JPS6315952A - Ultrasonic remedy apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an ultrasonic treatment device that can effectively prevent overheating of a vibrator for the ultrasonic treatment device when no load is applied.

"Prior Art" An ultrasonic treatment device excites an ultrasonic vibrator with an oscillation circuit, and performs treatment using the ultrasonic vibrations generated thereby. In this case, when the ultrasonic transducer is pressed against a living body or immersed in water, the ultrasonic transducer is in a loaded state, and in order to apply vibration to these loads, it is necessary to Requires a certain amount of power.

On the other hand, when the ultrasonic vibrator is left in space and vibrates freely, the ultrasonic vibrator is in an unloaded state. In this no-load state, if the power supply to the ultrasonic transducer is not suppressed, the ultrasonic transducer becomes supercharged and overheats, causing problems such as damage to the ultrasonic transducer and noise during operation.

Therefore, conventionally, when there is no load, the output level setting volume of the ultrasonic treatment device is reduced to suppress the output power.

In addition, we focused on the fact that when there is no load, the matching on the output side shifts and the output current value of the output stage circuit increases, and when this output current value exceeds a predetermined basic value, the output level is automatically lowered. An ultrasonic therapy device was also developed.

``Problem to be solved by the invention = li By the way, adjusting the output volume one by one when there is no load has the disadvantage of being cumbersome to operate.Also, even when using an ultrasonic transducer, there is no contact with the human body. Depending on the state, there may be a temporary no-load state, but it is impossible to manually adjust the output in response to such cases, so the power consumption due to temporary mismatching on the output side In addition to the occurrence of loss, there also occurred the problem that the life of the ultrasonic transducer would be shortened due to driving under such conditions.

On the other hand, conventional devices that automatically lower the output level are configured to lower the set level by comparing the current value of the output stage with a reference value, so once the set level is lowered, the There was a drawback that the setting level could not be restored, and unless a reset process or the like was performed, the set level would remain lower even if the load state resumed.

This invention was made in view of the above-mentioned circumstances, and it is possible to reliably detect the no-load state of the ultrasonic transducer and automatically lower the setting level. It is an object of the present invention to provide an ultrasonic therapy device that can raise the output level to an appropriate level again when the load state is restored.

"Means for Solving the Problems" In order to solve the above-mentioned problems, the present invention provides that the phase difference between the current supplied to an ultrasonic transducer and the voltage applied to the ultrasonic transducer is a reference value. When the above conditions occur, a no-load detection unit detects that the ultrasonic vibrator is in a no-load state, and a predetermined output of the ultrasonic treatment device is determined based on the output signal of this no-load detection unit when no load is detected. level switching means for lowering the level below the level.

``Operation'' When the ultrasonic vibrator becomes unloaded, the resonance state collapses and a phase difference occurs between voltage and current. When this phase difference exceeds a predetermined value, the no-load detector detects that there is no load, and the output level of the ultrasonic treatment device is switched to the low level side based on the detection signal of the no-load detector.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In this figure, 1 is a variable constant voltage power supply circuit, and when a "0" signal is supplied to the control terminal C,
Outputs enough voltage to drive the ultrasonic transducer under load, and when the "l" signal is supplied to control terminal C, outputs a voltage that does not overheat when the ultrasonic transducer is driven with no load. It is supposed to be done. Variable constant voltage power supply circuit! The output of is supplied to the collector of the output transistor 3 via the coil 2. The output transistor 3 has an oscillation circuit 4 at its base.
The output signal is supplied, and the emitter is grounded. Between the collector of the output transistor 3 and the ground, a matching coil 6, a matching capacitor 7,
An ultrasonic transducer 8 and a current detection resistor 9 are connected in series. Comparators 10 and 11 compare the voltages at one end and the other end of the ultrasonic transducer 8 with the ground potential. The output signal of this comparator 10.11 is supplied to the input terminal of the exclusive OR gate 12, and the output signal of the exclusive OR gate 12 is
Monostable multi-by-break I3 trigger terminal T
is supplied to Monostable multivi break 13
is configured to be retriggerable, and outputs an "I" signal with a predetermined pulse width each time it is triggered. In this case, the output pulse width of the monostable multi-by-break 13 is
It is set to be sufficiently longer than one cycle of the output signal of the oscillation circuit 4. And Monostable Multivi Break 1
The output signal No. 3 is supplied to the control terminal C of the variable constant voltage power supply circuit 1, so that while the monostable multi-by-break 13 is outputting the “1” signal, the variable constant voltage The output voltage of the power supply circuit 1 can be switched to a low level side.

Next, the operation of this embodiment with the above configuration will be explained.

FIGS. 3A and 3B show the output signals of the comparators 10 and 11 in each loaded state, and as shown, the phases of the two river force signals match.

In this case, the frequency of each signal is the same as the output signal of the oscillation circuit 4. And comparator 10. The reason why the output signals of II are in the same phase is as follows.

FIG. 2 is an equivalent circuit of the ultrasonic transducer 8. As shown, the ultrasonic transducer 8 has a resistance component R6 and an inductance component. , and a series circuit of the capacitor component co, and the capacitor component CI can be replaced with a circuit in which the capacitor component CI is connected in parallel. In this case, Ro, L. , Co, is in a resonant state, the impedance of this series resonant circuit is only the resistance component R0. In this state, if the capacitor component CI and the coil 6 and capacitor 7 shown in FIG. The phases of the detected signals match. The coil 6 and capacitor 7 are set to match the above conditions, and Ro, Lo, and Co
The resonant circuit is set to be in a resonant state under load.

In this way, when the load is 6, the signals obtained from both ends of the ultrasonic transducer 8 are for the same level, and as a result, the signals obtained from both ends of the ultrasonic transducer 8 are for the same level. The +1 output signals are in phase as shown in FIGS. 3(a) and 3(b). And comparator 10. I
When the output signals of I are in phase, the output signal of the exclusive knob OR gate 12, which is their exclusive OR, always becomes a "0" signal as shown in FIG. 3(c). As a result, the monostable multivibrator 13 is not triggered, and the output voltage of the variable constant voltage power supply circuit l becomes a voltage value sufficient for driving the ultrasonic transducer 8 with a load.

On the other hand, if the ultrasonic vibrator 8 vibrates freely in the air and is in poor contact with the human body, it will be in an unloaded state. Then, when the ultrasonic transducer 8 becomes (!II) deaf,
Since the above-mentioned resonance state collapses, the impedance of the ultrasonic transducer 8 includes a capacitance component or an inductance component, and as a result, the current flowing through the ultrasonic transducer 8 and the applied voltage are out of phase (generally phase is delayed). Therefore, in the no-load state, the output signal of comparator 10.1.1 is
Exclusive or gate 1 is now shown in b).
2 outputs a pulse train as shown in FIG. 4(c). In this case, the number of pulses output by the exclusive OR gate 12 is two per period of the output signal of the oscillation circuit 4, as shown in the figure. As a result, the monostable multi-by-break 13 is retriggered twice in each period of the output pulse of the oscillation circuit 4, and as a result,
The "l" signal continues to be output from the output terminal as shown in FIG. 4(d). When the l'' signal is output from the monostable multivib break 13, the output voltage of the variable constant voltage power supply circuit 1 is switched to the low level side, thereby preventing the ultrasonic transducer 8 in the no-load state from overheating. Prevented.

Furthermore, when the ultrasonic transducer 8 becomes loaded deaf again, the ultrasonic transducer 8 returns to the above-mentioned resonance state, so the comparator 10. The +1 output signal becomes as shown in FIGS. 3(a) and 3(b). As a result, the output signal of the monostable multi-by-break 13 falls to the "O" signal.
The output voltage of the variable constant voltage power supply circuit l is switched to the high level side. In other words, the voltage is switched to a voltage value sufficient for load driving.

As described above, in this embodiment, when there is a change from no load to a load, the output voltage of the variable constant voltage power supply circuit 1 is immediately automatically switched to the high level voltage for the load. In this case, since the load detection means A11 uses phase difference detection, reliable detection can be performed even when the output current value is small.

Note that instead of the load detection means shown in the above embodiment, the means described below may be used.

That is, the pulse signals obtained at points P,, Pl shown in FIG. so that the pulse signal is at the "0" level. As a result, when the load is applied, the point P,
What if the pulse of is delayed (,'5S [2C mouth)? ), point P
The level of the pulse at point P at the rising edge of the pulse becomes "1". In this way, point P.

No load is detected by looking at the value of the pulse at point P1 at the rising timing of the pulse. Further, any means other than the above may be used as long as the no-load detection is performed by comparing the phase difference between the pulses obtained at the points P1 and P.

In addition, in the above embodiment, if the display is based on the output signal of the monostable multivibrake I3, it is possible to recognize the no-load state and the loaded state while treating, so that the ultrasonic transducer and the human body can You can know whether the contact status is good or bad. Therefore, an advantage is obtained that ultrasonic treatment can be performed while maintaining a good contact state.

"Effects of the Invention" As explained above, according to the present invention, when the phase difference between the current supplied to the ultrasonic system lion and the voltage applied to the ultrasonic transducer exceeds the reference value, , a no-load detection section that detects that the ultrasonic transducer is in a loaded state of 5++, and based on the output signal of this no-load detection section, reduces the output of the ultrasonic treatment device to a predetermined level or less when no load is detected. Since the level switching means is included, the following effects can be achieved.

■When the no-load state occurs, the output level of the ultrasonic therapy device decreases, thereby preventing the ultrasonic transducer from overheating.

■Since no-load detection is performed electrically rather than by mechanical means, there are no moving parts and handling is easy.

■Level switching is performed automatically, and when a loaded state is reached, the level is automatically switched to the high level side, so there is no need to perform any level switching operations.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.
FIG. 2 is an equivalent circuit diagram of the ultrasonic transducer 8 shown in FIG. 1, and FIGS. 3 and 4 are waveform diagrams of various parts of the circuit for explaining the operation of the same embodiment. I... Variable constant voltage power supply circuit (level switching means), 1
0.11- Comparator, 12...Exclusive or gate, 13...Monostable multi-by-break (The above 10 to 13 are no-load detection parts.)

Claims (1)

[Claims] No-load detection that detects that the ultrasonic transducer is in a no-load state when the phase difference between the current supplied to the ultrasonic transducer and the voltage applied to the ultrasonic transducer exceeds a reference value. 1. An ultrasonic treatment device comprising: a unit and a level switching unit that reduces the output of the ultrasonic treatment device to a predetermined level or less when no load is detected based on the output signal of the no-load detection unit.