Medical generator with grid outage detection

Abstract

We provide power-resistant medical generators. [Solution] The generator 11, which was disconnected from the power grid during operation, can be reconnected to the supply grid 23 without concern or additional precautions. For example, the device connector that was unplugged during operation can be plugged back into the device, and the power switch 22 that was activated during operation can be switched back on. The control device 14 can then access the data, as well as measurements and settings, that were stored during the organized shutdown operation.

Description

Technical Field

[0001] The present invention relates to a medical generator with grid power outage detection.

Background Art

[0002] From European Patent No. 2853217, the basic configuration of a surgical generator is known. The surgical generator includes a rectifier on the input side and a power factor improvement circuit that supplies a DC voltage link to which a DC voltage converter is connected. The power factor improvement circuit and the DC voltage converter together constitute the current supply unit of the generator. The power factor improvement circuit has the ability to communicate with a system control device via a data interface to perform rapid power adjustment.

[0003] Further prior art is known from European Patent No. 2475319.

[0004] In addition to the power supply unit, the medical generator includes a functional module having, for example, a high-frequency oscillator for generating a strong HF current, and this HF current can be supplied to one or more instruments to achieve a surgical effect on a patient. The control of the functional module and, if applicable, the control of the current supply unit are also typically provided by a system control device operating in a program control manner.

[0005] This type of generator is widespread. In the case of an unexpected power supply interruption, such as unplugging the main power connector, other power interruptions, or an unintentional power outage due to an unintended switch-off during operation, data may be lost in the system control, and an undesirable state may occur.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

[0007] Based on the above, the objective of the present invention is to provide a power outage-resistant medical generator. [Means for solving the problem]

[0008] This objective is achieved by the generator described in claim 1.

[0009] The medical generator according to the present invention includes a power grid monitoring device, which has an evaluation circuit connected to the grid voltage input on the input side and monitors the presence of grid voltage. The power grid monitoring device is configured to generate a shutdown signal if the grid voltage is lost during operation, and the shutdown signal is appropriate for switching off the functional module to transition it to a safe state before the power supply unit can no longer supply power from the storage unit, and therefore the energy stored therein, to the functional module. The shutdown of the functional module and transition to a safe state can be achieved by closing a medium valve, backing up data where applicable in a predetermined sequence, such as sensor data, or backing up data from the progress of a control program running on the control device (e.g., regarding the duration of treatment already performed). For example, in a generator for argon plasma coagulation, upon receiving a shutdown signal, the oscillator supplying power to the instrument may be immediately turned off, while the valve for supplying argon to the instrument may be closed only afterward. A variety of other shutdown sequences are possible.

[0010] The storage unit may comprise one or more storage capacitors (e.g., electrolytic capacitors) located at one or more positions in the generator circuit, particularly within the power supply unit. For example, the power supply unit may comprise a power factor correction circuit that supplies power to a DC voltage link to which one or more capacitors are connected. One or more DC voltage converters may be connected to the DC voltage link, and these DC voltage converters may also have a capacitor or group of capacitors on their output side. Thus, the term “storage unit” refers to those capacitors or groups of capacitors that supply power to a unit that needs to be transitioned to a safe state in the event of a power outage. This unit may be an entire functional module or only a part of it, for example, a control device that can be part of a functional module.

[0011] The power supply unit, through its storage unit, can supply operating current to the functional module for a supply period of, for example, 100 milliseconds (ms) or more when the grid voltage input is current-free. Due to the dimensions of each storage unit, the supply period is at least long enough to transition the functional module, in particular its control, to a safe shutdown state within the supply period. Running programs can be terminated in an organized manner, and data such as sensor data and operational data can be saved.

[0012] Preferably, the power grid monitoring device is configured to generate a shutdown signal only after a preset standby period, the standby period being shorter than the supply period. This ensures that the difference between the supply period and the standby period is longer than the shutdown period required for the transition or control of the functional module.

[0013] Setting a standby period prevents power grid monitoring devices from generating shutdown signals based on irrelevant grid interference. Thus, the generator is inherently resistant to minor grid disturbances that are harmless. Such irrelevant, and therefore acceptable, grid disturbances can be, for example, a complete or partial loss of a power half-wave, or other power grid disturbances, such as short-term voltage fluctuations. If the standby period is, for example, 10 milliseconds or slightly more, a loss of a whole power half-wave will still not result in the generation of a shutdown signal. However, if the grid voltage is completely lost, a shutdown signal will be generated after the standby period ends, and the control of the functional module will transition to a safe state. Grid voltage loss can be a general blackout. Grid voltage loss can also be caused by unintentionally unplugging the generator's main power connector (e.g., by moving the generator in an operating room) or by unintentionally activating the generator's main power switch.

[0014] A control device provided for the control of the functional module and the entire generator may comprise one (or more) controllers (computational units) configured to process a control program and operated under the control of the program. The control program is configured to control the supply of voltage, current, or a medium such as gas or liquid to the connected instrument, thereby achieving a desired operating mode. The operating mode determines the surgical effect to be achieved for the patient. For each mode, specific electrical characteristics of the power supply to the instrument are predefined and can only be changed within predefined limits. Such electrical characteristics include, for example, voltage, frequency, modulation type, pulse-pause ratio in the case of on-off modulation, current intensity limits, power limits, and the temporal progression of the indicated parameters.

[0015] The control program is configured to initiate and process a shutdown sequence upon receiving a shutdown signal. During the shutdown sequence, the operation of the functional module can be terminated, acquired sensor data and other data where applicable can be backed up, and running programs can be terminated as needed. By storing the data, the control program can systematically continue its operation when the grid voltage returns. For example, the control program can be configured to store user input and / or program data, such as setting mode, upon receiving a shutdown signal during the shutdown sequence. In this way, the setting mode is maintained across power grid voltage failures. Treatment data recorded in this mode, such as application duration or application intensity, is also maintained so that the operation of the functional module can continue in a patient-safe manner after the power grid voltage returns.

[0016] The shutdown sequence also switches off powerful loads, such as oscillators supplying power to surgical instruments, immediately after receiving the shutdown signal, thereby allowing the energy present in the storage unit to be used primarily for further supplying the system control unit or another control device. This simplifies the shutdown of the control device (especially the entire system control unit) and the storage of all necessary data without the need for a separate energy storage unit for this purpose.

[0017] The power grid monitoring device is preferably connected to the grid voltage input via a full-wave rectifier, thereby monitoring the presence of both half-waves of the grid voltage. Between the grid connection and the full-wave rectifier, a net filter may be placed, having one or more reactive components, such as coupled or uncoupled inductors and especially capacitors, to avoid the propagation of electrical disturbances from the generator to the grid and from the grid to the generator.

[0018] Power grid monitoring devices are configured to detect both low-ohm and high-ohm grid voltage faults. In particular, power grid monitoring devices are configured to reliably detect these different fault scenarios, even when residual voltage exists within the grid filter due to energy storage components present within the grid filter, in the case of high-ohm voltage faults.

[0019] A low-ohm grid voltage fault exists when the grid voltage drops to zero, thereby bringing the two grid lines to the same potential ("blackout"), or when the grid voltage drops to such an extent that the generator can no longer operate correctly ("brownout"). A high-ohm grid voltage fault exists, for example, when the mains power connector is unintentionally pulled out of its socket, or when the equipment connector is pulled out of the generator. This can at least temporarily apply a DC voltage component to the grid voltage input of the power supply unit, and therefore to the input of the power grid monitoring device, and this DC voltage component can originate, for example, from a charged capacitor in the input-side grid filter.

[0020] Both fault scenarios are detected by a power grid monitoring device. For this purpose, the power grid monitoring device includes a high-pass filter connected to the input rectifier, which prevents DC voltage from passing through. Furthermore, the power grid monitoring device may include not only an impulse generating circuit but also a clock generator circuit that determines the standby period. The clock generator circuit can be configured as a re-triggerable monoflop that generates a shutdown signal if it is not triggered from the grid side within the standby period by a new impulse. These impulses are newly generated by each power half-wave.

[0021] Further details of advantageous embodiments of the present invention are the subject of the dependent claims, specification, and assigned drawings. [Brief explanation of the drawing]

[0022] [Figure 1] FIG. 1 is a schematic view of a medical generator according to the present invention provided with a power grid fault detection. [Figure 2] FIG. 2 is a basic circuit diagram of the power supply unit of the generator according to FIG. 1. [Figure 3] FIG. 3 is a schematic and simplified view of the power supply unit and the assigned power grid monitoring device. [Figure 4] FIG. 4 is an exemplary diagram of the time course of the rectified grid AC voltage. [Figure 5] FIG. 5 is a diagram of the time progression of the supply voltage and the shutdown signal according to the grid voltage in FIG. 4. DETAILED DESCRIPTION OF THE INVENTION

[0023] In FIG. 1, an instrument 10 for treating a human or animal patient and a generator 11 are schematically shown, and the generator serves to supply power to the instrument 10. The instrument 10 can be an electrosurgical instrument configured in a monopolar or bipolar or multipolar mode. For example, this instrument can serve to perform tissue coagulation, cutting, fusion, or another electrosurgical procedure. The generator 11 can also be configured to supply other media, such as liquid, vapor, aerosol, or gas, such as argon, to the instrument 10, in addition to supplying power for electrosurgical procedures. The generator can also include a suction device, for example, to suction gas, fumes, or liquid from the surgical field. The instrument 10 can also be an instrument for argon plasma coagulation or a cryosurgical instrument, etc.

[0024] To supply the appliance 10, the generator 11 comprises a functional module 12 that provides one or more of the indicated media (electricity, gas, liquid) for the appliance 10. In Figure 1, the functional module 12 is shown only as a pure power supply module having a high-frequency oscillator 13 and a control device 14. The control device may also be configured to control the entire generator and thus form system control. However, the functional module 12 may additionally or alternatively comprise additional or other supply modules, such as sources of cryogenic fluid, flushing fluid, etc.

[0025] The oscillator 13 comprises at least one output 15 to which the instrument 10 is connected, to which a high voltage and respective current are supplied for performing the desired surgical purpose. The oscillator 13 preferably includes a high-frequency alternating current having a frequency above 200 kHz but at least preferably below 5 MHz. To generate the HF voltage, the HF oscillator 13 can have any known circuit configuration.

[0026] The HF oscillator 13 (and any other supply module) operates under the control of a control device 14 configured to set the characteristics of the current or voltage generated by the HF oscillator 13. Such characteristics may be, for example, the voltage and / or current height, output power, the type and degree of modulation applied to the current, and the crest factor. In this way, the control device 14 can set the operating mode, for example, coagulation, cutting, tissue fusion, etc. Furthermore, sensor units may be provided in or on the HF oscillator 13 to acquire data such as the amount of voltage output to the instrument, the amount of current, the treatment period, the amount of energy, and the tissue resistance. These sensor units can transmit their respective data to the control device 14. The control of the oscillator 13 by the control device 14 is represented by arrow 16. The transmission of data from the oscillator 13 to the control device 14 is represented by arrow 17.

[0027] To control the HF oscillator 13, the control device 14 comprises a programmable unit such as a controller 14a, a computing unit, or a network of controllers or computers. The controller or multiple controllers 14a or computers are configured to operate in a program-controlled manner. Furthermore, the control device 14 comprises one or more data memories (not shown) for recording and storing one or more programs, data resulting from processing the programs, and data supplied from the sensor unit (arrow 17).

[0028] The control device 14 further includes an input / output device 18 having operating elements for user input and output elements. The input elements may be keys, buttons, touchscreens, etc. The output means may be a display for representing optical information, a control lamp, a measuring instrument, etc. However, the input / output means may also be located outside the generator 10 and may be formed by a portable device connected to the generator 10 by a wired or wireless data connection.

[0029] The functional module 12 is connected to the power supply unit 20, and its grid voltage input 21 is connected to a general power supply grid 23 via a power switch 22, which is at least optionally provided. The power switch 22 is configured to selectively close or interrupt at least one, preferably both, of the lines leading to the grid voltage input. A grid filter is typically provided between the power switch 22 and the grid voltage input 21. For the connection between the generator 10 and the supply grid 23, there is a connecting cable, such as a commercially available cold device cable having a grid-side connector and an equipment-side connector.

[0030] AC voltage grids are typically grids with a grid frequency of 50 Hz or 60 Hz and an effective voltage between 110 volts and 240 volts. However, the present invention is also suitable for use in generators for other grids.

[0031] The power supply unit 20 has at least one, typically multiple, operating voltage outputs 24, 25 to supply the operating voltage required for the functional module 12 at each of the operating voltage inputs 24a, 25a. The operating voltage is a DC voltage. For example, several hundred volts of DC voltage can be applied to operating voltage output 24, but only DC voltages suitable for the operation of the control device, including the control device 14, such as 3, 5, 12, or 24V, can be applied to operating voltage output 25. Other voltages are also possible depending on the configuration of each control device.

[0032] The power supply unit 20 is connected to the supply grid 24 via a power switch 22 with a grid voltage input 21 to draw the required operating power. The voltages applied at the operating voltage outputs 24 and 25 are preferably stabilized DC voltages, supplying DC current to the HF oscillator 13 and the control device 14.

[0033] The power supply unit 20 includes a storage unit 26 that can supply operating power to the functional module 12, symbolized as an ohmic load in Figure 3, during a supply period V (Figure 5) if the power supply unit 20 does not receive current from the supply grid 23 at its grid voltage input 21. For example, such a situation could be an unexpected failure of the grid voltage, an unintentional or intentional disconnection of the grid connector of the generator 11, or the activation of the power switch 22. Thus, the supply period V depends on the capacity of the storage unit 26, the load stored in the storage unit 26, and the maximum power requirements of the functional module 12 during the processing of the shutdown sequence.

[0034] In this invention, it is important that an operating voltage (and current) is supplied to the control device 14, which is at least entirely or partially programmed, during the supply period V (shutdown sequence) when the grid voltage is lost. Conversely, for the HF oscillator 13, it is acceptable for the operating voltage supplied to the HF oscillator 13 to decrease during the supply period Z. However, to avoid undesirable surgical effects in the shutdown sequence situation, and thus harm to the patient, the voltage applied to the operating voltage output 24 for the operation of the RF oscillator 13 can also be maintained throughout the supply period Z. Alternatively, to consume as little energy as possible during the shutdown sequence, the HF oscillator can be turned off immediately after receiving the shutdown signal in the shutdown sequence situation.

[0035] The storage device 26 may consist of one or more capacitors, preferably electrolytic capacitors, which may be located at different positions within the power supply unit. Referring to Figure 2, a schematic diagram of the basic structure of the power supply unit 20 is shown.

[0036] The power supply unit 20 includes, for example, a full-wave rectifier 27 in the form of a full-wave bridge (Grätz bridge) adjacent to a power factor correction circuit (PFC) on its input side. Part of the power factor correction circuit consists of an inductor L and a diode D connected in series with each other, preferably connecting the positive output of the full-wave rectifier 27 to the positive connection of a storage capacitor 28. The connection point between the inductor L and the diode D is connected to an electronic switch T in the form of, for example, a bipolar transistor, a field-effect transistor, or an IGBT, and the emitter or source of the electronic switch is connected to ground M as well as the negative connection of the storage capacitor 28. The electronic switch T includes a control electrode connected to a PFC clock generator 29. The periodic opening and closing of the electronic switch T charges the storage capacitor 28 to a DC voltage higher than the peak voltage of the grid AC voltage.

[0037] A DC / DC converter connected to the input side of the storage capacitor 28 is adjacent to the power factor correction circuit (PFC), and the DC / DC converter also serves to galvanically isolate the operating voltage outputs 24, 25 from the grid voltage input 21. In principle, any DC / DC converter of known configuration can be used for this purpose. In this embodiment, the DC / DC converter comprises a full-wave inverter 30 having a total of four control electronic switches T1, T2, T3, T4 controlled by an inverter clock generator 31. The primary winding of a transformer 32 is connected to the full-wave inverter 30, and the transformer may have one or more secondary windings 33, 34. The secondary windings and supply storage capacitors 35, 36 are connected to their respective operating voltage outputs 24, 25 via full-wave rectifiers GL1, GL2.

[0038] For further explanation of the illustrated embodiment, we first assume that in the event of a sudden grid failure, it is important that operating power is supplied to the control device 14 until the program running on the control device 14 is systematically terminated and data, such as data received from the HF oscillator 13 and other data, is backed up, for the systematic shutdown of the generator 11 and thus the systematic restart of the generator. In this case, the relevant storage unit 26 is formed by storage capacitors 36 and 28. The latter is converted in terms of its capacitance based on the transmission coefficient between the primary and secondary windings 34 of the transformer 32, minus any possible efficiency losses. In the event of a grid failure, power is needed for the systematic termination of the operation of the control device 14 and transition to a specified shutdown condition, so the storage unit 26 is suitable for supplying power to the control device 14 over a supply period V, and therefore for its length or longer.

[0039] According to the present invention, the generator 11 includes a power grid monitoring device 37 configured to provide a shutdown signal sig from its output 38 to the input 39 of a functional module 12 when a loss of grid voltage at the grid voltage input 21 is determined. This allows the functional module 12 to, upon receiving the shutdown signal sig, initiate a shutdown sequence, particularly of the control device 14, which then backs up data and terminates any running operational programs. Part of this can also be the shutdown of the HF oscillator 13, and, where applicable, the output of light and / or sound and / or other signals to inform the operator that the generator 10 is no longer operating. In some cases, it may also indicate that an initiated surgical procedure, such as a coagulation or fusion process, has not yet been properly completed, for example, during vascular sealing.

[0040] The power grid monitoring device 37 is evident from Figure 3. The power supply unit 20, formed by a power factor correction circuit (PFC) and a DC / DC converter, is shown only schematically along with its storage unit 26. Next, on the input side, a full-wave rectifier (Greats bridge) consisting of diodes D1-D4 is shown in front of a net filter indicated only by a capacitor 40.

[0041] Furthermore, diodes D5 and D6 are connected to the AC voltage input 21 to form a second Greitzbridge, i.e., a full-wave rectifier, together with diodes D1 and D3 (full-wave rectifier 27) of the first Greitzbridge. The rectified voltage drawn from the grid voltage input 21 is formed by two or more resistors 41a, 41b and supplied to the impulse forming circuit 43 via a voltage divider 41 that helps with level adaptation and a capacitor 42 that plays a role in removing the DC voltage component. Capacitor 44 and a discharge resistor 45 connected in parallel with capacitor 44 to form an RC element are part of the impulse forming circuit 43. A trigger circuit 46 is connected to the RC element and together with the RC element forms the impulse former 43.

[0042] The impulse generator 43 is connected at its output side to another impulse generator having another RC element consisting of a capacitor 47 and a discharge resistor 48, to which the trigger circuit 49 is also connected. This trigger circuit 49 is connected at its output side to the light-emitting diode of an optical coupler that forms the output 38 of the power grid monitoring device 37.

[0043] The generator 11, and especially the power grid monitoring device 37, as described above, operates as follows.

[0044] Case 1: The grid voltage of the supply grid 23 completely collapses during the operation of the generator 11. Therefore, the voltage at the AC voltage input 21 drops to virtually zero almost immediately. The power factor correction circuit (PFC) stops operating, and as a result, the storage capacitor 28 receives no additional charge. However, the DC / DC converter can continue to operate, at least as long as the voltage supplied to the storage capacitor 28 is sufficient for its operation. In doing so, the DC / DC converter can transfer at least a portion of the charge of the storage capacitor 28 to the capacitor 36.

[0045] We assume that grid voltage breakdown occurs at time t0, marked in Figure 5. Prior to this, i.e., prior to the loss of grid voltage, each power half-wave provides a charge on capacitor 44 via one of diodes D5 and D6, and capacitor 44 is discharged again substantially immediately by discharge resistor 45. Thus, at the output of trigger circuit 46, a power half-wave synchronous charging impulse is available to charge the RC element formed by capacitor 47 and resistor 48. As long as the charge is maintained, trigger circuit 49 signals the presence of grid voltage at output 38, for example, by lighting up the light-emitting diode of the optical coupler located therein. The power grid monitoring device can be considered as a re-triggerable monoflop continuously triggered anew by impulses provided at the output of trigger circuit 46 derived from power half-waves. However, once these impulses, starting from time t0, are lost, a certain discharge time for capacitor 47 elapses, and after its completion, trigger circuit 49 switches off (i.e., diode 38 turns off). The disappearance of diode 38 is the signal sig, which switches the functional module 12 off.

[0046] The period between the trigger impulse at time t0 and the switching of the trigger circuit 49, and therefore the extinguishing of the light-emitting diode at output 38, is the standby period, and this standby period is shown in Figure 5 as t K This is shown by [the source]. In other words, after the grid voltage loss, a waiting period K is observed, and at time t K Then the shutdown signal sig is generated.

[0047] The waiting period is specified as period T in Figure 4. A This has the advantage that very short-term grid disturbances, such as those present in the system, do not result in a shutdown process. The loss of an interference impulse or an entire power half-wave also does not result in the generation of a shutdown signal (sig). However, if multiple power half-waves are subsequently lost within a time interval, and their total duration is longer than the waiting period K, then a signal (sig) is generated.

[0048] The functional module 12 receives the shutdown signal sig and initiates the shutdown sequence. In particular, the control device 14 backs up the current data and program conditions in the shutdown sequence to enable organized continued operation after reboot.

[0049] From the dimensions of the storage unit 26 and the power requirements of the functional module 12 or at least the control device 14, a supply period V is obtained in which the energy stored in the storage unit 26 can guarantee the operation of the control device 14. In particular, the shutdown period Z required for the systematic shutdown of the control device 14 is preferably shorter than (or at most the length of) the difference between the supply period V and the standby period K. This condition is guaranteed by the respective dimensions of the storage capacitors 28 and 36 (Figure 2). In this regard, Figure 5 shows that the supply voltage UV begins to decrease only after the end of the supply period V.

[0050] Case 2: Intentionally or unintentionally disconnecting the power connector, thus isolating the generator 11 from the power grid 23, or opening the power switch 22 also results in a loss of power that would otherwise be supplied by the grid. Therefore, in this case as well, the voltage half-wave is no longer transmitted to the power grid monitoring device 37 via diodes D5 and D6. This also prevents capacitor 42 from simulating the presence of grid voltage if a DC voltage that may be supplied over capacitor 40 (i.e., within the net filter) is present. For this reason, the procedures described so far in this scenario are fully equivalent to those in the above scenario.

[0051] The medical generator according to the present invention comprises a power supply unit 20 having storage capacity, which is sufficient to enable the control device 14 for at least a period V, during which data, measurements, program conditions and settings, etc., present in the control device 14 can be backed up and stored for organized continuous operation. A power grid monitoring device 37 is provided to continuously monitor the grid voltage and output a shutdown signal sig as soon as the grid voltage is no longer present for a period longer than the standby period, in order to also determine grid voltage breakdown or isolation of the generator 11 from the supply grid 23. The standby period is preferably longer than the duration of a half-wave power wave, and preferably longer than the duration of a full-wave power wave.

[0052] In the concept of the present invention, for example, a generator 11 that has been disconnected from the power grid during operation can be reconnected to the grid without concern or additional precautions. For example, a device connector that has been unplugged during operation can be plugged back into the device, or a power switch that has been activated during operation can be switched back on. The control device 14 can then access the data, as well as measurements and settings, that were stored during the organized shutdown operation. [Explanation of Symbols]

[0053] 10 devices 11 Generators 12 Function Modules 13 HF Oscillator 14 Control Devices 15. Equipment output 16 Arrows 17 Arrows 18 Input / Output Devices 20 Power Supply Units 21 Grid voltage input 22 Power switch 23 Supply Grid 24 Operating voltage output 24A Operating Voltage Input 25 Operating voltage output 25a Operating voltage input 26 Storage section Z supply interval 27 Full wave rectifier PFC power factor correction circuit L Inductor D diode T Electronic switch 28 Storage Capacitor M Ground 29 PFC control unit DC / DC Voltage Converter 30 Full-wave inverters 31 Inverter Clock Generator 32 Transformers 33 First secondary winding 34 Second secondary winding 35 Storage Capacitor 36 Storage Capacitor 37 Grid monitoring devices 38 Outputs sig signal 39 Inputs 40 Grid filter capacitors 41. Voltage divider 41a,41b Resistance 42 Capacitors 43 Impulse Generating Circuit 44 Capacitors 45 Discharge resistance 46 Trigger Circuit 47 Capacitors 48 Discharge Resistance K Waiting period V Supply period Z Shutdown Period

Claims

1. A medical generator (11), The power supply unit (20) has a grid voltage input (21) that can be connected to an AC voltage power supply grid (23) and has at least one operating voltage output (24, 25), The device has at least one functional module (12) which includes at least one operating voltage input (24a, 25a) connected to the at least one operating voltage output (24, 25) and at least one instrument output (15) to which a surgical instrument (10) can be connected, The power supply unit (20) includes a storage unit (26) configured to supply operating current to the functional module (12) for a predetermined supply period (V) when there is no current grid voltage input (21), The medical generator (11) has a power grid monitoring device (37), A medical generator comprising a power grid monitoring device (37) having inputs (D5, D6) connected to the grid voltage input (21), and configured to generate a shutdown signal (sig) and transmit the shutdown signal to the functional module (12) in order to transition the functional module (12) to a safe state within a shutdown period (Z) when the grid voltage is lost.

2. The generator according to claim 1, wherein the power grid monitoring device (37) is configured to generate the shutdown signal (sig) only after a predetermined waiting period (K), and the waiting period (K) is shorter than the supply period (V).

3. The generator according to claim 2, characterized in that the difference between the supply period (V) and the standby period (K) is longer than the shutdown period (Z) required by the functional modules (12, 14) for the transition to a safe state.

4. The generator according to claim 1, characterized in that the functional modules (12, 14) each include at least one controller (14a) that operates in a manner controlled by a control program.

5. The generator according to claim 4, characterized in that the control program is configured to receive the shutdown signal (sig) and terminate the operation of the functional module (12) in response to the shutdown signal (sig).

6. The generator according to claim 1, characterized in that the power grid monitoring device (37) is connected to the grid voltage input (21) via full-wave rectifiers (D1, D3, D5, D6), and on the output side, it is connected to a clock generator circuit (47, 48, 49).

7. The generator according to claim 6, characterized in that the clock generator circuits (47, 48, 49) are configured to determine the standby period (K).

8. The generator according to claim 1, characterized in that the clock generator circuits (47, 48, 49) are configured as re-triggerable monoflops.

9. The power grid monitoring device (37) includes at least one grid-triggered impulse generating device (44, 45, 46) configured to generate a charge impulse (LP) for each power half-wave that generates a trigger impulse (TP), wherein the charge impulse (LP) is transferred to an RC element having a storage capacitor (47) and a discharge resistor (48) connected in parallel to the storage capacitor (47), the RC element defining a time constant (τ), and the storage capacitor (47) charging to a predetermined charge voltage (U Ｌ The generator according to claim 1, characterized in that it is charged by each charging impulse.

10. The generator according to claim 9, characterized in that a threshold switch (49) having a predetermined switching threshold is provided downstream of the RC elements (47, 48).

11. The generator according to claim 10, characterized in that the charging voltage, the switching threshold, and the time constant (τ) are adjusted to each other such that the switching threshold is achieved only after a plurality of charging impulses (LP) have stopped.

12. The generator according to any one of claims 1 to 11, characterized in that the power supply unit (20) comprises a grid rectifier (27) having an output connected to the grid voltage input (21) on the input side and to which a power factor correction circuit (PFC) is connected.

13. The generator according to claim 12, characterized in that the power factor correction circuit (PFC) is connected to supply power to at least one storage capacitor (28) which is part of the storage unit (26).

14. The generator according to claim 13, characterized in that a DC / DC converter is connected to the storage capacitor (26), and the output side is provided with a storage capacitor (36) which is part of the storage unit (26).

15. The generator according to claim 14, characterized in that the DC / DC converter is configured in an isolated manner.

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