[go: up one dir, main page]

EP0349915B1 - Method and apparatus for adjusting the spark gap of a non-invasive lithotriptor - Google Patents

Method and apparatus for adjusting the spark gap of a non-invasive lithotriptor Download PDF

Info

Publication number
EP0349915B1
EP0349915B1 EP19890111918 EP89111918A EP0349915B1 EP 0349915 B1 EP0349915 B1 EP 0349915B1 EP 19890111918 EP19890111918 EP 19890111918 EP 89111918 A EP89111918 A EP 89111918A EP 0349915 B1 EP0349915 B1 EP 0349915B1
Authority
EP
European Patent Office
Prior art keywords
spark gap
tips
electrodes
tip
time interval
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP19890111918
Other languages
German (de)
French (fr)
Other versions
EP0349915A1 (en
Inventor
Pavel Sunka
Václav RNDr. Babicky
Zbysek Barta
Jiri Mudr. Rndr. Benes
Karel RNDr. Kolácek
Václav Prof. MUDr. Kordac
Cestmir Rndr. Stuka
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Matematicko-Fyzikalni Fakulta University Karlovy V Praze
Original Assignee
Matematicko-Fyzikalni Fakulta University Karlovy V Praze
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matematicko-Fyzikalni Fakulta University Karlovy V Praze filed Critical Matematicko-Fyzikalni Fakulta University Karlovy V Praze
Publication of EP0349915A1 publication Critical patent/EP0349915A1/en
Application granted granted Critical
Publication of EP0349915B1 publication Critical patent/EP0349915B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K15/00—Acoustics not otherwise provided for
    • G10K15/04—Sound-producing devices
    • G10K15/06—Sound-producing devices using electric discharge

Definitions

  • the present invention relates to a method and arrangement for adjusting the position of tips of a spark gap of a generator of shock waves of a non-invasive lithotriptor and to arrangements for execution of said method.
  • Such a lithotriptor is known for example from FR-A-2 593 382.
  • the electrodes of such a device are subject to the passage of impulse currents of high amplitudes required for the generation of shock waves. These currents wear out the tips of the electrodes, thus increasing the length of the spark gap, so that it has to be readjusted frequently.
  • Spark gaps with adjustable tips are as a rule controlled mechanically, the method of their adjustment is, however, an empirical one and depends on the experience of the attendants.
  • the major part of regulation methods bases therefore on the picking-up of distances or positions of tips of the spark gap and is capable to compensate roughly the reduction of electrodes.
  • the change of geometry of the surface of electrodes which substantially influences the distribution of the electric field in the neighbourhood of tips of the spark gap and thus also the magnitude of the arc voltage can however not be taken into account by this method.
  • FR-A-2 593 382 discloses a lithotriptor whose spark gap is continuously readjusted depending on the number of discharges executed and/or the discharge voltage of the spark gap.
  • the time interval from the start of charging or from a charged condition of a functional capacitor of the generator up to the moment of discharge within the aqueous spark gap is determined and basing on this obtained time interval, the adjustment of tips of the spark gap of the generator is accomplished.
  • the respective arrangement for execution of said method comprising two adjustable electrodes has both tips of electrodes situated within a housing provided with slots which determine a spatial angle for propagation of the shock wave, whereby the upper guiding means of the tip of the electrode has a conical shape with an apex angle corresponding to the angle of opening of the reflector.
  • the arrangement can be provided with a mobile tip of the shape of a wire, opposite to which the upper guiding means of the tip of the other electrode of the shape of a cone with an apex angle corresponding to the angle of opening of the reflector is situated.
  • the main advantage of the method according to this invention and of the corresponding arrangement is the prolongation of the life time of the spark gap to a multiple of the life periods of existing spark gaps while securing a good capability of reproduction of individual shocks and thus achieving improvements of efficiency of healing.
  • the spark gap with adjustable tips can be provided with means for picking-up their mutual position, with a proper regulation unit and with a working unit, for instance with an electro-mechanical transducer for adjustment of the position of tips of the spark gap. In case the indication from the pick-up device, determining the position of tips of the spark gap is transmitted to a display, it is possible to regulate the position of tips also manually.
  • the spark gap is designed slidable and against another known arrangement the spark gap is coaxial.
  • Fig. 1 shows the voltage course of a spark gap for shock waves with indicated time intervals utilized for regulation, whereby U indicates the voltage on the spark gap, t the time in ⁇ s, we see that after an impulse charging of the functional capacitor, the voltage is slowly decreasing due to leakage over the resistance of the water of the spark gap. So far the time interval between the start of charging and the discharging over the aqueous spark gap is smaller than t min , the discharge occured prior than the functional capacitor has been sufficiently charged and the distance of electrodes has to be increased. If the time interval between the start of impulse charging and the discharge is larger than t max , corresponding to the variability of the discharge voltage U , or in case no discharge is experienced, the distance of electrodes has to be reduced.
  • the regulation thus proceeds as follows. At the start of charging of the functional capacitor or from another defined condition of charging the time interval up to the moment of discharge is measured within the aqueous spark gap, or up to another moment connected directly to the discharge of the aqueous spark gap. This time information is utilized for an adjustment of the distance of the electrodes. If a short time interval between start of charging and discharging, where no full charging of the functional capacitor took place, the distance of tips of electrodes has to be increased. In case of a long time interval between start of charging and discharging of the spark gap where already a partial discharge of the functional capacitor took place, the distance of tips has to be reduced.
  • the verification examinations have been performed at a capacity of the discharge capacitor 1 ⁇ F at a voltage 10 kV. At these conditions 300 shocks have been needed for crushing a large bilestone.
  • the arrangement for execution of the method according to the present invention as shown in Fig. 2 comprises a reflector 1, to which a functional capacitor 2 is joined.
  • the proper spark gap comprising an upper tip 3 and a lower tip 4, enclosed in a housing 5, which beyond its supporting function also supplies current to the upper tip 3, is situated in the focus of the ellipsoid of the reflector 1.
  • the housing 5 is provided with slots 6 which determine the spatial angle for propagation of shock waves generated by the discharge in the spark gap.
  • the upper guiding means 7 of the tip 3 of the electrode has the shape of a cone with an apex angle corresponding to the angle of opening of the reflector 1.
  • At least one of electrodes of the arrangement is provided with shifting means (not shown).
  • Fig. 3 shows an alternative embodiment of the spark gap.
  • the spark gap is situated in the reflector 1 and comprises a mobile tip 8 of wire shape opposite to which an upper guiding means 7 is situated having a conical shape with an apex angle corresponding to the opening angle of the reflector 1.
  • the mobile tip 8 is provided with a shifting device (not shown).
  • Fig. 2 and 3 operate as follows. After the reflector 1 is filled with water and the patient is brought in contact with its upper part, the place for healing is properly adjusted whereafter between tips 3, 4 a discharge is generated by means of the functional capacitor 2, the power therefrom is transmitted by the focussed shock wave to the place where the healing of the patient has to be performed. In case of wear of the spark gap or of tips 3, 4 respectively, their adjustment is accomplished by the shifting device (not shown).

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Surgical Instruments (AREA)

Description

  • The present invention relates to a method and arrangement for adjusting the position of tips of a spark gap of a generator of shock waves of a non-invasive lithotriptor and to arrangements for execution of said method.
  • Such a lithotriptor is known for example from FR-A-2 593 382.
  • The electrodes of such a device are subject to the passage of impulse currents of high amplitudes required for the generation of shock waves. These currents wear out the tips of the electrodes, thus increasing the length of the spark gap, so that it has to be readjusted frequently. Spark gaps with adjustable tips are as a rule controlled mechanically, the method of their adjustment is, however, an empirical one and depends on the experience of the attendants. The major part of regulation methods bases therefore on the picking-up of distances or positions of tips of the spark gap and is capable to compensate roughly the reduction of electrodes. The change of geometry of the surface of electrodes which substantially influences the distribution of the electric field in the neighbourhood of tips of the spark gap and thus also the magnitude of the arc voltage can however not be taken into account by this method.
  • FR-A-2 593 382 discloses a lithotriptor whose spark gap is continuously readjusted depending on the number of discharges executed and/or the discharge voltage of the spark gap. Although this method of readjustment allows an automatic operation of the lithotriptor, it suffers from the same problems as described above, as it cannot take account of irregular use of the tips, and, as will be shown in the following, the relation between discharge voltage and spark gap width is not unique, so that the direction of the necessary readjustment cannot be concluded with certainty from the discharge voltage.
  • It is the object of the present invention to eliminate to a high degree said drawbacks and to provide a method and an arrangement which provide means for maintaining a correct operation of generators of shock waves for the mentioned purpose.
  • This object is achieved with a method and an arrangement respectively, as claimed. Dependent claims are directed on features of preferred embodiments of the invention.
  • According to the present invention the time interval from the start of charging or from a charged condition of a functional capacitor of the generator up to the moment of discharge within the aqueous spark gap is determined and basing on this obtained time interval, the adjustment of tips of the spark gap of the generator is accomplished.
  • The respective arrangement for execution of said method comprising two adjustable electrodes has both tips of electrodes situated within a housing provided with slots which determine a spatial angle for propagation of the shock wave, whereby the upper guiding means of the tip of the electrode has a conical shape with an apex angle corresponding to the angle of opening of the reflector. According to an alternative embodiment the arrangement can be provided with a mobile tip of the shape of a wire, opposite to which the upper guiding means of the tip of the other electrode of the shape of a cone with an apex angle corresponding to the angle of opening of the reflector is situated.
  • The main advantage of the method according to this invention and of the corresponding arrangement is the prolongation of the life time of the spark gap to a multiple of the life periods of existing spark gaps while securing a good capability of reproduction of individual shocks and thus achieving improvements of efficiency of healing. The spark gap with adjustable tips can be provided with means for picking-up their mutual position, with a proper regulation unit and with a working unit, for instance with an electro-mechanical transducer for adjustment of the position of tips of the spark gap. In case the indication from the pick-up device, determining the position of tips of the spark gap is transmitted to a display, it is possible to regulate the position of tips also manually. Against an arrangement described in DE-C- 3,543.881 the spark gap is designed slidable and against another known arrangement the spark gap is coaxial.
  • The method and the arrangement according to the present invention will be in the following described in detail with reference to the drawings, wherein
    • Fig. 1 shows a diagram of the voltage course of a spark gap for shock waves versus the time,
    • Fig. 2 and 3 indicate diagrammatically elevations of two embodiments of respective arrangements.
  • With reference to Fig. 1 which shows the voltage course of a spark gap for shock waves with indicated time intervals utilized for regulation, whereby U indicates the voltage on the spark gap, t the time in µs, we see that after an impulse charging of the functional capacitor, the voltage is slowly decreasing due to leakage over the resistance of the water of the spark gap. So far the time interval between the start of charging and the discharging over the aqueous spark gap is smaller than tmin, the discharge occured prior than the functional capacitor has been sufficiently charged and the distance of electrodes has to be increased. If the time interval between the start of impulse charging and the discharge is larger than tmax, corresponding to the variability of the discharge voltage U, or in case no discharge is experienced, the distance of electrodes has to be reduced.
  • The regulation thus proceeds as follows. At the start of charging of the functional capacitor or from another defined condition of charging the time interval up to the moment of discharge is measured within the aqueous spark gap, or up to another moment connected directly to the discharge of the aqueous spark gap. This time information is utilized for an adjustment of the distance of the electrodes. If a short time interval between start of charging and discharging, where no full charging of the functional capacitor took place, the distance of tips of electrodes has to be increased. In case of a long time interval between start of charging and discharging of the spark gap where already a partial discharge of the functional capacitor took place, the distance of tips has to be reduced.
    • Example:
  • During the verification examinations of the arrangement a minimum time interval tmin of 40 µs and a maximum time interval of 300 µs has been determined. For up to 120 expositions of the shock wave the measured time interval did not depart beyond the time limit tmin - tmax. The distance of electrodes has been thereafter reduced by 0,2 mm. A following regulation has been subsequently accomplished only after 30 shocks.
  • The verification examinations have been performed at a capacity of the discharge capacitor 1 µF at a voltage 10 kV. At these conditions 300 shocks have been needed for crushing a large bilestone.
  • The arrangement for execution of the method according to the present invention as shown in Fig. 2 comprises a reflector 1, to which a functional capacitor 2 is joined. The proper spark gap comprising an upper tip 3 and a lower tip 4, enclosed in a housing 5, which beyond its supporting function also supplies current to the upper tip 3, is situated in the focus of the ellipsoid of the reflector 1. The housing 5 is provided with slots 6 which determine the spatial angle for propagation of shock waves generated by the discharge in the spark gap. The upper guiding means 7 of the tip 3 of the electrode has the shape of a cone with an apex angle corresponding to the angle of opening of the reflector 1. At least one of electrodes of the arrangement is provided with shifting means (not shown).
  • Fig. 3 shows an alternative embodiment of the spark gap. The spark gap is situated in the reflector 1 and comprises a mobile tip 8 of wire shape opposite to which an upper guiding means 7 is situated having a conical shape with an apex angle corresponding to the opening angle of the reflector 1. The mobile tip 8 is provided with a shifting device (not shown).
  • The arrangements shown in Fig. 2 and 3 operate as follows. After the reflector 1 is filled with water and the patient is brought in contact with its upper part, the place for healing is properly adjusted whereafter between tips 3, 4 a discharge is generated by means of the functional capacitor 2, the power therefrom is transmitted by the focussed shock wave to the place where the healing of the patient has to be performed. In case of wear of the spark gap or of tips 3, 4 respectively, their adjustment is accomplished by the shifting device (not shown).

Claims (3)

  1. Method of adjusting the position of tips of a spark gap of a generator of shock waves for non-invasive lithotrypsis,
    characterized in that
    a time interval from the start of charging or from a charging condition of a functional capacitor is measured up to the discharge of the aqueous spark gap, whereafter the adjustment of tips of the spark gap is accomplished on the basis of the thus determined time interval.
  2. Arrangement for execution of the method according to claim 1, comprising a reflector ellipsoid (1) and two movable electrodes, the spark gap defined by the tips (3, 4) of the electrodes being situated in the focus of the ellipsoid (1),
    characterized in that
    it comprises a means for determining a time interval from the start of charging or of the charged condition of the functial capacitor up to the discharge of the aqueous spark gap, in that both tips (3, 4) of electrodes are enclosed in a housing situated in the focus of the ellipsoid of the reflector, said housing (5) being provided with slots (6) determining a spatial angle in which the shock wave is propagated, in that an upper guiding means (7) of the tip of the electrode (3) has a conical shape with an apex angle corresponding to the angle of opening of the reflector (1) and in that at least one of both electrodes is provided with a shifting device.
  3. Arrangement according to claim 2,
    characterized in that
    it is provided with a mobile tip (8) of wire shape, opposite to which the upper guiding means (7) of the tip of the electrode (3) is provided, and in that the mobile tip (8) is provided with a shifting device.
EP19890111918 1988-07-01 1989-06-30 Method and apparatus for adjusting the spark gap of a non-invasive lithotriptor Expired - Lifetime EP0349915B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CS4771/88 1988-07-01
CS884771A CS270064B1 (en) 1988-07-01 1988-07-01 Method of surge generator's spark gap's points regulation for non-invasive lithotrity and device for realization of this method

Publications (2)

Publication Number Publication Date
EP0349915A1 EP0349915A1 (en) 1990-01-10
EP0349915B1 true EP0349915B1 (en) 1994-01-19

Family

ID=5391219

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19890111918 Expired - Lifetime EP0349915B1 (en) 1988-07-01 1989-06-30 Method and apparatus for adjusting the spark gap of a non-invasive lithotriptor

Country Status (4)

Country Link
EP (1) EP0349915B1 (en)
JP (1) JPH02154749A (en)
CS (1) CS270064B1 (en)
DE (1) DE68912424T2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007087470A3 (en) * 2006-01-27 2008-01-10 Gen Patent Llc Improved shock wave treatment device

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CZ297145B6 (en) * 1997-10-24 2006-09-13 Medipool Treuhand- Und Beteiligungsgesellschaft Für Medizintechnik Gmbh System for automatic adjustment of mutual distance of electrodes for setting spark gap in electrohydraulic systems with impulse wave
FR2799111B1 (en) * 1999-10-01 2002-06-28 Internova Int Innovation LITHOTRITING APPARATUS
US10063047B2 (en) 2011-09-28 2018-08-28 Ppg Industries Ohio, Inc. Intelligent window heat control system
US11509132B2 (en) 2011-09-28 2022-11-22 Ppg Industries Ohio, Inc. Intelligent window heat control system
EP3570761A4 (en) * 2017-01-17 2021-02-17 Soliton, Inc. Rapid pulse electrohydraulic (eh) shockwave generator apparatus with improved acoustic wavefronts
US11337311B2 (en) 2018-07-06 2022-05-17 Ppg Industries Ohio, Inc. Aircraft window with variable power density heater film
CN116687514B (en) * 2023-05-26 2024-07-02 索诺利(厦门)医疗科技有限公司 High-energy emitter capable of stably outputting energy for extracorporeal lithotripter

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3418510A (en) * 1965-11-30 1968-12-24 Navy Usa Triggered spark gap electric arcing device
FR2593382B1 (en) * 1986-01-31 1989-06-30 Technomed Int Sa HIGH FREQUENCY SHOCK WAVE GENERATING APPARATUS AND ITS USE FOR THE DESTRUCTION OF TARGETS SUCH AS FABRICS, CONCRETIONS, ESPECIALLY RENAL, BILARY CALCULATIONS
CS261485B1 (en) * 1986-10-29 1989-02-10 Jiri Mudr Rndr Benes Device for clinic out-of-body lithotripsy of gall stones

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007087470A3 (en) * 2006-01-27 2008-01-10 Gen Patent Llc Improved shock wave treatment device

Also Published As

Publication number Publication date
DE68912424D1 (en) 1994-03-03
EP0349915A1 (en) 1990-01-10
CS270064B1 (en) 1990-06-13
CS477188A1 (en) 1989-10-13
DE68912424T2 (en) 1994-05-11
JPH02154749A (en) 1990-06-14

Similar Documents

Publication Publication Date Title
US6217531B1 (en) Adjustable electrode and related method
EP0349915B1 (en) Method and apparatus for adjusting the spark gap of a non-invasive lithotriptor
GB2121089B (en) Apparatus for initiating explosions and method therefor
GB1082397A (en) Instrument for crushing stones in the urinary bladder
SE9600989D0 (en) Method and apparatus for space charge measurement in cables using a pulsed electroacoustic method
EP2274741A2 (en) Automatic adjustable voltage to stabilize pressure for shockwave medical therapy device
EP0473601A1 (en) Apparatus for triggering shock waves
EA199900818A1 (en) METHOD OF ELECTROCHEMICAL PREPARATION
JPS61260915A (en) Electric discharge machining power supply
RU2151559C1 (en) Device for stimulating tissue metabolism with shock wave impulses
US4346278A (en) Methods and apparatus for electrical discharge machining
US9802237B2 (en) Head of an exploding-wire electrohydraulic discharge device
US5504420A (en) Current-generating apparatus for therapeutic treatments in the field of biophysics and physiology
EP3682822A1 (en) Combined shockwave and ultrasound source
CN119811975B (en) Plasma degumming machine and ignition method
JPS5758977A (en) Pulse arc welding machine
JPS6416316A (en) Electric discharge machine
RU96111485A (en) METHOD FOR CONTROL OF ELECTRIC MODE OF ARC ELECTRIC STEEL FURNACE
EP0767025A1 (en) Laser guided discharge machining apparatus
JPH0199659A (en) Charge controlling method for pulse charge-type electrostatic precipitator
SU887107A1 (en) Electric-discharge machining method
JPS5480749A (en) Electrode device for forming electrostatic latent image
JPH02148781U (en)
CA2272953A1 (en) Method and device for pulsed arc welding
GB1584142A (en) Apparatus for preparing optical glass fibres for formation of end faces by spark erosion

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR NL

17P Request for examination filed

Effective date: 19900702

17Q First examination report despatched

Effective date: 19920925

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

RBV Designated contracting states (corrected)

Designated state(s): DE FR

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR

ET Fr: translation filed
REF Corresponds to:

Ref document number: 68912424

Country of ref document: DE

Date of ref document: 19940303

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19950609

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19950617

Year of fee payment: 7

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19970228

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19970301

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST