2 is a graph illustrating the relationship between output impedance and load current when there is one undulation. FIG. 3 is a graph illustrating the relationship between output impedance and load current when there are two undulations. FIG. 4 is a circuit diagram showing another embodiment of the matching method. [EXPLANATION OF SYMBOLS] 1 RF thermotherapy treatment device 2 high-frequency generator 4 matching circuit 6 Shirubeko 7 variable capacitor 8 controller 9 current detector 14 CPU 15 memory 16 motor control circuit 17 motor Z _O output impedance Z _L load impedance I load current P _m matching point _{P 0, P 1, P 2} , P 3, P 4 maximum point

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-17081 (JP, A) JP-A-63-34445 (JP, A) JP-A-3-7171 (JP, A) JP-A 62-17081 236564 (JP, A) JP-A-61-20563 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61N 1/40 A61N 5/04

Claims (1)

(57) [Claim 1] A load current of a matching circuit is detected, and an output impedance of the matching circuit is increased or decreased in a load current increasing direction, so that the load current reaches a maximum point (impedance adjustment).
In thermotherapy treatment device having a control means for controlling so as to maintain the consent), the control means of impedance of said matching circuit Yes
The output impedance is kept for a very short time
Scans intermittently at intervals to detect the maximum point of the load current,
In addition, the maximum point is the maximum point (a) of the load current before scanning.
If different from the impedance matching point), the maximum point before scanning the output impedance (impedance matching point)
So that it can be moved to the same position as
A thermotherapy device characterized by being constituted .