Particle contact detection method, control console of ophthalmic operation system and ophthalmic operation system

Abstract

The invention relates to a method for detecting the contact of particles (19) in contact with a treatment needle (6) of an ophthalmic surgical handpiece (2), in which the treatment needle (6) can be driven by an oscillation of an electric drive unit (10), for which purpose a generator unit (15) at least intermittently applies a time-varying electric drive signal to the electric drive unit (10). According to the invention, in a low-oscillation state of the treatment needle (6), the treatment needle (6) is oscillated with a maximum first oscillation amplitude (A1), an electrical contact signal (35) of the electrical drive unit (10) is detected on the basis of a second oscillation amplitude (A2) of the treatment needle (6), the second oscillation amplitude (A2) being greater than the first oscillation amplitude (A1), the detected electrical contact signal is evaluated, and determining the contact of the particles (19) with the treatment needle (6) on the basis of the evaluation.

Description

[0001] The invention relates to a method for detecting contact of particles with a treatment needle of an ophthalmic surgical handpiece. The treatment needle can be driven by oscillation of an electric drive unit, for which a time-varying electric drive signal is applied to the electric drive unit at least intermittently by a generator unit. The invention also relates to a console of an ophthalmic surgical system for operating an ophthalmic surgical handpiece, which can be connected to the console and includes a treatment needle and an electric drive unit for driving the treatment needle by oscillation. The console includes at least one generator unit for providing a time-varying electric drive signal to the electric drive unit. Finally, the invention also relates to an ophthalmic surgical system for treating an eye, which has at least one ophthalmic surgical handpiece for operating an eye lens. The ophthalmic surgical handpiece includes a treatment needle and an electric drive unit for driving the treatment needle by oscillation. The ophthalmic surgical system also includes a console for operating the ophthalmic surgical handpiece, to which the ophthalmic surgical handpiece can be connected at least during the intended operation. The console includes a generator unit, which can be coupled to the handpiece and is used to provide a time-varying electric drive signal to the electric drive unit of the handpiece.

[0002] The ophthalmic surgical system, its console and handpiece, and the particle contact detection method are particularly used to treat lens opacities of the eye lens of a living being (e.g., a human or an animal). In medicine, lens opacities are also called cataracts, etc. One possibility for treating lens opacities is to replace the lens of the eye with an artificial lens. For example, phacoemulsification is a technique for treating lens opacities. Phacoemulsification can be performed by the ophthalmic surgical system.

[0003] An important component for performing phacoemulsification is an ophthalmic surgical handpiece, hereinafter referred to as just the handpiece. The handpiece includes a treatment needle mechanically connected to a handpiece drive unit. During the intended operation, the treatment needle is driven by the oscillation of the drive unit. Typically, the tip of the drive needle is driven to implement vibrations in the ultrasonic range, for example in the range of about 10 kHz to about 80 kHz. When the needle tip of the treatment needle comes into contact with the eye lens to be exchanged or replaced, it causes phacoemulsification, that is, pulverization, and releases lens fragments or particles. Typically, during the treatment of phacoemulsification, an irrigation fluid is supplied to the eye. At the same time, an aspiration fluid is extracted from the surgical area of ​​the eye. For this purpose, the treatment needle is usually designed as a hollow needle, whereby a portion of the aspiration line with an opening in the needle tip area can be provided. The particles released during the phacoemulsification of the eye are removed from the surgical area via the aspiration line together with the aspiration fluid. After the eye lens is removed in this way, an artificial eye lens is implanted in its place. This can basically complete the treatment of the eye, and vision can be at least partially restored.

[0004] It is well known that due to the mechanical ultrasonic movement of the treatment needle, heat may be generated during eye treatment due to friction and other reasons. Firstly, this will reduce the effectiveness associated with the emulsification of the eye lens, and secondly, it will lead to an undesirable large amount of heat input locally into the eye, which may cause irreversible damage to the eye. Furthermore, especially in the case of longitudinal oscillation of the needle tip of the treatment needle, lens fragments or particles to be washed out or lens fragments or particles that have already adhered may be pushed away. This may extend the time required for the operation, which may also increase the energy input into the eye, resulting in heat generation. In this context, DE 102010 047 009A1, for example, discloses a control device for an ophthalmic surgical system, which allows the power of a drive unit to be controlled based on the particle characteristics of the particles determined by an optical system.

[0005] According to the teaching of DE 10 2010 047 009 A1, a separate optical system is required, and also image processing is required so that the particle properties can be determined and the amount of ultrasonic energy supplied to the handpiece can be controlled on this basis. If the image processing is performed at a high resolution, relatively comprehensive signal processing may be required and lead to a significant delay in the adjustment speed.

[0006] The problem to be solved by the present invention is to develop a method, a control console and an ophthalmic surgery system, the effect of which is, in particular, to further reduce the heat input during treatment of the eye, thereby achieving a relatively fast and reliable treatment of the eye.

[0007] As a solution, the invention proposes a method, a console and an ophthalmic surgery system as described in the independent claims.

[0008] Advantageous developments emerge from the features of the dependent claims.

[0009] Regarding the general method, the present invention particularly proposes that, in a low oscillation state of the treatment needle, the treatment needle oscillates at a maximum first oscillation amplitude, an electrical contact signal of the electric drive unit is detected based on a second oscillation amplitude of the treatment needle, the second oscillation amplitude is greater than the first oscillation amplitude, the detected electrical signal is evaluated, and the contact between the particles and the treatment needle is determined based on the evaluation.

[0010] With regard to the general control console, the present invention particularly proposes that the control console comprises a detection unit electrically coupled to the drive unit, the detection unit being adapted to detect an electrical contact signal of the electric drive unit based on a second oscillation amplitude in a low oscillation state of the treatment needle in which the treatment needle oscillates with a maximum first oscillation amplitude, the second oscillation amplitude being greater than the first oscillation amplitude. The control console further comprises an evaluation unit for evaluating the detected electrical contact signal and determining contact of the particles with the treatment needle based on the evaluation.

[0011] With respect to a general ophthalmic surgical system, the present invention particularly contemplates a console designed in accordance with the present invention.

[0012] The invention is based in particular on the idea that it is usually necessary to drive the treatment needle by oscillation only when the treatment needle contacts the eye lens or a fragment or particle of the eye lens to be replaced. Through the invention, it was recognized that the drive unit is not limited to unidirectional use for driving the treatment needle by oscillation; rather, it can also be used in reverse, in particular when the treatment needle contacts the lens fragment or particle, an electrical contact signal is output based on the movement of the treatment needle. As a result, the contact of the lens fragment or particle with the treatment needle can be determined by appropriately evaluating the electrical contact signal provided by the drive unit accordingly. In this case, the invention also makes use of the knowledge that the drive unit can usually be operated bidirectionally. That is, the application of an electrical drive signal can result in a mechanical movement of the treatment needle, and conversely, the mechanical movement of the treatment needle can result in an electrical contact signal. Therefore, the invention not only utilizes the drive function of the drive unit, but also simultaneously enables the sensor function of the drive unit to be utilized.

[0013] The invention makes use of the effect that contact of the treatment needle with the particles results in a mechanical movement of the treatment needle, and this results in an electrical contact signal of the drive unit due to the mechanical coupling to the drive unit. Depending on the design of the drive unit, the electrical contact signal can be, for example, a current or a voltage. The detection unit is designed to be appropriately adapted to the electrical contact signal so that the electrical contact signal output by the drive unit can be reliably detected. It goes without saying that corresponding statements also apply to the drive signal provided by the generator unit. The drive signal is a time-varying electrical drive signal, which can be, for example, a time-varying voltage, in particular an AC voltage, or a time-varying current, in particular an alternating current. The generator unit is suitably designed to be able to provide the drive signal.

[0014] The electrical drive signal is usually an AC voltage provided by a generator unit. To this end, the generator unit may include an electrical energy transducer or an electrical energy converter in the form of an inverter, a converter or the like. The electrical drive unit may be designed as an electrostatic drive unit or an electromagnetic drive unit. As an electrostatic drive unit, the drive unit may be designed in a piezoelectric-based manner. To this end, the drive unit may include a piezoelectric element or a plurality of piezoelectric elements mechanically and electrically connected to each other in a suitable manner. The piezoelectric-based drive unit thus formed allows the use of such an effect: when an AC voltage is applied to the piezoelectric elements as an electrical drive signal, their mechanical dimensions, such as position, etc., are changed. The treatment needle is mechanically connected to the piezoelectric-based drive unit, so that the desired drive effect can be achieved during the intended operation. In contrast, in the case of an electromagnetic drive unit, an electromagnetic-mechanical transducer can be provided accordingly, for example, the electromagnetic-mechanical transducer can be acted on by an alternating current as an electrical drive signal. For example, using an alternating magnetic field, a magnetizable actuator of the transducer can be actuated so that the desired mechanical movement can be generated. Typically, the electric drive unit has electrical terminals to which an electric drive signal can be applied to achieve the desired mechanical movement of the treatment needle.

[0015] The generator unit is preferably an electronic unit designed to provide an electric control variable for the electric drive unit. To this end, the generator unit can include an electronic circuit, such as an inverter or the like. In addition, the generator unit can of course also include a control unit in the form of a hardware circuit, in particular a programmable computer unit, which can be provided as a supplement or alternative to the hardware circuit. Therefore, the generator unit provides an electric drive signal. The generator unit is designed to provide the electric drive signal in a time-varying manner, preferably in an oscillating manner. The oscillation frequency is preferably greater than about 10kHz, particularly preferably about 40kHz. Depending on the type of electrical power provided to the drive unit, the amplitude of the oscillation can be set by the generator unit. Of course, the electric drive signal can also be provided in a clocked manner, for example in the form of a pulse sequence, such as a burst, etc. In order to be able to obtain a specific predeterminable type of oscillation of the treatment needle, the generator unit can also provide the electric drive signal at multiple frequencies and corresponding corresponding amplitudes and phase angles relative to each other.

[0016] The present invention makes use of the idea, in particular, that in a non-oscillating or low-oscillating state of the treatment needle, the drive unit is able to provide an electrical contact signal as soon as contact with particles occurs. Since the detection unit can be coupled to the electric drive unit, the electrical contact signal from the drive unit can be detected by the detection unit. Therefore, with respect to the oscillation caused by the drive signal, the movement of the treatment needle should be attenuated to such an extent that the contact signal can be reliably detected by the detection unit. To this end, it can be provided, for example, that after the generator unit has deactivated the drive signal, the attenuation of the oscillation of the treatment signal is detected and that the detection of the electrical contact signal from the drive unit is activated in the detection unit as soon as the detected signal is less than a specified or prescribable comparison value. In this way, a decoupling of the drive function of the drive unit from the sensor function can be achieved. Therefore, the present invention is based, among other things, on the use of the handpiece as a sensor unit in addition to its intended use during phacoemulsification therapy.

[0017] Preferably, the oscillation state of the treatment needle caused by the drive unit includes not only the oscillation of the treatment needle when the electrical drive signal from the generator unit is applied to the drive unit, but also includes a decay period after the generator unit deactivates the electrical drive signal, during which the oscillation of the treatment needle at least partially decays. Typically, the treatment needle will continue to oscillate during a limited decay period after the electrical drive signal is deactivated until the oscillation of the treatment needle is substantially decayed, preferably completely decayed due to the damping of the oscillation. In general, the present invention enables the detection of contact of particles with the treatment needle without the need for additional measures to be implemented on the ophthalmic surgical handpiece. This means that this additional function can be realized with relatively little expenditure by modifying the ophthalmic surgical system, in particular the console. The low oscillation state represents a state in which the treatment needle does not oscillate or has at most a first oscillation amplitude. The contact of the particle with the treatment needle results in a second oscillation amplitude of the treatment needle, which is detected by the evaluation unit as an electrical contact signal from the electrical drive unit, wherein the second oscillation amplitude is greater than the first oscillation amplitude. In the low oscillation state, the drive unit is deactivated. Therefore, the treatment needle is not driven by oscillation.

[0018] The evaluation of the detected electrical contact signal may include an evaluation of the curve profile, an evaluation of the cycle duration, an evaluation of the amplitude, etc. The evaluation may be implemented by an electronic evaluation unit suitable for this purpose, which may include a hardware circuit and / or a programmable computer unit for this purpose. The evaluation unit may at least partially consist of a detection unit or a control unit of the console. The size, hardness or speed of the particles may be further determined by the evaluation. To this end, within the scope of the evaluation, the electrical contact signal may be appropriately analyzed. In this case, the evaluation may take into account parameters that are empirically determined at an early stage during the production or initialization of the ophthalmic surgical system. The evaluation of the detected signal may also include spectral analysis and statistical methods, for example in order to be able to determine the direction in which the particles are in contact with the needle.

[0019] However, the present invention is not only suitable for detecting contact of particles with the treatment needle; it is also particularly suitable for removing blockages in the area of ​​the treatment needle, in particular blockages associated with aspiration. Since the ophthalmic surgical handpiece or its treatment needle only needs to be activated when in contact with the eye lens or particles of the eye lens, the present invention makes it possible to significantly reduce the heat input into the eye. Only when in contact with particles or the eye lens does the treatment needle need to be operated in an oscillating manner by the drive unit. Therefore, since this reduces the activation of the treatment needle oscillations, the treatment of the eye, in particular the eye lens, can be significantly improved, especially with regard to the heat input. In addition, since the adverse fluid dynamic effects known from the prior art can be reduced, the removal of particles and aspirated fluid can also be improved at the same time.

[0020] It is particularly advantageous that the present invention can be combined with a function which allows at least partially automatic deactivation of the output of the drive signal (for example because there are no or hardly any particles present, there is no longer contact with the eye lens, etc.). To this end, for example, provision can be made for a detection of the presence of particles in the aspirated fluid, as disclosed, for example, in DE 10 2020 118 887 A1 or other documents. Thus, the following operation of the handpiece can be achieved: essentially, the drive signal is output to the drive unit only when ultrasonic energy is required for emulsification purposes. If there is no contact with any particles or the eye lens, the energy output can be terminated automatically and the detection mode can be activated. Of course, as an alternative or in addition, provision can also be made for the energy output to be terminated manually by the surgeon. Overall, this can significantly reduce the heat input into the eye.

[0021] A development scheme proposes that the electrical contact signal is detected in addition to applying the electrical drive signal to the electrical drive unit. This development scheme allows the electrical wires that electrically couple the drive unit to the generator unit or the control console to also be used for the detection unit to detect the electrical contact signal. Because, in general, the amplitude or deflection of the drive signal can be much larger than the electrical signal when the particles are in contact with the treatment needle, it is not necessary to operate the detection unit when the drive signal is applied to the electrical drive unit. For this purpose, the detection unit can be separated from the wires by a separate switching device or switching unit to prevent excessive use of the detection unit. For example, this can be achieved by an electromechanical and / or electronic switching unit. Therefore, as soon as the generator unit deactivates the drive signal, the detection unit can preferably be connected to the wires. At the same time, this configuration allows the detection unit to detect the attenuation of the oscillation state of the treatment needle. This can further improve the process.

[0022] It is also proposed that the detection of the electrical contact signal is activated only after a specified time interval has passed since the moment when the electrical drive signal ends. For example, the specified time interval can be selected so that even in unfavorable conditions, the attenuation of the oscillations of the treatment needle after the drive signal is deactivated also reliably occurs. The start time of the specified time interval can be coupled to the deactivation time of the drive signal, in particular it can also coincide with it. For this purpose, a suitable control signal can be provided by the control unit of the generator unit or the control console, which control signal is able to trigger the start of the specified time interval. In addition, the expiration of the time interval can trigger an activation signal for the detection unit, which activates the detection unit to detect the electrical contact signal. This can produce automatic timing, thereby ensuring reliable operation of the detection unit.

[0023] Preferably, the time interval is determined based on the mechanical damping of the oscillations of the treatment needle. For example, the time interval may have been determined based on empirical measurements or the like. However, it may also be provided that the time interval is additionally determined based on the amplitude of the drive signal at deactivation. Preferably, the time interval is determined such that the oscillations of the treatment needle have substantially decayed at the end of the time interval. Depending on the requirements, in addition to the mechanical damping and / or the amplitude of the drive signal, other values ​​may also be taken into account, if necessary, in addition or alternatively, for determining the time interval. The time interval may be determined in the range of a few microseconds to a few milliseconds. However, the time interval is preferably shorter than 0.5 seconds.

[0024] It is also proposed that the detection of the electrical contact signal by the detection unit is deactivated when the generator unit is activated to output the electrical drive signal. This development takes into account the fact that, in the active state of the drive unit, the amplitude of the drive signal is greater than the amplitude of the electrical contact signal, and the detection unit can only perform unsatisfactory detection or capture, or cannot perform detection or capture at all. Therefore, the operation of the detection unit is unnecessary and can be deactivated, for example in order to save energy, protect the detection unit from excessive use, avoid malfunctions, etc. For example, the deactivation can include an electrical separation of the detection unit from the drive unit. The electrical separation can be achieved by the switching unit explained above. However, it can also be provided that the detection unit can include a limiting unit, which automatically deactivates the detection unit when the signal value is greater than another specified comparison value, or only deactivates the evaluation. The process according to the invention can be further improved thereby.

[0025] An advantageous development provides that, after the determination of contact of the particles with the treatment needle, the generator unit is activated to output the electrical drive signal. This development allows the treatment needle to automatically enter the active operating state or allows the generator unit to automatically activate to output the electrical drive signal, so that the electrical drive signal is only provided when there is also contact with the particles or the eye lens. This allows for improved control of the treatment needle and thus a particularly low heat input to the eye.

[0026] With regard to the console, it is also proposed that the generator unit and the detection unit are electrically connected in parallel on the drive unit side. The advantage of this configuration is that no additional wires are required to connect the handpiece to the console or to establish an electrical connection between the console and the drive unit of the handpiece. The wires used to electrically connect the generator unit to the electric drive unit can also be used by the detection unit at the same time to capture the electrical contact signal. Therefore, the present invention can be implemented without any changes to the handpiece. Therefore, the present invention can also be applied to existing handpieces without modifying them. Therefore, preferably, a parallel connection of the generator unit and the detection unit is provided on the console side. In addition, it is natural that the generator unit and the detection unit can also be designed at least partially as an integral unit, so that in this respect, only a single component is required in the console. This is also found to be advantageous, especially when it is necessary to modify an existing console to use the present invention. In this case, it is only necessary to replace the existing component with the generator unit with a corresponding component including the generator unit connected to the detection unit. Therefore, the expenditure on the console can also be kept very low, and therefore the present invention can be implemented in an ophthalmic surgery system with little expenditure as a whole. In principle, the generator unit and the detection unit can also be electrically connected in series on the drive unit side. In this case, the generator unit is preferably designed to allow an electrical connection of the detection unit and the drive unit, which connection provides as little resistance as possible, particularly preferably, such as an electrical short circuit, when the generator unit stops providing the drive signal.

[0027] The advantages and effects indicated for the method according to the invention also apply equally to the control console and the ophthalmic surgery system, and vice versa. In particular, method features can therefore also be expressed as device features, and vice versa.

[0028] Further features of the invention become clear from the claims, the drawings and the description of the drawings. The features and feature combinations mentioned in the above description, as well as the features and feature combinations mentioned in the following description of the drawings and / or shown only in the drawings, can be used not only in the respectively specified combinations, but also in other combinations without departing from the scope of the invention. Therefore, embodiments of the invention which are not explicitly shown and explained in the drawings, but which appear and can be created by individual combinations of features of the explained embodiments, are also to be considered to be included and disclosed. The disclosure is also to be considered to extend to embodiments and feature combinations, which therefore do not have all the features of the independent claims as stated in the initial wording. Furthermore, the disclosure is to be considered to extend to embodiments and feature combinations, which, in particular by the explanations set out above, exceed or depart from the feature combinations set out in the dependent references of the claims.

[0029] Further advantages and features of the invention are explained with reference to the following drawings, in which:

[0030] Figure 1 A schematic diagram showing an ophthalmic surgical handpiece of an ophthalmic surgical system for emulsifying an ocular lens of a human eye during a contemplated operation,

[0031] Figure 2 Shows that there is Figure 1 Schematic diagram of an ophthalmic surgery system with a handpiece and a console, wherein the handpiece is detachably connected to the console via a connecting line,

[0032] Figure 3 Shows Figure 2 Schematic block diagram of a detection unit and an evaluation unit of a console in the embodiment of the present invention, wherein the console is electrically connected to the Figure 1 The drive unit of the handpiece,

[0033] Figure 4 A schematic diagram is shown showing a graph of an electrical contact signal from a drive unit of a handpiece, wherein particles are in contact with a treatment needle of the handpiece,

[0034] Figure 5 Shows Figure 1 Schematic diagram of the treatment needle tip of the handpiece and particles moving away from it,

[0035] Figure 6 It shows that Figure 5 Schematic diagram of a treatment needle in which particles partially block the suction opening.

[0036] Figure 7 It shows that Figure 5 Schematic diagram shown, in which particles completely block the suction opening of the treatment needle,

[0037] Figure 8 It shows that Figure 5 Schematic diagram shown, where the particle is in lateral contact with the tip of the treatment needle,

[0038] Fig. 9 shows a schematic signal / time diagram for comparing the effect of the process according to the invention with the process of the prior art, and

[0039] Fig.10 Shows Figure 4 Detailed schematic diagram of the particle size distribution, where the curve is used to describe the particle size distribution when the particle size distribution is Figures 6 to 8 The voltage at the electric drive unit of the handpiece when any one of them contacts the treatment needle.

[0040] Figure 1 An ophthalmic surgical system ( Figure 2) is a schematic diagram of an ophthalmic surgical handpiece 2. The handpiece 2 includes a treatment needle 6, one end of which protrudes from a cannula 5 connected to the housing of the handpiece 2. The treatment needle 6 is designed as a hollow needle and provides a part of the aspiration line 3. On the treatment side, the treatment needle 6 includes a needle tip 7, which also provides an outlet opening for the aspiration line 3. The needle tip 7 is used to emulsify the eye lens 13 of the eye 9.

[0041] The handpiece 2 further comprises an electric drive unit 10, which in this case is designed as a piezoelectric-based drive unit. The piezoelectric-based drive unit 10 comprises at least one piezoelectric element, and preferably comprises a stack of a plurality of piezoelectric elements (not shown here), which are mechanically connected to each other and to the end of the treatment needle 6 opposite the needle tip 7. These piezoelectric elements are also electrically connected to each other. Thus, it is possible to control the treatment needle 6 in a manner that depends on the drive signal 36 ( Figure 4 ) in a manner that transmits the vibrations of the electric drive unit 10 to the treatment needle 6, so that appropriate oscillating movements of the needle tip 7 can be performed during the intended use.

[0042] In order to carry out a treatment within the scope of ophthalmic surgery, for example in the treatment of cataracts, a treatment needle 6, in particular its needle tip 7, is introduced into the region of the eye 9 to be treated, in particular the region of the eye lens 13 to be treated. The treatment needle 6 is excited by the electric drive unit 10 to produce ultrasonic oscillations, so that the eye lens 13 can be pulverized or emulsified. During the treatment, an irrigation fluid is supplied via the irrigation line 4. At the same time, an aspiration fluid is discharged from the eye 9 via the aspiration line 3. At the same time, lens fragments or particles are removed from the eye 9 together with the aspiration fluid. During the treatment, the supply of irrigation fluid and the discharge of aspiration fluid are preferably controlled in order to prevent the anterior chamber of the eye 9 from collapsing.

[0043] Figure 2 A schematic diagram of an ophthalmic surgical system 100 is shown, the system comprising a console 1 connected via a connection line 14 to a Figure 1 In the handpiece 2 in the handpiece. In the present configuration, provision is made for the connecting line to comprise, in addition to the electrical line 11, a portion of the suction line 3 and a portion of the suction line 4. The respective line portions of the flushing line 4 and the suction line 3 are fluidically coupled to the corresponding line portions in the handpiece 2. In an alternative configuration, provision can be made for the connecting line 14 to have a multi-part design, for example by providing respective separate tubes for the respective portions of the suction line 3 and the flushing line 4. On the handpiece side, the connecting line 14 can be securely connected to the handpiece 2. At the other end of the connecting line 14, a suitably designed accessory for detachably connecting the connecting line 14 to the console 1 is preferably provided. However, this is not depicted in the figures.

[0044] from Figure 2It is also evident that the console 1 comprises a flushing fluid regulator 20 connected to the flushing line 4. The flushing fluid regulator 20 is also fluidically connected to a flushing fluid reservoir 21. The flushing fluid regulator 20 is also communicatively connected to the control unit 8 of the console 1. The flow rate and / or the pressure of the flushing fluid in the flushing line 4 can be set by the flushing fluid regulator 20 in a manner dependent on control signals from the control unit 8. For example, the flushing fluid reservoir 21 can be arranged to be integrated into the console 1. However, it can also be provided that the flushing fluid reservoir 21 is designed to be at least partially separated from the console 1 and connected to the flushing fluid regulator 20 via a separate line. In this case, a detachable connection can also be provided.

[0045] Corresponding structures can also be provided for pumping fluid. Figure 2 It is evident that the console 1 comprises a suction fluid regulator 22 connected to the suction line 3. Furthermore, the suction fluid regulator 22 is fluidically connected to a suction fluid collection container 23, which in this case is also contained in the console 1. In this case, it can also be provided that the suction fluid collection container 23 is designed to be at least partially separated from the console 1 and connected via a pipeline. The suction fluid regulator 22 sets the flow rate and / or negative pressure of the suction fluid in the suction line 3. The suction fluid regulator 22 is also communicatively connected to the control unit 8 and is controlled by the control unit. The control unit 8 is appropriately designed so that the pressure in the capsular bag can be maintained at a substantially constant level during the treatment of the eye 9.

[0046] The console 1 further comprises a generator unit 15 for providing a time-varying electric drive signal to the electric drive unit 10 of the handpiece 2. In the present example, the electric drive signal is formed by an AC voltage, the frequency of which can be set in the range of about 10 kHz to about 80 kHz. Preferably, the frequency is preferably about 40 kHz. Depending on the power setting of the treatment, the amplitude of the AC voltage can be in the range of about 0 V to about 1000 V, for example about 300 V. The generator unit 15 is detachably connected to the wire 11 so that the AC voltage can be applied to the electric drive unit 10 during the intended operation. Depending on the application of the AC voltage, the treatment needle 6 is mechanically excited to oscillate, so that the desired treatment can be performed on the eye 9, in particular the eye lens 13. In the present example, the operation of the generator unit 15 can also be controlled by the control unit 8, for which purpose the generator unit 15 is communicatively connected to the control unit 8. Thus, for example, the control unit 8 can control the operation of the handpiece 2, in particular the operation of the treatment needle 6. For example, the frequency, amplitude, etc. can be set by generating an appropriate amount of AC voltage by the generator unit 15. In this way, mechanical powers of up to about 50 W can be provided for treatment at the oscillating needle tip 7. Typically, this mechanical power is sufficient to emulsify even particularly hard cataracts.

[0047] During the treatment, an undesirably strong heat build-up may occur not only, but especially, in the region of the cornea 12 of the eye 9. In this case, the heat build-up may be so strong that the cornea 12 is damaged, for example, resulting in burns. This may cause permanent damage. It is therefore desirable to keep the unnecessary heat input as low as possible. In particular, the longitudinal oscillations of the treatment needle 2 may also generate forces that act in opposition to the aspiration-like suction in the region of the needle tip 7. This may result in particles or lens fragments that are to be flushed out in the suction range being pushed away. This may therefore result in the operation lasting longer and the total energy input into the eye 9 increasing.

[0048] In this context, a significant improvement can be achieved by the invention, in particular by making the oscillating operation of the treatment needle 6 dependent on contact with particles 19 or lens fragments. Apart from contact, the treatment needle 2 does not need to be driven by oscillation.

[0049] For this purpose, the drive unit 10 is used in a similar manner to the sensor unit. Therefore, the console 1 also comprises a detection unit 16, which is likewise connected to the electrical line 11. Thus, the detection unit 16 is connected to the electrical line 11 so as to be connected in parallel with the generator unit 15. The detection unit 16 is also in communication connection with the control unit 8, more specifically with the evaluation unit 17 of the control unit 8. By means of the detection unit 16, an electrical contact signal 35 from the electrical drive unit 10 on the electrical line 11 can be detected when the particles 19 contact the treatment needle 6. For this purpose, the generator unit 15 is deactivated during the detection so that it does not output any drive signal 36 to the electrical drive unit 10. Thus, in a non-oscillation or low-oscillation state of the treatment needle 6, more specifically, an electrical contact signal 35 from the electrical drive unit 10 can be detected by the detection unit 16. The detected electrical signal 35 can then be evaluated by the evaluation unit 17, so that the contact of the particles 19 with the treatment needle 6 can be determined based on the evaluation. Thus, the control unit 8 can obtain information about when the treatment needle 6 contacts any particles or lens fragments.

[0050] In principle, two operating states can therefore be distinguished during the treatment. In a first operating state, ultrasonic energy is used to pulverize or emulsify the eye lens 13. In this operating state, there is at least partial contact between the treatment needle 6 or the needle tip 7 and the eye lens 13. Therefore, in this operating state, the ultrasonic energy should be output directly and preferably without delay from the treatment needle 6 to the eye lens 13. In the second operating state, ultrasonic energy cannot be used to pulverize or emulsify the eye lens 13, because there is no contact between the treatment needle 6 (in particular the needle tip 7) and the eye lens 13. In order to keep the ultrasonic energy output as low as possible in this operating state and / or to avoid pushing away particles 19 or lens fragments to be rinsed, the ultrasonic energy output should be stopped or at least reduced. Therefore, it is advantageous to detect the switch between these two operating states as quickly as possible.

[0051] Furthermore, at the first signs of blockage, the suction should be increased by increasing the negative pressure in the suction line 3. Preferably, the output of ultrasonic energy should be started or increased at least simultaneously therewith. This makes it possible for the particles 19 to rest directly on the vibrating needle tip 7 and to be comminuted or emulsified very quickly. This shortens the comminution time and thus significantly reduces the heat input introduced into the eye 9. By increasing the suction, it is also possible to avoid the particles 19 being pushed away by the needle tip 7 due to the ultrasonic energy, which can likewise reduce the duration of the treatment.

[0052] Figure 3 A schematic block diagram shows a possible schematic structure of a detection unit 16 and an evaluation unit 17 for implementing the process according to the invention. The invention is based in particular on detecting an electrical contact signal 35 when the treatment needle 6 is in a non-oscillating or low-oscillating state.

[0053] Thus, in the detection state, the generator unit 15 is deactivated and does not provide any drive signal 36 for the electric drive unit 10 of the handpiece 2. Thereafter, i.e. preferably after the oscillating state of the treatment needle 6 caused by the electric drive unit 10 has decayed, the detection unit 15 can use the electric drive unit 10 in the manner of a sensor. If the particles 19 come into contact with the treatment needle 6, a force acts on the piezoelectric element of the electric drive unit 10, whereupon a voltage is generated due to the piezoelectric effect, which voltage can be tapped at the electrodes in contact with the piezoelectric element and thus can be tapped across the entire electrical line 11. It is worth noting that no individual piezoelectric element is designed as a sensor; rather, all piezoelectric elements of the handpiece 2 are used as sensors. The curve of this voltage is Figure 4 1 is depicted as an electrical contact signal 35. This voltage can be detected via the electrical line 11 and the detection unit 16 and can be evaluated by means of the evaluation unit 17. This will be explained below. Furthermore, it is assumed in this example that the deactivation of the generator unit 15 does not lead to an attenuation or substantial attenuation of the electrical contact signal 35 generated by the electric drive unit 10 in this operating state by the generator unit 15. Alternatively, the generator unit 15 can be designed appropriately for this purpose.

[0054] The detection unit 16 comprises an amplifier 24 and a first comparator 25 and a second comparator 26. The amplifier 24 and the first comparator 25 and the second comparator 26 are also connected to a digital signal processing unit 29 of the evaluation unit 17, which provides the amplifier 24 and the first comparator 25 and the second comparator 26 with appropriate operating parameters, as explained below. On the input side, the amplifier 24 is connected to the electrical wire 11. In the present example, the amplifier 24 acts as a linear amplifier and amplifies the electrical signal 35. The amplified electrical contact signal 35 is then provided to the analog-to-digital converter 28 of the evaluation unit 17. In addition, on the input side, the first comparator 25 is also connected to the electrical wire 11. The first comparator 25 compares the signal on the electrical wire 11 with a first comparison value. The first comparison value is selected so that the operation of the generator unit 15 can be reliably detected. The amplifier 24 has a corresponding overload capacity design. Therefore, it can be determined whether the generator unit 15 is activated by the output signal of the first comparator 25. The corresponding output signal is provided to the evaluation unit 17 via the comparison data supply 27. In addition, on the input side, the second comparator 26 is connected to the output of the amplifier 24. The second comparator 26 compares the output signal of the amplifier 24 with a second comparison value, which is selected so that the electrical contact signal 35 can be reliably detected relative to the interference signal. The corresponding comparison result is also provided to the evaluation unit 17 via the comparison data supply 27. Therefore, the evaluation unit 17 can obtain information about whether the electrical contact signal 35 is present.

[0055] The evaluation unit 17 comprises a digital signal processing unit 29 connected to both the analog-to-digital converter 28 and the comparison data supply 27. The digital signal processing unit 29 processes the corresponding signals and determines when the electrical contact signal 35 is present and its characteristics. In addition, the digital signal processing unit 29 is connected to a system control unit 30 of the control unit 8, through which system information is provided to the digital signal processing unit 29. For example, the system control unit 30 may include a database or the like. In addition, the digital signal processing unit 29 also provides parameters, such as a gain factor, etc., for the amplifier 24, and provides a first comparison value and a second comparison value for the first comparator 25 and the second comparator 26, respectively. Thus, the detection unit 16 can be set based on needs during the expected operation to reliably determine the contact of the particles 19 with the treatment needle 6. By means of the digital signal processing unit 29, appropriate control signals can be provided to the ultrasound power control unit 31 and the ultrasound mode unit 32. The ultrasound power of the generator unit 15 can be set by the ultrasound power control unit 31. In addition, the pulse mode of the ultrasound power that the generator unit 15 wants to provide can be set by the ultrasound mode unit 32. Therefore, these two units are also connected to the generator unit 15. Furthermore, the digital signal processing unit 29 provides appropriate data to the contact determination unit 33. Based on the data provided by the digital signal processing unit 29, the contact determination unit 33 determines whether there is contact between the particle 19 and the treatment needle 6. The output signal can also be provided to the generator unit 15, for example in order to activate the output of the ultrasonic power output or the electrical drive signal 36.

[0056] Furthermore, the digital signal processing unit 29 provides data to a fluid control unit 34, which provides appropriate control signals to the irrigation fluid regulator 20 and the aspiration fluid regulator 22. Thus, for example, the pressure and / or flow conditions in the irrigation line 4 and the aspiration line 3 can be appropriately set, so that a treatment that is as reliable and successful as possible can be achieved. For example, this can include increasing the negative pressure in the aspiration line 3 in the event of a blockage being detected. The digital signal processing unit 29 can evaluate the electrical contact signal 35, for example with respect to amplitude, frequency, decay behavior, etc., in order to calculate further data therefrom, for example data for units 31 to 34. In the present example, the evaluation unit 17 comprises a suitably designed programmable computer unit. It goes without saying that, for this purpose, a suitable hardware circuit or a combination with a computer unit can also be provided in an alternative configuration. In some cases, depending on the structure, in an alternative exemplary embodiment, the amplifier 24 can also be omitted. The digital signal processing unit 29 can further include one or more digital filters, pattern recognition, contact classification, etc. The digital signal processing unit 29 can also provide a system observation, wherein it can be assumed that when it is determined that there is no contact between the particle 19 and the treatment needle 6, there will generally be no particles 19 or lens fragments in the area of ​​the treatment needle 6. The output of ultrasonic energy can therefore be reduced or even terminated. This can reduce the heat input into the eye 9, in particular in the incision area. Conversely, if contact is detected, the ultrasonic energy can be activated or automatically increased, so that emulsification can be performed. In addition, other states or characteristics of the particles 19, such as size, hardness or speed, can also be detected or determined, so that it can be determined, for example, by observation over time, whether the activation, deactivation, increase or decrease of the ultrasonic energy output can be advantageously set, or a specific pulse mode can be applied during the ultrasonic output. In an advantageous configuration, it can be provided to start with a higher ultrasonic energy output and then reduce it over time.

[0057] The function of the present invention will also be based on Figure 4The depicted graph is explained, which shows the voltage curve on the wire 11. The abscissa represents time and the ordinate represents voltage. Obviously, there is no drive signal 36 before the contact time 37. At this time, the ultrasonic energy output generated by activating the generator unit 15 is deactivated. Therefore, the drive signal 36 is substantially close to zero. The particle 19 contacts the treatment needle 6 at the contact time 37. Since the generator unit 15 does not substantially attenuate the electrical contact signal 35 appearing on the wire 11, the detection unit 16 is able to detect the voltage of the contact signal 35. This is depicted by a short pulse starting at time 370 after the contact time 37. The amplitude A2 of the electrical contact signal 35 is smaller than the amplitude A3 of the drive signal 36. The amplitude A2 preferably does not exceed 90%, preferably does not exceed 50%, and particularly preferably does not exceed 30% of the amplitude A3 of the drive signal 36. Preferably, the amplitude A2 is at least twice the amplitude A1 of the system oscillation noise 50 representing a low oscillation state. Therefore, the amplitude A2 of the electrical contact signal 35 can be clearly distinguished from the amplitude A1 of the system oscillation noise 50. The first comparator 25 and the second comparator 26 are used for this purpose; by means of their digital values, they assist the digital signal processing unit 29 in making the contact determination. The digital signal processing unit 29 allows the detected electrical contact signal 35 to be evaluated so that the generator unit 15 can be activated to output the electrical drive signal. This is carried out directly after the electrical contact signal 35 is detected. Figure 4 At the time resolution shown, the start of the drive signal almost coincides with the start of the contact signal 35, so for clarity, Figure 4 The electrical drive signal is not shown. However, Figure 4 The start of the electrical drive signal 36 when using the previous conventional method is shown, wherein a blockage on the needle tip 7 is detected. The drive signal 36 starts at a start time 39, which is delayed by a time interval 38 from the time point at which the drive signal is started according to the method of the present invention, wherein the time interval 38 may be about 80 ms. In any case, the present invention can achieve that the electrical drive signal can be automatically activated in time after the particles 19 contact the treatment needle 6, thereby achieving emulsification. Therefore, the present invention allows the ultrasonic energy input into the eye 9 to be controlled in an automatic or at least partially automatic manner, thereby reducing the total heat input.

[0058] Figures 5 to 8 The schematic diagram shows how the contact between the particles 19 and the treatment needle 6 may be implemented. Figure 6 to Figure 7 In this embodiment, the treatment needle 6 is excited longitudinally; this is indicated by an arrow 18 in the direction of the longitudinal extension of the treatment needle 6. Figure 5 The diagram shows a situation where the particles 19 are still at a small distance from the treatment needle 6. In this state, the ultrasonic energy output is preferably still inactive. Figure 6A partial blockage situation is shown, in which particles 19 partially block the opening of the suction line 3. As explained above, such contact can be determined so that the ultrasonic energy output can be automatically activated, thereby emulsifying the particles 19. The same operation can also be performed in Figure 7 The case shown is implemented in which the particles 19 are completely blocked. In this case, contact can also be determined and the ultrasonic energy output can be automatically activated, so that the particles can be emulsified. Figure 8 The situation is shown where the treatment needle 6 is excited to oscillate laterally due to contact with the particles 19, as a result of the particles 19 being in lateral contact with the treatment needle 6. This can also be determined by the process according to the invention and the ultrasonic energy output can therefore also be automatically activated.

[0059] In another configuration, it can also be provided that when there is no blockage, the ultrasonic energy output can be automatically deactivated by further system observation, for example as disclosed in US 9,144,517. The disclosure of this US patent should be considered to be included in the present application. Thus, an almost fully automatic ultrasonic energy supply can be controlled so that ultrasonic energy is only supplied when it is needed to advance the treatment. In addition, for this purpose, for example, it is also conceivable to change the flow rate in the suction line 3. For example, if Figure 5 As depicted, if a flow change in the suction line 3 is detected before the particle 19 comes into contact with the needle tip 7, it can be provided, for example, that the ultrasonic output is activated even if contact has not yet occurred. If contact occurs, the power can be increased. Furthermore, in another configuration, it can be provided that, in the case where contact is determined and the drive signal 36 is deactivated, the negative pressure in the suction line 3 is first increased in a first step. Only after sufficient blockage is determined is the ultrasonic output activated in a second step. In this case, the use of the invention therefore results in initially only acting on the suction fluid regulator 22 in the first step. Then, only in the second step is the generator unit 15 acted on.

[0060] The invention can achieve the following advantages: by detecting and determining the contact of the particles 19 with the treatment needle 6 more quickly, an optimized activation of the ultrasound power can be achieved. In this case, the sensor system can be arranged in the handpiece 2, and not necessarily in the pump of the console 1 (as in the case of detection of blockage based on changes in pressure and / or flow), for example at a distance of two meters, where the corresponding tube connections may have interactions, in particular thus resulting in a dead time in the measurement path, which may be, for example, 60 to 70 ms. The equivalent phacoemulsification time (EPT) or the duration of the treatment can be reduced due to the faster activation of the ultrasound output, which in fact occurs almost immediately when required. Furthermore, due to the faster increase in negative pressure that can be achieved in the aspiration line 3 in the event of contact, the aspirated particles can remain on the needle tip 7 of the treatment needle 6 for a longer time, so that efficiency can be achieved and EPT or heat input can be reduced. The invention allows the use of ultrasound energy based on particle contact, rather than relying on traditional blockage detection. Particle contact on the outside or end face of the treatment needle 6 can be detected. Therefore, ultrasonic energy can be provided when the treatment needle 6 undergoes twisting and / or lateral movement, and the reliability of contact detection can be improved during the engraving stage of drawing grooves on the eye lens 13. In contrast, the prior art only provides blockage detection based on flow change, where the particle 19 causes a change in the flow of the aspirated fluid or is located in the flow path.

[0061] A further application of event-based ultrasonic energy supply can be combined with current fluid blockage detection. Figure 5 As shown, if the particle 19 is advantageously located in front of the outlet opening of the aspiration line 3 but has not yet come into mechanical contact with the treatment needle 6, the fluid blockage detection can be used to trigger the ultrasonic activation. Loss of contact can also be detected in the same way. In addition, the present invention can determine additional triggering events related to the contact of the particle 19 with the treatment needle 6, for example, whether the particle 19 contacts the end face or the outside of the treatment needle 6. The present invention enables fast contact detection. At the same time, the present invention can be implemented with little expenditure, especially low cost. No modification of the handpiece is required.

[0062] Fig. 9 The advantages of the present invention over the prior art are compared again. Fig. 9 Six time-synchronized signal diagrams 40 to 45 are shown, the abscissa of which each represents time and the ordinate represents voltage as signal value. With respect to the abscissa, the diagram is divided into region A and region B. Region A relates to Figures 5 to 7 Region B involves Figure 8 The situation depicted.

[0063] Graphs 40 and 41 relate to the application of the present invention. Signal graph 40 shows contact detection according to the present invention, specifically, in area A of the signal graph, end face contact on the needle tip 7, and in area B of the signal graph, transverse contact with the longitudinal extension of the treatment needle 6. It is clear from signal graphs 40 and 41 that, according to the present invention, the electrical drive signal 36 in the form of an ultrasonic pulse 47 can be output almost immediately after the contact is determined at time 37. This applies to both end face contact and side contact. Graphs 42 and 43 show the corresponding situation of the prior art. As depicted based on graph 42, it is clear that in area A, the detection of blockage is severely delayed, as shown in graph 48. As depicted in graph 43, the output of the electrical drive signal in the form of an ultrasonic pulse 49 is implemented with a corresponding delay. In addition, in the case of transverse contact with the longitudinal extension of the treatment needle 6, no ultrasonic pulse 49 is output. Therefore, this situation cannot be reliably identified in the prior art. Graphs 44 and 45 show even more clearly the advantages brought about by the use of the present invention. Graph 44 depicts the electrical signal 35 captured by the present invention for areas A and B. According to area A of diagram 45, it is clear that the reaction time of the present invention is shorter than that of the prior art, which is marked by time interval 38 in diagram 45. In area B, in the case of contact transverse to the longitudinal extension of treatment needle 6, the prior art does not provide any reaction in contrast to the present invention.

[0064] Fig.10 Schematic diagram of a voltage / time graph is shown. In this case, the output of the drive signal 36 is deactivated. In this case, the voltage on the wire 11 is also depicted. At time 37, the particle 19 comes into contact with the treatment needle 6. As a result, the latter is excited to oscillate, and this generates a damped AC voltage as an electrical contact signal 35 via the drive unit 10. This signal can be detected by the detection unit 16 and can therefore be provided to the evaluation unit 17. Obviously, the oscillation amplitude of the electrical contact signal 35 depicted here is approximately 80% of the amplitude of the drive signal 36; see also Figure 4 Therefore, the detection unit 16 has a corresponding design so that it will not enter an overload state due to the drive signal 36 .

[0065] The exemplary embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0066] List of Reference Numerals

[0067] 1 Console

[0068] 2 Handpiece

[0069] 3 Suction line

[0070] 4 Flush the pipeline

[0071] 5 Casing

[0072] 6 Treatment needle

[0073] 7 Needle Tip

[0074] 8 Control unit

[0075] 9 Eyes

[0076] 10 Electric drive unit

[0077] 11 Wire

[0078] 12 Cornea

[0079] 13. Lens

[0080] 14 Connection cable

[0081] 15 Generator Unit

[0082] 16 Detection Unit

[0083] 17 Evaluation Units

[0084] 18 Arrow

[0085] 19 particles

[0086] 20 Flush the fluid regulator

[0087] 21 Flush Fluid Reservoir

[0088] 22 Suction fluid regulator

[0089] 23 Aspiration fluid collection container

[0090] 24 Amplifier

[0091] 25 First comparator

[0092] 26 Second comparator

[0093] 27 Comparative Data Supply Department

[0094] 28 Analog-to-digital converter

[0095] 29 Digital Signal Processing Unit

[0096] 30 System control unit

[0097] 31 Ultrasonic power control unit

[0098] 32 Ultrasonic Mode Units

[0099] 33 Contact determination unit

[0100] 34 Fluid Control Unit

[0101] 35 Electrical contact signal

[0102] 36 Electric drive signal

[0103] 37 Contact Time

[0104] 38 Time interval

[0105] 39 Start time

[0106] 40 Signal Charts

[0107] 41 Signal Charts

[0108] 42 Signal Charts

[0109] 43 Signal Charts

[0110] 44 Signal Charts

[0111] 45 Signal Charts

[0112] 47 Ultrasonic pulse

[0113] 48 Flow-related blockage detection

[0114] 49 Ultrasonic pulse

[0115] 50 System oscillation noise

[0116] 100 Ophthalmic Surgical Systems

[0117] 370 Time

[0118] A1 Amplitude of system noise

[0119] A2 Amplitude of the electrical contact signal

[0120] A3 Amplitude of the electric drive signal

Claims

1. A method for detecting contact of a particle (19) with a treatment needle (6) of an ophthalmic surgical handpiece (2), wherein: The treatment needle (6) can be driven by oscillation of the electric drive unit (10), for which purpose a time-varying electric drive signal is at least intermittently applied to the electric drive unit (10) by a generator unit (15). It is characterized in that In the low oscillation state of the treatment needle (6), the treatment needle (6) oscillates at a maximum first oscillation amplitude (A1), and the electrical contact signal (35) of the electric drive unit (10) is detected based on a second oscillation amplitude (A2) of the treatment needle (6), the second oscillation amplitude (A2) being greater than the first oscillation amplitude (A1), the detected electrical contact signal (35) is evaluated, and the contact between the particle (19) and the treatment needle (6) is determined based on the evaluation.

2. The method according to claim 1, It is characterized in that The electrical contact signal (35) is detected outside of applying the electrical drive signal to the electrical drive unit (10).

3. A method according to any one of the preceding claims, It is characterized in that The detection of the electrical contact signal (35) is activated only after a specified time interval has elapsed from the moment when the electrical drive signal ends.

4. The method according to claim 3, It is characterized in that The time interval is determined based on the mechanical damping of the oscillations of the treatment needle (6).

5. A method as claimed in any one of the preceding claims, It is characterized in that Based on the evaluation of the electrical contact signal (35), at least the size, hardness or speed of the particle (19) is determined.

6. A method as claimed in any one of the preceding claims, It is characterized in that When the generator unit (15) is activated to output the electrical drive signal, the detection unit (16) is deactivated to detect the electrical contact signal (35).

7. A method as claimed in any one of the preceding claims, It is characterized in that After it is determined that the particle (19) is in contact with the treatment needle (6), the generator unit (15) is activated to output the electrical drive signal.

8. A console (1) of an ophthalmic surgical system (100) for operating an ophthalmic surgical handpiece (2), the ophthalmic surgical handpiece being connectable to the console (1) and comprising a treatment needle (6) and an electric drive unit (10) for driving the treatment needle (6) by oscillation, the console (1) comprising at least one generator unit (15) for providing a time-varying electric drive signal to the electric drive unit (10), It is characterized in that A detection unit (16) electrically coupled to the drive unit (10), the detection unit (16) being adapted to detect an electrical contact signal (35) of the electric drive unit (10) based on a second oscillation amplitude (A2) in a low oscillation state of the treatment needle (6) in which the treatment needle oscillates with a maximum first oscillation amplitude (A1), the second oscillation amplitude being greater than the first oscillation amplitude (A1), and being characterized by an evaluation unit (17) for evaluating the detected electrical contact signal (35) and determining contact of the particles (19) with the treatment needle (6) based on the evaluation.

9. The console as claimed in claim 8, It is characterized in that The generator unit (15) and the detection unit (16) are electrically connected in parallel on the drive unit side.

10. An ophthalmic surgical system (100) for treating an eye (9), the ophthalmic surgical system comprising at least: - an ophthalmic surgical handpiece (2) for operating on an ocular lens (13), comprising a treatment needle (6) and an electric drive unit (10) for driving the treatment needle (6) by oscillation, and a console (1) for operating the ophthalmic surgical handpiece (2), the ophthalmic surgical handpiece (2) being connectable to the console at least during the intended operation, and comprising a generator unit (15) which is coupleable to the handpiece (2) and is used to provide a time-varying electrical drive signal to the electrical drive unit (10) of the handpiece (2), It is characterized in that The console (1) is designed as claimed in any one of claims 8 and 9.

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