RU2815292C2 - Ophthalmic jet system with eddy current pressure sensor - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: group of inventions relates to medicine. Systems and method are disclosed for measuring fluid pressure in an ophthalmic surgical system. System comprises a fluid flow channel and a system with a pressure sensor for measuring pressure in the fluid flow channel. System with a pressure sensor comprises a conducting movable membrane having a first side and a second side, wherein the first side of the membrane faces the fluid flow channel, and an eddy current position sensor located on the second side of the membrane without contact with the membrane. Eddy current position sensor comprises a winding of a position sensor, made with possibility of excitation by alternating current of high frequency, and electronic devices for conversion of signals, made with possibility to determine change of inductance, or impedance, or resonance frequency in the winding of the position sensor when the gap between the membrane and the winding of the position sensor is changed and with the possibility of converting this change into a displacement signal consistent with fluid pressure. Method of measuring pressure of a fluid medium can be implemented using the system.

EFFECT: use of this group of inventions will make it possible to expand the range of technical means of measuring fluid pressure in an ophthalmic surgical system.

18 cl, 6 dwg

Description

TECHNICAL FIELD

[0001] The present invention is directed to systems and methods related to ophthalmic surgery and, more particularly, to control of fluid pressure during ophthalmic surgery.

BACKGROUND OF THE INVENTION

[0002] In ophthalmic surgical procedures, fluids are often aspirated from the eye during the procedure. For example, in vitreoretinal surgery, a device may be used to aspirate vitreous material from the eye. As another example, in cataract surgery, a device may be used to fragment or emulsify the lens and aspirate the broken or emulsified lens from the eye. In these or other procedures, a balanced salt solution (BSS) or other irrigating fluid may be introduced into the eye and removed during the procedure as part of the aspirated fluid.

[0003] In such ophthalmic surgical procedures, it may be desirable to control the pressure of the aspirated fluid during aspiration. This can assist the operator in guiding the procedure, monitoring intraocular pressure, and/or determining the presence of partial or complete occlusion in the suction line. Additionally, it may be desirable to control the pressure of the fluid introduced into the eye. It may also assist the operator in guiding the procedure and/or monitoring intraocular pressure.

[0004] Known systems for irrigation and aspiration of fluid and/or pressure measurement in ophthalmic procedures are disclosed in US Patent No. 6,261,283, US Patent No. 6,293,926, US Patent No. 6,572,349, US Patent No. 6,632,214, US Patent No. 6,740,074, US Patent No. 6,902 .542 , U.S. Patent No. 6,962,488, U.S. Patent No. 7,393,189, U.S. Patent No. 8,011,905, U.S. Patent No. 8,545,198, U.S. Patent No. 8,790,096, U.S. Patent No. 9,482,216, and U.S. Patent No. 9,931,447, the disclosures of which are incorporated herein by reference in their entirety. Prior art pressure sensors are further disclosed in US Patent No. 5,910,110 and US Patent No. 5,470,312, the disclosures of which are incorporated herein by reference in their entirety.

[0005] Known systems for monitoring fluid pressure during ophthalmic procedures include the use of a strain gauge to measure membrane deflection upon fluid contact and the use of optical measurement of membrane deflection upon fluid contact. The strain gauge system involves contact of the strain gauge with the membrane on the side of the membrane opposite to the fluid. This contact method may have limited frequency response and relatively high hysteresis and may require additional sensor protection to meet safety requirements. The optical system involves reflecting light off a membrane to measure its displacement. Since this is a non-contact method, such a system may be sensitive to optical adjustment and/or changes in membrane surface quality.

[0006] Accordingly, there is a need for improved systems and methods for monitoring fluid pressure during ophthalmic procedures.

SUMMARY OF THE INVENTION

[0007] The present invention relates to systems and methods for measuring fluid pressure in an ophthalmic surgical system.

[0008] In some embodiments, the ophthalmic surgical system includes a handle with an operating tip for performing an ophthalmic surgical procedure within the eye; an irrigation system for delivering irrigation fluid to the eye during an ophthalmic surgical procedure, the irrigation system comprising an irrigation source, an irrigation channel in the handle, and an irrigation tube between the irrigation source and the irrigation channel in the handle; a suction system for aspirating fluid from the eye during an ophthalmic surgical procedure, the suction system comprising an suction channel in the handle, an suction tube extending from the suction channel in the handle, and a pump for providing suction through the suction tube and the suction channel in the handle; and a system with an eddy current pressure sensor. In some embodiments, an example eddy current pressure sensor system comprises a conductive movable membrane having a first side and a second side, with the first side of the membrane facing a flow path for either an aspiration fluid aspirated from the eye or an irrigation fluid delivered to the eye; and an eddy current position sensor placed on the second side of the membrane without contact with the membrane, wherein the eddy current position sensor contains a position sensor winding configured to be excited by high frequency alternating current, and electronic devices for signal conversion configured to detect changes in inductance or impedance or changing the resonant frequency in the position sensor winding when the gap between the membrane and the position sensor winding changes and with the ability to convert this change into a displacement signal consistent with the pressure of the fluid.

[0009] In some embodiments, the position sensor winding is housed in a non-conductive housing. In some embodiments, the eddy current encoder includes a high frequency generator for driving the encoder winding at a high frequency.

[0010] In some embodiments, the ophthalmic surgical system includes a jet module in combination with a jet cassette, wherein the jet module and jet cassette together comprise an irrigation channel through which an irrigation fluid is delivered to the eye during an ophthalmic surgical procedure, an aspiration channel through which an aspirated fluid is removed from the eye during an ophthalmic surgical procedure, and an eddy current pressure sensor system as disclosed herein.

[0011] In some embodiments, a method of measuring fluid pressure in an ophthalmic surgical system includes passing a fluid through a fluid flow path during an ophthalmic surgical procedure, wherein a conductive movable membrane is positioned such that a first side of the membrane faces the fluid flow path. fluid flow; excitation of the position sensor winding with high frequency alternating current, while the position sensor winding is located on the second side of the membrane without contact with the membrane; and detecting a change in inductance or impedance or resonant frequency in the encoder winding when the gap between the membrane and the encoder winding changes due to a change in fluid pressure in the fluid flow path and converting this change into a bias signal consistent with the fluid pressure. In some embodiments, the fluid flow channel may be an aspiration channel. In some embodiments, the fluid flow channel may be an irrigation channel.

BRIEF DESCRIPTION OF GRAPHIC MATERIALS

[0012] The accompanying drawings depict embodiments of the systems and methods disclosed herein and, together with the description, serve to explain the principles of the present invention.

[0013] In FIG. 1 depicts an example of an ophthalmic surgical console that may be used in the systems and methods of the present invention.

[0014] In FIG. 2 is a schematic representation of an example inkjet system that may be used in the systems and methods of the present invention.

[0015] In FIG. 3 is an exploded view of an example cassette that may be used in the systems and methods of the present invention.

[0016] In FIG. 4 depicts examples of a membrane and jet module that is part of an ophthalmic surgical console that can be used in the systems and methods of the present invention.

[0017] In FIG. 5 is a schematic illustration of an example of a pressure sensor that may be used in the systems and methods of the present invention.

[0018] In FIG. 6 is a schematic representation of the pressure sensor of FIG. 6, showing magnetic fields and induced eddy currents.

[0019] The accompanying graphics can be better understood from the following detailed description.

DETAILED DESCRIPTION

[0020] In order to facilitate an understanding of the principles of the present invention, reference will now be made to the embodiments depicted in the drawings and specific terminology will be used to describe them. However, it should be understood that this is not intended to limit the scope of the present invention in any way. As will generally be apparent to one skilled in the art to which the invention relates, any changes and additional modifications with respect to the described systems, devices, tools, methods and any other application of the principles of the present invention are fully contemplated. In particular, the features, components and/or steps described in relation to one embodiment may be combined with the features, components and/or steps described in relation to other embodiments of the present invention. For simplicity, in some cases the same reference numbers are used in all graphics for the same or similar elements.

[0021] In FIG. 1 depicts an example of an ophthalmic surgical console 100 that may be used in the systems and methods of the present invention. The ophthalmic surgical console 100 may be similar to ophthalmic surgical consoles as shown and described in US Pat. No. 9,931,447, the entire disclosure of which is expressly incorporated herein by reference. The ophthalmic surgical console 100 may be similar to known and used ophthalmic surgical consoles, such as the CONSTELLATION® Vision System offered by Alcon Laboratories, Inc. (Fort Worth, Texas), or the CENTURION® Vision System offered by Alcon Laboratories, Inc. (Fort Worth, TX), or any other ophthalmic surgical console suitable for use according to the principles described herein.

[0022] As shown in FIG. 1, an example of an ophthalmic surgical console 100 includes a housing 102 with a computer system located therein and an associated display screen 104 displaying data related to the operation and performance of the system during an ophthalmic surgical procedure. Console 100 also includes a foot pedal 106 that an operator can use to control one or more functions.

[0023] Console 100 contains one or more systems that can be used when performing an ophthalmic surgical procedure. For example, the console 100 includes a jet system 200 (FIG. 2), which includes an irrigation system for delivering fluid to the eye and an aspiration system for aspirating fluid from the eye. The console 100 may also include an ultrasonic generator system for driving an ultrasonic vibration handle, such as for phacoemulsification during cataract surgery, and/or a pneumatic vitreotome system for driving a vitrectomy handle. Systems may overlap and interact to perform different aspects of procedures.

[0024] In FIG. 2 is a schematic representation of an example inkjet system 200 that may be used in the systems and methods of the present invention. The inkjet system 200 may be similar to inkjet systems as shown and described in US Pat. No. 9,931,447, or similar to known and used inkjet systems such as those presented in the CONSTELLATION® Vision System, or in the CENTURION® Vision System, or similar to any other inkjet system, suitable for use in accordance with the principles described in this document.

[0025] The jet system 200 includes an irrigation system 300 and a suction system 302, each of which communicates with a handle 118. The irrigation system 300 includes an irrigation source 304, such as a sterile solution reservoir, an irrigation valve 306 that regulates flow from the reservoir to the surgical area intervention, a flexible irrigation tube 308, an irrigation channel 310 in the handle 118, and a manifold 312, which can be considered a component of the handle 118. The handpiece 118 includes a working tip 334 (such as a phacoemulsification tip or a vitrectomy needle), and in some embodiments, an irrigation manifold 312 may be located adjacent to the operating tip 334.

[0026] The example irrigation system 300 extends between the irrigation source 304 and the handle 118 and carries irrigation fluid through the irrigation channel for flow to the surgical site (labeled eye 10 in FIG. 2) during the surgical procedure. Irrigation source 304 may be a mechanically pressurized fluid source, such as, for example, a down pressure system. In other embodiments, the irrigation source 304 may be a source suspended from a stand (eg, an IV stand), which may be adjustable or non-adjustable. Other fluid sources may be used. In one example, the sterile fluid is saline; however, other fluids may be used.

[0027] In some embodiments, the irrigation tube 308 is formed from a plurality of segments, with some segments being rigid and others being flexible. Also in some embodiments, at least a portion of the irrigation system 300 is implemented in a cassette 314 that cooperates with the console 100 of FIG. 1 to provide fluid communication between the irrigation source 304 and the patient's eye 10. The fluid pressure in the irrigation channel for flow may be monitored by a handle pressure sensor or by a pressure sensor 602 (as described below).

[0028] An example suction system 302 includes an suction channel 316 in the handle 118, a flexible suction tube 318, a pump 322, a breathing valve 324, a drain line reservoir 326, and a drain or drain reservoir 328. A handle connector 330 connects the suction channel 316 in the handle 118 to the suction tube 318. The cassette connector 332 connects the suction tube 318 to the suction line in the cassette 314. As can be seen, the suction system 302 extends from the surgical site (eye 10) to the drainage reservoir 328. The suction system 302 includes an suction channel 316 for the passage of fluid. , may be in fluid communication with the opening of the operating tip 334 of the handle 118. The suction system 302 is used to aspirate the fluid, as well as any other materials to be aspirated from the eye, such as emulsified particles or vitreous fibers, through the suction channel. to pass flow away from the eye during a surgical procedure.

[0029] In some embodiments, the suction tube 318 is formed from a plurality of segments, with some segments being rigid and others being flexible. Also in some embodiments, at least a portion of the aspiration system 302 is implemented in a cassette 314 that cooperates with the console 100 of FIG. 1 to provide fluid communication between the handle 118 and the drain reservoir 328. The drain reservoir 328 may be a bag or any suitable container, and in some embodiments, it may be a drain instead of a separate reservoir.

[0030] When the suction path is blocked, such as when lens fragments enter and occlude parts of the suction path during surgery, the surgical system may detect a vacuum, or pressure difference, using a pressure sensor in the handle or using a pressure sensor 600 (as described below). The surgical system may control the breathing valve 324 to open it and relieve the vacuum or pressure difference in the suction path and reduce the effect of blockage. This reduces the magnitude of any wave generated and maintains a set vacuum level so as not to reduce the effectiveness of the procedure.

[0031] In FIG. 3 depicts an exploded view of an example cartridge 314 that can be used with the inkjet system 200 of FIG. 2 according to the present invention. The main body of the cassette 314 may be formed by an upper body 410 and a lower body 420 connected to each other. The housings 410 and 420 may be formed from a rigid thermoplastic material, such as polycarbonate and/or polysulfone, to provide rigidity and structure. The pump engagement surface portion 450 may be located in the cassette 314 to engage the pump 322. The pump 322 may be an elastomeric pump configured to force a fluid stream into the aspiration flow path. A cover 452 with an arcuate elastomeric channel cover 454 may be positioned as part of the pump 322 above the pump engagement surface portion 450. The cassette 314 may also include a breathing valve chamber 430 and an irrigation valve chamber 440. The breathing valve chamber 430 may be configured to receive the breathing valve 324. The irrigation valve chamber 440 may be configured to receive the irrigation valve 306.

[0032] Portions of the irrigation flow path and the aspiration flow path may extend as channels and/or tubes within the cassette body 314. The breathing valve chamber 430 may be located in the breathing channel 350 so that the breathing valve 324 can be selectively closed. and open to allow vacuum to be eliminated through the vent 350. In some embodiments, the vent 324 may be a rotary check valve made of a flexible high-density polymer such as polyethylene or acetal, whereby the vent 324 may be press-fitted into the chamber 430 for breathing valve. Thus, the breathing valve 324 can rotate within the breathing valve chamber 430, driven by a valve motor (not shown) with an angle-code converter to selectively open and close the breathing channel 350.

[0033] The cassette 314 has holes 462, 464 and cutouts 466, 468 for aligning the cassette 314 with the console 100 when the cassette 314 is inserted into the console 100. The cassette 314 may be removable and a disposable or consumable item that can be used for a single patient procedure. . The new cassette 314 can be used for a new procedure.

[0034] In FIG. 3 also shows a membrane 402 that can be used in a pressure sensor for an aspiration system and a membrane 404 that can be used in a pressure sensor for an irrigation system. Diaphragm 402 is held in place in cassette 314 by a retaining ring 406. Diaphragm 404 is held in place in cassette 316 by a retaining ring 408. Retaining rings 406, 408 may be secured to the cassette body 314, and membranes 402, 404 may be secured between a corresponding retaining ring 406, 408 and the cassette body 314 and/or otherwise attached to a corresponding retaining ring 406, 408 and/or the cassette body 314, such as by adhesive or welding. Membranes 402, 404 and their functions in the pressure sensor are described below.

[0035] In FIG. 4 depicts a membrane 402 and a jet module 500 that is part of an ophthalmic surgical console 100 that can be used in the systems and methods of the present invention. Inkjet module 500 is configured to receive cartridge 314 and interact with cartridge 314 as part of inkjet system 200. Inkjet module 500 has projections 562, 564 that align with openings 462, 464 of cartridge 314, and projections 566, 568 that align with cutouts 466, 468 cassettes, 314 for inserting cassette 314 into console 100.

[0036] The jet module 500 has a pump housing area 550 for receiving mechanical parts of the pump 322 for engagement with the arcuate elastomeric channel cover 454 of the cassette 314. The jet module 500 has areas 506, 524 for receiving the irrigation valve 306 and the breathing valve 324, respectively. The inkjet module 500 further has areas 502, 504 for receiving membranes 402, 404, respectively. The regions 502, 504 may be shaped and sized according to the membranes 402, 404, respectively. For example, membranes 402, 404 may be circular, and regions 502, 504 may be circular. The inkjet module 500 may have a non-conductive pressure sensor coil housing 510 for housing the pressure sensor coil 600 and/or a non-conductive pressure sensor coil housing 512 for housing the pressure sensor coil 602. Alternatively, the pressure sensor winding 600 and/or the pressure sensor winding 602 may be provided with traces (eg, copper or other suitable conductor) on a printed circuit board.

[0037] In FIG. 5 is a schematic illustration of an example pressure sensor 600 that may be used in systems and methods of the present invention. As shown in FIG. 5, pressure sensor 600 includes a position sensor that includes position sensor coil 610. As will be appreciated by those of ordinary skill in the art, position sensor winding 610 is shown schematically. In some embodiments, as mentioned above, position sensor winding 610 (and/or position sensor winding 612 of pressure sensor 602) may be configured with traces on a printed circuit board. As can be understood from Fig. 4 and 5 and the descriptions herein, the position sensor is a non-contact sensor, i.e. it is not in physical contact with the membrane 402. The position sensor is also not in contact with the fluid being measured, since the membrane isolates the fluid from the position sensor.

[0038] The membrane 402 is a conductive sheet or plate that moves in response to fluid pressure applied to it. For example, membrane 402 may be a thin, metallic material such as stainless steel or other suitable metallic or conductive material. As an example, the membrane may be approximately 0.5 inches in diameter and approximately 0.003 inches thick. Other suitable materials, shapes and sizes are possible and contemplated within the scope of the present invention.

[0039] The position sensor winding 610 is a conductive winding that is part of an alternating current circuit. The position sensor winding 610 may be relatively small, such as 2-4 millimeters in diameter and approximately 0.5 millimeters in height, although other suitable sizes are possible and contemplated within the scope of the present invention.

[0040] The system further includes an alternating current source and high-frequency generator 620, and a measurement device 630 that may include signal conditioning circuitry that measures the impedance, inductance, or changes in the resonant frequency of the encoder winding 610 to perform measurements, as described below. The high frequency generator generates a suitable frequency for the purposes described below, for example 2 MHz or any other suitable frequency. The position sensor winding 610 is connected to the rest of the circuit via wires. When encoder winding 610 is energized by a high-frequency generator, it generates a magnetic field due to the current passing through the winding.

[0041] Pressure sensor 600 operates as an eddy current pressure sensor. In fig. 6 is a schematic illustration of the pressure sensor 600 of FIG. 5, showing magnetic fields and induced eddy currents. When encoder coil 610 is energized with alternating current, it generates a magnetic field 710 as shown. This magnetic field 710 induces local electrical currents in the form of eddy currents 720 within the conductive membrane 402, which is in close proximity to the position sensor winding 610. Eddy currents 720 generate a magnetic field 730 that is opposite to magnetic field 710. Eddy currents 720 and the resulting magnetic field 730 cause a change in the inductance or impedance or resonant frequency of the encoder winding 610.

[0042] As can be understood from FIG. 3, membrane 402 is in contact with fluid being aspirated from the eye through the suction line. The membrane 402 is non-invasive and isolates the fluid from the rest of the pressure sensor 600. When the fluid pressure on the membrane 402 changes, the position of the membrane 402 changes slightly in response to the change in pressure. Consequently, the position of the membrane 402 changes relative to the stationary position of the position sensor winding 610. These changes in position cause different eddy currents 720 and different magnetic fields 730, which in turn result in differences in the inductance or impedance or resonant frequency of the pressure sensor winding 610.

[0043] The measuring device 630 is configured to measure changes in the inductance, or impedance, or resonant frequency of the position sensor winding 610. Electronic signal conditioning devices detect the change in inductance or impedance or resonant frequency as the gap between the membrane 402 and the position sensor winding 610 changes. Electronic signal conditioning devices convert this change into a usable offset signal, i.e. based on these measurements, a position sensor is used to determine the position of the membrane 402. Electronic devices for signal conversion may include available electronic devices such as the LDC 1614 Inductance to Digital Converter offered by Texas Instruments. By calibrating the obtained positions with the fluid pressure, a correspondence is established whereby the fluid pressure is determined based on the measurements of the measuring device 630. Thus, an eddy current pressure sensor 600 is used to determine the pressure of the fluid acting on the membrane 402.

[0044] While pressure sensor 600 is depicted as a pressure sensor for an aspiration fluid, an eddy current pressure sensor as disclosed herein can also be used as a pressure sensor 602 for an irrigation fluid. For example, in FIG. 5 and 6, membrane 402 may be membrane 404, pressure sensor 600 may be pressure sensor 602, and position sensor winding 610 may be position sensor winding 612 (as schematically depicted in FIG. 2). The membrane 404 may be similar to the membrane 402 as described herein, and the irrigation fluid pressure sensor 602 may be configured and operated as described herein with respect to the aspiration fluid pressure sensor 600. If two or more eddy current pressure sensors as described herein are used in the same system (eg, one for aspiration fluid and one for irrigation fluid), it may be desirable to use different sensors at different frequencies to avoid interference.

[0045] The use of an eddy current pressure sensor 600 and/or 602 in an ophthalmic surgical system, as described herein, provides measurement of fluid pressure in an ophthalmic procedure in a non-contact, non-invasive manner. This system provides advantages over prior art ophthalmic surgical systems that have used membrane-contacting strain gauge transducers in the contact method, which potentially has the disadvantages of limited frequency response and relatively high hysteresis in addition to the potential for additional transducer protection to meet safety requirements. In addition, the use of an eddy current pressure sensor 600 and/or 602 in an ophthalmic surgical system as described herein provides advantages over prior art ophthalmic surgical systems that have used optical pressure sensors, which potentially have disadvantages related to sensitivity to optical adjustment and/or or changes in membrane surface quality. Use of the eddy current pressure sensor 600 and/or 602 in an ophthalmic surgical system as described herein does not require narrow beam light generation, complex optical adjustments, or high speed image processing as required by prior art optical pressure sensors in ophthalmic surgical systems. . Instead, the use of an eddy current pressure sensor 600 and/or 602 in an ophthalmic surgical system, as described herein, offers faster response and simpler implementation.

[0046] The use of eddy current pressure sensor 600 and/or 602 in an ophthalmic surgical system as described herein is also advantageous due to its compact size and ease of operation. The position sensor does not contact the membrane directly. The position sensor does not require a clear optical image on the membrane. Both the sensor and the control electronics can be temperature compensated during the production process and further compensated during operation.

Those of ordinary skill in the art will appreciate that the embodiments covered by the description are not limited to the specific illustrative embodiments described above. Accordingly, while exemplary embodiments are shown and described, a wide range of modifications, variations and analogues are contemplated in the foregoing description. It is understood that such changes may be made to the foregoing without departing from the scope of the present invention. Accordingly, it is appropriate that the appended claims be construed broadly and as described herein.

Claims (32)

1. An ophthalmic surgical system containing: a handle with a working tip for performing an ophthalmic surgical procedure inside the eye; an irrigation system for delivering irrigation fluid to the eye during an ophthalmic surgical procedure, the irrigation system comprising an irrigation source, an irrigation channel in the handle, and an irrigation tube between the irrigation source and the irrigation channel in the handle; a suction system for aspirating fluid from the eye during an ophthalmic surgical procedure, the suction system comprising an suction channel in the handle, an suction tube extending from the suction channel in the handle, and a pump for providing suction through the suction tube and the suction channel in the handle; And a pressure sensor system comprising: a conductive movable membrane having a first side and a second side, the first side of the membrane facing a flow path for either an aspiration fluid aspirated from the eye or an irrigation fluid delivered to the eye; high frequency generator; an eddy current position sensor placed on the second side of the membrane without contact with the membrane, wherein the eddy current position sensor contains a position sensor winding configured to be excited by high-frequency alternating current, and electronic devices for signal conversion configured to detect changes in inductance or impedance, or a resonant frequency in the position sensor winding when the gap between the membrane and the position sensor winding changes and with the ability to convert this change into a displacement signal consistent with the pressure of the fluid. 2. The ophthalmic surgical system according to claim 1, characterized in that the electronic devices for signal conversion are designed to determine the inductance in the winding of the position sensor. 3. The ophthalmic surgical system according to claim 1, characterized in that the electronic devices for signal conversion are configured to determine the impedance in the position sensor winding. 4. The ophthalmic surgical system according to claim 1, characterized in that the electronic devices for signal conversion are designed to determine the resonant frequency in the winding of the position sensor. 5. The ophthalmic surgical system of claim 1, wherein the first side of the membrane faces a flow path for an aspiration fluid aspirated from the eye. 6. The ophthalmic surgical system of claim 1, wherein the first side of the membrane faces a flow path for an irrigant fluid delivered to the eye. 7. Ophthalmic surgical system according to claim 1, characterized in that the winding of the position sensor is placed in a non-conductive housing. 8. An ophthalmic surgical system comprising an inkjet module in combination with an inkjet cassette, wherein the inkjet module and inkjet cassette together contain: an irrigation flow path through which irrigation fluid is delivered to the eye during an ophthalmic surgical procedure; an aspiration flow path through which the aspirated fluid is aspirated from the eye during an ophthalmic surgical procedure; And a pressure sensor system comprising: a conductive movable membrane having a first side and a second side, the first side of the membrane facing either an irrigation flow path or an aspiration flow path; high frequency generator; an eddy current position sensor placed on the second side of the membrane without contact with the membrane, wherein the eddy current position sensor contains a position sensor winding configured to be excited by high frequency alternating current, and electronic devices for signal conversion configured to detect changes in inductance or impedance, or a resonant frequency in the position sensor winding when the gap between the membrane and the position sensor winding changes and with the ability to convert this change into a displacement signal consistent with the pressure of the fluid. 9. Ophthalmic surgical system according to claim 8, characterized in that the electronic devices for signal conversion are configured to determine the inductance in the winding of the position sensor. 10. Ophthalmic surgical system according to claim 8, characterized in that the electronic devices for signal conversion are designed to determine the impedance in the position sensor winding. 11. Ophthalmic surgical system according to claim 8, characterized in that the electronic devices for signal conversion are designed to determine the resonant frequency in the winding of the position sensor. 12. Ophthalmic surgical system according to claim 8, characterized in that the first side of the membrane faces the aspiration channel for flow. 13. The ophthalmic surgical system according to claim 8, characterized in that the first side of the membrane faces the irrigation channel for flow. 14. Ophthalmic surgical system according to claim 8, characterized in that the winding of the position sensor is placed in a non-conductive housing. 15. A method for measuring the pressure of a fluid in an ophthalmic surgical system, the method comprising: passing a fluid through the fluid flow channel during an ophthalmic surgical procedure, wherein the conductive movable membrane is positioned such that a first side of the membrane faces the fluid flow channel; excitation of the position sensor winding with high frequency alternating current, while the position sensor winding is located on the second side of the membrane without contact with the membrane; detecting a change in inductance or impedance or resonant frequency in the position sensor winding when the gap between the membrane and the position sensor winding changes due to a change in fluid pressure in the fluid flow path and converting this change into a bias signal consistent with the fluid pressure. 16. The method for measuring fluid pressure in an ophthalmic surgical system according to claim 15, wherein the step of determining a change in inductance or impedance or resonant frequency in the position sensor winding includes determining a change in inductance in the position sensor winding. 17. The method for measuring fluid pressure in an ophthalmic surgical system according to claim 15, wherein the step of determining a change in inductance or impedance or resonant frequency in the position sensor winding includes detecting a change in impedance in the position sensor winding. 18. The method for measuring fluid pressure in an ophthalmic surgical system according to claim 15, wherein the step of determining a change in inductance or impedance or a resonant frequency in the position sensor winding includes determining a change in the resonant frequency in the position sensor winding.