CA1099790A - System for monitoring integrity of a patient return circuit - Google Patents
System for monitoring integrity of a patient return circuitInfo
- Publication number
- CA1099790A CA1099790A CA306,537A CA306537A CA1099790A CA 1099790 A CA1099790 A CA 1099790A CA 306537 A CA306537 A CA 306537A CA 1099790 A CA1099790 A CA 1099790A
- Authority
- CA
- Canada
- Prior art keywords
- radiofrequency
- return lead
- photovoltaic cell
- return
- current
- 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
Links
Landscapes
- Surgical Instruments (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A monitor for a patient return circuit of a radiofrequency electro-surgical device in which an interrogation or measurement circuit is powered by a photovoltaic cell. Characteristics of the photovoltaic cell can limit the interrogation or measurement current to a value considered to be safe to a patient.
A monitor for a patient return circuit of a radiofrequency electro-surgical device in which an interrogation or measurement circuit is powered by a photovoltaic cell. Characteristics of the photovoltaic cell can limit the interrogation or measurement current to a value considered to be safe to a patient.
Description
~g5~7~1~
This invention relates to electrosurgical devices. ~ore par-ticularly, this invention relates to a device for monitoring the integrity of a patient return circuit of an electrosurgical clevice.
In the use of radiofrequency electrosurgical devices, it is essen-tial that a passive electrode and return lead be intact to prevent radio-frequency burn danger to a patient or to operating room personnel. It has been a common practice to use an interrogation or measurement current to demonstrate that the intended return circuit is intact. However, if exces-sive interrogation or measurement currents reach the patient through the interrogation or measurement circuit, such excessive interrogation or mea- ;
surement current can be lethal or ~an permanently injure the patient, par-ticularly in a failure mode circumstance.
A secondary circuit failure mode problem exists in some present day electrosurgical equipment where, in the failure mode situation, sizable shock or even lethal currents can be passed through a patient to ground from a return lead interrogation or measurement current secondary circuit source.
It is an object of this invention to provide a system which in-herently l~nits the direct current voltage available to circulate in radio-frequency return leads in both a normally operatirg mode and circuit failure mode which could occur.
A further obiect of this invention is to provide a passive electrode and return lead monitoring circuit for a ra~iofrèq~ency electrosurgical device which provides an interrogation or measurement current which cannot exceed a fixed value.
A further object of this invention is to provide sllch a monitoring circuit in which power circuitsofa radiofrequency electrosurgical generator supply power to the monitoring circuit but are fully isolated there-from.
In accordance with this invention there is provided a system for monitoring the integrity of a patient intended return of a radioErequency -1- ~
~979~
electrosurgical device includiDg a passive electrode and a return lead means attached to the passive electrode, said system comprising a monitoring cir- -~
cuit in~luding said return lead means, a photovoltaic cell3 and current sensing means where said return lead means, said photovoltaic cell, and said current sensing means are connected in series; means for illuminating the photovoltaic cell, and means actuated by the current sensing means for indi_ cating a discontinuity in the monitoring circuit, the voltage in the monitor-ing circuit being limited by the li~iting voltage of the photovoltaic cell.
Briefly, this inventioD provides a monitoring circuit for a passive electrode and return lead of a radiofrequency electrosurgical device in which an interrogation or measurement current is provided by a photovoltaic cell.
The photovoltaic cell can be powered by a ra(liating source or lamp which, in turn, can be powered by an appropriate electrical power source. The elect-rical power source can be a portion of circuit~y of a radiofrequency generator of the electrosurgical device. The power circuits of the radiofrequency gen-erator are fully isolated from the photovoltaic cell because there is no direct connection therebetween. The voltage and current supplied by the photo-voltaic cell to the monitoring circuit is limited by the electrical charact-eristics of the photovoltaic cell and irherently cannot exceed a given output ~oltage at optical saturation of the photovoltaic cell. The output voltage of the photovoltaic cell at optical saturation can be sufficiently low that there J
is limited potential danger to the patient even in a failure mode circumstance.
The interrogation or measurement current can be used to actuate a sensing means such as a relay or the like in the monitoring circuit. The relay can actuate an alarm and can act to disable the radiofrequency generator in the event of failure of integrity of the passive electrode and intended return circuit.
The above and other objects and features of the in~ention will be apparent to those skilled in the art to which this invention pertains from the following detailed description and the drawings, in which:
7~13 ~ igure 1 is a schematic circuit diagram show.ing a device for monitoring the integrity of a patient return circuit for an electrosurgical device constructed in accordance with an embodiment of this invention; and ~ ig~re 2 is a schematic circuit diagram showing a device for mon-itoring the integrity of a patient return circuit for an electrosurgical device constructed in accordance with another embodiment of this inve~tion.
In the following detai.led description and the drawings, like ref~
erence characters indicate like parts.
In ~igure 1 is shown a circuit for a radiofrequency electrosurgical device having a patient return monitori.ng circuit constructed in accordance with an embodiment of this invention. The ~evice includes a radiofrequency generator 10 coupled through a condenser 12 to a primary winding 13 of a coupling transfo~er 14. One side of a secondary winding 15 of the coupling transformer 14 is coupled to a power lead 16 through a condenser 17. The power lead 16 is the inner or shielded conductor of a coaxial cable 18. The outer conductor or shield of the coaxial cable 18 is connected to ground as is the other side of the secondary winding 16 of the couplir~ transformer 14.
The power lead 16 is connected to one end of a primary winding of a hand-p.iece transformer 22, which is mounted in a handpiece 23. The other end of the primary winding 21 is coupled to the shield of the coaxial cable 18 through a capacitor 24. A secondary winding 26 of the handpiece transformer 22 powers an active electrode 27. One end of the seconclary winding 26 is : connected to the active electrode~ and the other end of the secondary winding 26 is connected to the power lead 16.
Return ~rom a patient 29 is provided through a passive electrode 31 and a return lead 32~ which is connected to the passive electrode and is coupled to ground through a coupling condenser 33. An interrogation or mon-itoring current is provided by a photovoltaic cell 34, which is coupled to the return lead 32 and to an interrogation or monitoring lead 36, which is also ~99~9~
connected to the passive electrode 3L. The photovoltaic cell 34 i9 coupled to the return lead 3~ through a radiofrequency inductor 37 and through the coil of a relay 38 and to the interrogation or monitoring lead 36 through a radiofrequency inductor 39. The inductors 37 and 39 prevent radiofrequency return current from circulating through the photovoltaic cell and through the sensitive coil of the relay 38. A capacitor 41 is connected between the return lead 32 and the interrogation or monitoring lead 36 to carry radio-frequency current to the output winding coupling capacitor 33 should there be a break in the return lead 32.
The photovoltaic cell 34 can be illuminated by an appropriate lamp 42, which can be powered by leads 43 and 44. The leads 43 and ~4 can be connected to an appropriate portion of the circuitry of the radiofrequency generator lO, not shown in detail, to provide the necessary voltage to operate the lamp 42. As long as the monitoring circuit including the return lead 32, the interrogation or moni*oring lead 367 the photovoltaic cell 34 and the coil of the relay 38 is unbroken and the lamp 42 is illuminated, relay poles 38A and 38B are held in the position shown. The pole 38A connects leads 49 and 51, which can be a part of the circuitry of the radiofrequency generator J
which must be connected to permit the radiofrequency generator to power the coupling transformer 14 and the active electrode 27.
In the event of a break in the return lead 32, the relay 38 is de-energized, and the poles 38A and 38B swing to their other positions. Then the leads 49 and 51 are diconnected so that the radiofrequency generator is disabled to power the active electrode~ In addition, the pole 38B connects a lead 53 to a lead 54 A warning horn 56 and a warring lamp 57 are connected between the lead 54 and a lead 59. The leads 53 and 59 can be connected to an appropriate portion of the circuitry of the radiofrequency generator to provide a voltage for operatir~ the warning horn 56 and the warning lamp 57.
The photovoltaic cell 34 can be design~d to have an output of 0.6 ~gg~
volts D.C. and a current of 60 milliamperes. Such a photovoltaic cell in open circuit, no load condition can have a limiting voltage of 0.8 volts ~.C.
Such a cell can operate a sensitive relay such as a ~-Potter-Brumfield relay MDP-2109. The lamp ~2 can be a low voltage annunciator incandescent tun~sten filament lamp such as a ~Sylvania 6R~ or 12RB arnunciator lamp. Such a lamp, ~hen operated at 50% of full output rating has a very long life and supplies sufficient radiant energy to optically saturate the photovoltaic cell.
In Figure 2 is shown a circuit for a radiofrequency electrosurgical device which includes a patient return monitoring circuit constructed in accordance with another embodiment of this inven~ion. The device of Figure
This invention relates to electrosurgical devices. ~ore par-ticularly, this invention relates to a device for monitoring the integrity of a patient return circuit of an electrosurgical clevice.
In the use of radiofrequency electrosurgical devices, it is essen-tial that a passive electrode and return lead be intact to prevent radio-frequency burn danger to a patient or to operating room personnel. It has been a common practice to use an interrogation or measurement current to demonstrate that the intended return circuit is intact. However, if exces-sive interrogation or measurement currents reach the patient through the interrogation or measurement circuit, such excessive interrogation or mea- ;
surement current can be lethal or ~an permanently injure the patient, par-ticularly in a failure mode circumstance.
A secondary circuit failure mode problem exists in some present day electrosurgical equipment where, in the failure mode situation, sizable shock or even lethal currents can be passed through a patient to ground from a return lead interrogation or measurement current secondary circuit source.
It is an object of this invention to provide a system which in-herently l~nits the direct current voltage available to circulate in radio-frequency return leads in both a normally operatirg mode and circuit failure mode which could occur.
A further obiect of this invention is to provide a passive electrode and return lead monitoring circuit for a ra~iofrèq~ency electrosurgical device which provides an interrogation or measurement current which cannot exceed a fixed value.
A further object of this invention is to provide sllch a monitoring circuit in which power circuitsofa radiofrequency electrosurgical generator supply power to the monitoring circuit but are fully isolated there-from.
In accordance with this invention there is provided a system for monitoring the integrity of a patient intended return of a radioErequency -1- ~
~979~
electrosurgical device includiDg a passive electrode and a return lead means attached to the passive electrode, said system comprising a monitoring cir- -~
cuit in~luding said return lead means, a photovoltaic cell3 and current sensing means where said return lead means, said photovoltaic cell, and said current sensing means are connected in series; means for illuminating the photovoltaic cell, and means actuated by the current sensing means for indi_ cating a discontinuity in the monitoring circuit, the voltage in the monitor-ing circuit being limited by the li~iting voltage of the photovoltaic cell.
Briefly, this inventioD provides a monitoring circuit for a passive electrode and return lead of a radiofrequency electrosurgical device in which an interrogation or measurement current is provided by a photovoltaic cell.
The photovoltaic cell can be powered by a ra(liating source or lamp which, in turn, can be powered by an appropriate electrical power source. The elect-rical power source can be a portion of circuit~y of a radiofrequency generator of the electrosurgical device. The power circuits of the radiofrequency gen-erator are fully isolated from the photovoltaic cell because there is no direct connection therebetween. The voltage and current supplied by the photo-voltaic cell to the monitoring circuit is limited by the electrical charact-eristics of the photovoltaic cell and irherently cannot exceed a given output ~oltage at optical saturation of the photovoltaic cell. The output voltage of the photovoltaic cell at optical saturation can be sufficiently low that there J
is limited potential danger to the patient even in a failure mode circumstance.
The interrogation or measurement current can be used to actuate a sensing means such as a relay or the like in the monitoring circuit. The relay can actuate an alarm and can act to disable the radiofrequency generator in the event of failure of integrity of the passive electrode and intended return circuit.
The above and other objects and features of the in~ention will be apparent to those skilled in the art to which this invention pertains from the following detailed description and the drawings, in which:
7~13 ~ igure 1 is a schematic circuit diagram show.ing a device for monitoring the integrity of a patient return circuit for an electrosurgical device constructed in accordance with an embodiment of this invention; and ~ ig~re 2 is a schematic circuit diagram showing a device for mon-itoring the integrity of a patient return circuit for an electrosurgical device constructed in accordance with another embodiment of this inve~tion.
In the following detai.led description and the drawings, like ref~
erence characters indicate like parts.
In ~igure 1 is shown a circuit for a radiofrequency electrosurgical device having a patient return monitori.ng circuit constructed in accordance with an embodiment of this invention. The ~evice includes a radiofrequency generator 10 coupled through a condenser 12 to a primary winding 13 of a coupling transfo~er 14. One side of a secondary winding 15 of the coupling transformer 14 is coupled to a power lead 16 through a condenser 17. The power lead 16 is the inner or shielded conductor of a coaxial cable 18. The outer conductor or shield of the coaxial cable 18 is connected to ground as is the other side of the secondary winding 16 of the couplir~ transformer 14.
The power lead 16 is connected to one end of a primary winding of a hand-p.iece transformer 22, which is mounted in a handpiece 23. The other end of the primary winding 21 is coupled to the shield of the coaxial cable 18 through a capacitor 24. A secondary winding 26 of the handpiece transformer 22 powers an active electrode 27. One end of the seconclary winding 26 is : connected to the active electrode~ and the other end of the secondary winding 26 is connected to the power lead 16.
Return ~rom a patient 29 is provided through a passive electrode 31 and a return lead 32~ which is connected to the passive electrode and is coupled to ground through a coupling condenser 33. An interrogation or mon-itoring current is provided by a photovoltaic cell 34, which is coupled to the return lead 32 and to an interrogation or monitoring lead 36, which is also ~99~9~
connected to the passive electrode 3L. The photovoltaic cell 34 i9 coupled to the return lead 3~ through a radiofrequency inductor 37 and through the coil of a relay 38 and to the interrogation or monitoring lead 36 through a radiofrequency inductor 39. The inductors 37 and 39 prevent radiofrequency return current from circulating through the photovoltaic cell and through the sensitive coil of the relay 38. A capacitor 41 is connected between the return lead 32 and the interrogation or monitoring lead 36 to carry radio-frequency current to the output winding coupling capacitor 33 should there be a break in the return lead 32.
The photovoltaic cell 34 can be illuminated by an appropriate lamp 42, which can be powered by leads 43 and 44. The leads 43 and ~4 can be connected to an appropriate portion of the circuitry of the radiofrequency generator lO, not shown in detail, to provide the necessary voltage to operate the lamp 42. As long as the monitoring circuit including the return lead 32, the interrogation or moni*oring lead 367 the photovoltaic cell 34 and the coil of the relay 38 is unbroken and the lamp 42 is illuminated, relay poles 38A and 38B are held in the position shown. The pole 38A connects leads 49 and 51, which can be a part of the circuitry of the radiofrequency generator J
which must be connected to permit the radiofrequency generator to power the coupling transformer 14 and the active electrode 27.
In the event of a break in the return lead 32, the relay 38 is de-energized, and the poles 38A and 38B swing to their other positions. Then the leads 49 and 51 are diconnected so that the radiofrequency generator is disabled to power the active electrode~ In addition, the pole 38B connects a lead 53 to a lead 54 A warning horn 56 and a warring lamp 57 are connected between the lead 54 and a lead 59. The leads 53 and 59 can be connected to an appropriate portion of the circuitry of the radiofrequency generator to provide a voltage for operatir~ the warning horn 56 and the warning lamp 57.
The photovoltaic cell 34 can be design~d to have an output of 0.6 ~gg~
volts D.C. and a current of 60 milliamperes. Such a photovoltaic cell in open circuit, no load condition can have a limiting voltage of 0.8 volts ~.C.
Such a cell can operate a sensitive relay such as a ~-Potter-Brumfield relay MDP-2109. The lamp ~2 can be a low voltage annunciator incandescent tun~sten filament lamp such as a ~Sylvania 6R~ or 12RB arnunciator lamp. Such a lamp, ~hen operated at 50% of full output rating has a very long life and supplies sufficient radiant energy to optically saturate the photovoltaic cell.
In Figure 2 is shown a circuit for a radiofrequency electrosurgical device which includes a patient return monitoring circuit constructed in accordance with another embodiment of this inven~ion. The device of Figure
2 includes a radiofrequency generator 110, which is coupled to a primary winding 113 of a coupling transformer 11~. One side of a secondary winding 115 of the transformer is coupled through a condenser 117 to a power lead 116, which is the central or shielded conductor of a coaxial cable 118. The other side of the secondary winding and the outer conductor of the coa~ial cable 118 are cor~ected to ground. The coaxial cable powers an active elec-trode I27 carried by a handpiece 123 in the same manner as already described ~ith reference to the first form of monitoring circuit. Return from a patient 129 is provided through a first passive electrode section 130 and a second passive electrode section 131. A return lead 132 is connected to the passive electrode section 130. A monitoring or measurement lead 136 is con-nected to the passive electrode section t31. The return lead 132 is coupled to ground through a coupling capacitor 133. A photovoltaic cell 13~ ~upplies a monitoring or measurement current through a circuit includirg a radio-frequency inductor 139, a monitorirg or measurement lead 136, the passive electrode section 131~ the patient 129, the passive electrode section 130, the return lead 132, a radiofrequency inductor 137, and~a coil of a relay 138. As long as a lamp 142 illuminates the photovoltaic cell 134, the patient is in good electrical contact with both of the passive electrode sections 130 -~ trade mark - 5 -and 131, and the return lead 132 and the monitorin~; or measurement lead 136 are intact so that the monitoring circuit is complete, the relay 138 is energized, and a pole 138A connects leads L~9 and 151. The leads 149 and 151 can be part of the circuitry of the radiofrequency generator 110 (not shown in detail) which must be connected to permit the radiofrequency ge~erator to power the coupling transformer 114 and the active electrode 127. However, if the patient does not have good electrical contact with one of the passive electrode sections 130 and 131, or if there is a break in the return lead 132 or in the monitoring or measurement lead 136, -the poles of the relay 138 swing to their other position at which the leads 149 and 151 are not connect-ed and a pole 138B forms a connection which energizes a horn L56 and a warn-ing lamp 157 in the same marrner as described with re:Lation to the first form OI monitoring circuit. The maximum magnitude of the monitoring or measure-ment current which passes through the patient 129 is limited by the charac-teristics of the photovoltaic cell to a value sufficiently low that there is Jsubstantially no danger to the patient.
The circuits for monitoring a patient return circuit illustrated in the drawings and described above are subject to modification without de-parting from the spirit and scope of the appended claims.
The circuits for monitoring a patient return circuit illustrated in the drawings and described above are subject to modification without de-parting from the spirit and scope of the appended claims.
Claims (11)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A system for monitoring the integrity of a patient intended return of a radiofrequency electrosurgical device including a passive electrode and a return lead means attached to the passive electrode, said system comprising a monitoring circuit including said return lead means, a photovoltaic cell, and current sensing means where said return lead means, said photovoltaic cell, and said current sensing means are connected in series; means for illuminating the photovoltaic cell, and means actuated by the current sensing means for indicating a discontinuity in the monitoring circuit, the voltage in the monitoring circuit being limited by the limiting voltage of the photovoltaic cell.
2. A system as in Claim 1 wherein the monitoring circuit includes radiofrequency inductance means isolating the photovoltaic cell and the current sensing means from the passive electrode and the return lead means.
3. A system as in Claim 1 wherein the monitoring circuit includes a second return lead means connected to the passive electrode, the second return lead means, the return lead means, the photovoltaic cell, and the current sensing means are connected in series, the return lead means is coupled to ground, and capacitor means couples the second return lead means and the return lead means.
4. A system as in Claim 3 wherein the passive electrode includes two sections, the return lead means is connected to one of the sections, and the second return lead means is connected to the other section.
5. A system as in claim 1 wherein the radiofrequency device includes a radiofrequency generator, an active electrode and means actuated by the radiofrequency generator for supplying radiofrequency current to the active electrode, and the means activated by the sensing means disables the radio-frequency electrosurgical device from supplying radiofrequency current to the active electrode when indicating the discontinuity.
6. A system as in Claim 1 wherein the radiofrequency electrosurgical device includes a radiofrequency generator, an active electrode and means actuated by the radiofrequency generator for supplying radiofrequency current to the active electrode, a warning device and means activated by the current sensing means to activate the warning device when indicating the discontinuity.
?. A system for monitoring the integrity of a patient return of a radiofrequency electro surgical device which includes a passive electrode including a pair of sections, a first return lead means connected to one of said sections, a second return lead means connected to the other of said sections, a photovoltaic cell and a current sensing means connected in series between the first return lead means and the second return lead means, means for illuminating the photovoltaic cell, and means actuated by the current sensing means for indicating a discontinuity in the lead means, the voltage in the monitoring system being limited by the limiting voltage of the photo-voltaic cell.
8. A system as in Claim 7 which includes radiofrequency inductance means isolating the photovoltaic cell and the sensing means from the passive electrode sections, the first return lead means and the second return lead means.
9. A system as in Claim 7 which includes capacitor means coupling the first return lead means and the second return lead means.
10. A system as in Claim 7 wherein the radiofrequency electrosurgical device includes a radiofrequency generator, and active electrode and means actuated by the radiofrequency generator for supplying radiofrequency current to the active electrode, and the means activated by the current sensing means to disable the radiofrequency generator from supplying radiofrequency current to the active electrode when indicating the discontinuity.
11. A system as in Claim 7 wherein the radiofrequency electrosurgical device includes a radiofrequency generator, an active electrode and means actuated by the radiofrequency generator for supplying radiofrequency current to the active electrode, a warning device and means activated by the current sensing means to activate the warning device when indicating the discontin-uity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA306,537A CA1099790A (en) | 1978-06-29 | 1978-06-29 | System for monitoring integrity of a patient return circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA306,537A CA1099790A (en) | 1978-06-29 | 1978-06-29 | System for monitoring integrity of a patient return circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1099790A true CA1099790A (en) | 1981-04-21 |
Family
ID=4111817
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA306,537A Expired CA1099790A (en) | 1978-06-29 | 1978-06-29 | System for monitoring integrity of a patient return circuit |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1099790A (en) |
-
1978
- 1978-06-29 CA CA306,537A patent/CA1099790A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4121590A (en) | System for monitoring integrity of a patient return circuit | |
| US3683923A (en) | Electrosurgery safety circuit | |
| CA1196967A (en) | Electrosurgical generator safety apparatus | |
| US4106494A (en) | Heart defibrillating and monitoring system | |
| US5485059A (en) | Lighting circuit for vehicular discharge lamp | |
| ES2278051T3 (en) | DETERMINE ELECTRIC FAULTS IN ELECTRICAL ENERGY SYSTEMS WITHOUT GROUND CONNECTION USING A DIRECTIONAL ELEMENT. | |
| US4123673A (en) | Control circuit for an electrical device | |
| EP0372050B1 (en) | Electrical safety apparatus | |
| US3808502A (en) | Isolator circuit for use with electrical medical equipment | |
| US5390382A (en) | Patient support tables and monitors | |
| US5051733A (en) | High voltage indicator device | |
| CN2318639Y (en) | Earth monitor for electrostatic earthed system | |
| JPS6132016B2 (en) | ||
| US11255924B2 (en) | Socket detection apparatus and method for supporting anomaly detection of earth wire and neutral wire | |
| US4649454A (en) | Apparatus and method for detecting an open ground connection | |
| CA1099790A (en) | System for monitoring integrity of a patient return circuit | |
| US7233866B2 (en) | Device for the management of electrical sockets | |
| CN210514439U (en) | Live working safety detection device for grounding electrode circuit | |
| KR100544916B1 (en) | Approching warning system of fixed type for electric power line | |
| CN210222113U (en) | Circuit protection detection system of protector | |
| US3609458A (en) | Electronic safety system | |
| EP0054940B1 (en) | Non-grounding checking system | |
| RU2017300C1 (en) | Device for measurement of leakage currents in trolleybus and for protective disconnection of trolleybus from supply network when leakage current exceeds specified value | |
| KR102585619B1 (en) | Non-contacting type alarming system for applied electric current and alarming method | |
| CN2055302U (en) | Medical two-direction micro current excess-current protector |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |