GB2126098A
Expired / Lapsed
GB
⏱️ 0.0 years remaining
Diathermy apparatus
Assignee: METRONEX ENGINEERING Pty Ltd
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Filing: 1983-07-21
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Granted: —
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Expires: 2003-07-21
Abstract
Abstract A diathermy apparatus for generating and supplying high frequency A.C. current for tissue heating, the tissue forming at least part of the load, the apparatus including power supply means 2 for generating power at high frequency, maximum power transfer means having tuning means 6 for providing an impedance match between the load and the power supply means and means for detecting the magnitude of the power transferred from the supply means to the load, the detecting means including directional coupling means 7 and indicating means 17, 18, 19, 20 for indicating substantially the magnitude of the power transferred to the load, the tuning means 6 being adjustable so that the impedance of the load the supply means may be matched to maximise the magnitude of the indication of the indicating means 17, 18, 19, 20 and thus to transfer maximum available power to the load. <IMAGE>
Inventors
- 👤 John Andrew Whittingham
Bibliographic Details
Application Number
—
Jurisdiction
GB
Data Source
google_patents
Last Synchronized
2026-10-23 00:59
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/40; A61N1/403
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
139 words
Diathermy apparatus for generating and supplying high frequency A.C. current to a patient for tissue heating, the tissue forming at least part of the load for the apparatus, the apparatus including power supply means for generating power at a high frequency, maximum power transfer means having tuning means for providing an impedance match between the load and the supply means and means for detecting the magnitude of the power transferred from the supply means to the load, the detecting means including directional coupling means and indicating means for indicating substantially the magnitude of the power transferred to the load, the tuning means being adjustable so that the impedance of the load and the supply means may be matched to maximise the magnitude of the indication of the indicating means and thus to transfer maximum available power to the load.
Claim 2
Dependent Claim
139 words
Diathermy apparatus for generating and supplying high frequency A.C. current to a patient for tissue heating, the tissue forming at least part of the load for the apparatus, the apparatus including power supply means for generating power at a high frequency, maximum power transfer means having tuning means for providing an impedance match between the load and the supply means and means for detecting the magnitude of the power transferred from the supply means to the load, the detecting means including directional coupling means and indicating means for indicating substantially the magnitude of the power transferred to the load, the tuning means being adjustable so that the impedance of the load and the supply means may be matched to maximise the magnitude of the indication of the indicating means and thus to transfer maximum available power to the load.
Claim 3
Dependent Claim
38 words
Diathermy apparatus as claimed in claim 1, wherein the output impedance of the power supply means is substantially constant and is relatively low and the impedance of the load may be higher than the power supply means impedance.
Claim 4
Dependent Claim
36 words
Diathermy apparatus as claimed in claim 1 or claim 2, wherein the output power level of the power supply means is adjustable so that the magnitude of the available power applied to the load is variable.
Claim 5
Dependent Claim
63 words
Diathermy apparatus as claimed in claim 3, wherein the power supply means includes an oscillator, a preamplifier having at least one stage responsive to a control voltage to vary the power gain of the preamplifier, the power supply means also including a power amplifier, the control voltage being variable to enable the control of the
magnitude of the power applied to the patient.
Claim 6
Dependent Claim
71 words
Diathermy apparatus as claimed in any of claims 1 to 4, wherein the directional coupling means is operative to provide a forward voltage proportional to the power output of the power supply means and to provide a reflected voltage proportional to the power reflected from the tuning means, the magnitude of the power transferred to the load through the tuning means being the difference between the forward and the reflected power.
Claim 7
Dependent Claim
83 words
Diathermy apparatus as claimed in claim 5 and further including means for generating an output signal proportional to the difference of the squares of the forward voltage and the reflected voltage, the output signal being supplied to an output meter of the indicating means for visually indicating the power transferred to the load through the tuning means whereby the tuning means may be adjusted until the indicating means indicates a maximum at which point maximum available power may be transferred to the load.
Claim 8
Dependent Claim
72 words
Diathermy apparatus as claimed in claim 5 or claim 6, wherein the maximum power transfer means includes an automatic tuning circuit coupled to receive a mismatch signal proportional to the ratio of the forward voltage and the reflected voltage or the reflected voltage to the forward voltage and to adjust the tuning means in response to the mismatch signal so as to reduce the degree of impedance mismatch and maximise power transfer.
Claim 9
Dependent Claim
53 words
Diathermy apparatus as claimed in claim 7 and further including power limiting means coupled to receive the mismatch signal and operatively associated with the power supply means, the power limiting means being operative in response to the mismatch signal reaching a predetermined level to limit the power output of the power supply means.
Claim 10
Dependent Claim
32 words
Diathermy apparatus as claimed in claim 7 or claim 8, wherein the automatic tuning circuit includes a ratio amplifier for providing the mismatch signal from the outputs of the directional coupling means.
Claim 11
Dependent Claim
26 words
Diathermy apparatus as claimed in claim 9, wherein the tuning circuit further includes a derivative amplifier for obtaining the rate of change of the mismatch signal.
Claim 12
Dependent Claim
34 words
Diathermy apparatus as claimed in claim
1 0, wherein the tuning circuit further includes a null detector coupled to the derivative for detecting zero rate of change in the derivative of the mismatch signal.
Claim 13
Dependent Claim
40 words
Diathermy apparatus as claimed in claim
1 1, wherein the tuning circuit further includes servo motor logic and control means coupled to the null detector and at least one servo motor, the control means being adapted to receive the
mismatch.
Claim 14
Dependent Claim
35 words
Diathermy apparatus as claimed in any one of claims 1 to 11 including timing means for
controlling the period of operation of the power supply means for providing a treating cycle of pre
determined duration.
Claim 15
Dependent Claim
55 words
Diathermy apparatus as claimed in any one
of claims 1 to 13 including pulse control means
coupled to the power supply means for controlling
the power supply means for pulsing the power output of the supply means to provide power output the mark space ratio ot which may be varied by the pulse control means.
Claim 16
Dependent Claim
13 words
Diathermy apparatus substantially as hereinbefore described with particular reference to the accompanying drawing.
Claim 17
Dependent Claim
13 words
Diathermy apparatus substantially as hereinbefore described with particular reference to the accompanying drawing.
References Cited (Backward Citations)
GB743884A
Cited
GB1156893A
Cited
GB1159279A
Cited
GB1201586A
Cited
GB1602354A
Cited
EP0047354A1
Cited
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