Ophthalmic cutting instrument with integrated suction pump

Abstract

To provide ophthalmic cutting instruments that are excellent in the follow-up performance of a system even when a long suction line is used and have high responsiveness to a change in pressure.SOLUTION: An apparatus for extracting lens material from an eye includes a distal, disposable portion releasably coupleable to a proximal, reusable portion. The disposable portion includes a cutting tube 1112 having a distal cutting tip and an inner lumen having an open distal end. The disposable portion includes an aspiration pump fluidly coupled to the inner lumen of the cutting tube and a cutting tube drive mechanism 119 configured to vibrate the cutting tube. The reusable portion includes an aspiration pump motor configured to drive the aspiration pump and a coupler releasably coupling the pump motor to the aspiration pump.SELECTED DRAWING: Figure 17A

Description

[Technical Field]

[0001] TECHNICAL FIELD The present technology relates generally to ophthalmic microsurgical tools and systems, and more particularly to ophthalmic microsurgical tools and systems having an integrated pump. [Background technology]

[0002] Certain conventional ophthalmic procedures require dissecting and fragmenting lens tissue and solid intraocular objects, such as intraocular lenses and vitreous bodies, so that they can be extracted from the eye. For example, lens extraction for cataract surgery is one of the most common outpatient surgical procedures, with over 3 million procedures performed annually in the United States alone. The most commonly used method for lens extraction during cataract surgery is phacoemulsification, which incorporates the use of ultrasonic energy to dissect the lens and subsequent suction to remove lens fragments through an instrument. Other methods of lens fragmentation and extraction may involve the use of instruments such as hooks, knives, or lasers to tear and fragment the lens, followed by extraction through a corneal incision from within the eye. Fragmentation of intraocular lens tissue from within the eye is crucial in cataract surgery because it allows removal of the cataract through an incision typically no larger than 2.8–3.0 mm.

[0003] A typical phacoemulsification system includes a console in operative communication with a phacoemulsification handpiece. The console typically includes a cabinet containing a power supply, pump, and associated electronic hardware. The console provides electronic control of the handpiece, aspiration, and irrigation. The handpiece includes a resonating burr attached directly to a set of piezoelectric crystals at a first end and a needle-shaped cutting tube at a second end. The crystals provide the ultrasonic vibrations required to drive the resonating burr and attached cutting tube during phacoemulsification.

[0004] During a typical phacoemulsification procedure, the tip of the cutting tube, which extends beyond the distal end of the irrigating sleeve, is inserted into the anterior segment of the eye through a small incision in the outer tissue of the eye. The tip of the cutting tube contacts the lens of the eye, causing the vibrating tip to fragment the lens. Fragments are aspirated from the eye through the internal lumen of the cutting tube, along with irrigation fluid, which is delivered to the eye through the irrigation sleeve during the procedure and directed toward a waste container. During cutting, irrigation fluid is delivered (i.e., passively or actively) to the eye through the irrigation sleeve positioned beyond the cutting tube. The irrigation fluid is intended to maintain pressure balance within the eye and prevent collapse of the anterior chamber during removal of the emulsified lens. Summary of the Invention [Problem to be solved by the invention]

[0005] A challenge associated with conventional phacoemulsification devices and other devices using remote aspiration sources is that the aspiration lines are fairly long and flexible, contributing to fluid system compliance. Finally, such systems often contain compressed gas or other substances, which further enhance the compliance of the system. Long, flexible lines containing compressed substances affect the response time at the tip when aspiration is turned on and off. Yet another problem in some systems, such as Venturi-based systems, is that the waste disposal enclosure, the container, and the gas or other compressed material therein, are exposed to vacuum pressure and react to pressure changes, causing a delay in the onset and termination of aspiration at the tip and poor responsiveness in some systems.

[0006] For example, during cataract surgery, conventional methods and devices for delivering irrigation to the eye may use large volumes of circulating irrigating balanced salt solution (BSS). For example, bottles and bags of BSS may range from 250 cc to 500 cc. Corneal endothelial cells can be damaged in several ways, including the large volume of ultrasonic energy delivered to the eye and the large volume of irrigation fluid circulating through the anterior chamber. Furthermore, when large volumes of irrigation fluid are used, the flow rate through the eye is not as high, therefore, there may be additional turbulence of the irrigation fluid, which may further damage the corneal endothelial cells. [Means for solving the problem]

[0007] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority under 35 U.S.C. §119(e) to co-pending U.S. provisional patent application serial numbers 62 / 800,198, filed February 1, 2019, 62 / 815,673, filed March 8, 2019, and 62 / 868,688, filed June 28, 2019. The disclosures of these provisional applications are incorporated herein by reference in their entireties.

[0008] According to a first aspect, an apparatus for extracting lens material from an eye is disclosed. The apparatus includes a distal disposable portion releasably coupleable to a proximal reusable portion. The distal disposable portion includes a cutting tube having a distal cutting tip and an inner lumen having an open distal end. The cutting tube is sized and configured to extend through the anterior chamber of the eye to the capsular bag. The distal disposable portion includes an aspiration pump housed within the disposable portion and fluidly coupled to the inner lumen of the cutting tube, and a cutting tube drive mechanism configured to oscillate the cutting tube. In use, the apparatus is configured to aspirate lens material from the capsular bag into the inner lumen. The proximal reusable portion is configured to remain outside the eye. The proximal reusable portion includes an aspiration pump motor configured to drive the aspiration pump and a coupler releasably operably coupling the pump motor and the aspiration pump.

[0009] The aspiration pump may be a peristaltic pump. The peristaltic pump may be a linear peristaltic pump having a central camshaft extending longitudinally through a symmetrical dual-chamber pump manifold. The central camshaft may have a rotational axis coaxially aligned with the longitudinal axis of the distal disposable portion. The aspiration pump motor rotates the central camshaft. The linear peristaltic pump may further include two tubes extending through the pumping manifold, each of the two tubes having a longitudinal axis aligned parallel to the rotational axis of the central camshaft. A first of the two tubes is positioned on one side of the camshaft, and a second of the two tubes is positioned on a second, opposite side of the camshaft. The linear peristaltic pump may further include a proximal flow path and a distal flow path. The proximal flow path may split into two flow paths connected at their proximal ends to two tubes in the pumping manifold. The two tubes may merge distal to the pumping manifold to form the distal flow path. The camshaft can further include multiple lobed cams operating in time to drive multiple cam followers toward and away from the two tubes to sequentially and progressively compress the two tubes to force a volume of fluid toward the distal flow path. The movement of the multiple cam followers occurs in a plane perpendicular to the rotational axis of the camshaft and the longitudinal axes of the two tubes. The multiple cam followers can sequentially compress the two tubes in a wave-like manner. The multiple cam followers can exert no force on the longitudinal direction of the two tubes and can generate little friction between the two tubes.

[0010] The device can further include an external vacuum source operably coupled to at least one of the proximal reusable portion and the distal disposable portion. The external vacuum source can be configured to provide a continuous level of negative pressure within the inner lumen. The level of continuous negative pressure can be lower than the level of negative pressure generated by the aspiration pump in the distal disposable portion.

[0011] The cutting tube drive mechanism can induce oscillatory motion of the cutting tube via a mechanical hinge. The cutting tube drive mechanism can incorporate no more than two nodal inflection points between the point of application of the drive force and the distal cutting tip of the cutting tube. The cutting tube drive mechanism can include a base, a rocker, and a pivot pin, where the rocker is movably coupled to the base by the pivot pin and configured to rotate relative to the base about the pivot pin's axis of rotation. The cutting tube passes through the center of the rocker, and the pivot pin is substantially aligned along the longitudinal axis of the cutting tube, which forms the fulcrum for the rocker.

[0012] The drive mechanism can drive a piezoelectric stack and a spring stack, the piezoelectric stack and the spring stack being positioned on opposite sides of the cutting tube. The spring stack can generate an upward force against a first end of the rocker and urge a second, opposite end of the rocker downward against the piezoelectric stack. As the cutting tube moves in at least one direction, the piezoelectric stack expands under a change in voltage, causing the rocker to rotate about the axis of rotation of the pivot pin. As the piezoelectric stack retracts, the upward force of the spring stack against the first end of the rocker can push the second, opposite end of the rocker downward while maintaining contact with the retracted piezoelectric stack. The drive mechanism can further include a motor-driven cam and cam follower coupled to the rocker. The drive mechanism can further include a motor and a motor shaft, the motor shaft having an offset weight configured to cause movement of the rocker when the motor shaft rotates. The rocker can be a linear rocker, and the pivot pin is aligned with the rocker along the longitudinal axis of the cutter tube. The rocker may be an offset rocker, with the pivot pin located proximate the rocker along the longitudinal axis of the cutter tube.

[0013] The cutting tube drive mechanism can produce an applied driving force to generate longitudinal and / or torsional vibrational motion. The vibrational motion can be in the ultrasonic or sub-ultrasonic frequency range. The vibrational frequency of the distal cutting tip can be between about 0.5 Hz and 5000 Hz.

[0014] The cutting tube can incorporate a non-circular cross-sectional shape along at least a portion of its length. The non-circular cross-sectional shape can include an oval, elliptical, lentoid, teardrop, or diamond shape. The cutting tube can incorporate at least a first tapered profile extending laterally from a central axis of the cutting tube. The cutting tube can have an asymmetric cross-section forming a single tapered shape extending from one side of the cutting tube and a circular shape on the opposite side of the cutting tube. The cutting tube can have a cross-sectional shape that varies along its length. The cutting tube can incorporate a non-circular shape only on the distal-most length of the cutting tube. The distal-most length can be approximately 1 mm.

[0015] The proximal reusable portion can further include a throttle mechanism for varying the speed of the aspiration pump motor, the throttle mechanism operably coupled to the actuator. The device can further include an irrigation lumen connectable to a source of irrigation fluid. The irrigation lumen can include an annular space at least partially surrounding the cutting tube.

[0016] In a related aspect, an apparatus for extracting lens material from an eye is provided, including a cutting tube having a distal cutting tip and an internal lumen, the cutting tube sized and configured to extend through the anterior chamber of the eye to the capsular bag, and a cutting tube drive mechanism configured to oscillate the cutting tube via a mechanical hinge, the cutting tube drive mechanism incorporating no more than two nodal inflection points between the application of a drive force and the distal cutting tube of the cutting tube.

[0017] The cutting tube drive mechanism can include a base, a rocker, and a pivot pin, where the rocker is movably coupled to the base by the pivot pin and configured to rotate relative to the base about the pivot pin's axis of rotation. The cutting tube can extend through the center of the rocker, with the pivot pin substantially aligned along the longitudinal axis of the cutting tube and serving as a fulcrum for the rocker. The drive mechanism can further include a piezoelectric stack and a spring stack, where the piezoelectric stack and the spring stack are disposed on opposite sides of the cutting tube. The spring stack can generate an upward force against a first end of the rocker and urge a second, opposite end of the rocker downward against the piezoelectric stack. Under a change in voltage, the piezoelectric stack can expand, rotating the rocker about the pivot pin's axis of rotation and moving the cutting tube in at least one direction. Retraction of the piezoelectric stack can cause the upward force of the spring stack against the first end of the rocker to push the second, opposite end of the rocker downward while maintaining contact with the retracted piezoelectric stack. The drive mechanism can further include a motor-driven cam and cam follower coupled to the rocker. The drive mechanism can further include a motor and a motor shaft, the motor shaft having an offset weight configured to cause movement of the rocker when the motor shaft rotates. The rocker can be a straight rocker, and the pivot pin is aligned with the rocker along the longitudinal axis of the cutting tube. The rocker can be an offset rocker, and the pivot pin is located near the rocker along the longitudinal axis of the cutting tube. The cutter tube drive mechanism can create an applied drive force to generate longitudinal and / or torsional vibration motion. The vibration motion can be in the ultrasonic or sub-ultrasonic frequency range. The vibration frequency of the distal cutting tip can be between approximately 0.5 Hz and 5000 Hz.

[0018] The device may further include an aspiration pump fluidly coupled to the inner lumen of the cutting tube, such that, in use, the device is configured to aspirate lens material from the capsular bag into the inner lumen. The aspiration pump may be a peristaltic pump. The peristaltic pump may be a linear peristaltic pump having a central camshaft extending longitudinally through a symmetrical dual-chamber pumping manifold, the central camshaft having an axis of rotation coaxially aligned with the longitudinal axis of the distal disposable portion. The camshaft may include multiple lobed cams actuated in time to drive multiple cam followers toward or away from the two tubes through the pump manifold to sequentially and progressively compress the two tubes to force a fluid volume toward the distal flow path. Each of the two tubes may include a longitudinal axis aligned parallel to the axis of rotation of the central camshaft. A first of the two tubes may be located on one side of the camshaft, and a second of the two tubes may be located on a second, opposite side of the camshaft. The movement of the multiple cam followers can occur in a plane perpendicular to the rotational axis of the camshaft and the longitudinal axis of the two tubes. The multiple cam followers can compress the two tubes sequentially like a wave. Furthermore, the multiple cam followers do not apply force to the two tubes in the longitudinal direction, and can generate almost no friction between the two tubes.

[0019] In a related aspect, there is provided an apparatus for extracting lens material from an eye, the apparatus having a cutting tube with a distal cutting tip and an inner lumen with an open distal end, the cutting tube sized and configured to extend through the anterior chamber of the eye to the capsular bag, and in use, the apparatus configured to aspirate lens material from the capsular bag into the inner lumen. The apparatus includes a cutting tube drive mechanism configured to torsionally oscillate the cutting tube. The cutting tube has a non-circular cross-sectional shape along at least a portion of its length.

[0020] The vibrational motion may be in the ultrasonic or sub-ultrasonic frequency range. The non-circular cross-sectional shape may include an oval, elliptical, lentoid, teardrop, or diamond shape. The non-circular cross-sectional shape may include at least a first tapered shape extending laterally from the central axis of the cutting tube. The non-circular cross-sectional shape may be asymmetric and incorporate a single tapered profile extending from one side of the cutting tube and a circular profile on the opposite side of the cutting tube. The cutting tube may incorporate the non-circular cross-sectional shape only on the distal-most length of the cutting tube. The distal-most length may be approximately 1 mm.

[0021] In some variations, the above methods, apparatus, devices, and systems can include one or more of the following, in any possible combination: More details of the devices, systems, apparatus, and methods are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description and drawings. [Brief explanation of the drawings]

[0022] These and other aspects are described in detail with reference to the following drawings. Generally speaking, the figures are not to absolute or relative scale and are for illustrative purposes, and the relative placement of features and elements may be altered for clarity of illustration.

[0023] [Figure 1] FIG. 1 is a block diagram of a phacoemulsification system. [Figure 2A] FIG. 1 is a cross-sectional view of a phacoemulsification handpiece. [Figure 2B] FIG. 10 is a perspective view of the distal end of a cutting tube incorporating a tapered profile shape. [Figure 2C] FIG. 2C is a plan view of the cut tube of FIG. 2B. [Figure 2D] 10A-10C are cross-sectional views of implementations of cut tubes incorporating varying shapes of tapered profiles. [Figure 2E]10A-10C are cross-sectional views of implementations of cut tubes incorporating varying shapes of tapered profiles. [Figure 2F] 10A-10C are cross-sectional views of implementations of cut tubes incorporating varying shapes of tapered profiles. [Figure 2G] 10A-10C are cross-sectional views of implementations of cut tubes incorporating varying shapes of tapered profiles. [Figure 2H] 10A-10C are cross-sectional views of an implementation of a cutting tube incorporating varying shapes of tapered profiles and internal (lumen) shapes. [Figure 2I] 10A-10C are cross-sectional views of an implementation of a cutting tube incorporating varying shapes of tapered profiles and internal (lumen) shapes. [Figure 2J] 1 is a cross-sectional view of an implementation of a cutting tube incorporating varying shapes of tapered profile and internal (lumen) shapes. [Figure 2K] 1 is a schematic cross-section of a Kelman-style cut tube. [Figure 2L] 2K shows the distal end of the cut tube of FIG. 2K incorporating a tapered profile shape. [Figure 2M] FIG. 10 is a perspective view of the distal end of a cutting tube incorporating an asymmetric tapered profile shape. [Figure 3] FIG. 1 is a block diagram of a phacoemulsification system according to an implementation including a handpiece with an integrated aspiration pump. [Figure 4] FIG. 4 is a block diagram of the phacoemulsification system of FIG. 3 illustrating fluidic components. [Figure 5A] 4 illustrates an implementation of the handpiece of FIG. 3. [Figure 5B] 5B shows the handpiece of FIG. 5A with the durable portion removed from the disposable portion. [Figure 5C] 5C shows the handpiece of FIG. 5B illustrating a pulsating vacuum valve. [Figure 6] 1 shows the distal end region of the handpiece with an irrigation sleeve attached over the lens cutting tip. [Figure 7A]7 shows the distal end region of the handpiece of FIG. 6 with the irrigating sleeve and tip removed. [Figure 7B] 7 shows the lens cutting tip of FIG. 6. [Figure 7C] The phacoemulsification handpiece of FIG. 7A is shown with a back-polishing tip having a back-polishing nub. [Figure 8A] 7 shows a back-abrasive tip attached to the handpiece of FIG. 6 and an irrigation sleeve attached over the back-abrasive protective sleeve. [Figure 8B] 1 shows the back-abrasive tip attached to the handpiece and the irrigation sleeve attached over the back-abrasive protective sleeve. [Figure 8C] FIG. 8C is a cross-sectional view of the back-ground tip of FIG. 8B. [Figure 9A] 7C shows the lens cutting tip of the handpiece of FIG. 7B with a cleaning reservoir. [Figure 9B] 7C shows the lens cutting tip of the handpiece of FIG. 7B with a cleaning reservoir. [Figure 10A] 1 shows a symmetrical sinusoidal motion profile of the cut tube. [Figure 10B] 1 illustrates an asymmetric non-sinusoidal motion profile of a cut tube. [Figure 10C] A symmetrical motion profile of the cutting tube is shown, where the extension velocity profile is the same as the retraction velocity profile of the elongate member. [Figure 10D] 1 shows an asymmetric motion profile of the cut tube, where the extension velocity profile is the same as the retraction velocity profile of the cut tube. [Figure 10E] Additional examples of extension velocity profiles and cut tube retraction velocity profiles are shown, where both profiles are different. [Figure 10F] Additional examples of extension velocity profiles and cut tube retraction velocity profiles are shown, where both profiles are different. [Figure 10G]The non-sinusoidal motion of the distal tip of the cut tube (bottom panel) is shown relative to the extension velocity profile (top panel). [Figure 11A] 10 illustrates the implementation of a vacuum profile for a piston pump of a handpiece. [Figure 11B] 1 shows the overlap between the piston pump and the asymmetric non-sinusoidal motion profile for the cutting tube (solid line) and the vacuum profile for suction through the cutting tube (dotted line). [Figure 11C] 1 shows the overlap between the piston pump and the asymmetric non-sinusoidal motion profile for the cutting tube (solid line) and the vacuum profile for suction through the cutting tube (dotted line). [Figure 11D] 1 shows the overlap between the piston pump and the asymmetric non-sinusoidal motion profile for the cutting tube (solid line) and the vacuum profile for suction through the cutting tube (dotted line). [Figure 11E] 1 shows the overlap between the piston pump and the asymmetric non-sinusoidal motion profile for the cutting tube (solid line) and the vacuum profile for suction through the cutting tube (dotted line). [Figure 11F] The overlap between the asymmetric non-sinusoidal motion profile for the cutting tube (solid line) and the vacuum profile for suction through the cutting tube (dotted line) is shown. [Figure 11G] 10 illustrates the implementation of a vacuum profile for a peristaltic pump in a handpiece. [Figure 12] FIG. 10 is a perspective view showing the durable and disposable portions of an embodiment of a handpiece separated from one another. [Figure 13A] FIG. 1 is a side view illustrating an implementation of a handpiece for cutting and aspirating material from an eye configured for use with a microsurgical control system. [Figure 13B] FIG. 1 is a side view illustrating an implementation of a handpiece for cutting and aspirating material from an eye configured for use with a microsurgical control system. [Figure 13C] 13A-13B show variations of the rotating cam of the handpiece of FIGS. [Figure 13D] 13A-13B show variations of the rotating cam of the handpiece of FIGS. [Figure 13E] 13A-13B show variations of the rotating cam of the handpiece of FIGS. [Figure 13F] 13A-13B additionally illustrate various components of the device of FIG. [Figure 13G] 13A-13B additionally illustrate various components of the device of FIG. [Figure 13H] 13A-13B additionally illustrate various components of the device of FIG. [Figure 13I] 13A-13B additionally illustrate various components of the device of FIG. [Figure 13J] 13A-13B additionally illustrate various components of the device of FIG. [Figure 13K] 13A-13B additionally illustrate various components of the device of FIG. [Figure 13L] 13A-13B additionally illustrate various components of the device of FIG. [Figure 14A] 1 is an example of a handpiece for cutting and aspirating material from the eye. [Figure 14B] 1 is an example of a handpiece for cutting and aspirating material from the eye. [Figure 15A] 10A and 10B illustrate schematically the movement of a piston on a cam surface. [Figure 15B] 10A and 10B illustrate schematic illustrations of piston movement on other cam surfaces. [Figure 15C] 10A and 10B illustrate schematic illustrations of piston movement on other cam surfaces. [Figure 15D] 10A and 10B illustrate schematic illustrations of piston movement on other cam surfaces. [Figure 16A] 1 illustrates an implementation of a cutting tube drive mechanism incorporating an offset rocker. [Figure 16B] 16B is a side view and a cross-sectional view of the cutting tube drive mechanism of FIG. 16A. [Figure 16C] 16B is a side view and a cross-sectional view of the cutting tube drive mechanism of FIG. 16A. [Figure 16D]116A illustrates the implementation of FIG. 116A with a dome-shaped interface between the piezoelectric stack and the offset rocker. [Figure 17A] 1 illustrates an implementation of a cutting tube drive mechanism incorporating a straight rocker. [Figure 17B] 17B is a side view and a cross-sectional view of the cutting tube drive mechanism of FIG. 17A. [Figure 17C] 17B is a side view and a cross-sectional view of the cutting tube drive mechanism of FIG. 17A. [Figure 18] FIG. 10 is a perspective view showing an implementation of a cutting tube drive mechanism incorporating a hinge clamp. [Figure 19A] 1 illustrates an implementation of a cutting tube drive mechanism incorporating parallel disc springs. [Figure 19B] 19B is a side view and a cross-sectional view of the cutting tube drive mechanism of FIG. 19A. [Figure 19C] 19B is a side view and a cross-sectional view of the cutting tube drive mechanism of FIG. 19A. [Figure 20A] 1 illustrates an implementation of a cutting tube drive mechanism. [Figure 20B] FIG. 20B is a cross-sectional view of the cutting tube drive mechanism of FIG. 20A. [Figure 21A] 1 illustrates an implementation of a cutting tube drive mechanism incorporating a motor-driven cam. [Figure 21B] 21B is the cutting tube drive mechanism of FIG. 21A with a hidden base. [Figure 21C] FIG. 21B is an enlarged view of the cam mechanism of FIG. 21A. [Figure 21D] 21D shows the cam mechanism of FIG. 21C with a hidden cam. [Figure 22A] FIG. 1 is a perspective view of an implementation of a suction pump configured to be incorporated into the working portion of a microsurgical instrument. [Figure 22B] FIG. 22B is a top view of the suction pump of FIG. 22A. [Figure 22C] 22B shows the camshaft of the suction pump of FIG. 22A. [Figure 22D] 22B shows the camshaft of the suction pump of FIG. 22A. [Figure 23A] FIG. 22B is an end view of the suction pump of FIG. 22A illustrating the lateral movement of the cam follower as the camshaft rotates. [Figure 23B] FIG. 22B is an end view of the suction pump of FIG. 22A illustrating the lateral movement of the cam follower as the camshaft rotates. [Figure 23C] FIG. 22B is an end view of the suction pump of FIG. 22A illustrating the lateral movement of the cam follower as the camshaft rotates. [Figure 23D] FIG. 22B is an end view of the suction pump of FIG. 22A illustrating the lateral movement of the cam follower as the camshaft rotates. [Figure 24A] 1 shows an example of the aspiration flow rate provided by the aspiration pump. [Figure 24B] 4 illustrates another example of the suction flow rate provided by the suction pump. [Figure 25A] 1 illustrates an implementation of a cutting tube drive mechanism incorporating a vibration motor. [Figure 25B] 1 illustrates an implementation of a cutting tube drive mechanism incorporating a vibration motor. [Figure 25C] 1 illustrates an implementation of a cutting tube drive mechanism incorporating a vibration motor. [Figure 26A] 10 illustrates another implementation of a cutting tube drive mechanism incorporating a vibration motor. [Figure 26B] 10 illustrates another implementation of a cutting tube drive mechanism incorporating a vibration motor. [Figure 26C] 10 illustrates another implementation of a cutting tube drive mechanism incorporating a vibration motor. [Figure 27A] 10 illustrates another implementation of the cutting tube drive mechanism. [Figure 27B] 10 illustrates another implementation of the cutting tube drive mechanism.

[0024] It should be understood that the drawings are merely illustrative and are not intended to be drawn to scale. It should be understood that devices described herein may include features that are not necessarily depicted in each figure. DETAILED DESCRIPTION OF THE INVENTION

[0025] Described herein are systems, devices, and methods of ophthalmic microsurgical tools useful for intraocular fragmentation and removal of the lens, vitreous, and other tissues during intraocular surgery. The various systems, devices, and methods are configured to perform one or more functions useful in ophthalmic procedures, including, but not limited to, cutting, fragmenting, emulsifying, aspirating, and / or irrigating material present at a target location during an intraocular procedure.

[0026] As used herein, "material" can include fluids (from the eye or provided to the eye), tissues, or tissue fragments, such as lens tissue, vitreous tissue, cells, and other fluids or tissues or other substances that may be present during an ocular procedure (e.g., cataract procedure, vitrectomy procedure, etc.).

[0027] The systems, devices, and methods described herein are configured to apply vacuum and deliver fluid to maintain pressure balance within the eye. The systems, devices, and methods described herein that apply vacuum and / or deliver fluid may also be configured to cut, fragment, emulsify, or otherwise reduce material at or near the surgical site. The systems, devices, and methods described herein that allow a vacuum to be applied can deliver the vacuum using pulsed vacuum, with or without interrupted pulsed positive pressure, to provide momentary retrograde flow.

[0028] It should be understood that the various features and functions of the devices described herein may be applied to one or more of the devices described herein, even if not explicitly listed in combination. It should also be understood that the various features and functions of the devices described herein may also be applied to conventional devices and systems known in the art that are useful for cutting, fragmenting, emulsifying, or impacting tissue at or near a surgical site, including, but not limited to, phacoemulsification systems, vitrectomy systems, bag polishing systems, and other tools useful for performing, for example, cataract or vitreous surgery.

[0029] FIG. 1 is a functional block diagram of a phacoemulsification system 10. The system 10 has a control unit 12, which may include a variable speed peristaltic pump 14 that provides a vacuum source for aspiration, an ultrasonic power supply 16, and a microprocessor computer 18 that provides control outputs to a pump speed controller 20 and an ultrasonic power level controller 22. A vacuum sensor 24 provides an input to the computer 18 indicative of the vacuum level at the output of the peristaltic pump 14. The vacuum sensor 24 may be located within a handpiece 30. Suitable ventilation is provided by a vent 26. The control unit 12 supplies ultrasonic power over line 28 to the phacoemulsification handpiece 30. An irrigation fluid source 32 is fluidly coupled to the handpiece 30 via line 34. Irrigation fluid and ultrasonic power are applied to a patient's eye 36 by the handpiece 30. Aspiration of the eye 36 is achieved by the peristaltic pump 14 via lines 38 and 40. The supply of cleaning fluid from cleaning fluid source 32 can be via gravity or by using an additional cleaning fluid pump integrated into control unit 12. Computer 18 responds to a preset vacuum level in output line 42 from peristaltic pump 14 via a signal from vacuum sensor 24.

[0030] FIG. 2A is a cross-sectional view of a phacoemulsification handpiece 30. The handpiece 30 includes a cutting tip 112, which may be a tube with a lumen 110, a handpiece shell 114, an ultrasonic horn 116, and multiple stacks of ultrasonic crystals. The handpiece 30 may include a first set of ultrasonic crystals 118 and a second set of ultrasonic crystals 120. The first set of ultrasonic transducers 118 may be positioned perpendicular to the longitudinal axis of the cutting tube 112 to generate what is conventionally referred to as "torsional" motion. The second set of ultrasonic transducers 120 may be positioned coaxially with the longitudinal axis of the cutting tube 112 to generate what is conventionally referred to as "longitudinal" or "axial" motion. The crystals 118 are deflected to generate the torsional motion. The torsional motion can include any of a variety of motions relative to the longitudinal axis of the cutting tube 112, but includes substantially more lateral motion than axial motion. The crystal 120 is deflected to generate longitudinal motion, which can also include any of a variety of motions of the cutting tube 112 relative to its longitudinal axis, including substantially axial motion from side to side. The crystals 118, 120 may also be configured to generate both longitudinal and torsional motion.

[0031] The ultrasonic crystals do not need to be positioned perpendicular to the longitudinal axis of the cutting tube 112 to produce the torsional motion described in more detail below.

[0032] Horn 116 is held within shell 114 by isolator 117. Crystals 118 and 120 are held within shell 114 and in contact with horn 116 by back cylinder 122 and bolts 124. Crystals 118 and 120 vibrate ultrasonically in response to signals generated by ultrasonic generator 126. Ultrasonic generator 126 provides a drive signal to power ultrasonic handpiece 30.

[0033] Piezoelectric crystals generally have a resonant frequency where the input voltage corresponds to a maximum current and amplitude. This often occurs when the voltage and current are in phase with each other. Ultrasonic drive systems, such as those described herein and commonly used in ultrasonic welders, ultrasonic cutters, ultrasonic cleaners, and the like, use a horn 116 to amplify the movement of the cutting tube 112. The horn length may be configured to be a multiple of a half-wavelength of the sound waves traveling through the horn material. Thus, the end of the horn 116 becomes the node that moves with the greatest amplitude. The horn 116 is often stepped or configured to amplify the movement of the tube 112 by tapering the distal end of the horn 116 to travel a greater distance than the proximal end of the horn 116, which is rigidly connected to the piezoelectric crystals 118, 120. The horn 116 is often designed to match the resonance of the piezoelectric crystals 118, 120 to achieve the most efficient energy transfer.

[0034] The cutting tube 112 of a conventional phacoemulsification handpiece is circular in cross section. Torsional or lateral movement (i.e., movement substantially transverse to the longitudinal axis of the cutting tube 112) can create microscopic cavitation bubbles on the low-pressure side (i.e., trailing side) of the circular cutting tube 112, which implode when the direction of travel is reversed. The cutting tubes 112 described herein can incorporate non-circular geometries configured to mitigate the creation of cavitation bubbles on one or both sides of the cutting tube 112 during substantially transverse movement of the cutting tube 112 during a torsional or lateral cutting action. Non-circular shapes can include oval, elliptical, lentoid, teardrop, diamond, or other non-circular shapes. The geometric shape may include one or more airfoils or hydrofoils extending from the central axis of the cutting tube 112 .

[0035] 2B-2C show that the cutting tube 112 of the handpiece 30 can include first and second tapers or tapered profiles 111a, 111b extending laterally from the central axis A of the tube 112. FIG. 2C shows that the planar shape of the cutting tube 112 can be substantially rectangular along at least a portion of its length. The geometry of the cutting tube 112 can mitigate the generation of these cavitation bubbles on the subsequent low-pressure side as the cutting tube 112 moves laterally. FIG. 2B shows a distal end view of a substantially straight cutting tube 112. FIG. 2C is a planar view of the cutting tube 112 illustrating that tapered profile 111a forms the leading edge and tapered profile 111b forms the trailing edge when undergoing a twisting motion toward the right (arrow T). The tapered profiles 111a, 111b extend outward from the lumen 113 on opposite sides of the longitudinal axis A of the cutting tube 112. The distance between the longitudinal axis A of the tapered profile 111 and the wing tips can vary from about 0.25 mm to about 1.5 mm, or from about 0.5 mm to about 1.0 mm. Thus, the end-to-end distance D (i.e., wingspan) between the tapered profiles 111a, 111b can be from about 0.5 mm to about 3 mm, or from about 1 mm to 2 mm. The aspect ratio of the wing-shaped cutting tube 112 can be relatively high (see FIG. 2E) or relatively low (see FIG. 2F). The aspect ratio of the wing-shaped cutting tube 112 can be between 1.1 and 4. The cross-sectional shape of the wing-shaped cutting tube 112 can incorporate tapered profiles 111a, 111b that are substantially symmetrical with respect to the chord line C. Alternatively, the wing-shaped cutting tube 112 can incorporate a camber or have a curvature with respect to the chord line C. The wing tips of each tapered profile 111 can be curved, as shown in FIG. 2F, or more angular, as shown in FIG. 2G. The lumen 113 of the cutting tube 112 can be substantially cylindrical, as shown in FIGS. 2B, 2D-2G, or can have a non-circular geometric shape, such as an ellipse, lentoid, oval, or other geometric shape, as shown in FIGS. 2H-2J.

[0036] In some implementations, the tapered profile of the cutting tube described herein can reduce or eliminate the amount of turbulence over the cutting tube profile, thereby increasing the amount of laminar flow associated with tube movement compared to a cutting tube with a circular profile. The cutting tubes described herein can incorporate surface treatments and / or coatings on their exterior surfaces to further reduce or mitigate the potential for turbulence. For example, the cutting tube may be mechanically polished or buffed, electropolished, plasma treated, coated with a substance such as PTFE, or any number of other suitable coatings or methods. The treatments and / or coatings reduce the roughness of the cutting tube and / or reduce friction of the fluid on the cutting tube, thereby allowing portions of the cutting tube to form laminar flow as the cutting tube moves through the fluid and reducing turbulence.

[0037] In some implementations, the cutting tube 112 may be asymmetric in cross section (see FIG. 2M). The cutting tube 112 may have a single tapered profile 111 extending from only one side of the cutting tube 112, while the other side of the cutting tube 112 may have any of a variety of other geometric shapes or profiles, including a circular profile 108. As described in more detail herein, the movement of the cutting tube 112 may be asymmetric (e.g., the speed or velocity of movement in a first direction may be different from the speed or velocity of movement in a second, different direction). The twisting or side-to-side movement of the cutting tube 112 may be asymmetric such that the movement is optimized for the shape of the cutting tube 112 (or the shape of the cutting tube 112 is optimized for the movement). For example, as shown in FIG. 2M, one side of the cutting tube 112 has a tapered profile 111, while the other side does not, instead having a circular profile 108. Compared to movement of the cutting tube 112 along directional arrow S when the tapered profile 111 is the leading edge and the circular profile 108 is the trailing edge, movement of the cutting tube 112 along directional arrow F when the circular profile 108 is the leading edge and the tapered profile 111 is the trailing edge may be faster. In this manner, the trailing edge of the cutting tube 112 may resemble a smooth hydrofoil having a tapered profile shape when the cutting tube 112 is moving quickly, and when the cutting tube 112 is moving slowly, the trailing edge of the cutting tube 112 may become rounded. This allows the shape of the trailing edge, along with the movement of the cutting tube 112, to be optimized for disrupting lens tissue while mitigating cavitation. The striking or leading edge profile of the cutting tube 112 may be round or any profile optimized for striking and breaking apart lens fragments, while the trailing edge may be optimized for cavitation mitigation, for example, by incorporating a hydrofoil or tapered profile 111. The asymmetric movement of the cutting tube 112 allows each edge to be optimized for its own purpose.

[0038] The wing-like shape can be present from the distal-most end of the cutting tube 112 to the proximal-most end of the cutting tube 112. In some implementations, only the distal portion of the cutting tube 112 has a wing-like shape. For example, only the distal-most 1 mm of the cutting tube 112 may be wing-like. The irrigation sleeve may be shaped to match the shape of the tapered profile 111 at its distal end. Alternatively, the irrigation sleeve may be a standard circular shape but may be positioned immediately adjacent to the area of ​​the tapered profile 111 at the distal end of the cutting tube 112.

[0039] The wing-shaped cutting tube 112 may be straight along its longitudinal axis A, as shown in FIGS. 2A-2B, or may be bent or curved along at least a portion of its length. In some implementations, the cutting tube 112 may incorporate a Kelman-style tip (see FIGS. 2K-2L) having a bend that forms an angle θ with respect to the longitudinal axis A. The effect of a bent or curved tip is to provide a greater rotational displacement or side-to-side cutting motion at the distal-most tip 115 compared to the relatively smaller rotational displacement of the more proximal region of the cutting tube 112 as it extends through the incision. As the cutting tube 112 rotates about its longitudinal axis A, the distal-most tip of the cutting tube 112 sweeps back and forth along a greater distance. The swept distal tip of the cutting tube 112 may incorporate tapered profiles 111a, 111b, as best shown in FIG. 2L.

[0040] In some implementations, a tab 117 or other surface feature can be coupled to the exterior surface of the cutting tube 112 at a distance from the distal tip 115. The tab 117 and cutting tube 112 can be constrained to move only rotationally. A cutting tube drive mechanism 119, such as a piezoelectric, motor, electromagnetic, voice coil, or other drive mechanism, is configured to apply a force to the tab 117, causing a small rotational movement of the tab 117 and, therefore, the cutting tube 112. The cutting tube 112 can be constrained to move only torsionally. As an example, the cutting tube drive mechanism 119 can incorporate a piezoelectric crystal stack that presses against the tab 117, urging it away from the stack. The crystal stack can be energized to push the tab 117 in a first direction, and a reverse energy can return the tab 117 in the opposite direction (arrow P in FIG. 2L). In this configuration, the piezoelectric crystal stack and tab 117 can be fixed relative to one another. Other cutting tube drive mechanisms are described in more detail below. 2L, the cutting tube 112 incorporating the tabs 117 is shown having an airfoil-like shape. The shape of the tube 112 need not incorporate these tapered profiles 111a, 111b, but may be cylindrical.

[0041] It should be understood that any of the cutting tubes described herein can incorporate the tapered profile 111 such that the airfoil shape mitigates cavitation, regardless of the drive mechanism (i.e., piezo, voice coil, motor-driven cam, or other drive mechanism) used to drive the torsional motion. Similarly, the airfoil-shaped cutting tube can be incorporated into any of the various handpieces described herein, including handpieces that incorporate an aspiration pump and / or a trigger or finger pedal in at least a portion of the handpiece.

[0042] 3 is a functional block diagram of a phacoemulsification system 1010 according to one implementation. The system 1010 can include a control unit 1012, which can include an ultrasonic power supply 1016 and a processor 1018 that provides control outputs to a pump controller 1020 and an ultrasonic power level controller 1022. The control unit 1012 can supply ultrasonic power to a handpiece 1030 on line 1028 (e.g., 400 V for driving the piezoelectric crystal). The handpiece 1030 can include an integrated aspiration pump 1014 powered by the control unit 1012. The control unit 1012 can supply power to the aspiration pump 1014 of the handpiece 1030 through a line that can be the same or a different line from line 1028 (e.g., a lower voltage than for the piezo, 5-12 V for driving the motor). It should be understood that the handpiece 1030 can incorporate electronics such that the handpiece 1030 can be used independently of the control unit 1012. An irrigation fluid source 1032 can be fluidly coupled to the handpiece 1030 via an irrigation line 10344. Irrigation fluid and ultrasonic power can be applied to the patient's eye 36 by the handpiece 1030. Suction of the eye 36 can be achieved by an aspiration pump 1014 within the handpiece 1030 via an aspiration line 1038. Delivery of irrigation fluid from the irrigation fluid source 1032 can be provided via gravity and / or using an irrigation fluid pump within the control unit 1012.

[0043] 4 is a functional block diagram of a phacoemulsification system 1010 illustrating the fluid dynamics of the system 1010. The fluid dynamics of the system 1010 can include an irrigation fluid source 1032, an irrigation fluid line 1034, an aspiration pump 1014 in the handpiece 1030, a waste line 1038 (sometimes referred to herein as an aspiration line), and a waste container 1044. The system 1010 can optionally include an irrigation fluid pump configured to pump irrigation fluid from the irrigation fluid source 1032. The irrigation fluid source 1032 can optionally include one or more pressure sensors and / or valves for controlling flow through the irrigation line 1034 and is fluidly coupled to the handpiece 1030 either directly or via an irrigation port 1044. The irrigation fluid can travel from the irrigation fluid source 1032 and through the irrigation fluid line 1034 toward the handpiece 1030 during a phacoemulsification procedure. An optional irrigation fluid reservoir 1046 may be incorporated within the distal end of the handpiece 1030, as described in more detail below. An optional irrigation fluid reservoir 1046 may be incorporated within the distal end of the handpiece 1030, as described in more detail below. The handpiece 1030 and / or irrigation line 1034 may optionally include one or more valves and / or sensors configured to provide additional control of fluid flow into the handpiece 1030. The handpiece 1030 and / or waste line 1038 may optionally include one or more valves and / or sensors configured to provide additional control of fluid flow from the handpiece 1030. The pump 1014 may aspirate fluids and other materials from the eye 36 through the waste line 1038 and direct the materials toward the waste container 1044.

[0044] The system 1010 can also include a remote suction pump in the area of ​​the control unit 1012 in addition to the suction pump 1014 in the handpiece 1030. The suction pump in the control unit 1012 can be configured to apply continuous, semi-continuous, and / or discontinuous pulsating suction. The suction pump in the control unit 1012 can be configured to apply a continuous low-level flow rate. The suction pump in the control unit 1012 can be any of a variety of different suction pumps, including volumetric flow or positive displacement pumps (e.g., peristaltic, linear peristaltic, piston, scroll pumps) or vacuum-based pumps (e.g., venturi, pneumatic, diaphragm, or rotary vane). In implementations, the suction pump in the control unit 1012 can include a low-pressure, peristaltic pump integrated within the control unit 1012 to support the suction provided by the integrated suction pump 1014 in the handpiece 1030. For example, while the first portion is in service, suction through the handpiece 1030 may be provided by a remote suction pump in the control unit 1012, and while the second portion is in service, suction through the handpiece 1030 may be provided by an integrated suction pump 1014 in the handpiece 1030. Additional implementations of suction support are described in more detail below.

[0045] 5A-5B are cross-sectional views illustrating an implementation of the handpiece 1030 of FIG. 3 having an aspiration pump 1014 driven by a pump motor 1115. The handpiece 1030 is configured for procedures (such as cataract surgery) performed in a minimally invasive, end-on approach through a clear corneal incision. The handpiece 1030 requires less energy, time, and fluid to remove tissue from the eye compared to conventional phaco.

[0046] The handpiece 1030 includes a hollow cutting tip or cutting tube 1112 that is reciprocated by a cutting tube drive mechanism. The cutting tube 1112 can be vibrated by any of a variety of drive mechanisms, including the piezoelectric drive mechanisms described above, as well as electric, magnetostrictive, electromagnetic, hydraulic, pneumatic, mechanical, voice coil, or other types of drive mechanisms known in the art. While the cutting tube 1112 is described as vibrating by a piezoelectric drive mechanism, it should be understood that other cutting tube drive mechanisms are also contemplated. In some implementations, the cutting tube 1112 is reciprocated by a drive mechanism that includes a motor contained within the handpiece 1030. The motor configuration can vary, including any of a variety of rotary motors, stepper motors, AC motors, DC motors, piezoelectric motors, voice coil motors, or other motors. The motor can also be coupled to a reduction system, such as a harmonic drive, to obtain the desired output speed.

[0047] In some implementations, the cutting tube 1112 is oscillated by a piezoelectric drive mechanism. The cutting tube 1112 may be coupled to a horn 1116, which is driven by a piezoelectric crystal 1120. The crystal 1120 may be held in contact with the horn 1116 and within the housing 1114 by a back cylinder 1122 and a bolt 1124. The crystal 1120 may be deflected to generate longitudinal and / or torsional movement when a drive signal is provided by the control unit 1012 to power the handpiece 1030. The piezoelectric crystal 1120 may be a natural piezoelectric substrate, such as a quartz single crystal, or a piezoelectric ceramic, such as lithium niobate, gallium arsenide, zinc oxide, aluminum nitride, or lead zirconate titanate (PZT). In some implementations, the piezoelectric crystal 1120 is formed of a polymer film piezoelectric, such as polyvinylidene fluoride. Such plastic-based crystal stacks are low-cost and potentially disposable.

[0048] Conventional ultrasonic horns are configured to increase the amplitude of vibrational displacement achieved by a piezoelectric transducer. Conventional ultrasonic horns are rigidly connected to an ultrasonic transducer using a threaded stud at the proximal end and are tapered at the distal end. Conventional ultrasonic horns are resonant. As used herein, "horn" can, but need not, function as conventional ultrasonic horns do. That is, the horn can, but need not, resonate during use. The horns described herein can be used in a non-resonant, direct-drive manner, as described in more detail herein. The use of the term "horn" herein is not intended to be limited to the conventional use of the term ultrasonic horn.

[0049] The cutting tube drive mechanism described herein can incorporate a piezoelectric stack. Piezoelectric elements can be damaged or cracked if misaligned with other components. Disk-shaped piezoelectric stacks can be positioned perfectly parallel to one another and are therefore less susceptible to damage. However, the piezoelectric stacks described herein can be positioned non-concentrically with respect to the cutting tube and can directly drive the movement of various components that are not necessarily perfectly parallel. This means that if there is any angle at the interface with the piezoelectric stack, point loads can cause cracks.

[0050] Piezoelectric stacks can be multilayers of thin piezoelectric / electrostrictive ceramic sheets. These stacks have a relatively low drive voltage (100 V), fast response, high generating force, and high electromechanical coupling. However, their displacement, typically on the order of 10 microns, is generally insufficient for cutting tube displacement. As previously mentioned, the cutting tip motion can be what is known as "torsional," or primarily a side-to-side motion rather than a longitudinal anterior-posterior motion. This tip motion is considered a more efficient lens removal motion, especially for dense, hard lens nuclei. Regardless of the direction or orientation of the cutting tip motion, the primary purpose of the piezoelectric drive mechanism is to amplify the small movement of the piezoelectric material into a sufficient physical displacement or stroke of the cutting tip.

[0051] Described herein are various interrelated implementations of cutting tube drive mechanisms configured to achieve a minimum tip speed of 3 meters per second, ranging from sub-ultrasonic (i.e., less than 20,000 Hz) frequency ranges, including less than 10,000 Hz, less than 5,000 Hz, less than 4,000 Hz, and less than 3,000 Hz, to subsonic frequency ranges of less than 20 Hz, less than 15 Hz, less than 10 Hz, less than 5 Hz, and less than about 0.5 Hz. In some implementations, the target tip speed is approximately 5 meters per second to reliably cut high-density materials. The cutting tube drive mechanism can amplify the cutting tube motion while mitigating the potential for damage from incorporating moving parts. The cutting tube drive mechanism can incorporate a piezoelectric stack, a motor-driven cam, or a vibrating motor that directly drives the cutter tube via a conventional hinge to generate the vibratory motion. The vibratory motion achieved can be in the sub-ultrasonic frequency range. The drive mechanism can incorporate fewer than two nodal inflection points between the point of application of the drive force and the distal tip of the cutting tube. The drive force can be applied to generate lateral movement ("torsion") as well as longitudinal movement. It should be understood that the torsional movement need not be constrained to a single plane. To generate oscillatory movement, the drive mechanism can also drive the cutting tube via a living hinge.

[0052] 16A-16D show implementations of a cutting tube drive mechanism 119 incorporating a conventional or mechanical hinge coupled to a rocker or rocker plate. The rocker 1605 can be an offset rocker 1605. The cutting tube drive mechanism 119 can include a base 1610 configured to couple to or integrate with the interior of a handpiece (not shown). The rocker 1605 can be movably attached to the base 1610 via a rocker pivot pin 1615, allowing the rocker 1605 to freely rotate relative to the base 1610 about the axis of rotation of the pivot pin 1615. A piezoelectric stack 1120 can be coupled to the base 1610 at its lower end and to the rocker 1605 at its upper end. The cutting tube 1112 can extend through a generally central region of the base 1610 and the rocker 1605. The piezoelectric stack 1120 can be positioned offset or to one side of the base 1610. The piezoelectric stack 1120 can be coupled to the base 1610 and the rocker 1605 via a movable coupling. For example, the cutting tube drive mechanism can incorporate a pair of toggles 1620a, 1620b. The lower toggle 1620a can be attached to the base 1610 via a lower toggle pin 1622, and the upper toggle 1620b can be attached to the rocker 1605 via an upper toggle pin 1624. The toggles 1620a, 1620b can rotate freely relative to the base 1610 and the rocker 1605. This movement allows some non-parallelism between the proximal end of the piezoelectric stack 1120 that contacts the base 1610 and the distal end of the piezoelectric stack 1120 that contacts the rocker 1605, thereby mitigating damage to the ends of the piezoelectric stack 1120. The pivoting of the toggles 1620a, 1620b allows for misalignment and counteracts imprecision in the transfer of motion from parallel to non-parallel. Additionally, a dome 1621 may be placed near the interface with the piezoelectric stack 1120 to eliminate point loads (see FIG. 16D).

[0053] The cutting tube drive mechanism 119 can include a spring post 1625 and a spring stack 1627. As described above, the cutting tube 1112 can extend through a central region of the base 1610 and the rocker 1605. The piezoelectric stack 1120 can be positioned offset from or to one side of the base 1610. The spring post 1625 and spring stack 1627 can be positioned on opposite sides of the piezoelectric stack 1120 such that the cutting tube 1112 is positioned between the piezoelectric stack 1120 positioned on one side and the spring on the opposite side.

[0054] The spring stack 1627 can be one or more Belleville springs that surround a boss 1638 at the upper end region of the spring post 1625 (see FIG. 16C ). The boss 1638 of the spring post 1625 can extend at least partially into a hole 1637 that passes through the rocker 1605. The spring post 1625 can also include a lower boss 1638 configured to mate with a corresponding hole on the base 1610. The boss 1638 on the spring post 1625 can slide freely axially within the holes 1637 on the rocker 1605 and the base 1610. The boss 1638 can hold the spring stack 1627 in a desired position on the spring post 1625.

[0055] The top surface of the spring stack 1627 engages the bottom surface of the rocker 1605, and the bottom surface of the spring stack 1627 contacts the ledge of the spring post 1625. The spring stack 1627 can exert an upward force against the bottom surface of the rocker 1605. The force on the rocker 1605 can be transferred as a preload to the top of the piezoelectric stack 1120 via the toggles 1620a and 1620b. The preload ensures that constant contact is maintained between the piezoelectric stack 1120 and other components, so that movement of the piezoelectric stack 1120 is not impeded.

[0056] The cutting tube 1112 can extend through a bore in the rocker 1605 and a bore in the base 1610. The cutting tube 1112 can be secured to each other via adhesive, welding, or other fastening methods. A support bushing 1630 can be incorporated to help prevent the tube from cracking after extended use. The support bushing 1630 can be bonded to the top surface of the rocker 1605, aligned with the bore through the rocker 1605. FIG. 16C shows a side cross-sectional view of the offset rocker 1605. The tube 1112 is shown attached to the base 1610 via a stiffener bushing 1635. The stiffener bushing 1635 can ensure that the tube 1112 is forced to bend relative to the base 1610 when the piezoelectric stack 1120 is actuated.

[0057] The piezoelectric stack can be altered by varying voltage, including AC or DC variable voltage. In one implementation, an AC current (e.g., 100 Hz to 20 KHz) applied to the piezoelectric stack 1120 causes it to expand and contract. As the piezoelectric stack 1120 expands, the rocker 1605, and therefore the tube 1112 attached to the rocker 1605, can bend about the base 1610. As the piezoelectric stack 1120 contracts, the spring stack 1627 can help the piezoelectric stack 1120 quickly return to its starting length and ensure consistent contact between the piezoelectric stack 1120 and the two toggles 1620a, 1620b. The cutting tube 1112 can undergo bending as it extends through the rocker 1605. Additional movement due to bending and "whipping" of the portion of the tube 1112 below the rocker 1605 is also possible. The cutting tip movement is generally much larger than would be expected for a piezoelectric stack 1120 due to the presence of additional "whipping" motion by the cutting tube 1112. The piezoelectric stack 1120 incorporated into the cutting tube drive mechanism described herein is characterized by an arbitrary piezoelectric charge coefficient, i.e., d 33 ,d 31 , d 15 The present invention can be mechanically configured to use

[0058] 17A-17C show interrelated implementations of the cutting tube drive mechanism 119 incorporating a conventional or mechanical hinge coupled to a rocker or rocker plate. The rocker can be a straight rocker 1605. The straight rocker 1605 can be movably mounted to a base 1610 via a rocker pivot pin 1615, allowing the rocker 1605 to freely rotate relative to the base 1610 about the axis of rotation of the pivot pin 1615. The location of the hinge (i.e., the rocker pivot pin 1615 shown in FIGS. 17A-17C) is further toward the distal end of the cutting tube 1112 compared to the location of the hinge in the offset rocker implementation shown in FIGS. 16A-16C. The rocker pivot pin 1615 in the straight rocker 1605 can be substantially aligned along the longitudinal axis of the tube 1112 and the rocker 1605, creating a fulcrum for the rocker 1605. The position of the rocker pivot pin 1615 relative to the tube 1112 may change the wag characteristics at the tip of the tube 1112 and may change the "whip" effect the tube 1112 exhibits during use. In a straight rocker, the pivot pin is substantially aligned with the rocker along the longitudinal axis of the cutting tube. In an offset rocker, the pivot pin is located proximal to the rocker along the longitudinal axis of the cutting tube.

[0059] The piezoelectric stack 1120 can be coupled at its lower end to the base 1610 and at its upper end to the rocker 1605. The cutting tube 1112 can extend through a generally central region of the base 1610 and the rocker 1605. The piezoelectric stack 1120 can be positioned offset to one side of the base 1610. The piezoelectric stack 1120 can be attached or unattached to the base 1610 and the rocker 1605. The interface can incorporate one or more features to mitigate damage and point loads to the piezoelectric stack 1120, as described elsewhere herein.

[0060] The cutting tube drive mechanism 119 can include a spring post 1625 and a spring stack 1627 positioned opposite the piezoelectric stack 1120 so that the cutting tube 1112 is positioned between the piezoelectric stack 1120 and the spring. The tube 1112 passes through the rocker 1605 and the base 1610 and can be attached to and detached from the rocker 1605 and the base 1610 as described above. The spring stack 1627 is compressed when at rest, thereby exerting an upward force on a first end of the rocker 1605 and a preload force on the piezoelectric stack 1120 by a second, opposite end of the rocker 1605. As the piezoelectric stack 1120 expands or grows with varying voltage, it rotates the rocker 1605 about the axis of rotation of the pivot pin 1615 on the base 1610, thereby moving or "rocking" the tube 1112 in at least one direction. As the piezoelectric stack 1120 retracts, the upward force exerted by the spring stack 1627 against the first end of the rocker 1605 causes the retracting piezoelectric stack 1120 to urge the second, opposite end of the rocker 1605 downward. The rocker 1605 rotates in the opposite direction, causing the tube 1112 to swing in the opposite direction. The spring stack 1627 can force the rocker 1605 to rotate and maintain contact with the end of the piezoelectric stack 1120.

[0061] The cutting tube drive mechanism 119 can include a piezoelectric stabilizer 1665. The piezoelectric stabilizer 1665 surrounds the location where the piezoelectric stack 1120 and spring post 1625 contact the base 1610 and can prevent the piezoelectric stack 1120 from moving out of position during operation. Any of the implementations described herein can incorporate the piezoelectric stabilizer 1665.

[0062] FIG. 18 shows an interrelated implementation of a cutting tube drive mechanism 119 incorporating a hinge clamp. The hinge clamp can include a lower clamp 1640 and an upper clamp 1645. The tube 1112 can be inserted through holes on the upper clamp 1645 and the lower clamp 1640. The lower clamp 1640 can be rotatably attached to the upper clamp 1645 via a hinge pin 1647. The lower clamp 1640 can be attached to a handle (not shown). The piezoelectric stack 1120 can fit between the upper clamp 1645 and the lower clamp 1640. The piezoelectric stack 1120 can be attached and detached from the clamps 1640, 1645 as described elsewhere. When attached, a clamping force can be applied to the upper clamp 1645 and the lower clamp 1640, causing a preload force to be applied to the piezoelectric stack 1120 disposed therebetween. The tube 1112 can be attached to the upper and lower clamps 1645, 1640 with a preload force applied, and when the clamping force is released, the preload force is transferred to the tube 1112 and maintained on the piezoelectric stack 1120. As the piezoelectric stack 1120 grows, the upper clamp 1645 rotates about the hinge pin 1647, thereby swinging the tube 1112 in one direction. As the piezoelectric stack 1120 retracts, the upper clamp 1645 rotates in the opposite direction, swinging the tube 1112 in the opposite direction. The preload applied to the tube 1112 ensures that the upper clamp 1645 retracts and maintains constant contact with the piezoelectric stack 1120. Additional clamps, such as portions of the upper and lower clamps 1645, 1640 on the outer regions of the tube opposite the hinge pin 1647, can ensure constant contact between the piezoelectric stack 1120 and other components.

[0063] 19A-19C illustrate an interrelated implementation of a cutting tube drive mechanism 119 that also incorporates a hinge clamp. It should be understood that the various drive mechanisms described herein can incorporate one or more features of any other drive mechanism described herein, even if that feature is not explicitly described for a particular implementation. The hinge clamp can include a lower clamp 1640 and an upper clamp 1645. The lower clamp 1640 can be attached to the base 1610 via adhesive, welding, or other bonding means. The upper clamp 1645 can be attached to the lower clamp 1640 via a hinge pin 1647 such that the upper clamp 1645 is free to rotate about the hinge pin 1647. The piezoelectric stack 1120 can fit between the upper clamp 1645 and the lower clamp 1640.

[0064] The cutting tube 1112 can pass through both the upper clamp 1645 and the lower clamp 1640. The cutting tube 1112 can be attached to the upper and lower clamps via adhesive, welding, or other attachment, although the tube 1112 need not be mechanically coupled. A support bushing 1650 can slide around the tube 1112 or be attached to the cutting tube 1112 as described elsewhere.

[0065] The cutting tube drive mechanism 119 can include a spring stack 1627 and a preload screw 1655. The preload screw 1655 can be positioned parallel to the cutting tube 1112. The preload screw 1655 can be threaded through the upper clamp 1645 and the lower clamp 1640 and into a preload nut 1660 below the lower clamp 1640. The spring stack 1627, which can include a Belleville spring, can be captured between the head of the preload screw 1655 and the top surface of the upper clamp 1645. During installation, when the preload screw 1655 is tightened into the preload nut 1660 below the lower clamp 1640, the screw head compresses the spring stack 1627 against the upper clamp 1645. This applies a preload force to the piezoelectric stack 1120, which is positioned between the upper and lower clamps 1645, 1640.

[0066] 16A-16C, in which the piezoelectric stack 1120 and preload mechanism are located on opposite sides relative to the position of the cutting tube 1112, the piezoelectric stack 1120 and preload screw 1655 can be located on the same side relative to the position of the cutting tube 1112. The top surface of the piezoelectric stack 1120 can engage the bottom surface of the upper clamp 1645, and the bottom surface of the piezoelectric stack 1120 can engage the top surface of the lower clamp 1640, thereby positioning and clamping the piezoelectric stack 1120 between the upper and lower clamps 1645, 1640. The piezoelectric stack 1120 can be secured to the upper and lower clamps 1645, 1640 via adhesive or other mechanical fastening.

[0067] As the piezoelectric stack 1120 grows, it can push the top clamp 1645 upward. The top clamp 1645 rotates about the hinge pin 1647, compressing the spring stack 1627 against the head of the preload screw 1655. As the piezoelectric stack 1120 retracts, the spring stack 1627 pushes the top clamp 1645 downward about the axis of the hinge pin 1647 while maintaining constant contact with the top end of the piezoelectric stack 1120. The preload screw 1655 allows the amount of preload to be dialed in during manufacturing to achieve the desired load.

[0068] 20A-20B show an interrelated embodiment of a cutting tube drive mechanism 119 incorporating a biplane configuration. The drive mechanism 119 can include a base 1610, a top plate 1670, and two interposed piezoelectric stacks 1120a, 1120b. The two piezoelectric stacks 1120a, 1120b can be unattached or attached to the top plate 1670 and base 1610. FIG. 20B shows that the two piezoelectric stacks 1120a, 1120b can fit into pockets on the base 1610 to control the position of the piezos. The drive mechanism 119 can further include a preload screw 1655 and nut 1660. The screw 1655 can extend through the base 1610 and into corresponding threads available from the underside of the top plate 1670. When the preload screw 1655 is tightened, a preload force is applied to the piezoelectric stacks 1120a, 1120b via the top plate 1670. The tube 1112 can pass through the top plate 1670 and through a central bore 1675 in the preload screw 1655 (see FIG. 20B). The tube 1112 can be unattached or attached to the top plate 1670 and preload screw 1655. As discussed elsewhere herein, the piezoelectric stacks can be altered by varying the voltage. In one implementation, two separate alternating currents can be applied to the piezoelectric stacks 1120a, 1120b. The alternating currents can be out of phase so that one piezoelectric element 1120a expands as the other piezoelectric element 1120b contracts, and vice versa. This can cause the top plate 1670 to rock, which in turn causes the tube 1112 to rock back and forth. The alternating currents can be timed relative to one another in any way that produces the desired effect at the end of the tube 1112 .

[0069] The drive mechanism described above is configured to provide a torsional motion to the cutting tube at a minimum peak tip speed (e.g., at least 2.5 meters / second, but less than about 12 meters / second). In any of the implementations described herein, the piezoelectric stack 1120 can be stacked parallel to the longitudinal axis of the tube 1112 (i.e., vertical stacking) or perpendicular to the tube. Whether stacked parallel or perpendicular to the tube 1112, the direction of stretch can be along the longitudinal axis of the tube 1112. The piezoelectric stack 1120 can be, for example, a d 33 ,d 31 ,d 15 It can be mechanically configured to use any piezoelectric charge coefficient, including

[0070] It should be understood that the drive mechanism 119 need not be a piezoelectric drive mechanism. Figures 21A-21D illustrate an implementation of a cutting tube drive mechanism incorporating a motor-driven cam capable of achieving a minimum tip speed. The drive mechanism 119 can include a base 1610 and a motor 1680 configured to rotate a cam 1682. The cam 1682 can incorporate a wave pattern on both ends. As the cam 1682 rotates, the wave pattern of the cam 1682 drives a cam follower 1684 up and down. The cam follower 1684 is coupled to a rocker 1605 via a cam follower pin 1681. As the cam follower 1684 moves up and down, the rocker 1605 rocks about a rocker hinge pin 1615. As the rocker 1605 rocks back and forth, the cutting tube 1112 can rock back and forth. A support bushing 1650 can be incorporated to help distribute forces on the tube 1112 and prevent the rocker 1605 from damaging the tube 1112. Figure 21B is a side view of the drive mechanism 119 with a hidden base 1610. The base 1610 can include a second support bushing 1650 that can contact the tube 1112 and provide a bending point for the tube 1112 as it is driven back and forth.

[0071] FIG. 21C shows an enlarged view of the cam mechanism. The upper cam surface 1686 of the cam 1682 can feature a radius so that the cam following surface 1683 of the cam follower 1684 can ride smoothly along the cam surface of the cam 1682. The cam 1682 features an upper cam surface 1686 and a lower cam surface 1688. The shapes of the upper and lower cam surfaces 1686, 1688 can be opposite each other so that the axial distance between the upper and lower cam surfaces 1686, 1688 is constant. The cam 1682 features a cam restraint rib 1690 that slides within a cam restraint slot 1692 on a cam restraint 1694. The cam restraint 1694 can be fixed to the base 1610 or can be integral with the base 1610. The cam restraining slot 1692 can prevent the cam 1682 from moving axially as the cam 1682 rotates and applies a force to the cam follower 1684. FIG. 21D shows a close-up view of the cam mechanism with the hidden cam 1682. The lower cam follower surface 1698 contacts the lower cam surface 1688 of the cam 1682, driving the cam follower 1683 downward. The lower cam follower surface 1698 can have the same radius as the upper cam follower surface 1683 to ensure smooth movement along the cam 1682.

[0072] 25A-25C and 26A-26C show an implementation of a cutting tube drive mechanism 119 incorporating an oscillating motor and a mechanical hinge incorporating a rocker 1605. The drive mechanism 119 can include a base 1610 configured to couple to a handpiece (not shown). The rocker 1605 can be attached to the base 1610 via a rocker pivot pin 1615, which allows the rocker 1605 to rotate freely relative to the base 1610. The motor 1680 can be coupled to the base 1610, such as to the top surface of the base 1610, at a coupling 1695. The coupling 1695 is configured to allow the motor 1680 to pivot from side to side. In some implementations, the coupling 1695 can have rounded ridges or other shapes. The coupling 1695 can be one of the other movable couplings described elsewhere herein. The cutting tube 1112 can extend through a bore in the rocker 1605 and through a bore in the base 1610. The motor shaft 1685 can extend through a bore in the rocker 1605. The motor shaft 1685 can rotate freely relative to the rocker 1605. An eccentric or offset weight 1696 can be attached to the motor shaft 1685. As the motor shaft 1685 rotates, the mass of the weight 1696 oscillates side to side, causing the rocker 1605 to move or oscillate laterally. In some implementations, the motor 1680 has a housing that is rigidly attached to the rocker 1605, causing the rocker 1605 and cutting tube 1112 to oscillate. In other implementations, the motor shaft 1685 is attached to a cam wobble plate that pushes against a cam follower that is rigidly connected to the rocker 1605 and cutting tube 1112. In another embodiment, the motor housing can oscillate, for example via a rounded ridge, dome, or other geometric shape, and the oscillating end is rigidly attached to the rocker 1605 and cutter tube 1112. This can reduce the mass of the rocker 1605 and cutter tube 1112.

[0073] 26A-26C show another implementation of the cutting tube drive mechanism 119 incorporating an oscillating motor and a spring. In this implementation, the motor 1680 can be coupled at its lower end to a motor support 1697 via welding, adhesive, or another mechanism. The motor support 1697 can extend from the bottom of the rocker 1605. A motor shaft 1685, which can extend through the rocker 1605 so that it is free to rotate, can be coupled to an offset weight 1696 configured to rotate the rocker 1605 back and forth about a pivot pin 1615 as the motor shaft 1685 rotates. This causes the tip of the tube 1112 to oscillate back and forth. A spring post 1625 with a spring stack 1627 can be located on the opposite side of the pivot pin 1615 from the motor 1680. As the rocker 1605 rotates counterclockwise, it compresses the spring stack 1627, which urges the rocker 1605 back clockwise.

[0074] In a related implementation, the cutting tube drive mechanism can include a motor-driven cam. The drive mechanism can incorporate a small motor driving a wheel 1687 having a pin 1689 located near the outer periphery of the wheel 1687 (see FIG. 27A). The pin 1689 can be located in a slot 1691 in a pivot arm 1693 that is attached to the cutting tube 1112 a distance from the distal cutting tip. The cutting tube 1112 can be fixed longitudinally by a pivot pin 1615 but is movable about the axis of rotation of the pivot pin 1615. The axis of rotation of the pivot pin 1615 is substantially parallel to the axis of rotation of the wheel 1687. As the wheel 1687 rotates, the eccentrically located pin 1689 moves up and down within the slot 1691 in the pivot arm 1693. The pivot arm 1693 can in turn swing about the axis of rotation of the pivot pin 1615 causing a corresponding swing of the distal cutting tip of the cutting tube hub 1112 .

[0075] FIG. 27B shows an interrelated implementation of the cutting tube drive mechanism. The drive mechanism may again include a wheel 1687 driven by a small motor. The wheel 1687 may include an eccentrically located pin 1689 located near the outer periphery of the wheel 1687. The pin 1689 may be coupled by a link arm 1699 to a pivot arm 1693 attached to the cutting tube 1112 a distance from the distal cutting tip. The cutting tube 1112 may be longitudinally fixed by a pivot pin 1615 but movable about its axis of rotation. As the wheel 1687 rotates, the pin 1689 causes the cutter tube 1112 to swing laterally about the axis of rotation of the pivot pin 1615.

[0076] 16A-16D, 18, 19A-19C, 20A-20B, 21B, and 25A-25C show the lower (i.e., proximal) end of the cutting tube 1112 extending beyond the base 1610. A vacuum may be applied to the proximal end of the tube 1112 to evacuate material through the lumen of the tube 1112. The vacuum may be applied via a suction pump 1014 within the handpiece, which is described in more detail below. It should be understood that the cutting tube drive mechanism may be incorporated within the disposable portion of the handpiece 1030.

[0077] The aspiration pump 1014 of the handpiece 1030, which can be integrated into, on, or attached to the handpiece 1030, can aspirate fluids and materials from the eye. As previously described, the handpiece 1030 includes a hollow cutting tip or cutting tube 1112 configured to vibrate, for example, by a multi-stage piezoelectric crystal 1120 or another cutting tube drive mechanism (i.e., a voice coil, a motor-driven cam mechanism, or a vibration motor with an eccentric weight) to break down the diseased lens. Fluids and materials from the eye enter the lumen 1110 via the cutting tube 1112. The lumen 1110 of the cutting tube 1112 is fluidly coupled to a waste line 1038. The aspirated material can be directed by the aspiration pump 1014 via the waste line 1038 toward a waste container 1044. An irrigation sleeve 1113 can be positioned over the cut tube 1112 to supply irrigation fluid from the irrigation line 1034 to the eye via one or more irrigation openings 1111 (shown, for example, in FIG. 9A).

[0078] As best shown in FIG. 5B and also in FIG. 12 , the handpiece 1030 can include a disposable portion 1031 configured to releasably couple to a durable reusable portion 1033. The disposable portion 1031 includes components of the handpiece 1030 configured to directly contact fluids and matter from the eye. The disposable portion 1031 of the handpiece 1030 can include a cutting tube 1112, an irrigation sleeve 1113, an aspiration pump 1014, and connection sites for connecting the irrigation line 1034 and waste line 1038 to the handpiece 1030. The irrigation line 1034 and waste line 1038 do not need to extend through the reusable proximal portion 1033. The reusable portion 1033 includes components of the handpiece 1030 configured to remain outside of the fluid pathway. The reusable portion 1033 can be sterilized and reused. The reusable portion 1033 can include a component configured to drive the suction pump 1014 and one or more components configured to drive the cutting tube 1112. For example, the pump motor 1115, the horn 1116, the piezoelectric crystal 1120, and the housing 1114 for containing the crystal 1120 can all be part of the reusable portion 1033. It should be understood that the reusable portion 1033 can also be disposable. For example, the drive mechanism for the cutting tube 1112 can be manufactured from low-cost materials so that it is economically feasible for the portion 1033 to be disposed of after the procedure. Low-cost materials, such as polymer-based piezoelectric materials, can allow for significant cost reductions.

[0079] The disposable portion 1031 can include one or more components of the cutting tube drive mechanism 119. For example, a cutting tube drive mechanism including a rocker and a pivot pin, and one or more components configured to rotate the rocker about the pivot pin, including piezoelectric stack(s) 1120 and associated couplings, clamps, and preload components, can be disposed within the disposable portion 1031. The cutting tube drive mechanisms shown in Figures 16A-16D, 17A-17C, 16A-16D, 17A-17C, 18, 19A-19C, 20A-20B, 21A-21D, and 25A-25C and 26A-26C can all be incorporated into the disposable portion 1031 of the handpiece.

[0080] The coupling between the disposable portion 1031 and the reusable portion 1033 may be purely mechanical or may include both mechanical and electronic coupling. For example, the disposable portion 1031 may have an electronic input configured to electronically couple with a portion of the reusable portion 1033. Alternatively, the disposable portion 1031 may have an input configured to mechanically couple and interact with the reusable portion 1033. Electronics configured to operate the cutting tube drive mechanism may remain in the reusable portion 1033 of the handpiece such that, upon coupling, the disposable and reusable portions may engage the cutting tube drive mechanism to operate a piezoelectric stack, motor, or the like.

[0081] The disposable portion 1031 or the durable portion 1033 of the handpiece 1030 can include one or more inputs or actuators. The handpiece 1030 can be remotely operated. An instrument may be referred to herein as a "device" or "tool" or "peripheral" or "handpiece" or "handheld unit." The use of the term "handpiece" herein can include a handpiece coupled to a robotic arm or robotic system or other computer-assisted surgical system in which a user operates the controls of the instrument using a computer console. The computer translates the user's movements and the actuation of the controls to be performed by the robotic arm on the patient.

[0082] Each of these components, as well as the connections between the disposable and durable reusable portions 1031, 1033 of the handpiece 1030, are described in more detail below.

[0083] The systems described herein can include a single reusable driver portion (sometimes referred to herein as a "durable portion") configured to operatively couple in an interchangeable manner with one or more disposable working portions (sometimes referred to herein as "disposable portions"). The disposable working portions can be configured for different types of ophthalmic procedures, including lens fragmentation, phacoemulsification, vitrectomy, bag polishing, aspiration, irrigation, coagulation, illumination, visualization, intraocular lens (IOL) insertion, etc. The operating parameters of the instrument can vary depending on, for example, the configuration of the disposable working portion attached to the reusable driver portion.

[0084] It should be understood that the various features and functions of the devices described herein may be applied to one or more of the devices described herein, even if not explicitly listed in combination. It should also be understood that the various features and functions of the devices described herein may be applied to conventional devices and systems known in the art that are also useful for cutting, fragmenting, emulsifying, or otherwise impacting tissue at or near a surgical site, including, but not limited to, phacoemulsification systems, vitrectomy systems, bag polishing systems, and other tools useful for performing cataract or vitreous surgery.

[0085] 5A-5B, the cutting tube 1112 may be a conventional phacoemulsification needle having a proximal end 1128 configured to mate with a horn 1116 that extends through to the distal end region of the disposable portion 1031 upon coupling of the disposable and durable portions 1031, 1033 of the hand piece 1030. The cutting tube 1112 is shown as slightly curved away from the longitudinal axis of the hand piece 1030 and having a beveled tip. It should be understood that the cutting tube 1112 could also be coaxial with the longitudinal axis of the hand piece 1030, extending substantially straight from the distal end of the hand piece 1030. Any of a variety of geometries and tip shapes are contemplated herein. At least the distal end region of the cutting tube 1112 and irrigation sleeve 1113 are configured to be minimally invasively inserted into the eye for cutting, aspiration, and irrigation, such as during cataract procedures.

[0086] As described in more detail below, the cutting tube 1112 is configured to oscillate (e.g., longitudinally, torsionally) to jackhammer or shear the lens tissue and aspirate the emulsified lens tissue and fluid from the eye. The movement of the cutting tube is described in more detail below. As used herein, "oscillating" or "oscillating motion" can include any periodic, repetitive motion that occurs according to a pattern and need not be sinusoidal. The oscillating motion can include a reciprocating sliding motion that occurs in a back-and-forth direction relative to the handheld unit, as described above. The oscillating motion can include repeatedly advancing and retracting the cutting tube along its longitudinal axis. While the repeated advancement and retraction can occur along the longitudinal axis, the path taken by the oscillating motion need not be linear. The path of motion can occur nonlinearly (i.e., away from the longitudinal axis during at least a portion of the motion), along an elliptical or curvilinear path. The path of motion can be rotational, orbital, or twisting about the longitudinal axis of the device, or other types of motion relative to the longitudinal axis of the device, including three-dimensional motion in which the cutting tube moves side to side as well as back and forth. The oscillating motion includes a repeating pattern profile that changes depending on where in the oscillating cycle the motion occurs. The oscillating motion can also be asymmetric in profile, as described in more detail below.

[0087] The elongated component of the oscillating instrument may be referred to herein as a "shaft" or "cutter" or "cutting tube" or "elongated member" and may be configured for different techniques, including phacoemulsification, vitrectomy, bag polishing, or other techniques. At least a portion of the cutter may be tubular and have a lumen extending therethrough such that fluid may be delivered and / or aspirated from the lumen through the inner lumen between a distal opening and a proximal opening.

[0088] Any of various configurations of the elongated cutting tube 1112 are contemplated herein. The cutting tube 1112 may have inner and outer members, or the cutting tube 1112 may include only a single tubular element configured to swing relative to the handpiece 1030 to cut and aspirate material. While the cutting tube 1112 is described as having an inner elongated member coaxially disposed within the outer tubular member, the inner elongated member may be a solid rod and need not include an inner lumen. In some implementations, the cutting tube 1112 has a sharpened cutting tip or bevel, which may include a needle point. The handpiece 1030 may include a cutting element having a sharpened needle point, which may be a solid element extending through the outer tubular member, and suction is applied through the lumen of the outer tubular member so that fluid and tissue are drawn into the annular gap extending between the inner and outer members. The cutting tube 1112 may have an inner lumen 1110 and a distal end configured to cut tissue. The distal end can be sharpened, while the opening to the tube can cut diagonally or perpendicular to the elongated axis of the elongated member. The inner lumen 1110 of the cutting tube 1112 can be configured to aspirate material therein, such as ophthalmic lens material, lens fragments, vitreous, and / or fluid from the eye. Thus, suction can be applied through the inner lumen 1110 of the cutting tube 1112. However, suction can also be applied through the lumen of a tubular outer member extending over the cutting tube 1112, with suction occurring through the annular space between the two. In such a configuration, the gap between the tubular outer and inner members can vary, for example, from about 0.001 inches to about 0.100 inches. In some embodiments, suction can be applied through both the inner elongated member having a lumen and the lumen through the outer tubular member.

[0089] 6 and also FIG. 9A illustrate the distal end region of the disposable portion, showing the cutting tube 1112 extending beyond the distal end of the irrigating sleeve 1113. The irrigating sleeve 1113 can include one or more openings 1111 near its distal end, through which irrigation fluid can be delivered into the eye near the end of the cutting tube 1112. The irrigating sleeve 1113 can extend proximally beyond the cutting tube 1112 and couple to the distal end region of the disposable portion 1031. The distal end region of the disposable portion 1031 can include a nosecone or tip 1132 configured to receive the irrigating sleeve 1113. The tip 1132 and irrigating sleeve 1113 can each be removably attached to the handpiece 1030. The irrigating sleeve 1113 can be a standard irrigating sleeve (e.g., the Irrigating Tip by MST, Redmond, WA) having a substantially flexible distal tubular portion 1117 and a low-compliance proximal coupling portion 1118. The tip 1132 can include external threads 1133 (see FIG. 9B ) or other coupling features at a forward end region configured to engage corresponding threads or features on the proximal coupling portion 1118 of the irrigating sleeve 1113.

[0090] The tip 1132 can be configured for any of a variety of techniques a user may desire to perform with the handpiece 1030 during a procedure. Any of a variety of tips 1132 can be reversibly coupled to the distal end region of the disposable portion 1031 depending on the intraocular procedure the user wishes to perform. The tip 1132 may be configured for phacoemulsification, bag polishing, vitrectomy, and other procedures. The tip 1132 can be reversibly coupled to the disposable portion 1031. FIG. 7A shows the distal end region of the disposable portion and cutting tube 1112 without the tip 1132 attached. FIG. 7B illustrates a first implementation of the replaceable tip 1132, and FIG. 7C illustrates a second implementation of the replaceable tip 1132. The proximal end region of the replaceable tip 1132 can incorporate a reversible coupling feature 1136 and a sealing element 1138, such as an O-ring. The coupling feature 1136 can have a variety of configurations including, but not limited to, threads, snap locks, interference fits, bayonets, or other features configured to allow the tip 1132 to be attached and sealed to the disposable portion 1031.

[0091] The interchangeable tip 1132 shown in FIG. 7B includes a lens removal sleeve 1130 configured for use during phacoemulsification. The lens removal sleeve 1130 can be fixedly coupled to and extend from a distal end region of the tip 1132. The lens removal sleeve 1130 is sized and shaped to be concentrically disposed over the cutting tube 1112 along at least a portion of the proximal length of the tube 1112. The lens removal sleeve 1130 is configured to protect corneal tissue from damage where the cutting tube 1112 extends through the corneal incision during movement of the cutting tube 1112 when performing phacoemulsification. The lens removal sleeve 1130 can be formed of a substantially flexible material, such as silicone, or a substantially rigid material, such as a hard plastic extrusion or metal hypotube. In some implementations, the lens removal protection sleeve 1130 can be a rigid tube with an inner diameter that closely matches the outer diameter of the cutting tube 1112, resulting in low clearance between the two. The low clearance between the cutting tube 1112 and the lens removal protection sleeve 1130 means that the lens removal protection sleeve 1130 maintains a small outer diameter that minimizes the incision size through the cornea while allowing relative sliding movement between the inner and outer shafts. The cutting tube 1112 can have a maximum outer diameter dimension between 0.5 mm and 1.4 mm. The lens removal protection sleeve 1130 can be rigidly coupled to the tip 1132, or can be replaceable or retractable. The length of the lens removal protection sleeve 1130 can vary, but is generally at least as long as necessary to cover the area of ​​the cutting tube 1112 that extends through the incision. The user can cover the vibrating cutting tube 1112 to use different types of tips during the procedure, for example, for capsular bag polishing and cortical tissue removal after lens extraction. By increasing the length of the lens removal protective sleeve 1130, half of the stroke length of the vibrating cutting tube 1112 can be covered, reducing the exposed stroke length of the vibrating cutting tube 1112.The lens removal protection sleeve 1130 can be longitudinally positionable to adjust the effective stroke length of the vibrating cutting tube 1112 from zero to 100% of its uncovered stroke length. The lens removal protection sleeve 1130 can be positioned so that the vibrating cutting tube 1112 remains recessed to a consistent depth within the lens removal protection sleeve 1130. This can prevent ocular tissue from contacting the vibrating cutting tube 1112, effectively providing a suction-only mode of operation. When positioned to shorten the effective cutting tube stroke length, the lens removal protection sleeve 1130 can prevent tissue from "lollipopping" at the end of the cutting tube 1112 by pushing stuck tissue out of the cutting tube 1112 as the tip of the cutting tube 1112 retracts within the lens removal protection sleeve 1130.

[0092] The color of the interchangeable tip 1132 and / or tip 1132 sleeve can provide information about the length of the sleeve and what purpose it is useful for. FIG. 7B illustrates a lens removal tip 1132 with a shorter lens removal protection sleeve 1130 configured to protect the cornea during phacoemulsification. FIG. 7C illustrates a bag polishing tip 1132 with a longer bag polishing protection sleeve 1131 coupled to a bag polishing nub 1142 (see also FIGS. 8A-8C). The lens removal tip 1132 may be a first distinguishable color, such as blue, and the bag polishing tip 1132 may be a second distinguishable color, such as white. Other markers, indicators, colors, etc. are also contemplated to easily distinguish between the tips. The bag abrasive protective sleeve 1131 of the bag abrasive tip 1132 in FIG. 7C has a length sufficient to receive the cutting tube 1112 such that the distal end of the cutting tube 1112 is always contained within the bag abrasive protective sleeve 1131 and the inner lumen of the bag abrasive nub 1142 extends beyond the distal tip of the fully extended cutting tube 1112, thereby completely isolating the action of the cutting tube 1112 from the ocular structures. FIGS. 8A-8C show the bag abrasive tip 1132 positioned at the distal end region of the disposable portion 1131. The cutting tube 1112 is completely contained within the bag abrasive protective sleeve 1131. The bag abrasive nub 1142 is positioned beyond the distal tip of the irrigation sleeve 1113.

[0093] Surgeons typically perform a bag polishing step after cataract lens removal. The bag polishing nubs 1142 are gently slid along the surface of the capsular bag to release any adhering cortical material. The released cortical material is then aspirated through the small holes in the bag polishing nubs 1142. The nubs 1142 may include small holes 1143 running along at least one side of their diameter (see FIG. 8C). The holes 1143 may have any of a variety of sizes, shapes, and distributions along the wall, depending on the total number of holes 1143 incorporated. The holes 1143 may have a diameter ranging from about 0.002 inches to about 0.030 inches, preferably from about 0.008 inches to about 0.012 inches. In implementation, the holes 1143 may face downward relative to the perspective of a user holding the handpiece 1030, or they may face sideways or upward relative to a user holding the handpiece 1030. In some implementations, the hole 1143 may be partially or completely located on the distal surface of the nub 1142. The distal surface of the nub 1142 may be substantially rounded, such as semi-hemispherical, or the distal surface may be substantially flat. The flat surface of the nub 1142 may be angled relative to the radial axis of the nub 1142. Relief holes may be located along at least a portion of the bag abrasive tip 1132, such as the bag abrasive protective sleeve 1131 or the nub 1142. The relief holes may be substantially smaller than the hole 1143, for example, between about 0.0001 inches and about 0.008 inches, more preferably between 0.001 inches and about 0.004 inches. The relief holes can function as bypasses when the hole 1143 is blocked. The relief holes also allow the vacuum to dissipate when the user releases the trigger 1180 of the handpiece 1030 when the hole 1143 is blocked and the handpiece 1030 is idle. The built-up vacuum may dissipate via fluid movement through the relief holes. The nub 1142 may include a surface texture to release cortical tissue. The shape of the nub 1142 may be substantially atraumatic so that contact between the nub 1142 and the capsular bag during a scrubbing action does not pose a risk of puncturing the capsular bag.

[0094] It should be understood that any of a variety of accessory tips can be coupled to the distal end of the disposable portion 1031. In some implementations, the sleeve is a vitreous-style cutting sleeve with a side opening for guillotine-style cutting. The sleeve can be inserted over the cutting tube 1112 so that the cutting tube 1112 extends therethrough and is coaxially positioned within the outer tube so that the cutting tube 1112 slides back and forth within the outer tube. This style of cutting element is particularly useful for chopping and removing harder lens material. The outer tube can be a stationary tubular element coupled to the distal end region of the hand-held portion 1030, and the cutting tube 1112 can be movable so that it swings within the lumen of the outer tube. The distal tip of the cutting tube 1112 can be formed with a cutting edge, such as a short, sharp bevel. In operation, tissue enters the outer tube through the side opening and can be dissected by the cutting edge as the cutting tube 1112 reciprocates within the outer tube. The cutting tip of this vitrectomy modality can further include a removable or retractable outer sheath, for example, to slide over the side opening as the shaft is inserted into the anterior chamber. During insertion, the cutting region of the shaft can remain covered within the outer protective sheath to prevent snagging on the incision or other ocular tissue prior to cutting. After insertion, the sheath can be retracted or otherwise removed when the operator is ready to begin cutting and / or aspiration. Retraction can be manually activated by the user or automatically by the device upon activation of cutting and / or aspiration. Once cutting / aspiration is complete and the instrument is ready to be removed from the eye, the sheath can be advanced distally to re-cover the opening.

[0095] The replaceable tip 1132 can be used with a cutting tube 1112 that is substantially straight, especially if the sleeve of the tip 1132 is rigid. In some implementations where the cutting tube 1112 is curved away from the longitudinal axis or incorporates features that are angled relative to the longitudinal axis, the sleeve of the replaceable tip 1132 may be flexible so that the sleeve can be inserted over the cutting tube 1112.

[0096] A single reusable driver portion 1033 can be configured to operably couple to one or more disposable working portions 1031 in an interchangeable manner. The disposable working portions 1031 can be configured for different types of procedures, including lens fragmentation, emulsification, vitrectomy, bag polishing, aspiration, irrigation, coagulation, illumination, visualization, IOL insertion, etc. Accordingly, the disposable working portion 1031 can be used for any of a variety of procedures, including vitrectomy, phacoemulsification, intraocular lens insertion, etc. The operating parameters of the instrument can vary depending, for example, on the disposable working portion 1031 attached to the reusable driver portion 1033 and / or the particular procedure being performed, different stages of the procedure, the surgeon's personal preference, whether the procedure is being performed on the anterior or posterior segment of the patient's eye, etc. The components of the working portion 1031 can vary depending on the type of procedure, and each of the different working portions 1031 can be operably coupled to and operated by the single reusable driver portion 1033, regardless of the procedure it is configured to perform. The different disposable working portions 1031 are described in more detail below.

[0097] 5A-5B, the irrigation fluid line 1034 can be connected to the disposable portion 1031 of the hand piece 1030 via an irrigation port 1144. The location of the irrigation port 1144 can vary, but generally, the irrigation port 1144 is positioned relative to the irrigation fluid line 1034 so that the irrigation fluid line 1034 is not integrated into, embedded in, or extends a significant length of the hand piece 1030, as is the case with conventional hand pieces. In one implementation, the irrigation port 1144 can be located near the distal end region of the disposable portion 1031, near where the irrigation sleeve 1113 joins with the tip 1132. The irrigation port 1144 provides a substantially rigid connection to the otherwise flexible irrigation line 1034 so that fluid from the irrigation source 1032 can be delivered to the eye through the irrigation sleeve 1113. The location of the suction port 1154 can also vary.

[0098] An irrigation source 1032 can be coupled to the irrigation sleeve 1113 via an irrigation fluid line 1034. The irrigation sleeve 1113 can extend over at least a portion of the protective sleeves 1130, 1131, as shown in FIG. 8C or 9A. The irrigation sleeve 1113 can be detached from the handpiece 1030, for example, as part of a removable tip 1132, or can be detached separately from the tip 1132 via threads or other coupling features. FIG. 9A shows the irrigation sleeve 1113 threaded onto the forward end of the tip 1132 having external threads 1133 and extending over the proximal region of the cutting tube 1112.

[0099] In some implementations, the handpiece 1030 can incorporate an irrigation fluid reservoir 1046 that communicates with the irrigation flow path between the irrigation port 1144 and the irrigation sleeve 1113. In implementations, the irrigation fluid reservoir 1046 is located within the tip 1132 near the distal tip of the disposable portion 1031 of the handpiece 1030, allowing for substantially immediate replenishment of the aspirated fluid volume (see FIG. 9B). The reservoir 1046 can be configured to store a volume of fluid from the irrigation line 1034 near where the irrigation fluid is being delivered through the sleeve 1113. The reservoir 1046 can be filled with irrigation fluid such that in the event of a cut tube blockage and resulting increase in vacuum pressure, a sudden burst or “surge” of fluid removed when the blockage is cleared, the irrigation fluid stored in the reservoir 1046 can be available to very quickly replace the removed surge volume. Fluid from the reservoir 1046 can be drawn into the eye nearly instantaneously upon an increase in negative pressure to maintain sufficient pressure within the eye to avoid anterior chamber collapse. The reservoir 1046 can be a compliant chamber, such as a balloon or elastic membrane, or incorporate another compliant element configured to urge fluid from the reservoir 1046 when there is a decrease in anterior chamber pressure. In some implementations, the reservoir 1046 is contained at one end by a spring-loaded piston that can move elastically to change the volume of fluid in the reservoir 1046 as the pressure within the eye changes. The piston may be mechanically connected to a pump mechanism of the device so that any pulse of suction is actively timed with the injection of fluid into the eye.

[0100] The distal cutting tube 1112, including any protective sleeve, tip, or irrigation sleeve, can have a maximum cross-sectional diameter suitable for minimally invasive procedures in the eye to minimize corneal incision size. In some implementations, the maximum cross-sectional diameter of the cutting tube 1112 is approximately 1.25 mm. The maximum cross-sectional diameter can be smaller or larger, such as less than approximately 2 mm in diameter, less than approximately 3 mm in diameter, up to approximately 4 mm in diameter, or up to approximately 5 mm in diameter. As described elsewhere herein, the opening distal to the cutting tube 1112 can have a smaller inner diameter relative to the inner diameter of the remainder of the lumen 1110 extending through the cutting tube 1112 to mitigate clogging issues. In some implementations, the difference between the nominal inner diameter of the cutting tube 1112 and the inner diameter of the distal opening can be between approximately 0.003 inches and approximately 0.006 inches. In some implementations, the cutting tube 1112 can have a nominal inner diameter of about 0.0375 inches that narrows to about 0.033 inches at the distal opening. The nominal inner diameter of the cutting tube 1112 can be between about 0.012 inches and about 0.036 inches. Thus, ocular tissue pieces smaller than the tip diameter can be aspirated through the lumen 1110 of the cutting tube 1112 and, once within the inner lumen 1110, are less likely to clog or become clogged because the inner diameter of the remainder of the lumen 1110 is larger than the inner diameter of the distal opening.

[0101] Referring again to FIGS. 5A-5B, the phacoemulsification handpiece 1030 may include an aspiration pump 1014 integrated within the disposable portion 1031 of the handpiece 1030. The aspiration pump 1014 may be located within, on, or near the handpiece 1030, thereby minimizing the length of the aspiration line 1038 between the vacuum source provided by the pump 1014 and the distal tip of the cutting tube 1112 within the eye 36. Integrating the vacuum source within the handpiece 1030 (e.g., near the distal cutting tip) minimizes the volume of the aspiration flow path, improving control and responsiveness while reducing latency or hysteresis. Conventional phaco devices and other devices that use a vacuum source remote from the handpiece suffer from slow response and low effective vacuum applied to the treatment site. Conventional systems have long, compliant aspiration lines connecting the vacuum source to the handpiece. Compliance within the fluid system can increase the time it takes for suction to be transmitted from the suction source to the treatment site when the suction source is activated (or deactivated). Compliance within the fluid system can cause a loss of vacuum delivered to the treatment site, resulting in a difference in the effective vacuum from the theoretical vacuum setting at the source. Furthermore, the longer the fluid line between the vacuum source and the treatment site, the greater the friction losses, further reducing the available vacuum at the treatment site. For example, a remote vacuum source set to 600 mmHg may only effectively deliver 200 mmHg to the treatment site for a period of time. Due to latency and hysteresis, conventional phaco devices with remote vacuum sources are prone to sudden increases in the volume of aspirated fluid after clogging, especially when the vacuum source is set to a high flow rate. The actual surge volume in conventional systems is very large (e.g., 20 mL or more), roughly equivalent to the degree of volumetric compliance of the aspiration line extending between the remote vacuum source and the handpiece. This represents a significant surge volume to manage, considering that the average patient has an anterior chamber volume of less than 0.3 mL. Users tend to set the vacuum source at a low level to mitigate the increased risk of surge volume associated with high flow rates.

[0102] The handpieces described herein avoid the line losses associated with conventional systems, allowing for greater effective vacuum application at the treatment site and responding more quickly to pressure changes. The handpieces described herein also have improved responsiveness and control, even when used at higher vacuum settings. When an occlusion occurs due to lens debris blocking the distal opening, the vacuum increases (e.g., to approximately 500-600 mmHg or greater). When the occlusion breaks the seal and passes through, the surge associated with the devices described herein is significantly improved compared to conventional devices with remote vacuum sources. For example, the surge volume of the devices described herein can be as low as less than approximately 100 cubic mm, 200 cubic mm, or even approximately 300 cubic mm, whereas conventional phaco machines can have surge volumes 10, 20, 50, or 100 times greater than this volume. Because the handpieces described herein have a relatively short aspiration flow path between the vacuum source and the target treatment site, surge volumes are smaller. The short aspiration flow path can also be substantially rigid or non-compliant, further reducing surge volumes. For example, the aspiration flow path of the devices described herein, which is greater than 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90%, can be stiffened to reduce aspiration flow path compliance to less than 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%. The substantially non-compliant and short aspiration flow path of the devices described herein reduces potential surge volumes and also reduces dead space that can cause lag effects and lack of responsiveness.

[0103] The configuration of the pump 1014 within the handpiece 1030 can vary. Preferably, the aspiration pump 1014 has a small form factor so as not to significantly impact the relative ergonomics of the handpiece 1030. The aspiration pump 1014 can be a piston pump, roller pump, peristaltic pump, linear peristaltic pump, scroll pump, venturi, rotary vane, gear, screw, diaphragm, centrifugal, or other pump. In one implementation, the aspiration pump 1014 of the handpiece 1030 is a roller pump or a peristaltic pump (see FIGS. 5A-5C). In another implementation, the aspiration pump 1014 of the handpiece 1030 is a piston pump (see FIGS. 13A-13L). In another implementation, the aspiration pump 1014 of the handpiece 1040 is a linear peristaltic pump (see FIGS. 21-22D, 23A-23D, 24A-24B). The suction pump 1014 may be a piston pump as described in U.S. Patent Publication No. 2018 / 0318133, published November 8, 2018, and incorporated herein by reference.

[0104] The pump 1014 can be configured to apply continuous, semi-continuous, and / or pulsating suction. The handpiece 1030 can also include multiple suction sources, each of which can be programmed to apply a different flow rate (simultaneously, as desired). For example, the handpiece 1030 can include a first suction pump internal to the handpiece 1030 configured to apply a continuous or semi-continuous flow rate (low or high levels of suction) and a second suction pump internal to the handpiece configured to apply a pulsating flow rate. Different flow rates and flow rate types can also be applied by a single pump, which can be selectively activated to achieve different suction types.

[0105] 5A-5C, the aspiration pump 1014 of the handpiece 1030 is a roller or peristaltic pump housed within a housing 1145 near the distal end of the disposable portion 1031 of the handpiece 1030 configured to draw fluid and material into the distal tip of the cutting tube 1112 and direct it toward the waste line 1038. The aspiration pump 1014 may include a roller housing 1146, one or more peristaltic rollers 1148, and a fluid tube 1150 housed within a peristaltic housing wall that may be formed by the inner surface of the housing 1145 of the disposable portion 1031. The fluid tube 1150 may be wound in a helical or spiral configuration from near the distal end of the housing 1145 toward the proximal end of the housing 1145. The number of helical or complete turns that the fluid tube 1150 makes may vary, but may be at least 1, 2, 3, 4, or 5 turns. The fluid tube 1150 can communicate at a first end with the lumen 1110 of the cutting tube 1112, such as via a port (not shown), and at a second end with a suction port 1154. The waste line 1038 can be connected to the disposable portion 1031 via the suction port 1154. Alternatively, the waste line 1038 need not itself be connected to the suction port 1154 but can be a continuation of the same conduit 1150 of the roller pump 1014. The one or more peristaltic rollers 1148 can be radially arranged cylindrical pins configured to compress the fluid tube 1150 against the inner, peristaltic housing wall 1145. The number of rollers can vary, including one, two, three, four, five, or more rollers 1148. As the peristaltic rollers roll along the tube 1150, fluid is urged toward the waste line 1038 and drawn into the lumen 1110 of the cutting tube 1112. The peristaltic rollers 1148 may be disposed between the coaxial roller housing 1146 and the fluid tube 1150, and the fluid tube 1150 may be disposed between the peristaltic rollers 1148 and the peristaltic housing wall 1145. The rollers 1148 may be rolled by the inner coaxial cylindrical roller housing 1146, and thus the suction pump 1014 functions like a roller bearing with rolling pins.Alternatively, the relative positions of the tubing 1150, pin 1148, and roller housing 1146 may be reversed, with the rollers at a larger radius than the tubing, squeezing the tubing inward. The roller housing 1146 may be a cylindrical element having a proximal end driven by a pump motor 1115 within the durable portion 1033 of the handpiece 1030, described in more detail below. The roller housing 1146 may be coupled to the pump motor 1115 upon coupling of the disposable portion 1031 and the durable portion 1033. Any of a variety of coupling features are contemplated herein. For example, the roller housing 1146 and pump motor 1115 may be coupled via a dog clutch or spline or other type of reversible coupling connecting the two rotating components. The proximal end of the roller housing 1146 may include a set of regularly spaced recesses (or protrusions) that engage with a corresponding set of protrusions (or recesses) on the distal end of the motor 1115. Alternatively, the roller 1148 and roller housing 1146 may be part of the reusable portion instead of the disposable portion, thereby eliminating the need for a coupling mechanism to connect the two rotating components and reducing component costs of the disposable portion.

[0106] The vacuum can be applied in discrete pulses of negative pressure by the aspiration pump 1014 in the handpiece 1030, for example, by actuation of one or more valves, or due to the movement of one or more pistons, or by a pattern of roller movement. As described elsewhere herein, the cycling of the negative and positive pressure pulses can vary (e.g., from 1 Hz to about 10,000 Hz, or from 100 Hz to about 5,000 Hz, or from about 500 Hz to about 2000 Hz) and can be of very small volume (e.g., from 10 uL to about 1 mL). The cycling of the negative pressure can be very rapid (e.g., from about 5,000 Hz to about 10,000 Hz) or not very rapid (e.g., from 1 Hz to about 1000 Hz).

[0107] Peristaltic pumps may provide negative pressure in a less pulsating manner than, for example, piston pumps. However, peristaltic pumps may provide a semi-continuous, somewhat uneven suction. As each roller 1148 contacts and begins to roll against the tubing 1150, there may be a brief pause in the vacuum. As each roller 1148 moves, the vacuum is generated relatively smoothly until the next roller 1148 contacts the tubing 1150. Thus, depending on the number of rollers 1148 and the timing at which the rollers 1148 contact the tubing 1150, a pulsating effect can be achieved with a peristaltic pump. In contrast, piston pumps can create a sharp spike of vacuum as the piston retracts. This sudden spike of vacuum can be utilized to provide pulsating suction, for example, by incorporating multiple pistons that retract sequentially.

[0108] It should be understood that conventional phacoemulsification handpieces (e.g., those utilizing a piezoelectric resonant drive system) can incorporate an aspiration pump within or on the handpiece, as described above. The aspiration pump can be located near the distal end of the handpiece, e.g., in front of the piezoelectric crystal. The aspiration pump can be located near the proximal end of the handpiece, e.g., behind the piezoelectric crystal. The aspiration pump can be integral with the handpiece or snap-on or modularly coupled to an area of ​​the handpiece to generate suction near the cutting tube and minimize the length of compressible tubing. Aspiration pumps on conventional phacoemulsification handpieces can be in a variety of configurations, including peristaltic, linear peristaltic, scroll, piston, or other pump types, as described elsewhere herein.

[0109] Pulsatile suction can also be achieved using a valve within the handpiece 1030 to control the exposure of the cutting tube 1112 to the vacuum pressure generated in the handpiece 1030. A valve can be incorporated to provide more pulsating, discontinuous suction regardless of the type of pump 1014 and whether the pump is integrated into the handpiece 1030 or external to the handpiece 1030. For example, a conventional phacoemulsification system having a remote pump within the console may incorporate one or more valves near the cutting tube of the handpiece 1030 to control the exposure of the cutting tube to the negative pressure generated. One or more valves may be incorporated within the handpiece, located near the distal end (i.e., location of the cutting tube) or near the proximal end of the handpiece.

[0110] The valve allows for application of full vacuum through the cutting tube 1112 in short pulses. One or more valves may be coupled to the handpiece 1030 and disposed along a portion of the aspiration pathway. The valve may be movable from a closed configuration, which blocks the aspiration pathway, to a fully open position, which opens the aspiration pathway to the lumen of the cutting tube 1112. The valve may be disposed in any position between the closed and fully open positions. The valve may be a movable element configured to move relative to the opening to open and close the aspiration pathway. For example, the valve may be moved to a first position that exposes a small portion of the opening. The valve may be moved to a second position that exposes a larger portion of the opening. The valve may be moved to the first position for a period of time until the vacuum pressure within the cutting tube 1112 reaches a certain percentage of the target maximum pressure (e.g., 75% of the target 760 mmHg or 570 mmHg). Once the target vacuum pressure is reached, the valve may be actuated to move to achieve cycling of the aspiration pressure. The first stage may serve to establish a desired aspiration pressure that is then transitioned into a cycle / periodic or modulated phase of the vacuum. The valve movement may be accomplished by manual actuation by a user or automatically upon initiation of movement of the pump 1014 or cutting tube 1112. It should be understood that the valve for aspiration via the cutting tube 1112 can be used to control the application of suction from the pump 1014 within the handpiece 1030 or to control the application of suction from a pump remote from the handpiece 1030.

[0111] A small reservoir or vacuum accumulator may be incorporated within the area of ​​the handpiece 1030. The accumulator may maintain for a period of time the vacuum level achieved by the suction pump 1014 within the handpiece 1030. Momentarily opening one or more valves within the handpiece 1030 may expose the vacuum reservoir to the lumen 1110 of the cutting tube 1112, allowing for discontinuous, pulsed application of suction. In some implementations, the valves are as described in U.S. Publication No. 2018 / 0318132, filed May 3, 2018, which is incorporated herein by reference. Valve configurations and arrangements can vary, including poppet, ball, needle, leaf, pinch, or other rotary-sliding type valves useful for controlling vacuum.

[0112] FIG. 5C illustrates an example of a valve within the handpiece 1030 configured to momentarily expose the lumen 1110 of the cutting tube 1112 to a vacuum. The vacuum may be stored in an accumulator or any available internal volume space within the vacuum system. As described above, the roller housing 1146 may be a cylindrical element driven to rotate by the pump motor 1115. The roller housing 1146 may include an inner bore 1147 configured to be placed in fluid communication with the lumen 1110 of the cutting tube 1112 via one or more through-holes 1149 in the cylindrical wall of the roller housing 1146. When the through-holes 1149 in the roller housing 1146 align with openings from the inner lumen 1110 of the cutting tube 1112, the lumen 1110 is exposed to a vacuum generated by the suction pump 1014. The more through-holes 1149 in the wall of the roller housing 1146, the greater the number of vacuum pulses per rotation of the housing 1146. The communication between the through-hole 1149 and the inner lumen 1110 may be sealed with one or more O-ring seals 1151 .

[0113] Additionally, cycles of negative pressure can be interspersed with brief backflows through the application of positive pressure between pulses of negative pressure. In some implementations, cycles of negative pressure include brief periods of vacuum interspersed with brief periods of reduced vacuum or no vacuum. In some implementations, cycles of negative pressure include brief periods of vacuum interspersed with brief periods of positive pressure, thereby causing brief backflows of fluid through the cut tube, for example, between each roll of the peristaltic pin or each cycle of piston movement.

[0114] Whether or not positive pressure is applied between the vacuum pulses, the pulsating vacuum creates discrete pulses of negative pressure through the cutting tube, between about 4 in. Hg and about 30 in. Hg, preferably as close to a perfect vacuum as possible with very little pressure loss. In some implementations, the handpiece 1030 can create discrete pulses of negative pressure through the inner lumen of the cutting tube 1112 at a periodic frequency. The handpiece 1030 can also create discrete pulses of positive pressure having the same periodic frequency. Thus, the discrete pulses of negative pressure are interspersed with discrete pulses of positive pressure. The periodic frequency of the pulses can be relatively fast, for example, at least between about 0.5 Hz and about 5000 Hz, or between 1 Hz and 4000 Hz, or between about 10 Hz and about 2000 Hz. In some implementations, the periodic frequency of the discrete pulses of negative pressure is between about 1 Hz and about 500 Hz. Discrete pulses of negative pressure aspirate a first amount of material into the inner lumen through the opening at a periodic frequency. Discrete pulses of positive pressure expel a second amount of material from the inner lumen through the opening at a periodic frequency. The amount of material moved per cycle varies but is generally relatively small, e.g., about 0.1 mL to about 1.0 mL, or about 0.5 mL. In some implementations, the nominal amount of fluid removed per pulse is about 100 microliters, or between about 10 microliters and about 1000 microliters. The second amount of material can be substantially less than the first amount of material within this general range of fluid volume. The discontinuous pulses of negative pressure can be interspersed with discrete periods of reduced vacuum, no vacuum, or positive pressure at the same frequency.

[0115] In some implementations, the handpiece 1030 is limited from achieving maximum vacuum by incorporating a feature that automatically bypasses the cutting tube lumen 1110 depending on whether a threshold vacuum has been reached. For example, a bleed valve, shunt, or other bypass mechanism can be incorporated to prevent a threshold amount of vacuum from being applied to the eye at the distal opening of the cutting tube 1112. A bypass that turns suction on or off can limit the maximum amount of vacuum that can be generated within the eye, even if the opening to the cutting tube 1112 is clogged. This bypass can prevent a vacuum from building if the tip of the cutting tube is blocked and reduce surges upon removal of that blockage. The bypass mechanism can be adjustable or selective, allowing the user to choose whether to seek the maximum vacuum possible or apply less than the maximum vacuum. Implementation of a vacuum bypass is described in more detail below with respect to FIG. 13L.

[0116] The disposable portion 1031 or the durable portion 1033 of the handpiece 1030 can include one or more inputs or actuators. The one or more inputs can vary, including triggers, buttons, sliders, dials, keypads, switches, touchscreens, or other inputs that can be retracted, pressed, squeezed, slid, struck, or actuated to activate, modify, or cause a response of the handpiece 1030. In one implementation, the handpiece 1030 includes a trigger 1180 located on an area of ​​the disposable portion 1031 (see FIGS. 6 and 12). The one or more user inputs can be remote from the handpiece 1030 (e.g., on the system 1010 or on an external computing device in operative communication with the system 1010) or in a wired or wireless actuator, such as a foot pedal.

[0117] The handpiece 1030 may include separate inputs for activating functions of the device and / or the system 1010 in operative communication with the device (i.e., cutting, infusion, aspiration (including continuous or semi-continuous aspiration), pulsed vacuum, and / or pulsed vacuum with backflow between pulses, etc.). Alternatively, the input may be a multi-way button or trigger 1180 for activating one or more functions. For example, the handpiece 1030 may be configured for fluid delivery, fluid aspiration, and cutting. The trigger 1180 may activate functions such as an irrigation-only function, a continuous aspiration-only function, an irrigation plus continuous aspiration function, or an irrigation plus pulsed aspiration plus cutting function. While cutting without aspiration is generally not desired, a cutting-only function is also contemplated herein. By way of example and not limitation, a user may activate a first button or place the trigger 1180 in a first position to turn on an irrigation-only function or a continuous aspiration-only function. After actuating the first button, the user can actuate the second button or place the trigger 1180 in a second position to turn on the irrigation plus continuous suction function. Next, the user can actuate the third button or place the trigger 1180 in a third position to turn on the irrigation plus pulsed vacuum plus cutting function. The user can then begin cutting while the vacuum continues. In some implementations, activation of the second trigger is only possible after activation of the first trigger occurs. The input can be the multi-way trigger 1180 described above, having a first position configured to turn on both the vacuum and vibration of the cutting tube (i.e., vacuum plus cutting function) and a second position configured to pause vibration of the cutting tube while the vacuum continues through the cutting tube.

[0118] In some implementations, the handpiece 1030 can allow suction in the system to dissipate, for example, when a user desires to release an inadvertently captured capsular bag or when the device is idle. A venting mechanism can be operatively coupled to the trigger 1180 of the handpiece 1030, such as the multi-stage trigger 1180 shown in FIG. 12. When the trigger 1180 is idle, the venting mechanism can actively vent the device, and when the trigger 1180 is actuated to aspirate, the venting mechanism can be shut off. In some implementations, the trigger 1180 in its first, idle configuration can be upwardly biased so that suction is shut off upon release of manual pressure on the trigger. Downward movement of the trigger 1180 can initiate suction (including irrigation and / or vibration, as described elsewhere herein). When the trigger 1180 is in the idle configuration and upwardly biased, the system vents. When the trigger is urged downward to activate suction, venting is turned off.

[0119] In some implementations, the drive mechanism can be a piezoelectric drive mechanism or a motor-driven cam mechanism or a vibration motor with an eccentric weight, as described elsewhere herein (see, e.g., FIGS. 16A-21D, and 25A-25C, 26A-26C), which can achieve side-to-side movement or "wag" of the cutting tube 1112 via rockers, clamps, or other configurations, and can translate contraction and expansion of the piezoelectric along a first axis into movement of the cutting tube 1112 along a different axis generally perpendicular to the first axis. These cutting tube drive mechanisms can likewise be located within the disposable portion.

[0120] 5A-5C, the reusable durable portion 1033 of the handpiece 1030 can include a pump motor 1115 with or without a gearbox and a drive mechanism. The drive mechanism can include a horn 1116, a piezoelectric crystal 1120 housed within a housing 1114, and a power cord 1160 configured to connect to the control unit 1012 of the phacoemulsification system 1010 to provide ultrasonic power to the piezoelectric drive system and DC power to the pump motor 1115. The piezoelectric crystal 1120 can be positioned coaxially with the longitudinal axis of the cutting tube 1112 for longitudinal movement and / or perpendicular to the longitudinal axis of the cutting tube 1112 for torsional movement.

[0121] When the disposable portion 1031 is configured to contact the eye material, the durable portion 1033 is configured to remain outside the eye and not contact material extracted from the eye. The cutting tube 1112 of the disposable portion 1031 may be coupled to the horn 1116 of the durable portion 1033, which in turn is driven by the piezoelectric crystal 1120. It should be understood that the durable portion 1033 may include any of a variety of drive mechanisms, including magnetostrictive, electric, electromagnetic, hydraulic, pneumatic, mechanical, voice coil, or other than piezoelectric. It should be understood that the cutting tube drive mechanism may be within the disposable portion 1031 or with the durable portion 1033. Each of these components is described in more detail below.

[0122] The motor 1115 for the suction pump 1014 can be a brushless DC motor or any type of motor or driver suitable for rotating a shaft. In one implementation, the pump motor 1115 can be an electric motor including a stator 1162 and a rotor 1164. The rotor 1164 can be a cylindrical rotor configured to rotate through interaction with the stator 1162. The movable rotor 1164 can be coupled to the coaxial roller housing 1146 described above via a dog clutch or other type of coupling. The connection between the suction pump 1014 and the pump motor 1115 can incorporate a gear reduction via a gearbox or other mechanism. In one implementation, the durable portion 1033 incorporates a harmonic drive gear reduction configured to achieve at least a 30:1 reduction. The speed of the motor 1115 can be controlled by a potentiometer coupled to the trigger 1180 or a non-contact sensor configured to sense the movement of the trigger 1180.

[0123] In one implementation, the durable portion 1033 can include a potentiometer ribbon extending between the distal end regions of the durable portion 3210 and configured to actuate a potentiometer. For example, the proximal end of the potentiometer ribbon can include a cutout or other feature configured to engage with the potentiometer such that movement of the ribbon affects activation of the potentiometer. The trigger 1180 can be coupled to a button rod that is movable along the longitudinal axis of the device when the trigger 1180 is actuated to one of a plurality of positions. For example, when the trigger 1180 is moved from a first actuation position, the trigger can move the button rod proximally a distance such that the proximal end of the button rod extends a first distance into the proximal durable portion of the handpiece. Extension of the button rod into the durable portion can affect the speed of the motor by interacting with the distal end of the potentiometer ribbon extending within the durable portion. Movement of the potentiometer ribbon can result in actuation of a potentiometer that engages a cutout in the ribbon. The potentiometer can then vary the rotational speed of the motor. In some implementations, a non-contact sensor, such as a Hall Effect sensor, can be used to sense the distance the button rod moves as a result of the trigger being pressed.

[0124] 5A-5C, the motor 1115 can include a motor housing 1168 fixedly coupled to the forward end of a housing 1114 that contains a multi-stage piezoelectric crystal 1120. The crystal 1120 can be held within the housing 1114 by a back cylinder 1122 and bolts 1124. In other implementations, the piezoelectric stack can be part of the disposable portion, as described above.

[0125] In conventional phacoemulsification, piezoelectric crystal stacks are driven at very high frequencies (e.g., 40,000 cycles per second) to achieve amplitudes of approximately 0.004 inches (approximately 100 μm) at the distal cutting tip. Because conventional phacoemulsification piezoelectric crystals are driven at the resonant frequency of the system, they can only achieve sinusoidal, symmetrical motion at the cutting tip. Conventional piezoelectric stacks and resonant masses rely on harmonics to drive cutting tip motion, which cannot achieve asymmetrical motion without significantly increasing energy and inducing large vibrations.

[0126] In the handpiece 1030 described herein, the mass of the vibration system can be reduced as much as possible, and the cutting tube 1112 can be driven directly (with or without amplification components such as rockers) by the piezoelectric stack 1120 in a non-resonant manner at sub-ultrasonic (less than 20 kHz) frequencies. Despite being driven in a non-resonant manner, the cutting tube 1112 can have some additional "whip" motion that results in a larger overall displacement of the cutting tube 1112 than would otherwise be expected.

[0127] Direct piezoelectric drive allows for asymmetric movement of the cutting tube 1112, allowing the retraction speed to be slower than the advancement speed, if desired. This allows for an advancement speed fast enough to perform cutting while keeping the retraction speed below the cavitation threshold. In some implementations, this may involve increasing the frequency of the piezoelectric crystal stack 1120. As discussed above, the length of the horn 1116 is typically designed so that the distal end of the horn 1116 is at least ½ wavelength away from the end of the piezoelectric crystal stack 1120. There are several ways to potentially reduce this length, thereby reducing the length and size of the horn 1116. The equation wavelength λ = c / f is where λ is the wavelength, c is the wave speed, and f is the frequency. In some implementations, the frequency can be increased to reduce the wavelength and therefore the required length of the horn 1116. As discussed elsewhere herein, some implementations reduce the retraction speed of the cutting tube 1112 so that cavitation may be avoided. Using such an apparatus and method provides the opportunity to increase the frequency of the cutting tube 1112 so that the horn 1116 may be made smaller without adversely increasing the amount of cavitation. In yet another implementation, the stroke distance of the cutting tip 1112 can be decreased while increasing the frequency. Thus, the retraction speed of the cutting tube 1112 remains below the critical cavitation-inducing level. Increasing the frequency as described above allows the horn 1116 to be made smaller.

[0128] Cataracts are typically classified based on severity on a scale of 1 to 5. A handpiece 1030 incorporating a piezoelectric stack 1120 configured for non-resonant direct drive of the cutting tube 1112 may be particularly useful for cataracts in the 1-3 range. For hard cataracts above a 3 to approximately 4, a user may choose to switch to conventional resonant phacoemulsification. The systems described herein may be configured to switch between ultrasonic and non-ultrasonic modes. Switching between modes can be achieved by switching the handpiece entirely. For example, the console may be configured to couple with a conventional phacoemulsification handpiece as well as a non-ultrasonic direct drive handpiece. In another implementation, the same handpiece may be driven at different frequencies. For example, the drive mechanism may include a voice coil-type drive mechanism programmable to drive the cutting tube at ultrasonic or non-ultrasonic frequencies to achieve asymmetric cutting tube movement.

[0129] The displacement or travel distance of the cutting tube 1112 of the handpiece 1030 described herein can vary. The longitudinal amplitude or displacement of the tip of the cutting tube 1112 can be comparable to or greater than that of a conventional phacoemulsification needle (i.e., 100 μm or 0.004 inches). The longitudinal amplitude can be achieved via direct drive at a lower frequency than conventional phacoemulsification (e.g., about 10,000 cycles per second). In certain implementations, the displacement achieved by the cutting tube 1112 can be between about 0.005 mm and 1.0 mm, with a vibration frequency of the distal tip being about 0.5 Hz to 10,000 Hz, 0.5 Hz to 5000 Hz, more preferably 2000 Hz to 5000 Hz, or 2,500 Hz to 4,000 Hz, or 3,000 Hz to 3,600 Hz. In some implementations, the frequency is about 3,200 Hz. In this manner, the devices described herein may not be ultrasonic, thereby avoiding the generation of heat and cavitation associated with harmful effects within the eye during cataract surgery. In some implementations, the cutting tube 1112 of the handpiece 1030 may have a greater amplitude or displacement distance while being moved at a lower frequency than conventional phaco needles. In some implementations, the cutting tube 1112 is moved 0.012 inches to about 0.019 inches. The amplitude may be between 0.005 mm and about 1.0 mm, more preferably between 0.05 mm and about 0.1 mm. The vibration frequency may be less than 30,000 Hz, less than 25,000 Hz, less than 20,000 Hz, less than 15,000 Hz, or less than 10,000 Hz, and down to about 0.5 Hz, about 1 Hz, about 2 Hz, about 5 Hz, about 10 Hz, about 25 Hz, about 50 Hz, about 100 Hz, about 250 Hz, or about 500 Hz. The oscillation frequency can be set to approximately 0.5Hz to approximately 30,000Hz, 1Hz to approximately 5000Hz, or approximately 2Hz to approximately 2000Hz.

[0130] As described elsewhere herein, the suction pump 1014 of the handpiece 1030 may be used to apply a pulsed vacuum through the cutting tube 1112. The relative coordination of the vacuum pulse and the oscillatory motion of the cutting tube 1112 may vary. The vacuum pulse may be applied during at least a portion of the extension of the cutting tube 1112. The vacuum pulse may be applied during at least a portion of the retraction of the cutting tube 1112. The vacuum pulse may be applied during at least a portion of both the extension and retraction of the cutting tube 1112. In some implementations, the vacuum pulse may begin before the extension of the cutting tube 1112 and be maintained during the extension. The vacuum pulse may begin after the extension of the cutting tube 1112 has begun. A single vacuum pulse may be applied during multiple extensions and retractions. For example, vacuum may be applied continuously through the cutting tube 1112 for at least about 1 oscillation, at least about 2 oscillations, at least about 5 oscillations, at least about 10 oscillations, at least about 20 oscillations, at least about 30 oscillations, at least about 40 oscillations, at least about 50 oscillations, or up to about 100 oscillations of the cutting tube 1112. As an example, the cutting tube 1112 may oscillate 50 times during a single vacuum pulse lasting 25 ms, such that the oscillation frequency of the cutting tube 1112 is about 2000 Hz.

[0131] The piezoelectric crystal stack 1120 in the handpiece 1030 can be longer (e.g., approximately 2 inches in length) than conventional resonant-driven phacoemulsification to achieve the amplitudes found in conventional resonant phacoemulsification systems.

[0132] 5A-5C , the horn 1116 can extend from the distal end of the piezoelectric stack 1120. The piezoelectric crystal 1120 moves the horn 1116, which in turn moves the cutting tube 1112. Upon coupling of the disposable portions 1031 and 1033 of the handpiece 1030, the horn 1116 can be centrally inserted through the suction pump 1014 of the disposable portion 1031. The roller housing 1146, peristaltic rollers 1148, and tubing 1150 can thereby radially surround the horn 1116. The distal end of the horn 1116 can extend distally through the inner bore 1147 of the roller housing 1146, beyond the pump 1014, and is available for coupling with the cutting tube 1112 near the distal end region of the disposable portion 1031 of the handpiece 1030. As best shown in FIG. 5C , which shows the disposable portion 1031 detached from the reusable portion 1033, the horn 1116 can include an internally threaded recess 1170 configured to receive and engage the external threads 1172 on the proximal end of the cutting tube 1112. A proximal opening from the lumen 1110 of the cutting tube 1112 can communicate with the internal recess 1170 of the horn 1116. The internal recess 1170 of the horn 1116 can include an opening or port 1176 configured to communicate with the helical tube 1150 of the pump 1014. This port 1176 allows fluids and other materials drawn into the lumen 1110 of the cutting tube 1112 to enter the pump 1014 and be urged toward the waste line 1038. Upon alignment of the through-hole 1149 in the roller housing with the opening 1176 in the horn 1116, a vacuum is applied to the internal lumen 1110 of the cutting tube 1112. As the roller housing 1146 rotates, the through-holes 1149 and the openings 1176 in the horn 1116 move in and out of alignment with one another. This cycling effectively turns the suction through the cutting tube 1112 on and off.

[0133] The horn 1116 can be formed of any suitable material or combination of materials for the purposes described herein. The material used for the horn 1116 affects the speed of sound within the horn material, and therefore the length of the horn 1116 is required so that the tip is located at least one-half wavelength away from the piezoelectric crystal 1120. The horn 1116 may be formed of commonly used materials such as aluminum, stainless steel, or titanium. For example, the speed of sound in titanium is on the order of 6,070 m / s. In some implementations, other materials with lower sound speeds may be considered for the horn material. For example, copper has a speed of sound on the order of 3,900 m / s, and lead has a speed of sound on the order of 1,300 m / s. The slower the speed of sound, the smaller the horn 1116 may need to be so that the end of the horn has the maximum amplitude node.

[0134] In some implementations, rather than relying on resonance, the handpiece 1030 can incorporate a drive mechanism configured to directly drive the cutting tube 1112 back and forth or oscillate the cutting tube 1112 from side to side, as described elsewhere herein. The piezoelectric stack 1120 can respond to changes in voltage by decreasing or increasing in size. The voltage profile powering the piezoelectric stack 1120 can generate a movement profile for the cutting tube 1112 to produce the desired cutting tube movement. In some implementations, the voltage waveform sent to the piezoelectric stack 1120 can be generally non-sinusoidal, and thus the cutting tube 1112 moves in a generally non-sinusoidal pattern, as described elsewhere herein. The voltage may have a waveform that causes the piezoelectric stack 1120 to contract more slowly than it expands. This causes the cutting tube 1112 to move more slowly on a contraction stroke than an extension stroke. Based on the voltage waveform supplied to the piezoelectric stack 1120, any number of motion profiles may be commanded. For example, two or more overlapping voltage sine waves can be fed to the piezoelectric stack 1120, which creates an interference effect to generate a non-sinusoidal waveform. These drive mechanisms can be incorporated into the disposable or reusable portion of the handpiece 1030. In a preferred implementation, the drive mechanism incorporates a piezoelectric stack 1120 contained within the disposable portion of the handpiece 1030.

[0135] In yet another implementation, a combination of mechanisms and methods are incorporated into the device to drive the cutting tube 1112 with a non-sinusoidal motion profile. For example, an electromagnetic coil can be configured to move a ferrite or magnetic core forward upon application of current through the coil. The core can be configured to be driven forward by the electromagnetic coil, but then retracted rearward (i.e., proximally) by the force of a compressed spring. Thus, as the current through the coil increases, the core is driven forward. As the current decreases, the core retracts rearward. In this manner, by connecting the core to the cutting tube 1112, a sudden increase in the voltage on the coil can cause a quick forward extension, but the retraction can be slowed by the force of the compressed spring.

[0136] The cutting tube 1112 can be driven to have an asymmetric or sinusoidal motion profile. For example, some drive mechanisms that provide torsional cutting tube motion (see, e.g., Figures 16A-16D, 17A-17C, 18, 19A-19C, 20A-20B, 21A-21D, 25A-25C, 26A-26C, 27A-27B) do not necessarily provide an asymmetric motion profile.

[0137] The handpiece 1030 can perform multiple functions (i.e., irrigation, aspiration, and cutting functions) while maintaining complete portability, flexibility, and freedom of movement. Functions of the handpiece 1030 can be initiated using an input (trigger 1180) on the handpiece 1030 that can be activated with a single finger or thumb. Because the handpiece 1030 does not require a foot pedal, the user can perform the procedure more comfortably and naturally while standing (e.g., on two feet, or shifting weight from foot to foot as desired). As described above, the handpiece 1030 can be actuated using one or more inputs or triggers 1180 on the handpiece 1030 and / or remote from the handpiece 1030, such as on a control unit of the system 1010. The one or more inputs can be prompted by the user into a position that causes the drive mechanism to initiate one or more operations. For example, the trigger 1180 on the handpiece 1030 (or foot pedal) can be connected to a control unit which in turn interprets the signal and provides the appropriate drive waveform to the piezoelectric crystal stack 1120 .

[0138] The use of the term "handpiece" herein can include a handpiece coupled to a robotic arm, robotic system, or other computer-assisted surgical system in which a user operates instrument controls using a computer console. The computer translates the user's movements and actuation of the controls to be performed on the patient by the robotic arm. Thus, when the terms "hand" or "handpiece" are used herein, it should be understood that the hand can be the surgeon's own hand or the robotic "hand" operating the handpiece.

[0139] Disposable / durable part connections As described above, the handpiece 1030 can include a disposable portion 1031 configured to releasably couple to a durable portion 1033. The disposable portion 1031 generally includes components configured to be exposed to human fluids and substances, while the durable portion 1033 is intended to be reused with a new disposable portion 1031 coupled to it. The disposable and durable portions 1031, 1033 of the handpiece 1030 can be coupled to one another using a variety of mechanisms, such as threads, snap locks, bayonet locks, etc.

[0140] In some implementations, the proximal end region of the housing 1145 of the disposable portion 1031 can define a chamber having a proximal opening into which at least a portion of the durable portion 1033 can be inserted and coupled to the disposable portion 1031, such as via a bayonet locking mechanism (see FIGS. 5A-5C). For example, the horn 1116 and motor 1115 within the motor housing 1168 can be inserted through the proximal opening of the housing 1145 of the disposable portion 1031 such that the motor housing 1168 is received within the chamber of the housing 1145. The two portions 1031, 1033 can then be placed into locked engagement with one another, such as via a bayonet locking mechanism, by rotating a certain number of degrees once the horn 1116 and motor housing 1168 are received within the chamber. The connection between the disposable and durable portions 1031, 1033 can be a purely mechanical connection or both a mechanical and electrical connection. It should be understood that the motor 1115 may remain outside the chamber of the disposable portion, such that only the horn 1116 or another portion of the durable portion 1033 is inserted into the chamber of the disposable portion. The durable portion 1033 may be inserted into the disposable portion until the forward end of the rotor 1164 engages the proximal end of the roller housing 1146 of the aspiration pump 1014. The two portions can be rotated relative to one another (e.g., clockwise or counterclockwise) to secure the engagement and lock the two portions together. The coupling mechanism may include a release button configured to release the coupling of the two housing portions. In some implementations, the coupling may incorporate one or more markings on each housing to guide the user in aligning the respective portions for insertion before locking. The locking mechanism between the portions may be mechanical, such as a spring-loaded pin that must be retracted before removal. The coupling between the disposable and durable portions forms a smooth, continuous housing for the handpiece 1030.

[0141] The bond between the disposable and durable portions 1031, 1033 of the hand piece 1030 can incorporate one or more sealing elements to ensure the hand piece 1030 does not leak during use. For example, the one or more sealing elements can be O-ring-type seals 1152 positioned to prevent leakage where the horn 1116 of the durable portion is inserted into the disposable portion. For example, a first O-ring 1152 can be positioned distal to the opening from the recess 1170 in the horn 1116, and a second O-ring 1152 can be positioned around the horn 1116 at the proximal end of the recess opening (see FIGS. 5A-5C). Additionally, a compliant seal can be positioned around the proximal end region of the horn 1116 near where it extends outside the piezoelectric stack housing 1114. In another implementation, the cutting tip 1112 can include one or more seals within the disposable portion 1031. In this configuration, fluids from the surgical site do not contact the disposable interior. This has the advantage of eliminating the possibility of cross-contamination that exists with conventional phaco handpieces.

[0142] As mentioned above, some implementations of the cutting tube drive mechanism 119 may be part of the disposable portion 1031 of the hand piece (e.g., FIGS. 16A-16D), while other implementations of the cutting tube drive mechanism 119 may be part of the reusable, durable portion 1033 of the hand piece 1030 (see FIGS. 5A-5C). Any of a variety of configurations are contemplated herein, and it should be understood that the location of one or more components of the hand piece 1030, whether in the disposable or reusable portion, may vary.

[0143] Other Pump Configurations As discussed above, the aspiration pump 1014 in the handpiece can be any of a variety of low-profile aspiration pumps, including peristaltic, linear peristaltic, piston, scroll-type pumps, etc. FIGS. 5A-5C show an implementation of a handpiece 1030 having an aspiration pump 1014 that is a peristaltic pump. FIGS. 22A-22B show an implementation of a handpiece having an aspiration pump 1014 that is a linear peristaltic pump. FIGS. 13A-13L show various views of an implementation of a phacoemulsification system handpiece 1030 having an aspiration pump 1014 that is a piston pump. The aspiration pump can include one or more pistons 2799 movable within respective pumping chambers 2705 of a piston manifold 2798. The pistons 2799 are driven by a drive mechanism, such as a motor (not shown), which can be located within the durable portion 1033 of the handpiece 1030. 13F-13H show a vacuum manifold 2774 coupled to a piston manifold 2798 such that a vacuum chamber 2703 of the vacuum manifold 2774 is in fluid communication with one or more pumping chambers 2705 within the piston manifold 2798. One or more pistons 2799 driven by a motor create a vacuum within the pumping chambers 2705 as well as the vacuum chambers 2703 to draw material through the lumen 1110 of the cutting tube 1112.

[0144] It should be understood that any number of pistons 2799 can be positioned within each pumping chamber 2705. Multiple pistons 2799 bouncing back and forth within their pumping chambers 2705 can create a pulsatile vacuum or full vacuum that is delivered to the distal portion of the lumen of the cutting tube 1112 in pulses of negative pressure. A pulsatile vacuum allows for the application of a full vacuum through the cutting tube 1112 without risk of anterior chamber collapse. At the peak of the pulse, the system can generate a high vacuum. However, because it is pulsed, the average aspiration flow rate can be low enough as an irrigation inflow to adequately maintain anterior chamber support, even under these high vacuums at the peak of the pulse.

[0145] FIG. 14A shows a notch or proximal opening 2788 in a cutting tube 1112 disposed within a vacuum chamber 2703. A vacuum can pull lens material through the cutting tube 1112. The lens material can exit the lumen 1110 of the cutting tube 1112 through the proximal opening 2788 and enter the vacuum chamber 2703 of the vacuum manifold 2774. The lens material is not intended to travel proximal to the proximal opening 2788 of the cutting tube 1112. The vacuum chamber 2703 is configured to be in fluid communication with one or more pumping chambers 2705 through respective openings 2706 regulated by one-way valves 2707 (see FIG. 13I). The one-way valves 2707 can be configured in a variety of ways, including duckbill valves, ball check valves, lift check valves, stop check valves, and other types of valves that allow fluid flow in one direction and block fluid flow in the opposite direction. Movement of the piston 2799 in a first direction within the pumping chamber 2705 (i.e., toward the proximal or rearward direction of the handpiece) creates a vacuum that can be applied to the lumen of the cutting tube 1112 through an opening 2706 on a vacuum manifold 2774 that surrounds the cutting tube 1112. A gasket 3262 separates a vacuum chamber 2703, which may be defined by a central cavity, from an evacuation chamber 2709 (see FIG. 14A). Upon application of a vacuum to the lumen of the cutting tube 1112, material from the eye is drawn into the lumen 1110 of the cutting tube 1112, empties into the vacuum chamber 2703, and is drawn into the pumping chamber 2705 through a one-way valve 2707. Movement of the piston 2799 in a second, opposite direction within the pumping chamber 2705 (i.e., distally or toward the front of the handpiece) causes pressure to build within the piston manifold 2798, expelling material from the pumping chamber 2705 and out of the system. The material may be expelled from the system to a waste housing coupled to an outlet port, as described elsewhere herein.

[0146] Referring again to FIG. 13I, the vacuum manifold 2774 can further include an evacuate chamber 2709. The evacuate chamber 2709 is sealed from the vacuum chamber 2703 so that material drawn into the system can be purged from the system without being forced back out through the cutoff tube 1112. The seal between the chambers 2703 and 2709 can be provided by one or more O-rings 2786. The vacuum chamber 2703 is configured to be in fluid communication with one or more pumping chambers 2705 through respective one-way valves 2707 disposed within openings 2706. The evacuate chamber 2709 is in fluid communication with each of the one or more pump chambers 2705 through other openings 1038 regulated by respective valves 2713. The configuration of the valves 2713 can vary, including ball-type check valves. Movement of the pistons 2799 in a first direction within each pumping chamber 2705 (e.g., toward the proximal end of the hand piece 1030) draws material from the vacuum chambers 2703 through the valves 2707 and into the pumping chambers 2705. Movement of the pistons 2799 in a second, opposite direction within each pumping chamber 2705 (e.g., toward the distal end of the hand piece 1030) creates pressure within the piston manifold 2798. This pressure causes the valves 2713 within the piston manifold 2798 to open. Waste may enter the vacuum manifold 2774 via the waste channels 1038 (e.g., the three openings shown in FIG. 14A ). Waste may combine within the vacuum manifold 2774 and exit the device via the refuge chamber 2709. Although it should be understood that other shapes are contemplated herein, the refuge chamber 2709 is shown in FIG. 14A as an oval-shaped channel passing through the vacuum and piston manifolds 2774, 2798. During this purging of material, a one-way valve 2707 between the one or more pumping chambers 2705 and the vacuum chamber 2703 prevents backflow of material out of the vacuum chamber 2703 , lumen 1110 , and cutting tube 1112 .However, opening 1038 between one or more pumping chambers 2705 and evacuation chamber 2709 allows material to freely enter evacuation chamber 2709 and eventually exit through outlet or suction port 1154 of evacuation chamber 2709, at least until flow is blocked by valve 2713.

[0147] Referring again to FIG. 13J , proximal movement of piston 2799 creates a vacuum within pumping chamber 2705. Spring 2719 urges ball 2717 of valve 2713 proximally, away from opening 1038 between pump chamber 2705 and retract chamber 2709, thereby opening valve 2713. Distal movement of piston 2799 builds fluid pressure within pumping chamber 2705, forcing material toward opening 1038 of valve 2713. Ball 2717 of valve 2713 is urged distally against spring 2719, compressing spring 2719 and urging ball 2717 against opening 1038 of the valve, thereby closing the valve. Pump chamber 2705 is substantially free of material upon closing of valve 2713. In some implementations, valve 2707 may be slightly compliant, such as a silicone valve, such as a duckbill valve. The ball 2717 may be rigid and substantially non-compliant, such as a hard plastic or metal material. A compliant valve may deform when a positive back pressure is applied, whereas a non-compliant valve does not. If the valve between the vacuum chamber 2703 and the pumping chamber 2705 is a compliant valve and the ball 2717 is substantially non-compliant, as the piston moves distally, generating positive pressure to evacuate material from the pumping chamber 2705, the positive pressure can cause the compliant valve to deform, causing a small amount of fluid to purge or backflow from the cutting tube 1112. This backflow can occur with each back-and-forth cycle of the piston 2799. In some implementations, backflow may be further optimized by the design of the pumping chamber 2705. In the pumping chamber 2705, an outlet opening connecting the pumping chamber 2705 to the evacuating chamber 2709 may be located, for example, on a side of the chamber and configured so that the piston 2799 moves past the outlet opening. In this embodiment, once the piston 2799 has moved distally beyond the outlet opening, there is no other route for the fluid to escape.Thus, as the piston 2799 continues to move distally, a moment of positive pressure is created in the pumping chamber 2705 after the valve 2713 closes, causing a brief backflow of material at the distal end of the cutting tube 1112 .

[0148] As best shown in Figures 13F-13G, as well as Figures 13K-13L and 14B, each of the pistons 2799 can include an elongated central piston rod 2721 surrounded by a spring 2701 extending between piston heads 2723a, 2723b. The distal piston head 2723a and sliding O-ring seal 2794 are disposed within a pumping chamber 2705. The piston rod 2721, spring 2701, and proximal piston head 2723b are disposed within a piston chamber 2704 within a piston manifold 2798 located proximal to the pumping chamber 2705. The distal piston head 2723a, sliding seal 2794, and piston rod 2721 are slidable within the pumping chamber 2705. The pumping chamber 2705 has an inner diameter dimension that is smaller than the outer diameter dimensions of the piston chamber 2704 and spring 2701. Thus, as the piston 2799 moves toward the distal end region of the pumping chamber 2705, the spring 2701 is compressed within the piston chamber 2704 between the proximal piston head 2723b and the lower end of the pumping chamber 2705. The spring 2701 is biased to urge the piston 2799 proximally, toward the proximal end of the pumping chamber 2705.

[0149] The handpiece can include a rotating cam 2769 having a proximal end operably coupled to a motor directly or via a motor coupler. The rotating cam 2769 can convert rotational motion of the motor into linear motion of the pistons 2799. The springs 2701 are biased to urge the pistons 2799 proximally toward the proximal ends of the pumping chambers 2705. The rotating cams 2769, disposed proximal to the pistons 2799, are configured to urge the pistons 2799 distally toward the distal ends of their respective pumping chambers 2705. As the cam 2769 rotates, it sequentially applies a distally directed force to the proximal piston heads 2723b of the pistons 2799. The springs 2701 of the pistons 2799 are sequentially compressed. Further rotation of cam 2769 sequentially removes the distal force on proximal piston heads 2723 , causing springs 2701 to sequentially urge pistons 2799 backwards, creating a vacuum in the respective pump chambers 2705 via one-way valves 2707 .

[0150] As best shown in FIGS. 13C-13E , the rotating cam 2769 can be coupled to a motor coupler 2795. The motor coupler 2795 can have a bore 2789 at its proximal end configured to receive the gear head 2752 and one or more protrusions 2796 at its distal end. The protrusions 2796 are configured to matingly engage corresponding wedge-shaped protrusions 2797 on the proximal end of the cam 2769. The cam 2769 rotates as the gear head 2752 rotates. The distal end of the cam 2769 has a cam surface 2725 configured to provide reciprocating linear motion for the piston 2799. The shape of the cam surface 2725 can be designed to provide different motion profiles for the piston 2799 within each bore, thereby generating different vacuum profiles (i.e., smooth continuous, continuous with negative pressure spikes, or discontinuous pulsed negative pressure). The cam surface 2725 can be elliptical, eccentric, oval, or snail-shaped. During a first fraction of the cam's 2769 rotation, the proximal piston head 2723b slides along a ramped portion of the cam surface 2725, and the piston 2799 moves distally along the longitudinal axis of the device. During a second fraction of the cam's 2769 rotation, the proximal piston head 2723b slides over the cam surface 2725, which terminates in a ledge 2726. Once the piston head 2723b disengages from the ledge 2726, the distal force exerted by the cam 2769 on the piston 2799 is released. A spring 2701 surrounding the piston rod 2721 biases the proximal piston head 2723b proximally, toward the proximal end region of the piston chamber 2704. Thus, a complete rotation of the cam 2769 sequentially permits axial movement of each piston 2799. The piston head 2723b slides along the cam surface 2725 and extends distally at a first velocity, and the piston head 2723b disengages from the cam surface 2725 and retracts proximally at a second velocity that is much faster than the first velocity. The timing of this piston movement can vary based on the shape of the cam surface 2725 and the position of the ledge 2726 relative to the cam surface 2725.For example, the timing of when one piston retracts to create negative pressure in the chamber relative to when the next piston retracts to create negative pressure can be a function of the shape of the cam surface 2725. The cam surface 2725 can incorporate a ledge 2726, as shown in FIG. 13C , such that each piston quickly retracts upon reaching the ledge 2726. The pistons extend distally at a first rate as they move along the cam surface 2725, and then extend proximally at a second, faster rate as they fall off the ledge 2726. In other implementations, the cam surface 2725 has a first ramp connected to the ledge 2726 by a second ramp. The first ramp of the cam surface 2725 allows for the gradual extension of each piston, and the second ramp allows for the gradual retraction of each piston. Thus, each piston gradually retracts a distance before the piston falls off the ledge 2726 and quickly retracts the remainder of its rearward travel. The movement of the piston responsible for generating the suction force and the movement of the cutting tube can be coordinated by a rotating cam mechanism, as described in U.S. Patent Publication No. 2018 / 0318133, published November 8, 2018, which is incorporated herein by reference.

[0151] The vacuum pulse can be designed to occur suddenly, for example, by the piston 2799 falling off the ledge 2726 of the cam surface 2725 and being pushed proximally by the piston spring 2701 toward the proximal end of the pumping chamber 2705. The timing of this retraction by the ledge 2726 can be exploited to achieve a more pulsating vacuum profile. Pulsatile vacuum is beneficial for disintegrating lenses and removing lens material from the eye in that peak vacuum levels can be higher in these short bursts than can be achieved if a steady vacuum were applied because the flow rate is kept below a nominal rate (e.g., 50 cc / min). High peaks of vacuum are created, but an overall low flow rate can be maintained.

[0152] The timing of the retraction of the first piston and the next piston can be a function of the geometry of the cam surface 2725 and the relative movement of the pistons within the piston chamber. The vacuum pulses can be designed to occur more smoothly, so that the vacuum provided is substantially continuous, rather than discontinuous with momentary pauses between vacuum pulses. In some implementations, the first piston may retract and the second piston may not begin retracting until the dwell period of the retraction of the first piston has elapsed (see FIG. 15A), thereby creating a pulsed vacuum profile. As described above, the apparatus can include a cam 2769 having a cam surface 2725 configured to provide reciprocating linear motion of the piston 2799. FIG. 15A schematically illustrates the movement of pistons 2799a, 2799b, and 2799c along the cam surface 2725 of the cam 2769. The cam surface 2725 terminates in a sharp drop-off or ledge 2726. As cam 2769 rotates, pistons 2799a, 2799b, and 2799c slide along cam surface 2725, thereby extending distally. Upon reaching outlet 2726, first piston 2799a drops off ledge 2726 and quickly retracts proximally, creating a spike of negative pressure. The shape of cam surface 2725 creates a dwell period without negative pressure before the next piston 2799b reaches ledge 2726 and retracts, creating a second spike of negative pressure. The result is a series of discrete pulses of negative pressure.

[0153] In other implementations, the second piston may begin retraction during the retraction phase of the first piston, so that the vacuum profile is smoother and more continuous. Figures 15B-15D schematically show an implementation of cam 2769 in which the shape of cam surface 2725 is designed to have a more gradual slope for piston retraction before terminating at ledge 2726. The shape of cam surface 2725 can be designed so that one of multiple pistons 2799 retracts at a constant rate (i.e., creating a negative pressure within pumping chamber 2705). Figure 15B shows first piston 2799a near the end of its proximal travel within the piston chamber just before ledge 2726. Second piston 2799b is poised to begin its retraction along a gradual slope before first piston 2799a drops off ledge 2726. 15C and 15D illustrate further rotation of the cam 2769 and movement of the pistons along the cam surface 2725. Before the second piston 2799b falls off the ledge 2726, the third piston 2799c begins to retract along the gradual slope of the cam surface 2725. This timing of piston retraction creates a substantially continuous flow of fluid from the eye, compared to the discontinuous shape of the cam surface 2725 shown in FIG. 15A, where there are moments when a vacuum is not applied. However, the presence of the ledge 2726 can create a small spike of negative pressure on top of the continuous negative pressure applied by the retracting pistons. The first piston 2799a retracts a first distance along the cam surface 2725 at a first velocity, thereby generating a first negative pressure. The second piston 2799b can begin to retract along the cam surface 2725 at a first velocity and maintain that negative pressure before the first piston 2799a falls off the ledge 2726. The first piston 2799a then falls off the ledge 2726 and retracts the remaining distance at a second, faster rate, thereby creating a negative pressure spike.

[0154] As best shown in FIGS. 13K-13L, the piston stop 2727 can be coupled to a proximal end region of the piston manifold 2798. The piston stop 2727 can be a generally cylindrical element that surrounds the rotating cam 2769. The distal end region of the piston stop 2727 can define one or more protrusions 2729 configured to protrude into the proximal end regions of each of the piston chambers 2704 in the piston manifold 2798. The protrusions 2729 abut the proximal piston heads 2723b of the respective pistons 2799 when disposed in the proximal-most end regions of the respective piston chambers 2704. For example, if the handpiece 1030 includes three pistons 2799 disposed in three piston chambers 2704, the piston stop 2727 includes three protrusions 2729 configured to abut against the proximal piston heads 2723b of the respective pistons 2799. The piston stop 2727 provides a hard stop against the proximal linear movement of the piston 2799 upon expansion of the spring 2701, and therefore the overall volume of the pumping chamber 2705 that can be achieved. The relative position of the protrusion 2729 within the piston chamber 2704 is adjustable. In some implementations, an adjustment ring 2730 is disposed around the outer surface of the piston stop 2727 and can be accessible to the user through one or more windows 2731 in the housing of the hand-held portion 1030 (see FIGS. 13A-13B). The adjustment ring 2730 can have a threaded inner surface configured to engage with a corresponding pin 2732 on the outer surface of the piston stop 2727. The pin 2732 is configured to slide within the threads of the adjustment ring 2730 as the piston stop 2727 moves axially along the longitudinal axis of the device. As the piston stop 2727 is adjusted to be positioned further distally relative to the piston manifold 2798, the protrusion 2729 extends further into the piston chamber 2704, limiting the proximal linear movement of the piston 2799 upon expansion of the spring 2701. This, in turn, limits the size of the pumping chamber 2705.When the piston stops 2727 are adjusted to be positioned more proximally relative to the piston manifold 2798, the protrusions 2729 are withdrawn from the piston chambers 2704 and do not restrict (or restrict to a lesser extent) the proximal linear movement of the pistons 2799 upon expansion of the springs 2701. This, in turn, maximizes the size of the pumping chambers 2705. The piston stops 2727 can also be adjusted to determine the type of vacuum applied by the pistons within their respective chambers 2704 (e.g., a smooth continuous vacuum or a smooth continuous with pulsating vacuum spikes), as described in more detail below.

[0155] In some implementations, the vacuum source can create a vacuum spike that creates a vacuum profile that effectively "bounces" the cornea and eye up and down during application of the pulsed vacuum. For example, moving the piston 2799 backward can cause a vacuum spike that creates a vacuum profile resembling a "saw tooth" (i.e., suction-pause-suction). Limiting the backward movement of the piston 2799 within each pumping chamber 2705 can reduce the amount of suction impulse or shock created with each backward movement of the piston. The piston limit limits the maximum suction created with each piston movement, reducing the impact of this suction spike on the eye. The vacuum created with each backward movement of the piston 2799 can be greater than 500 mmHg, up to approximately 700 mmHg.

[0156] In some implementations, the device can be switched between two vacuum modes. The first mode can be a substantially continuous vacuum mode without negative pressure spikes due to the piston 2799 falling off the ledge 2726. The second mode can be a substantially continuous vacuum mode with negative pressure spikes. When in the first mode, retraction of the piston can be limited to a fraction of the maximum piston travel within the chamber. For example, a piston stop 2727 can be selectively used to limit piston travel within its chamber to a distance less than the maximum distance. As described elsewhere herein, the device can include a piston stop 2727 coupled to a proximal end region of the piston manifold 2798. The piston stop 2727 can be a generally cylindrical element that surrounds the cam 2769 such that the cam 2769 extends through the cylindrical piston stop 2727 and contacts the proximal end of the piston 2799. The piston stops 2727 may include protrusions 2729 configured to protrude into the proximal end regions of their respective piston chambers 2704 to contact the proximal ends of the pistons 2799. Thus, both the cams 2769 and protrusions 2729 of the piston stops 2727 are configured to contact the proximal ends of the pistons 2799, with the cams 2769 on the inner regions and the protrusions 2729 on the outer regions. The protrusions 2729 of the piston stops 2727 may provide a hard stop against linear movement of the pistons 2799 in the proximal direction. For example, the maximum piston movement within its piston chamber may be a distance of 5 mm. The protrusions 2729 of the piston stops 2727 may be advanced 2 mm into the piston chamber, thereby limiting the proximal retraction of the pistons 2799 to a maximum distance of 3 mm rather than 5 mm. As the cam 2769 rotates and the piston 2799 extends or retracts along the cam surface 2725, the protrusion 2729 of the piston stop 2727 can effectively prevent the piston 2799 from falling off the ledge 2726, creating a smooth and continuous negative pressure without negative pressure spikes.When the protrusion 2729 of the piston stop 2727 is withdrawn from the piston chamber, the piston 2799 can again travel a maximum distance and fall off the ledge 2726 creating a spike in negative pressure.

[0157] In some implementations, the handpiece is limited in achieving maximum vacuum by incorporating a feature that automatically bypasses the cutting tube 1112 depending on whether a threshold vacuum has been reached. For example, a bleed valve or other bypass mechanism can be incorporated to prevent the threshold vacuum from being applied intraocularly at the opening distal to the cutting tube 1112. A bypass that turns suction on or off can limit the maximum amount of vacuum that can be generated intraocularly, even if the opening to the cutting tube 1112 is clogged. This bypass can prevent a vacuum from building in the event of an obstruction, creating less of a surge upon removal of that obstruction. The bypass mechanism can be adjustable or selective, allowing the user to choose whether to seek the maximum vacuum possible or apply less than the maximum vacuum.

[0158] It is desirable to limit the maximum vacuum pressure that can be achieved with each proximal piston movement. Limiting the maximum vacuum pressure can provide additional safety with respect to the capsular bag and the entire eye. For example, the impact of the system on the integrity of the capsular bag and anterior chamber can be directly related to the amount of suction applied at the distal tip. Limiting the overall vacuum pressure (e.g., by at least 2%, 3%, 4%, 5%, 10%, 15%, 20%, 25%, or up to approximately 50% of the maximum achievable vacuum pressure) can prevent problems such as capsular bag rupture and anterior chamber "trampoline."

[0159] FIG. 13L illustrates an implementation of a vacuum bypass function 2708 configured to limit the maximum vacuum pressure within each pumping chamber 2705. The bypass feature 2708 can have any of a variety of configurations. In an implementation, the bypass feature 2708 can be a small longitudinal indentation, divot, or groove in the cylindrical wall of each pumping chamber 2705 (see FIG. 13L). As described above, the piston 2799 can include an elongated central piston rod 2721 surrounded by a spring 2701 extending between piston heads 2723a and 2723b. A sliding O-ring seal 2794 can be disposed around the distal piston head 2723a, which maintains the vacuum within the pumping chamber 2705. The piston 2799 shown in FIG. 13L is disposed within the cylindrical pumping chamber 2705 near the end of its proximal travel path, such that the proximal piston head 2723b abuts the piston stop 2727. When the piston head 2723b abuts the piston stop 2727, the seal 2794 can align with the bypass feature 2708 near the proximal end of the piston travel. The bypass feature 2708 can have a length along the longitudinal axis of the cylindrical chamber such that at least a portion of the feature 2708 is located distal to the seal 2794 and at least a portion of the feature 2708 is located proximal to the seal 2794. The presence of the bypass feature 2708 on both the distal and proximal sides of the seal 2794 (i.e., the high-pressure and low-pressure sides of the chamber 2705) means that at the proximal end of the piston travel, a quantity of ambient air can momentarily bleed from the high-pressure side to the low-pressure side of the chamber 2705 (i.e., distal to the seal 2794). The leakage or bleed of ambient air can limit the range of vacuum pressure that would otherwise be achieved upon proximal retraction of the piston 2799. Venting of the suction cavity may be to atmosphere, to a cleaning fluid path, to a waste path, or to another cavity that allows fluid or air to enter the suction cavity and reduce the vacuum level achieved within the suction cavity. Venting can relieve the vacuum level within the suction cavity and reduce the maximum vacuum level achievable during operation.The bypass feature 2708 can be designed to achieve a desired maximum pressure value depending on the length, width, and / or depth of the grooves, as well as the number of grooves incorporated. The geometry of the bypass feature 2708 can also control the rate at which this vacuum pressure is generated with each successive piston retraction.

[0160] The bypass feature 2708 can passively, as described above, or actively vent the vacuum to atmosphere. For example, the bypass feature 2708 can be activated by a user, as described in more detail below. The bypass feature 2708 can have an adjustable and / or user-selectable shape to provide additional user control over the desired maximum pressure value that can be achieved. In one implementation, the bypass feature 2708 can be a small hole extending through the wall of the pumping chamber 2705. The diameter, length, and / or location of the hole can be variable and selectable by the user to achieve desired control of the maximum suction pressure achieved.

[0161] In some implementations, the device can incorporate a vent mechanism that is useful in certain situations, such as if the capsular bag is inadvertently trapped or if lens material blocks the distal end of the cutting tube 1112. Similar to the bypass feature 2708 described above, the vent mechanism can include a small hole through the wall of the pumping chamber 2705 that can be selectively exposed or covered. The hole can be covered and / or exposed by a movable element actuable by a button or other input on the device's user interface, allowing a user to release the vacuum built up in the pumping chamber 2705 to the atmosphere. Releasing the vacuum can release material, such as the capsular bag, from the tip of the cutting tube 1112, for example. Selective activation of the vent mechanism can include pressing a button, which moves a movable element that normally covers the hole, exposing it to the atmosphere. Alternatively, selective activation of the vent mechanism can involve pressing a button to move a movable element that covers the normally open hole, preventing venting to the atmosphere. In one implementation, the button can be coupled to the multi-stage trigger 1180 of the device described elsewhere herein. As an example, when the trigger 1180 is in its neutral state and the device is stationary, the vacuum can be vented and the suction in the system can dissipate. When the trigger 1180 is depressed to activate the suction, the vent can be shut off. In this example, a user who has a capsular bag (or part of the lens blocking the lumen) sucked into the tip of the device can simply release the trigger 1180 to vent and free the tissue.

[0162] In addition to venting the tip of the cutting tube 1112, the vent purge mechanism can additionally create a small retrograde fluid flow from the distal tip of the device. A small fluid flow at the tip helps to fully expel any bags or other clogging material. In this implementation, the button that activates the purge mechanism can be a depressible button that, when depressed, can force a small amount of fluid out of the irrigation outlet. In this manner, releasing the trigger 1180 can vent the vacuum built up in the pumping chamber 2705, and pressing the purge button can force fluid out of the distal tip, further expelling the capsular bag.

[0163] Figures 22A-22B show perspective and top views of an implementation of an aspiration pump 1014 for incorporation into a disposable working portion 1031 configured to provide smooth, continuous suction through the cutting tube 1112. The working portion 1031 can be used in procedures where smooth flow of suction through the vibrating cutting tube 1112 is desired. Figures 22C-22D show the camshaft 405 of the aspiration pump 1014 of Figure 22A.

[0164] The aspiration pump 1014 may be a linear peristaltic pump having a symmetrical dual-chamber pumping manifold 420, a central camshaft 405 extending longitudinally through the manifold 420 along longitudinal axis A, a plurality of cam followers 410, and a pair of peripheral tubes 415. The pumping manifold 420 may be disposed within the working portion 1031 between the proximal and distal manifolds. The camshaft 405 may be coupled to a drive shaft at a proximal end region of the camshaft 405, for example, via a rotating camshaft coupler 2795 within the disposable portion 1031. As the pump motor 1115 rotates, the drive shaft drives the rotation of the camshaft 405, thereby powering the aspiration pump 1014. Additionally, the camshaft 405 may be coupled to a cutting tube 1112 at a distal end region of the camshaft 405, for example, via a rotating cam follower.

[0165] Two tubes 415 may be disposed on either side of a centerline C (see FIG. 23A ) of the pumping manifold 420. The two tubes 415 may each extend substantially linearly through the pumping manifold 420 to form a longitudinal axis T (see FIG. 22B ) through the pumping manifold 420 that is disposed parallel to a longitudinal axis A of the camshaft 405 extending through the pumping manifold 420. A first tube 415 a of the two tubes 415 may be disposed on one side of the camshaft 405, and a second tube 415 b of the two tubes 415 may be disposed on a second, opposite side of the camshaft 405. The proximal flow path splits into two flow paths connected at their proximal ends to a pair of tubes 415 within a proximal manifold (not shown). The two tubes 415 may be coupled to a distal manifold (not shown) distal to the pumping manifold 420. The distal flow path can be in fluid communication with the lumen of the distal cutting tube 1112 .

[0166] 22C-22D show the camshaft 405 of the suction pump 1014 of FIGS. 22A-22B. The camshaft 405 can incorporate a multi-lobed cam 425 that acts in time to drive multiple cam followers 410 toward or away from a pair of tubes 415 so that the tubes sequentially experience gradual compression, thereby forcing their fluid volume along their flow paths. The pair of tubes 415 can be aligned with the longitudinal axis A (axis of rotation) of the camshaft 405. The lateral movement of the cam followers 410 can be in a plane perpendicular to the longitudinal axis A of the camshaft 405 and the respective longitudinal axes T of the tubes 415 (see FIG. 22B). As an example, the tubes 415 can extend spatially parallel to or along the axis of rotation of the camshaft 405 through a pumping manifold. Tube 415 can be compressed by cam follower 410 along an axis that is substantially 90 degrees relative to the axis of rotation of camshaft 405. For example, cam follower 410 can be driven laterally along a horizontal position or along a vertical position relative to camshaft 405. The relative angle between cam follower 410 and tube 415 can be greater than or less than 90 degrees, but cam follower 405 does not translate axially along the sidewall of tube 415 as occurs in conventional peristaltic pumps that use rollers that compress and roll along the length of a tube to move a fluid volume along its flow path.

[0167] Each of the tubes 415 can be sequentially compressed in a wave-like manner by the cam follower 410. The maximum extent of compression closes the tube, trapping a discrete volume of fluid urged along the length of the tube, resulting in a flow of suction fluid moving through the tube 415. Conventional peristaltic pumps pump fluid through the tube by moving rollers or other components along the tube's longitudinal axis. Such linear movement along the tube can cause holes or tears in the tube's sidewalls over time. The suction pump 1014 described herein does not require movement of a compression element along the tube's longitudinal axis (i.e., axis T shown in FIG. 22B). Rather, compression of each tube 415 is in a plane perpendicular to the tube's longitudinal axis T. This arrangement avoids pulling or stretching the tube and creates little friction on its sidewalls. In other words, the cam followers do not exert a force in the direction of the longitudinal axis T of the two tubes 415a, 415b. The chamber volume remains constant, and the pump 1014 has a lower risk of tube failure or pump performance that may result from compression traveling along the length of the tubes.

[0168] As best shown in FIGS. 23A-23D, each of the plurality of cam followers 410 can include an inner slot 430 configured to receive a respective cam lobe 425. The cam lobe 425 can move up and down relative to and within the inner slot 430 as the camshaft 405 rotates about its longitudinal axis A. The cam follower 410 is biased laterally by the cam lobe 425 relative to a centerline C of the pump manifold 420. FIG. 23A shows one cam follower 410 aligned with the centerline C. The cam lobe 425 is shown substantially aligned with the centerline C and disposed at an upper end region of the slot 430 of the cam follower 410. As camshaft 405 rotates about its axis A along arrow A a first degree, cam follower 410 is urged along axis C′, away from centerline C, in the direction of arrow R, and cam lobe 425 moves downward through slot 430 in cam follower 410 (FIG. 23B). As camshaft 405 rotates about its axis A a further two degrees along arrow A, cam follower 410 is pushed back along axis C′, in the direction of arrow L, toward centerline C, and cam lobe 425 moves further downward through slot 430 in cam follower 410 (FIG. 23C). As camshaft 405 rotates about its axis A a further three degrees along arrow A, cam follower 410 is urged from centerline C, in the direction of L′, such that cam lobe 425 moves back through slot 430 in cam follower 410, toward the upper end region of slot 430 (FIG. 23D).

[0169] The lateral movement of the cam followers 410 can create a gradual, sequential compression of each tube 415 such that the suction formed in the distal flow passage communicating with the cutting tube is smooth or substantially non-pulsating. The geometry (e.g., pitch, length) of the camshaft 405, as well as the number of cam lobes 425 and cam followers 410, can be varied to achieve specific timing along the longitudinal axis T of the tube 415. The number of cam followers 410 in the pump 1014 can be varied, for example, from at least 2, 3, 4, 5, 6, 7, 8, 9, 10, up to approximately 20 cam followers 410. The greater the number of lobes and followers 410, the more closely the cam lobes 425 and cam followers 410 can approximate a completely smooth flow. For example, the implementation of the suction pump 1014 shown in FIG. 22B includes 10 cam lobes 425 and 10 cam followers 410. The suction pump 1014 is thereby able to create a smooth, sinusoidal curve as each cam follower 410 is urged laterally to compress the opposing tube 415 .

[0170] 24A shows how pump 1014 may initially undergo a warm-up period upon start-up as camshaft 405 begins to rotate. Cam follower 410 is urged back and forth within pumping manifold 420, sequentially compressing a pair of tubes 415 and building negative pressure within the flow paths of tubes 415a and 415b. The flow rate through tube 415a may be offset from the flow rate through tube 415b so that the target flow rate achieved is substantially constant with minimal pulsating flow through the distal flow path.

[0171] The pump 1014 may include fewer cam followers 410 than shown in the embodiment of FIGS. 22A-22B. In such an implementation, the timing of the camshaft 405 may be closer to an off-on type square curve (see FIG. 24B). The on-off square curve may provide a more consistent chamber length (i.e., the sealed volume within the tubing between the locations closed by the cam followers) compared to, for example, a helically driven peristaltic pump, in which the tubing is compressed closed using a more gradual motion. The cam lobes in the pump implementation shown in FIGS. 22A-22B follow a circular path relative to the entire device and a linear path relative to the cam follower. The cam follower compresses the tubing on both sides. Moving in one direction compresses one tubing, and moving in the opposite direction compresses the opposite tubing. However, the cam lobes need not be driven along a helical path with such gradual compression. Rather, the layout of the cam lobes can be positioned relative to one another, either radially or longitudinally along axis T, such that the spacing of each cam lobe can cause compression in tube 415 to achieve the desired timing.

[0172] 23A-23D, the shape of cam follower 410 not only provides for lateral movement of cam follower 410 as camshaft 405 rotates, but also provides efficient compression of a pair of tubes 415. Each cam follower 410 may incorporate a first compression zone 435 on an outer surface of cam follower 410 on a first side of centerline C and a second compression zone 437 on an outer surface of cam follower 410 on a second, opposite side of centerline C. Each of first and second compression zones 435, 437 may be positioned substantially aligned with centerline C'. As cam follower 410 moves along arrow R, first compression zone 435 compresses tube 415b (FIG. 23B). As cam follower 410 moves along arrow L', second compression zone 437 compresses tube 415a (FIG. 23D). Each cam follower 410 may also include two displacement zones 440, 442 for each compression zone 435, 437. When tube 415 is compressed by compression zone 435, 437, the corresponding two displacement zones 440, 442 can receive material from tube 415 that is being compressed by compression zone 435, 437 of cam follower 410.

[0173] The pair of tubes 415 can extend linearly along the longitudinal axis T and parallel to the longitudinal axis A of the camshaft 405. The pair of tubes 415 extend generally parallel to the rotational axis of the camshaft 405 through the pumping manifold. In this manner, compression on the tubes 415 occurs in a lateral movement along a horizontal plane relative to the plane of rotation of the camshaft, which can be a plane perpendicular to the longitudinal axis A (and also to axis T). Thus, this compression does not move axially along the sidewalls of the tubes, thereby advantageously reducing wear on the tube material. Furthermore, the configuration of the pair of straight tubes 415 can provide additional lateral force to the cam follower 410. For example, when one tube 415a is compressed by the cam follower 410, the opposing tube 415b, which was just compressed by the cam follower 410, can be spring loaded to return to its original shape. This spring force can assist in compressing the opposing tubes 415. Each tube 415 can help cause compression of the other by urging the cam follower 410 in the opposite direction of compression.

[0174] As described above, the proximal end region of the camshaft 405 can be coupled to a drive shaft, for example, via a coupler in the disposable part 1031, and the distal end of the camshaft 405 can be coupled to the cutting tube 1112. Thus, the drive mechanism that drives the suction pump 1014 can also drive the oscillation of the cutting tube 1112. Despite being physically coupled, the pump and oscillation can be functionally decoupled. The pump 1014 can be configured by the drive mechanism to turn on at a maximum flow level and full suction. The suction delivered through the cutting tube 1112 can be controlled by a bleed valve. The bleed valve can be open to the atmosphere so that suction is not drawn through the cutting tube 1112 upon activation of the pump 1014, even though the drive motor is running at full speed. The bleed valve can begin to close upon actuation of the trigger 1180, slowly increasing suction through the cutting tube 1112. The harder the trigger 1180 is actuated, the greater the suction until the bleed valve reaches a fully closed position and full suction is drawn through the lumen. This valve can be located distal to the suction pump 1014 and proximal to the cutting assembly.

[0175] The aspiration pump 1014 generally requires a slower rotational speed to drive the aspiration compared to the rotational speed required to oscillate the cutting tube 1112. For example, in vitreous surgery, it is desirable to achieve up to 5,000 cuts per minute and a vacuum capacity of 650 mmHg or 25 cc / min. The instrument can incorporate a compact transmission or gear train to achieve the desired oscillation speed. The gear train can be disposed between the camshaft 405 and the cutting tube 1112 and configured to engage and disengage the cutting tube 1112, acting as a clutch mechanism, as the tube 1112 oscillates. The gear train can provide a fixed ratio between the oscillation speed of the cutting tube and the rotational speed of the aspiration pump. In some implementations, the aspiration pump 1014 can be activated and operated at maximum speed. A valve can control the delivery of aspiration through the lumen of the cutting tube 1112. The input 1180 can be actuated to engage or disengage the cutting of the cutting tube 1112.

[0176] The lobed cams 425 of the camshaft 405 can drive and move a plurality of cam followers 410 configured to sequentially compress the tubes 415 and transmit the generated suction pressure to the cutting tube 1112 positioned within the eye. The plurality of cam followers 410 can be driven by the cams of the camshaft 405 to move in a plane substantially perpendicular to the longitudinal axis to sequentially compress the tubes 415. As an example, the tubes 415 can extend spatially parallel to or along the z-axis or the center of rotation of the camshaft 405. The tubes 415 can be compressed by the cam followers 410 along an axis aligned substantially 90 degrees with respect to the z-axis. For example, the cam followers 410 can be driven laterally along the x-axis or horizontally relative to the z-axis of the camshaft 405. The cam followers 410 can also be driven vertically relative to the z-axis of the camshaft 405 or vertically along the y-axis. The relative angle between the cam follower 410 and the tube 415 can similarly be greater than or less than 90 degrees, but the cam follower 405 does not translate axially along the sidewall of the tube 415 (i.e., along the z-axis). The cam follower 405 can also drive the oscillation of the cutting tube 1112, which can be a lens fragmentation working tip or a vitrectomy probe.

[0177] The configuration of the peristaltic pump in the disposable portion 1031 can vary and need not be a straight peristaltic pump. For example, the peristaltic pump can be a spiral design or a horseshoe-shaped peristaltic pump.

[0178] Asymmetric cutting and suction profiles As mentioned above, the handpieces described herein can include a cutting tube 1112 or other elongated shaft configured to be minimally invasively inserted into the eye to cut, aspirate, and / or inject material within the eye. The elongated shaft can be configured as a vitrectomy-style cutting element having a hollow elongated member extending through an outer member with a side opening configured to capture and cut tissue fragments. The elongated shaft can be configured as a phacoemulsification ("phaco")-style tip that also includes a movable cutting tube, with or without an outer member. The vibratory motion of the elongated shaft can be generated using any of a variety of mechanisms, such as piezoelectric drive systems described elsewhere herein. The specific vibratory motion can be created in a manner that avoids the adverse effects of conventional phacoemulsification on delicate eye tissue, such as corneal endothelial cells.

[0179] Conventional phacoemulsification employs two primary methods of action: 1) mechanical jack hammering and 2) cavitation. Jack hammering involves the vibratory motion of the tip, impacting the tissue at high speeds and breaking it down into smaller fragments. Cavitation also involves the generation of gas bubbles as a result of the high-speed vibration of the tip. The tip's retraction speed in conventional phacoemulsification is sufficient to create a low-pressure zone sufficient to induce the formation of gas bubbles as dissolved gases are drawn out of the liquid. As the tip transitions from retraction to advancement, these bubbles collapse and implode, generating extremely high temperatures (e.g., 3000°C) and pressures (e.g., 10,000 atm). The combination of high temperature and high pressure is generally believed to aid in the emulsification of tissue fragments. While the role of cavitation in the destruction of ocular tissue remains controversial, there is no debate about its role as a primary driver of the adverse effects of conventional phacoemulsification on surrounding ocular tissue during cataract surgery. During conventional phacoemulsification, high temperatures, shock waves, and the generation of free radicals within the eye are of concern to the health of corneal endothelial cells.

[0180] The handpieces described herein can include a drive mechanism that longitudinally oscillates the cutting tube in a manner that reduces, attenuates, or prevents cavitation problems during conventional phacoemulsification. In use, the drive mechanism retracts the cutting tube proximally with a retraction velocity profile and advances the cutting tube distally with an extension velocity profile. The retraction velocity profile can be different from the extension velocity profile. Furthermore, the movement profile of the cutting tube can be coordinated with the vacuum profile. For example, while a pulse of vacuum is applied through the cutting tube (i.e., through the distal opening), the cutting tube can simultaneously be fired distally. The pulsed vacuum can be generated internally within the handpiece 1030 and / or externally within the handle and valved, as described elsewhere herein. When the cutting tube is described as moving forward and distally relative to the treatment site, oscillation of the cutting tube is also considered. The cutting tube can be oscillated in a manner similar to that of a conventional phacoemulsification machine. Thus, the cutting tube can be vibrated while the pulse of vacuum is applied, and at or after a stage of the vacuum pulse, the vibration and vacuum can be turned off to allow the system to rest before starting the vibration and vacuum sequence again. Coordination between the movement and / or vibration of the cutting tube and the vacuum applied through the cutting tube is described in more detail below.

[0181] The maximum tip retraction velocity can be kept below the critical "cavitation threshold velocity" at which cavitation would otherwise occur within the eye. The average retraction velocity is slow, i.e., below the cavitation threshold velocity, while the average extension velocity is fast, i.e., close to or faster than the average retraction velocity of a typical phacoemulsification tip. In this way, the harmful effects of cavitation can be completely avoided while achieving the benefits of a mechanical jackhammer.

[0182] 10A and 10C show typical sinusoidal motion profiles for a phacoemulsification tip where the average tip velocity is substantially the same during proximal retraction and distal extension (see FIG. 10A). The maximum tip velocity of retraction velocity profile R is substantially the same as the maximum tip velocity of extension velocity profile E, and therefore the motion profiles substantially overlap (see V in FIG. 10C). maxR,E (See Fig. 10C). Figure 10C shows a motion profile where the extension and retraction velocity profiles are substantially the same. For example, a 40,000 Hz phaco machine with an amplitude of 0.1 mm produces a V of approximately 12.6 m / s with a time T of approximately 0.0125 ms. max 10B shows a vibratory cutting tube 1112 having a substantially non-sinusoidal motion profile in which the average tip velocity of the retraction velocity profile and the average tip velocity of the extension velocity profile are substantially different, which can provide an overall asymmetric motion profile for the vibratory cutting tube. The oscillating cutting tip 1112 has a maximum tip velocity (V maxE ) is substantially lower than the maximum tip speed (V maxR ), so that the motion profiles are substantially non-overlapping (see FIG. 10D). FIG. 10D shows that V maxR The device thus provides an operating profile where V avg may have

[0183] 10E-10F illustrate additional asymmetric motion profiles considered herein. The extension velocity E is proportional to V as the piezoelectric drive advances the cutting tube 1112 until it reaches its stroke limit and then drops to zero before being retracted. maxE As the cutting tube 1112 retracts, the retraction speed R increases linearly to V maxRwhere the velocity profile R can form a plateau during which the retraction velocity is approximately constant. The retraction phase is completed in a time T2 that is longer than the time T1 taken to complete the extension phase. There may be a dwell or pause period between the extension and retraction phases. V maxE can be approximately the same as a conventional phaco machine (e.g., between about 8 and 12 meters per second). maxR can be much lower than conventional phaco machines (e.g., less than about 0.02 meters / second). It should be understood that the rates of extension and retraction can vary, and any of a number of non-sinusoidal tip motion profiles are contemplated herein. In some implementations, V maxE is between about 2 m / s and 50 m / s, and V maxR can be between about 0.001 meters / second and 2 meters / second. In some implementations, at sub-ultrasonic frequencies, as described elsewhere herein, the tip speed can be at least 3 meters / second.

[0184] The velocity and motion profiles of the movable cutting tube can be approximately sinusoidal, such that the movement of the distal tip of the cutting tube oscillates in a sinusoidal pattern corresponding to the frequency of the applied voltage to the piezoelectric crystal and the resonance of the system it excites. Therefore, the velocity of the distal tip also oscillates sinusoidally as a derivative of the motion profile. Figure 10G illustrates the implementation of a non-sinusoidal movement of the distal tip of the cutting tube 1112 (lower panel) relative to its extension and retraction velocity profiles (upper panel). Both the velocity profile and the corresponding motion profile are shown to be non-sinusoidal. The distal tip can have a dwell time between extension and retraction cycles. Between t0 and t1, the distal tip can extend forward with a velocity profile that is sinusoidal or any other profile. At t1, the distal tip can pause for a dwell period between t1 and t2. The dwell period is approximately 0.050 milliseconds, or between approximately 0.001 and 0.025 milliseconds. At t2, the distal tip can retract with a velocity profile that can also follow a sinusoidal curve. The distal tip movement resembles a sine wave with a dwell at the most extended position.

[0185] A non-sinusoidal pattern, such as that shown in FIG. 10G , can reduce the likelihood of cavitation because the dwell period allows fluid within the eye displaced by the movement of the cutting tube 1112 during extension to return to a zero momentum state before retraction of the cutting tube 1112 begins. A sinusoidal pattern of cutting tube movement drives fluid away from the distal tip and then quickly retracts while the fluid may still be moving away from the distal tip, thereby increasing the likelihood of cavitation due to the relative velocity of the fluid with respect to the distal tip. The relative velocity of the fluid with respect to the distal tip is higher when the fluid within the eye moves away from the tip due to momentum while the distal tip itself begins to retract. The dwell period can allow the displaced fluid to return toward a zero momentum or zero velocity state before the distal tip begins to retract. In this implementation, the extension velocity profile and retraction velocity profile may be similar or identical, but the overall velocity profile and movement of the distal tip is non-sinusoidal. Other implementations are contemplated herein. For example, the cutting tube 1112 may decelerate more gradually as it approaches a fully extended position than does a typical sinusoidal pattern. As the cutting tube 1112 retracts, the profile follows a more symmetrical path. Any number of other non-sinusoidal patterns are possible.

[0186] It should be understood that the term "non-sinusoidal" as used herein can be defined as a motion or velocity profile that does not follow a simple sinusoidal pattern of oscillatory motion. A simple sinusoidal wave can be defined by a single frequency, a single phase shift, and a single amplitude. Certain complex profiles can be generated by adding or subtracting sinusoidal waves. However, these complex profiles may also be considered non-sinusoidal because the addition or subtraction does not follow a simple, single sinusoidal pattern. Non-sinusoidal cutting tube motion is referred to herein as extension and contraction, although side-to-side twisting motion is also contemplated.

[0187] The drive mechanism may retract the cutting tube 1112 in a proximal direction with a retraction velocity profile and advance the cutting tube 1112 in a distal direction with an extension velocity profile, such that the retraction velocity profile differs from the extension velocity profile. The average retraction velocity of the cutting tube from the retraction velocity profile may be lower than the average extension velocity of the cutting tube from the extension velocity profile. Thus, the drive mechanism operably coupled to the cutting tube 1112 is configured to asymmetrically oscillate the cutting tube 1112. The extension velocity profile E may be V maxE and the contraction velocity profile R can include V maxR V maxE V is smaller than maxR The V of the cutting tube 1112 can be included. maxR is generally kept below the threshold velocity at which cavitation bubbles would form. Without limiting the present disclosure to any particular threshold velocity, one skilled in the art will appreciate that the theoretical retraction velocity at which cavitation occurs is generally about 5 meters / second. Thus, the V of the cutting tube 1112 maxR may be maintained below about 5 meters / second.

[0188] It should be understood that cavitation prevention can also be achieved with a pure sinusoidal / resonant oscillatory motion of the cutting tube 1112. The sinusoidal resonant vibration is fast enough to disrupt the lens tissue, but slow enough to avoid cavitation during retraction. For example, the frequency of the vibration can be reduced or the stroke distance shortened. In one implementation, the amplitude of the cutting tube 1112 is 0.016 inches or approximately 0.4 mm, and the frequency is 3,900 Hz for the sinusoidal / resonant oscillatory motion. V in this configuration maxR / E may be kept below 5 m / s, which is fast enough to destroy lens tissue but slow enough to avoid cavitation. maxR / E can be at least about 3 m / s, but remain in the sub-ultrasonic frequency range.

[0189] The oscillatory motion of a cutting tube driven by a conventional phacoemulsification system may have some variability due to normal losses during motion (e.g., friction, variations in material compression under load and other environmental factors). This variability can affect the maximum and average velocities achieved during retraction and extension, and retraction and extension velocity profiles are not identical or perfectly sinusoidal. However, such normal variations during component motion are not intentionally engineered or designed to occur (i.e., a control processor operating according to program instructions stored in memory, or hardware in operative communication with a control processor designed to achieve different velocities depending on the phase of the cycle). Therefore, normal variations in velocity during motion are not considered to contribute to or result in an asymmetric motion profile. The asymmetric motion profiles described herein are consciously engineered or designed motion profiles intended to be substantially repeatable during each cycle and are not due merely to chance variation.

[0190] As described elsewhere herein, the aspiration pump 1014 of the handpiece 1030 can be configured to provide discrete pulses of negative pressure. The movement of the roller or piston creates vacuum pulses that can be coordinated or linked to the phases of movement of the elongated cutting tube 1112.

[0191] For example, pulses of suction can be drawn through the lumen 1110 of the cutting tube 1112 during at least a portion of the extension as the cutting tube 1112 moves distally and / or during at least a portion of the retraction as the cutting tube 1112 moves proximally. FIG. 11A illustrates the implementation of a vacuum profile over time of pulsating vacuum applied through the distal end region of the lumen 1110 of the cutting tube 1112 when the pump 1014 is a piston pump having multiple pistons. The multiple pistons are configured to move sequentially within their respective pump chambers, alternating between periods of increasing vacuum and periods of decreasing vacuum. It should be understood that pulsating suction can be achieved with other pump configurations, such as, for example, a peristaltic pump. In some implementations, the increase in vacuum can occur more rapidly than the decrease in vacuum that provides the vacuum profile. The pulsating vacuum profile applied through the lumen 1110 of the cutting tube 1112 can be synchronized with the movement profile of the cutting tube 1112 performing the cutting, such that at least a portion of a period of negative pressure is applied during a phase of movement. Figures 11B-11D show the movement of the cutting tube 1112 (solid line) relative to the period of negative pressure applied through the cutting tube 1112 (hatched line). The period of negative pressure (i.e., vacuum pulse) can occur before the forward stroke or distal extension E of the cutting tube 1112, during at least a portion of the forward stroke or distal extension E of the cutting tube 1112, during a dwell time after the distal extension E and before the proximal retraction R, and / or during at least a portion of the proximal retraction R of the cutting tube 1112. For example, Figure 11B shows a first pulse of vacuum pressure occurring during the extension E of the cutting tube 1112, as well as a dwell time after the extension E and before the retraction R. The first pulse of vacuum pressure ends during the retraction R phase, and the second pulse of vacuum begins and ends before the end of the same retraction phase. Figure 11C shows another implementation in which the first pulse of vacuum pressure begins during the extension E of the cutting tube 1112 and is maintained during the retraction R phase of the cutting tube 1112, as well as during the second extension E of the cutting tube. Figure 11B shows vacuum pulses having about twice the frequency of the tip movement, and Figure 11C and also Figure 11F show tip movement having about twice the frequency of the vacuum pulses.Both Figures 11B and 11C show vacuum pulses occurring during portions of the extension E and retraction R. Figure 11D shows another implementation of the coordination between cutting tube movement and the application of negative pressure. The cutting tube motion profile (solid line) need not correspond to a single trapezoidal vacuum pulse (hatched line). Rather, the cutting tube movement can allow for multiple extensions E and contractions R (or oscillations) during one vacuum pulse. Figures 11D and 11F show that the oscillatory movement of the cutting tube or tip can begin after the vacuum pulse is initiated. The cutting tube can undergo multiple extensions and contractions for each pulse of vacuum. Figure 11F shows two cycles of cutting tube extension and contraction for each pulse of vacuum. The cutting tube can be extended and retracted multiple times (1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50 times) with each pulse of vacuum, such that the ratio of hits per vacuum pulse is 1:1, 2:1, 3:1, 4:1, 5:1, 10:1, 20:1, 25:1, 30:1, 40:1, 45:1, 50:1, etc. Vibration of the cutting tube or tip can also be initiated before the vacuum pulse is initiated (see FIG. 11C ). It should be understood that the handpiece can apply vacuum pulses without any movement of the cutting tube, such that only the vacuum pulses are used to break down the lens. The vacuum pulses can vary in frequency from about 1 vacuum cycle / second to about 100, or from about 5 to about 50, or from about 10 to about 25 vacuum cycles / second, and any range or amount of vacuum cycles / second therebetween.

[0192] When the vacuum pulse returns to zero, the cutting tube movement and tip vibration can cease. The system can then enter a rest period for both movement and vacuum for a period of time before the next sequence begins. The frequency of extension and retraction of the cutting tube 1112 within a single pulse of vacuum can vary. For example, the cutting tube 1112 can undergo 1, 2, 3, 4, 5, or more extension / retraction movements with each pulse of vacuum, up to approximately 10, 15, 20, 25, 30, 35, 40, 45, 50, or 55. In one implementation, the retraction speed is half the extension speed. In other words, the retraction time takes twice as long as the extension time to travel the same distance. The frequency of this configuration is one-third lower than the frequency of a configuration in which the retraction speed is the same as the extension speed. For example, a 40 kHz, 0.1 mm phaco system has a frequency of 27 kHz.

[0193] The frequency of the vibration of the cutting tube 1112 can vary with different amplitudes and velocity thresholds. The amplitude can be between 0.005 mm and about 1.0 mm, more preferably between 0.05 mm and about 0.1 mm. The oscillation frequency can be less than 30,000 Hz, less than 25,000 Hz, less than 20,000 Hz, less than 15,000 Hz, or less than 10,000 Hz, and can be about 0.5 Hz or less, about 1 Hz or less, about 2 Hz or less, about 5 Hz or less, about 10 Hz or less, about 25 Hz or less, about 50 Hz or less, about 100 Hz or less, about 250 Hz or less, or about 500 Hz or less. The frequency of the cutting tube can be about 0.5 Hz to about 30,000 Hz, or about 1 Hz to about 5000 Hz, or about 2 Hz to about 2000 Hz.

[0194] As noted elsewhere herein, a vacuum pulse may be applied through the cutting tube 1112. The relative coordination of the vacuum pulse and the movement of the cutting tube 1112 may vary. A vacuum pulse may be applied during at least a portion of the extension of the cutting tube 1112. A vacuum pulse may be applied during at least a portion of the retraction of the cutting tube 1112. A vacuum pulse may be applied during at least a portion of both the extension and retraction of the cutting tube 1112. In some implementations, a vacuum pulse may begin before the extension of the cutting tube 1112 and be maintained during the extension. A vacuum pulse may begin after the extension of the cutting tube 1112 has begun. A single vacuum pulse may be applied during multiple extensions and retractions. For example, vacuum may be applied continuously through the cutting tube 1112 for at least about 1 oscillation, at least about 2 oscillations, at least about 5 oscillations, at least about 10 oscillations, at least about 20 oscillations, at least about 30 oscillations, at least about 40 oscillations, at least about 50 oscillations, at least about 100 oscillations, up to about 500 oscillations of the cutting tube 1112. The length of the vacuum pulse can be at least about 2 ms to about 25 ms for an oscillation frequency of about 25 kHz. As an example, the cutting tube 1112 can oscillate 50 times during a single vacuum pulse lasting 25 ms, such that the oscillation frequency of the cutting tube 1112 is about 2000 Hz.

[0195] In some implementations, the suction pump 1014 is a piston pump with multiple pistons. The movement of the multiple pistons can provide pulsating, discontinuous suction. The retraction periods of the multiple pistons can overlap in a manner that provides smooth, continuous suction (with or without negative pressure spikes between movements). FIG. 11E illustrates the movement of the cutting tube 1112 (solid lines) relative to periods of negative pressure applied through the cutting tube 1112 (hatched lines) when the suction pump 1014 is a piston pump with multiple pistons. Retracting a first piston can generate a first pulse of vacuum, retracting a second piston can generate a second pulse of vacuum that overlaps the first pulse, retracting a third piston generates a third vacuum pulse that overlaps the second vacuum pulse, and so on. This results in a substantially continuous vacuum pressure during both the extension and retraction of the cutting tube. The vacuum applied during overlapping pulses has a reduced maximum vacuum compared to pulsed vacuum implementations where the pulses do not significantly overlap, but this need not be the case.

[0196] In some implementations, the suction pump 1014 is a peristaltic pump having one or more rollers. Figure 11G shows an implementation of a vacuum profile over time of a pulsating vacuum applied through a distal end region of the lumen 1110 of the cutting tube 1112 when the pump 1014 is a peristaltic pump having one or more rollers.

[0197] It should be understood that any number of different relative frequencies are contemplated, and these are just a few examples of relative velocity and vacuum profiles.

[0198] Control Unit 3-4 , the handpiece 1030 may be part of the phacoemulsification system 1010 or may be coupled to the phacoemulsification system 1010 to provide irrigation and aspiration support, as well as power for the cutting tube drive mechanism and aspiration pump 1014 within the handpiece 1030. However, it should be understood that the handpiece 1030 may be used independent of the phacoemulsification system 1010. As mentioned above, the system 1010 may include a control unit 1012, which may include an ultrasonic power supply 1016 and a microprocessor 1018 that provides control outputs to a pump controller 1020 and an ultrasonic power level controller 1022.

[0199] The handpiece 1030 can be plugged into a socket coupled to the ultrasonic power supply 1016 of the system 1010. The proximal end of the reusable portion 1033 of the handpiece 1030 can include a power cord 1160 configured to provide power to the piezoelectric stack 1120 as well as the pump motor 1115. The power for the pump motor 1115 can be DC power, while the power for the piezoelectric stack 1120 can be ultrasonic power similar to conventional phacoemulsification systems.

[0200] The control unit 1012 of the system 1010 can be controlled, adjusted, and / or programmed remotely, such as via an external computing device and / or the handpiece 1030. The control unit 1012 of the system 1010 can also be controlled, adjusted, and / or programmed directly via one or more inputs. The inputs of the system 1010 can include one or more triggers, buttons, sliders, dials, keypads, switches, touchscreens, foot pedals, or other inputs that can be retracted, pressed, squeezed, slid, tapped, or otherwise actuated to activate, modify, or otherwise cause a response of the system 1010. In some implementations, the one or more inputs include a microphone configured to receive voice commands to control, adjust, and / or program one or more components of the system 1010, as well as a peripheral device in operative communication with the system 1010, such as a smartphone or tablet application.

[0201] One or more aspects of the handpiece 1030 and system 1010 can be user-programmable. For example, one or more aspects of the drive mechanism may include the travel distance of the cutting tube 1112, the vibration frequency of the cutting tube 1112, the maximum extension speed (V maxE ), minimum extension velocity (V minE ), maximum retraction speed (V maxR ), minimum retraction speed (V minR ), average elongation velocity (V avgE ), average retraction velocity (V avgR), or other aspects of the motion profile, can be programmed by the user to control the motion of the cutting tube 1112. In some implementations, the distance the cutting tube 1112 travels with each cycle can be adjustably programmed so that the amplitude and / or frequency of its vibration are selectable within a range. The amplitude range can be from 0.005 mm to approximately 0.4 mm. The frequency range can be from approximately 0.5 Hz to approximately 5000 Hz, or from approximately 2 Hz to approximately 2000 Hz. The oscillation frequency can be sub-ultrasonic, e.g., less than approximately 20,000 Hz, or within the ultrasonic range (e.g., approximately 20,000 Hz, up to approximately 120,000 Hz, up to the gigahertz range). The system 1010 (and / or handpiece 1030) can be programmed to place limits on certain movements when the input is activated. For example, a drive mechanism can be programmed to have a minimum and / or maximum upon actuation of an input, or in the case of fluid infusion and aspiration, the device can be programmed to have a minimum and / or maximum fluid pressure upon actuation of an input. Thus, the devices described herein can be programmed with user-adjustable inputs and pre-programmed instructions that affect one or more aspects of the device upon actuation of the input.

[0202] As described above, the system 1010 can additionally include a remote suction pump in the control unit 1012 in addition to the suction pump 1014 in the handpiece 1030. The suction pump 1014 integrated into the handpiece 1030 can be a relatively high-pressure pump. The remote suction pump can be a low-pressure pump, such as a peristaltic pump in the control unit 1012, that can provide fluid movement in the suction line 1038 toward the waste container 1044. The removal suction pump can be configured to directly receive the suction line 1038 and direct fluid into the waste container 1044. For example, the remote suction pump can include a rotating pump head with rollers around its periphery. As the pump head rotates, the rollers again push against the suction line 1038, causing fluid to flow in one direction within the suction line 1038 (i.e., toward the waste container 1044). The remote suction pump can also receive a pump cartridge with an integrated waste container 1044. The suction pump 1014 in the handpiece 1030 can be used during certain portions of the procedure, such as cutting the lens material, and the remote suction pump in the control unit 1012 can be used to clear any small particles remaining in the eye after cutting is complete. The remote suction pump can be activated by an input on the system 1010 and / or manually, such as when the handpiece 1030 is activated.

[0203] One or more aspects of the internal suction pump 1014 (and any remote suction pump) can be programmed by the user to control the vacuum applied at the distal end region of the cutting tube 1112, including, but not limited to, the suction flow rate, minimum vacuum pressure, maximum vacuum pressure, frequency of vacuum pulses, or other aspects of the vacuum profile. In some implementations, the suction flow rate can be adjustable and programmed within a range of between about 5-100 ml / min.

[0204] The handpieces described herein are configured to provide irrigation to a work site via an irrigation line 1034 from an irrigation fluid source 1032 fluidly coupled to the handpiece 1030. Conventional irrigation containers for ophthalmic surgery can be between 250 mL and approximately 500 mL each, resulting in a relatively large volume of irrigation fluid available for delivery to the eye. The amount of irrigation fluid required during a procedure using the handpiece 1030 described herein, and therefore the size of the irrigation fluid source 1032, can be dramatically reduced compared to conventional systems. As described above, the handpiece 1030 has an aspiration pump 1014 located near the distal cutting tip, such as a peristaltic pump, roller pump, scroll pump, piston pump, or the like, configured to create a pulsating vacuum profile. The strength of the pulsed vacuum used to aspirate fluid may be much stronger than the vacuum applied in conventional systems that do not incorporate pulsing. Very strong, very short pulses are sufficient to remove lenticular tissue, thus requiring only a relatively small amount of fluid. The ratio of lens tissue to fluid aspirated from the anterior chamber may be higher with the handheld devices described herein than with other currently used devices and methods. Additionally, the volume of fluid delivered using the devices described herein can be significantly reduced compared to known systems because irrigation occurs only upon activation of the device. The total volume of irrigation fluid required for a procedure using the devices described herein is significantly less (e.g., approximately 10 mL) compared to conventional systems. In some implementations, suction is provided by a vacuum source located within the handheld instrument (i.e., a pump 1014 integrated within the handpiece 1030). Suction can be activated with greater control than with currently used devices and methods. For example, the handpiece 1030 may use a finger control, allowing the surgeon to easily activate the device in a short timeframe in a more convenient and easier manner than the foot pedal used with most conventional phacoemulsification machines.Furthermore, because the vacuum source can be located within the handpiece 1030, the surgeon may have a significantly faster response time to turn the device on and off than with other devices where the vacuum source is located in a console several feet away and connected by tubing. The handpiece 1030 has a relatively low surge volume, so cycling the device on and off has minimal drawbacks. These features allow the surgeon to turn the handpiece 1030 on for only a short time when they are ready to remove the lenticular tissue. This contributes to less irrigation fluid being removed overall, and therefore less irrigation fluid needing to be delivered.

[0205] The human lens has a volume of approximately 0.10 mL to 0.15 mL. The total volume of irrigation solution required for treatment using the devices described herein is typically less than 250 mL, e.g., approximately 10 mL, 25 mL, 50 mL, 75 mL, 100 mL, 125 mL, 150 mL, or 200 mL. Typically, the devices described herein keep the ratio of irrigation solution to lens solution required for treatment very low, between approximately 50:1, 75:1, 100:1, 150:1, 200:1, and up to approximately 2000:1. As an example, using 10 mL of BSS results in a ratio of approximately 100:1. In contrast, using 250 mL of BSS results in a ratio of irrigation solution to lens tissue of approximately 2500:1.

[0206] The irrigation source 1032 can be suspended from a pole assembly of the system 1010, which includes one or more features typical of an intravenous (IV) pole of a more conventional system. The pole assembly can include a telescoping pole configured to be movable relative to a base to allow adjustment of the height of one or more hangers from which the irrigation source 1032 is suspended. The height of the irrigation source 1032 can be calculated to create an appropriate fluid pressure in the irrigation fluid line 1034. The pole assembly can incorporate one or more buttons, levers, or foot pedals configured to adjust the height of the irrigation source 1032 to change the irrigation fluid pressure and, correspondingly, the flow rate of fluid in the irrigation fluid line 1034. The height of the irrigation source 1032 can be adjusted manually and / or via powered adjustment. For example, the pole assembly can include a motorized system configured to move the telescoping pole relative to the base. Adjustment of the telescoping pole can be automatic and powered by the control unit 1012 depending on the fluid needs during the procedure. The irrigation fluid source 1032 can be suspended above patient level by a hanger on a pole assembly and one or more valves configured to control flow from the source 1032 through the irrigation fluid line 1034. The one or more valves can include pinch valves or pinch clamps configured to tightly pinch the irrigation fluid line 1034, thereby preventing fluid flow toward the handpiece 1030 or allowing fluid flow from the irrigation source 1032 when the valve is open. The valves can be manual valves or can be actuated in response to input by the control unit 1012.

[0207] It should be understood that the irrigation fluid source 1032 need not be suspended from an IV pole. The volume of the irrigation fluid source 1032 can be small enough to be placed near the surgical site. For example, the irrigation fluid can be supplied from a small container, such as a syringe-type container or a collapsible bag, that can provide irrigation flow without the need for gravity or suspension from an IV pole. The container can be fluidly coupled to the handpiece 1030 with a short irrigation line length. The container can be placed on the user's wrist or arm (e.g., via a wristband or armband) or on the patient's sterile drape during use of the handpiece 1030. In implementations, the irrigation fluid source 1032 can be limited to a volume of less than 250 mL, for example, between about 25 mL and about 100 mL, or as little as 10 mL to about 100 mL.

[0208] The relative amounts of fluid entering and leaving the surgical field of the eye are preferably balanced to prevent collapse of the anterior chamber of the eye. The irrigation fluid source 1032 can provide a constant pressure of irrigation fluid that does not change with the vacuum level provided by the aspiration pump 1014 within the handpiece 1030. The aspiration flow rate leaving the eye during peak vacuum can be higher than the irrigation flow rate entering the eye, resulting in momentary low intraocular pressure. To avoid this low-pressure situation, the pressure of the irrigation fluid source can be increased so that its nominal flow rate is higher than the maximum aspiration flow rate at the peak vacuum pulse. However, it is preferable to keep the pressure of the irrigation fluid source lower so that the intraocular pressure remains below a set amount during the procedure when no vacuum is applied. Alternatively, the handpiece 1030 can incorporate a mechanism that can deliver rapid rushes or discrete pulses of irrigation fluid into the eye, such as from an irrigation fluid reservoir within the handpiece 1030 near its distal tip, as described elsewhere herein. Pulses of irrigation fluid can be timed to occur between pulses of negative pressure when aspiration flow is at its maximum. Fluid balance within the eye can be more consistent, and pressure drops within the eye between peak vacuum points are minimized.

[0209] Aspects of the subject matter described herein can be implemented in digital electronic circuitry, integrated circuits, specially designed ASICs (application-specific integrated circuits), computer hardware, firmware, software, and / or combinations thereof. These various implementations may include implementation in one or more computer programs executable and / or interpretable on a programmable system including at least one special-purpose or general-purpose programmable processor coupled to receive signals, data, and instructions from, and transmit signals, data, and instructions to, a storage system, at least one input device, and at least one output device.

[0210] These computer programs (also referred to as programs, software, software applications, or code) contain machine instructions for a programmable processor and may be implemented in a high-level procedural and / or object-oriented programming language, and / or assembly / machine language. As used herein, the term "machine-readable medium" refers to any computer program product, apparatus, and / or device (e.g., magnetic disk, optical disk, memory, programmable logic device (PLD)) used to provide machine instructions and / or data to a programmable processor, and also includes a machine-readable medium that receives machine instructions as a machine-readable signal. The term "machine-readable signal" refers to any signal used to provide machine instructions and / or data to a programmable processor.

[0211] In various implementations, the description is provided with reference to figures. However, particular implementations may be practiced without one or more of these specific details or in combination with other known methods and configurations. In the description, numerous specific details, such as specific configurations, dimensions, and processes, are set forth to provide a thorough understanding of the implementations. In other instances, well-known processes and manufacturing techniques have not been described in particular detail so as not to unnecessarily obscure the description. References herein to "one embodiment," "an embodiment," "one implementation," "an implementation," or the like mean that a particular feature, structure, configuration, or characteristic being described is included in at least one embodiment or implementation. Thus, the appearances of "one embodiment," "an implementation," "one implementation," "an implementation," or the like in various places in this specification do not necessarily refer to the same embodiment or implementation. Furthermore, particular features, structures, configurations, or characteristics may be combined in any suitable manner in one or more implementations.

[0212] Use of relative terms throughout this description may indicate relative positions or directions. For example, "distal" may indicate a first direction, away from a reference point. Similarly, "proximal" may indicate a position in a second direction opposite the first direction. However, such terms are provided to establish a relative frame of reference and are not intended to limit the use or orientation of the anchoring delivery system to the specific configurations described in the various implementations.

[0213] Although the specification contains many specific details, these should not be construed as limitations on the scope of the claimed subject matter or what may be claimed, but rather as descriptions of features unique to particular embodiments. Certain features described herein in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, while features may be described above as acting in a particular combination and may even initially be claimed as such, one or more features from the claimed combination may, in some cases, be extracted from the combination, and the claimed combination may be directed to a subcombination or a variation of the subcombination. Similarly, although the figures depict operations in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown, or sequentially, or that all of the illustrated operations be performed, in order to achieve desirable results. Only some examples and implementations are disclosed. Variations, modifications, and enhancements of the described examples and implementations, as well as other implementations, may be made based on the disclosed content.

[0214] In the above description and in the claims, phrases such as "at least one" or "one or more" may appear following a linked list of elements or features. The word "and / or" may appear in a list of two or more elements or features. Unless implicitly or explicitly contradicted by the context of use, such phrases are intended to refer to any of the listed elements or features individually, or any of the listed elements or features in combination with any of the other listed elements or features. For example, the phrases "at least one of A and B," "one or more of A and B," and "A and / or B" are intended to mean "A alone, B alone, and A and B together," respectively. A similar interpretation is intended for lists containing more than two items. For example, the phrases "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, and / or C" are intended to mean "A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B, and C together," respectively.

[0215] Use of the term "based on" above and in the claims is intended to mean "based at least in part on," allowing for unrecited features or elements.

Claims

1. 1. A device for extracting material from an eye, comprising: a handpiece; The handpiece comprises: a proximal renewable portion configured to remain outside the eye and comprising a suction pump motor; a distal disposable portion releasably coupleable to the proximal reusable portion; It is equipped with the distal disposable portion a cutting tube configured to vibrate and including an inner lumen; a cutting sleeve having a side opening for guillotine-style cutting, the cutting sleeve being inserted over the cutting tube such that the cutting tube extends through the cutting sleeve and is coaxially disposed within the cutting sleeve; a suction pump contained within the disposable portion and fluidly coupled to the inner lumen of the cutting tube; the aspiration pump is releasably operably coupled to the aspiration pump motor of the proximal reusable portion such that the aspiration pump motor drives the aspiration pump; the aspiration pump is a linear peristaltic pump including a central camshaft extending longitudinally through a symmetrical dual-chamber pump manifold; the central camshaft has an axis of rotation coaxially aligned with a longitudinal axis of the distal disposable portion; the linear peristaltic pump further comprises two tubes extending through the pump manifold; each of the two tubes having a longitudinal axis aligned parallel to the axis of rotation of the central camshaft; a first of the two tubes is located on one side of the central camshaft; a second of the two tubes is disposed on an opposite second side of the central camshaft; the linear peristaltic pump further comprising a proximal flow path and a distal flow path; the central camshaft further comprises a plurality of lobed cams that are timed to drive a plurality of cam followers toward or away from the two tubes to create sequential, step-wise compression of the two tubes to force a fluid volume toward the distal flow passage; wherein movement of the plurality of cam followers is in a plane perpendicular to the axis of rotation of the central camshaft and the longitudinal axes of the two tubes.

2. The suction pump motor Rotating the central camshaft.

10. The apparatus of claim 1.

3. The proximal flow path includes: a pump manifold having a proximal end connected to the two tubes, the proximal end connected to the two tubes, the pump manifold having a split into two flow paths; the two tubes join distally of the pump manifold to form the distal flow path; 10. The apparatus of claim 1.

4. The plurality of cam followers include compressing the two tubes sequentially in a wave-like manner; 10. The apparatus of claim 1.

5. The plurality of cam followers include applying no force in the direction of the longitudinal axes of the two tubes and creating little or no friction between the two tubes; 10. The apparatus of claim 1.

6. 10. The device of claim 1, wherein the cutting tube achieves up to 5000 cuts per minute and a vacuum capacity of 650 mmHg or 25 cc / min of volume.

7. a gear train disposed between the central camshaft and the cutting tube, the gear train serving as a clutch mechanism for engaging and disengaging the cutting tube; 7. The apparatus of claim 6.

8. 8. The apparatus of claim 7, wherein the gear train creates a fixed ratio between the vibration speed of the cutting tube and the rotational speed of the suction pump.

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