US2698622A - Phase sensitive control for shortwave therapy devices - Google Patents

Phase sensitive control for shortwave therapy devices Download PDF

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Publication number
US2698622A
US2698622A US261036A US26103651A US2698622A US 2698622 A US2698622 A US 2698622A US 261036 A US261036 A US 261036A US 26103651 A US26103651 A US 26103651A US 2698622 A US2698622 A US 2698622A
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US
United States
Prior art keywords
voltage
phase
circuit
generator
resonator
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Expired - Lifetime
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US261036A
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English (en)
Inventor
Martens Gunter
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Hartford National Bank and Trust Co
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Hartford National Bank and Trust Co
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/46—Dielectric heating
    • H05B6/48—Circuits
    • H05B6/50—Circuits for monitoring or control
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/40—Applying electric fields by inductive or capacitive coupling ; Applying radio-frequency signals
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03L—AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES
    • H03L5/00—Automatic control of voltage, current, or power
    • H03L5/02—Automatic control of voltage, current, or power of power

Definitions

  • the impedance constituted by the treating element and the part of the body to be treated (load impedance) varies during the treatment due to movements of the patient, owing to which the energy given ofi to the patient is reduced.
  • Devices for treating patients with high-frequency energy which comprise a regulating device by means of which the energy supplied to the treating element is automatically maintained substantially constant. These devices employ a control factor for controlling the regulating device, which control factor is taken from the energy consumed by the generator or from the anode current of the output tube.
  • the present invention concerns apparatus supplying the resonance frequency.
  • a regulating device consisting of a comparison network, wherein deviations, due to load impedance variations, from the phase displacement of 90 between the oscillator voltage and the resonance voltage in the circuit of the patient are transformed into a control factor by means of which the variable impedance for tuning the circuit of the patient to the stabilized frequency of the generator is readjusted.
  • a bridge-circuit may be used, one branch of which comprises two resistors and the other branch comprises two discharge tubes, for example nine electrode tubes, functioning as mixing tubes.
  • a bridge-circuit comprises two nine electrode tubes 1, 2 and two resistors 3, 4, provision being made that in supplying voltages, between which a phase displacement of exists, to grids 5 and 6 the anode currents of the two discharge tubes are equal, for example 250 a.
  • the grids 5 are electrically interconnected and are supplied with alternating voltage obtained by coupling coil 7 inductively to coil 8, the latter forming part of the highfrequency generator whose circuit-arrangement is known per se so that it will not further be described.
  • the voltage produced by coil 7 is in phase with the highfrequency voltage across coil 8.
  • To the grid 6 of the discharge tube 2 is applied an alternating voltage from a tuned circuit including a coil 9 and a capacitor 10, which circuit is resonant with the oscillator frequency.
  • the voltage produced therein has a phase difference of 90 relatively to the voltage across oscillator coil 8.
  • the grid 6 of the discharge tube 1 is connected to coil 2 2- coupled to the circuit of the patient.
  • the phasedifference between the voltage produced therein and the voltage across the oscillator coil 8 is 90 only if the circuit of the patient is resonant with the oscillatorfrequency. If this circuit is not tuned to resonance the phase-difference is higher or lower than 90 depending on whether the impedance of this circuit behaves inductively or capacitively with respect to the resonance frequency.
  • the bridge-circuit is in equilibrium if the last-mentioned phase diiference is 90, consequently if the circuit of the patient is tuned to resonance.
  • a direct voltage is set up between the diagonal junction points 12, 13.
  • Point 12 is connected to control grid 14 of a triode 15 and point 13 is connected to control grid 16 of a triode 17.
  • Both triodes are connected in phase-opposition and the anode currents pass through parts 18 and 19 of the field winding of an electric motor 20.
  • the variable impedance preferably the rotary capacitor 21 in the patient circuit also including coupling coil 22 and output terminals 23, is readjusted.
  • the anode voltage for the triodes 15 and 17 is supplied to the point connecting parts 18 and 19 of the field winding.
  • the anode current of the discharge tube 2 has a constant value, whereas the anode current of the discharge tube It varies in accordance with load impedance variations, since these variations alter the phase difference between the voltages supplied to the grids 5 and 6. Hence, the anode current of tube 1 may become higher or lower than that supplied by tube 2, whereby the direction of rotation of the motor 20 is determined. It may easily be so chosen that the motor moves the capacitor 21 in a direction such that the capacitor variation restores the load impedance to a value at which the condition of resonance is satisfied. Upon reaching the last-mentioned position the bridge is again in equilibrium and the motor comes to a standstill.
  • a shortwave therapy apparatus for the medical treatment of patients comprising a stabilized high-frequency generator; a resonator inductively coupled to the generator and provided with a treating element to supply high-frequency energy to the patient and a variable impedance to adjust the resonance frequency of said resonator, said patient constituting a variable load on said resonator; and a regulating device to maintain said resonator in tune with said generator despite variations in said load, said device comprising a phase comparison network for comparing the phase of the generator voltage with the resonator voltage and whereby said network yields an output voltage depending on".
  • an electric motor coupled to the variable impedance n s a1d resonator and including a center tapped field w1nd1ng; and a push-pull amplifier for coupling said winding to said phase comparison network and including a pair of electron discharge devices each having a cathode, a control electrode and an anode, means to apply the output voltage of said network in phase opposition to said control electrodes, means connecting said anodes to the ends of 7 said field winding and means to apply a direct anode voltage to said center tap of the winding relative to said cathodes,
  • a shortwave therapy apparatus for the medical treatment of patients comprising a stabilized high-frequency generator; a resonator inductively coupled to the generator and provided with a treating element to supply high-frequency energy to the patient and a variable impedance to adjust the resonance frequency of said resonator, said patient constituting a variable load on said resonator; and a regulating device to maintain said resonator in tune with said generator despite variations in said load, said device comprising a phase comparison network for comparing the phase of the generator voltage with the resonator voltage and including a bridge circuit formed by two branches one of which includes two resistors, the other of which includes two electron discharge tubes each having first and second control grids, means coupled to said generator to apply to corresponding first grids of said tubes an alternating voltage in phase with said generator voltage, means coupled to said resonator to apply to the second grid of one tube an alternating voltage 90 degrees out of phase with said generator 2 voltage, and a tuned circuit coupled to said generator and resonant therewith to supply an alternating voltage to

Landscapes

  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Radiology & Medical Imaging (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Surgical Instruments (AREA)
  • Inverter Devices (AREA)
  • Electrotherapy Devices (AREA)
US261036A 1951-01-09 1951-12-11 Phase sensitive control for shortwave therapy devices Expired - Lifetime US2698622A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEP4919A DE971636C (de) 1951-01-09 1951-01-09 Kurzwellenapparat fuer Therapiezwecke

Publications (1)

Publication Number Publication Date
US2698622A true US2698622A (en) 1955-01-04

Family

ID=6093782

Family Applications (1)

Application Number Title Priority Date Filing Date
US261036A Expired - Lifetime US2698622A (en) 1951-01-09 1951-12-11 Phase sensitive control for shortwave therapy devices

Country Status (6)

Country Link
US (1) US2698622A (fr)
BE (1) BE508264A (fr)
CH (1) CH300414A (fr)
DE (1) DE971636C (fr)
FR (1) FR1047550A (fr)
GB (1) GB710669A (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2864371A (en) * 1954-06-14 1958-12-16 Casther S A Device for the control of electrical supply for electrotherapeutic purposes, especially for stimulotherapy
US2937640A (en) * 1951-11-02 1960-05-24 Siemens Reiniger Werke Ag Ultrasonic apparatus for medical treatment purposes
US3096768A (en) * 1960-05-27 1963-07-09 Tron Inc Fa Electrotherapy system
US4210152A (en) * 1978-05-01 1980-07-01 International Medical Electronics Ltd. Method and apparatus for measuring and controlling the output power of a shortwave therapy apparatus
US7510555B2 (en) 2004-05-07 2009-03-31 Therm Med, Llc Enhanced systems and methods for RF-induced hyperthermia
US7627381B2 (en) 2004-05-07 2009-12-01 Therm Med, Llc Systems and methods for combined RF-induced hyperthermia and radioimmunotherapy
US20090294300A1 (en) * 2006-11-13 2009-12-03 Kc Energy, Llc Rf systems and methods for processing salt water
US10525187B2 (en) * 2012-12-21 2020-01-07 Fresenius Medical Care Deutschland Gmbh Apparatus for removing protein-bound toxins from blood plasma

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4709701A (en) * 1986-04-15 1987-12-01 Medical Research & Development Associates Apparatus for medical treatment by hyperthermia

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2396004A (en) * 1943-11-24 1946-03-05 Weston Electrical Instr Corp High-frequency dielectric heating apparatus
US2467285A (en) * 1944-07-12 1949-04-12 Rca Corp High-frequency generating system
US2473188A (en) * 1944-06-17 1949-06-14 Rca Corp Radio-frequency dielectric heater with constant heating rate control

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE356917C (de) * 1922-08-14 Siemens & Halske Akt Ges Verfahren zum Hoerbarmachen elektrischer Wellen von hoher Frequenz
DE663548C (de) * 1933-01-17 1938-08-09 Tiberius Reiter Dr Einrichtung zur Behandlung mit kurzwelligen elektrischen Schwingungen
FR763868A (fr) * 1933-02-03 1934-05-08 Soc Fr Radioelectrique Nouveau procédé de réception homodyne
DE737011C (de) * 1935-05-05 1943-07-03 Electricitaetsgesellschaft San Einrichtung zum Abstimmen eines Behandlungskreises mit Lechersystem auf den Erregerkreis bei Kurzwellen- bzw. Ultrakurzwellentherapieapparaten
US2470443A (en) * 1944-07-21 1949-05-17 Mittelmann Eugene Means for and method of continuously matching and controlling power for high-frequency heating of reactive loads
GB611710A (en) * 1944-10-10 1948-11-03 Stanley Francis Warren Improvements in radio frequency heating, particularly for the permanent waving of hair
US2508321A (en) * 1945-09-05 1950-05-16 Raymond M Wilmotte Method and means of controlling electronic heating

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2396004A (en) * 1943-11-24 1946-03-05 Weston Electrical Instr Corp High-frequency dielectric heating apparatus
US2473188A (en) * 1944-06-17 1949-06-14 Rca Corp Radio-frequency dielectric heater with constant heating rate control
US2467285A (en) * 1944-07-12 1949-04-12 Rca Corp High-frequency generating system

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2937640A (en) * 1951-11-02 1960-05-24 Siemens Reiniger Werke Ag Ultrasonic apparatus for medical treatment purposes
US2864371A (en) * 1954-06-14 1958-12-16 Casther S A Device for the control of electrical supply for electrotherapeutic purposes, especially for stimulotherapy
US3096768A (en) * 1960-05-27 1963-07-09 Tron Inc Fa Electrotherapy system
US4210152A (en) * 1978-05-01 1980-07-01 International Medical Electronics Ltd. Method and apparatus for measuring and controlling the output power of a shortwave therapy apparatus
US7510555B2 (en) 2004-05-07 2009-03-31 Therm Med, Llc Enhanced systems and methods for RF-induced hyperthermia
US7627381B2 (en) 2004-05-07 2009-12-01 Therm Med, Llc Systems and methods for combined RF-induced hyperthermia and radioimmunotherapy
US20090294300A1 (en) * 2006-11-13 2009-12-03 Kc Energy, Llc Rf systems and methods for processing salt water
US10525187B2 (en) * 2012-12-21 2020-01-07 Fresenius Medical Care Deutschland Gmbh Apparatus for removing protein-bound toxins from blood plasma

Also Published As

Publication number Publication date
BE508264A (fr) 1952-07-07
DE971636C (de) 1959-03-05
CH300414A (de) 1954-07-31
GB710669A (en) 1954-06-16
FR1047550A (fr) 1953-12-15

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