Patent Description:
The optical elements of the eye include both a cornea (at the front of the eye) and a lens within the eye. The lens and cornea work together to focus light onto the retina at the back of the eye. The lens also changes in shape, adjusting the focus of the eye to vary between viewing near objects and far objects. The lens is found just behind the pupil, and within a capsular bag. This capsular bag is a thin, relatively delicate structure which separates the eye into anterior and posterior chambers.

With age, clouding of the lens or cataracts are fairly common. Cataracts may form in the hard central nucleus of the lens, in the softer peripheral cortical portion of the lens, or at the back of the lens near the capsular bag.

Cataracts can be treated by the replacement of the cloudy lens with an artificial lens. Phacoemulsification systems often use ultrasound energy to fragment the lens and aspirate the lens material from within the capsular bag. This may allow the capsular bag to be used for positioning of the artificial lens, and maintains the separation between the anterior portion of the eye and the vitreous humour in the posterior chamber of the eye.

During cataract surgery and other therapies of the eye, accurate control over the volume of fluid within the eye is highly beneficial. For example, while ultrasound energy breaks up the lens and allows it to be drawn into a treatment probe with an aspiration flow, a corresponding irrigation flow may be introduced into the eye so that the total volume of fluid in the eye does not change excessively. If the total volume of fluid in the eye is allowed to get too low at any time during the procedure, the eye may collapse and cause significant tissue damage. Similarly, excessive pressure within the eye may strain and injure tissues of the eye.

While a variety of specific fluid transport mechanisms have been used in phacoemulsification and other treatment systems for the eyes, aspiration flow systems can generally be classified in two categories: <NUM>) volumetric-based aspiration flow systems using positive displacement pumps; and <NUM>) vacuum-based aspiration systems using a vacuum source, typically applied to the aspiration flow through an air-liquid interface. These two categories of aspiration flow systems each have unique characteristics that render one more suitable for some procedures than the other, and vice versa.

Among positive displacement aspiration systems, peristaltic pumps (which use rotating rollers that press against a flexible tubing to induce flow) are commonly employed. Such pumps provide accurate control over the flow volume. The pressure of the flow, however, is less accurately controlled and the variations in vacuum may result in the feel or traction of the handpiece varying during a procedure. Peristaltic and other displacement pump systems may also be somewhat slow.

Vacuum-based aspiration systems provide accurate control over the fluid pressure within the eye, particularly when combined with gravity-fed irrigation systems. While vacuum-based systems can result in excessive fluid flows in some circumstances, they provide advantages, for example, when removing a relatively large quantity of the viscous vitreous humour from the posterior chamber of the eye. However, Venturi pumps and other vacuum-based aspiration flow systems are subject to pressure surges during occlusion of the treatment probe, and such pressure surges may decrease the surgeon's control over the eye treatment procedure.

Different tissues may be aspirated from the anterior chamber of the eye with the two different types of aspiration flow. For example, vacuum-induced aspiration flow may quickly aspirate tissues at a significant distance from a delicate structure of the eye (such as the capsular bag), while tissues that are closer to the capsular bag are aspirated more methodically using displacement-induced flows.

Conventionally, fluid aspiration systems include a console and a fluidic cassette mounted on the console. The fluidic cassette is typically changed for each patient and cooperates with the console to provide fluid aspiration. Generally, a single type of cassette is used by a particular console, regardless of whether the procedure will require positive displacement aspiration, vacuum-based aspiration, or both. <CIT>; <CIT>; and <CIT> provide examples of cassettes currently used in the marketplace.

Such a cassette is typically physically mated to the afore-discussed console. In providing the physical association between the cassette and the console, at least the aspiration/pumping aspects discussed above must be properly aligned as between the cassette and the console, at least in order to provide proper functionality to the fluid aspiration systems. As such, misalignment may lead to system malfunction, inoperability, or poor performance. However, currently available systems that provide for the alignment of placement and attitude of the cassette onto the console suffer from a variety of issues, including jamming, breakage, and inability to assess a sound alignment and cassette attitude, among others.

<CIT> discloses a surgical console that can operably couple to a number of user interfaces such as a foot pedal assembly. The operator can interface with the console through user interefaces or other interfaces such as endless digital potentiometer knobs. Also disclosed is an ophthalmic surgical console which includes a cassette receiver in which a cassette can be placed and clamped. <CIT> discloses a remote control console for a surgical control system. <CIT> discloses an aspiration control system. <CIT> discloses a control system for ophthalmic surgery.

In light of the above, it would be advantageous to provide improved devices, systems, and methods for eye surgery.

The present invention provides a phacoemulsificiation system and method as recited in the claims.

The present invention is best understood with reference to the following detailed description of the invention and the drawings in which:.

Reference will now be made in detail to embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the embodiments, it will be understood that they are not intended to limit the invention to those embodiments. On the contrary, the invention is intended to cover alternatives and modifications, which may be included within the scope of the invention as defined by the appended claims.

Referring to <FIG>, a system <NUM> for treating an eye E of a patient P generally includes an eye treatment probe handpiece <NUM> coupled to a console <NUM> by a cassette <NUM> mounted on the console. Handpiece <NUM> may include a handle for manually manipulating and supporting an insertable probe tip. The probe tip has a distal end which is insertable into the eye, with one or more lumens in the probe tip allowing irrigation fluid to flow from the console <NUM> and/or cassette <NUM> into the eye. Aspiration fluid may also be withdrawn through a lumen of the probe tip, with the console <NUM> and cassette <NUM> generally including a vacuum aspiration source, a positive displacement aspiration pump, or both to help withdraw and control a flow of surgical fluids into and out of eye E. As the surgical fluids may include biological materials that should not be transferred between patients, cassette <NUM> will often comprise a disposable (or alternatively, sterilizable) structure, with the surgical fluids being transmitted through flexible conduits <NUM> of the cassette that avoid direct contact in between those fluids and the components of console <NUM>.

When a distal end of the probe tip of handpiece <NUM> is inserted into an eye E, for example, for removal of a lens of a patient with cataracts, an electrical conductor and/or pneumatic line (not shown) may supply energy from console <NUM> to an ultrasound transmitter of the handpiece, a cutter mechanism, or the like. Alternatively, the handpiece <NUM> may be configured as an irrigation/aspiration (I/A) or vitrectomy handpiece. Also, the ultrasonic transmitter may be replaced by other means for emulsifying a lens, such as a high energy laser beam. The ultrasound energy from handpiece <NUM> helps to fragment the tissue of the lens, which can then be drawn into a port of the tip by aspiration flow. So as to balance the volume of material removed by the aspiration flow, an irrigation flow through handpiece <NUM> (or a separate probe structure) may also be provided, with both the aspiration and irrigations flows being controlled by console <NUM>.

So as to avoid cross-contamination between patients without incurring excessive expenditures for each procedure, cassette <NUM> and its flexible conduit <NUM> may be disposable. Alternatively, the flexible conduit or tubing may be disposable, with the cassette body and/or other structures of the cassette being sterilizable. Regardless, the disposable components of the cassette are typically configured for use with a single patient, and may not be suitable for sterilization. The cassette will interface with reusable (and often quite expensive) components of console <NUM>, which may include one or more peristaltic pump rollers, a Venturi or other vacuum source, a controller <NUM>, and the like.

Controller <NUM> may include an embedded microcontroller and/or many of the components common to a personal computer, such as a processor, data bus, a memory, input and/or output devices (including a touch screen user interface <NUM>), and the like. Controller <NUM> will often include both hardware and software, with the software typically comprising machine readable code or programming instructions for implementing one, some, or all of the methods described herein. The code may be embodied by a tangible media such as a memory, a magnetic recording media, an optical recording media, or the like. Controller <NUM> may have (or be coupled to) a recording media reader, or the code may be transmitted to controller <NUM> by a network connection such as an internet, an intranet, an Ethernet, a wireless network, or the like. Along with programming code, controller <NUM> may include stored data for implementing the methods described herein, and may generate and/or store data that records perimeters with corresponding to the treatment of one or more patients. Many components of console <NUM> may be found in or modified from known commercial phacoemulsification systems from Abbott Medical Optics Inc. of Santa Ana, California; Alcon Manufacturing, Ltd. Worth, Texas; Bausch and Lomb of Rochester, New York; and other suppliers.

<FIG> illustrates a surgical cassette of the present invention, including components of surgical cassette <NUM>. Surgical cassette <NUM> is an assembly of fluid pathways and connected tubing configured to manage one or more of the following: fluid inflow, fluid outflow, fluid vacuum level, and fluid pressure in a patient's eye E when coupled with console <NUM>. Surgical cassette <NUM> may include grip loop handle <NUM>, which provides a sterile means for holding and positioning surgical cassette <NUM> under finger grip control. In an embodiment, grip loop handle <NUM> is designed for an index finger to pass completely thru the loop of the handle. The grip loop handle <NUM> may also be designed for the pad of the thumb to rest on outer top surface of grip loop handle <NUM>.

In an embodiment, surgical cassette <NUM> may include a thumb shield <NUM>. As illustrated in <FIG>, thumb shield <NUM> may have a raised border above grip loop handle <NUM>, which is configured and dimensioned to surround a sterile gloved thumb to reduce potential for contact with non-sterile surfaces during insertion of surgical cassette <NUM> into console. Thumb shield <NUM> may have one or more surface elements. For example, thumb shield <NUM> may have one or more generally horizontally extending raised surfaces to constrain the tip of the thumb from extending beyond the upper shielded coverage of the frame of surgical cassette <NUM>. Thumb shield <NUM> may have in the alternative or in addition to the one or more horizontally extending raised surface, one or more generally vertically extending raised surfaces to constrain the side of the thumb from slipping sideways (left or right) beyond the coverage of the thumb shield <NUM> constraining surface(s).

In an embodiment, surgical cassette <NUM> may include drain bag port <NUM>. As illustrated in <FIG>, drain bag port <NUM> is an axially extending cylindrical port with a central opening to enable the transfer of fluid from the inside of the surgical cassette <NUM> manifold to an externally attached collection reservoir such as drain bag or collection vessel <NUM> (see <FIG>). In an embodiment as illustrated in <FIG>, drain bag port <NUM> may have one or more recessed notches 103a in the end face of drain bag port <NUM> to provide one or more gaps for fluid to flow into an externally attached bag. Such a feature helps to minimize the potential for the bag surface to obstruct fluid outflow through the port. Inside surface feature 103b may be configured to accept a male slip luer fitting to support the connection to external tubing sets.

As illustrated in <FIG>, surgical cassette <NUM> may include a drain bag hook <NUM>. Drain bag hook <NUM> is a mechanical feature extending outward from the surface of surgical cassette <NUM> and is configured to interface with a corresponding slot feature in the drain bag <NUM> (see <FIG>) to support the weight of the drain bag as it collects fluid.

Surgical cassette <NUM> may also include one or more clamping domes <NUM>. As illustrated in <FIG>, clamping domes <NUM> may be a raised pattern of spherical domed surfaces with a single high-point to provide low friction wiping contact surfaces during loading and concentrate axial clamping forces in specific zones after loading surgical cassette <NUM> with console <NUM>. It is also envisioned that the one or more clamping domes <NUM> may be of any shape or size suitable for its function or desired aesthetic look and feel.

In an embodiment, surgical cassette <NUM> may include peristaltic pump tube <NUM>. <FIG> shows the backside of surgical cassette and peristaltic pump tube <NUM>. Peristaltic pump tube <NUM> may be an elastomeric length of tubing that is configured to generate positive displacement of fluid flow in the direction of pump roller (not shown) when a portion of the tubing is compressed between the peristaltic pump rollers of console <NUM> and the backing plate pump profile <NUM> of the surgical cassette <NUM>. It is also envisioned that any type of flow-based pump and corresponding components may be used with surgical cassette <NUM>. In an embodiment, backing plate pump profile <NUM> may be comprised of contoured surfaces formed on the inside of cassette frame/front plate 100a to provide a compressing tubing while creating peristaltic pumping flow.

As illustrated in <FIG>, <FIG>, surgical cassette <NUM> may have axial mating plane surfaces <NUM>. Axial mating plane surfaces <NUM> are outer border faces of cassette frame/front plate 100a that form a surface mating with console <NUM> within cassette receiver <NUM> after loading.

In an embodiment, surgical cassette <NUM> may also include one or more peristaltic tube form retainers <NUM>. (See <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>) Clamping surfaces formed between the cassette frame/front plate 100a and backing plate 100b are configured to axially retain the tubing to maintain consistency of tubing stretch and provide centering of tubing within peristaltic pump profile <NUM>. Form retainers <NUM> may comprise mating sections 109a of cassette frame front plate 100a. Form retainers <NUM> are configured and dimensioned to shape peristaltic pump tube <NUM> and in the embodiment illustrated in the figures, to guide peristaltic pump tube <NUM> into an approximately <NUM> degree turn on each end of tube <NUM>.

In an embodiment as illustrated in <FIG>, <FIG>, backing plate 100b may be recessed within cassette frame/front plate 100a such that when surgical cassette <NUM> is inserted into console <NUM>, backing plate 100b does not touch the cassette receiver <NUM>. In the alternative, backing plate 100b may be configured and dimensioned to touch cassette receiver <NUM>.

Referring to <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, surgical cassette <NUM> may also include one or more pump tube interface ports <NUM>. Pump tube interface ports <NUM> are inlet and outlet transition ports to transition fluid flow from internal molded manifold fluid flow channels <NUM> to peristaltic pump tube <NUM>. In an embodiment, surgical cassette <NUM> may also include one or more manifold fluid flow channels <NUM>. Manifold fluid flow channels <NUM> are fluid flow pathways formed as raised surfaces allowing fluid to flow in internal channels between the raised surfaces and outer perimeter sealing border of gasket <NUM> to retain fluid within the manifold fluid flow channels <NUM> under positive pressure and vacuum conditions. Manifold fluid flow channels <NUM> may comprise irrigation flow channel 111a, which is a pathway with an inlet tubing port from balance salt solution (BSS) irrigation bottle metered by valves to one or more, preferably two outlet ports: (<NUM>) irrigation tubing outlet port <NUM> connected to an external surgical handpiece <NUM> flowing fluid to the eye, which may be metered or controlled by irrigation valve <NUM>; and (<NUM>) venting line 111b providing BSS irrigation fluid into an aspiration line of flexible conduits <NUM> which may be metered or controlled by vent valve <NUM>.

Manifold fluid flow channels <NUM> may also have aspiration flow channel 111b. Aspiration flow channel 111b may include a pressure/vacuum sensor element 111c, a pumping outlet port 111d, and two inlet ports comprising aspiration fluid inflow from tubing line connected to external surgical handpiece <NUM> and venting fluid inflow from BSS irrigation bottle, which may be metered by vent valve <NUM>. Manifold fluid flow channels <NUM> may also comprise vent flow channel 111c. Vent flow channel 111c is a pathway configured to provide BSS irrigation fluid into the aspiration line, which may be metered by vent valve <NUM> to reduce vacuum level in the aspiration line following handpiece <NUM> tip obstruction or occlusion. Manifold fluid flow channels <NUM> may also have manifold channel sealing surfaces <NUM>, which comprise the top surface or portion thereof of the channels <NUM>.

Referring to <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, surgical cassette <NUM> may include irrigation valve <NUM>, which in an embodiment may have a dome-like shape. Irrigation valve <NUM> may be an elastomeric deformable surface which allows irrigation flow from a BSS bottle to external surgical handpiece <NUM> when uncompressed and shuts off flow when deformed inwards towards manifold fluid flow channels <NUM>. Surgical cassette <NUM> may also include vent valve <NUM>, which in an embodiment may have a dome-like shape. Vent valve <NUM> may be an elastomeric deformable surface which allows irrigation flow from the BSS bottle through the aspiration line that coupled with the external surgical handpiece <NUM> resulting in vacuum level reduction when uncompressed and shuts off flow when deformed inwards towards manifold fluid flow channels <NUM>. The level of fluid flow may be controlled based upon the level of compression of valves (<NUM> and <NUM>) - from full flow to intermediate flow to no flow.

In an embodiment illustrated in <FIG>, <FIG>, and <FIG>, surgical cassette <NUM> may have irrigation valve control surface <NUM>. Irrigation valve control surface <NUM> may be a raised sealing surface in manifold fluid flow channels <NUM> that provides irrigation fluid flow reduction or shutoff from the BSS irrigation bottle to an irrigation inlet fitting of surgical handpiece <NUM> when irrigation valve control dome is compressed or activated. Surgical handpiece <NUM> may also include vent valve control surface <NUM>. Vent valve control surface <NUM> may be a raised sealing surface in manifold fluid flow channels <NUM> that provides shutoff of venting of irrigation fluid flow from the BSS irrigation bottle to an aspiration fitting of surgical handpiece <NUM> when vent valve <NUM> is compressed or activated.

In an embodiment illustrated in <FIG>, surgical cassette <NUM> may include irrigation inlet tubing port <NUM>, irrigation outlet tubing port <NUM>, and aspiration outlet tubing port <NUM>. Irrigation inlet tubing port <NUM> may be a connection port for tubing extending to the BSS irrigation bottle to deliver irrigation fluid to manifold fluid flow channels <NUM>. Irrigation outlet tubing port <NUM> may be a connection port for tubing extending to the surgical handpiece12 irrigation fitting to deliver irrigation fluid from manifold fluid flow channels <NUM> to patient's eye E. Aspiration outlet tubing port <NUM> may be a connection port for tubing extending to the surgical handpiece <NUM> aspiration fitting for removing fluid from a patient's eye E by means of a pump, such as a flow-based pump, preferably a peristaltic pump comprising the peristaltic pump tube <NUM>. In an embodiment, surgical cassette <NUM> may also include or in the alternative of drain bag port <NUM>, optional drain port 103c, which may be connected to an external tubing line or reservoir. In an embodiment, drain port 103c may be closed by a plug or similar device known in the art.

Surgical cassette <NUM> may include gasket <NUM> as illustrated in <FIG>, which may be an integrated elastomeric fluid channel sealing gasket. Gasket <NUM> may include a vacuum/pressure sensor diaphragm 120a, irrigation valve control dome <NUM>, and vent valve control dome <NUM>. Gasket <NUM> may also include fluid channel sealing surfaces 120b. Vacuum/pressure sensor diaphragm 120a may be a sealed flexible annular membrane with a central magnetic coupling disk which deforms: (<NUM>) proportionally outwards under fluid pressure conditions compressing a magnetically-coupled force displacement transducer of console <NUM> allowing for non-fluid contact measurement of fluid pressure level inside the aspiration fluid pathways of surgical cassette <NUM>; and (<NUM>) proportionally inwards under fluid vacuum conditions extending the magnetically-coupled force displacement transducer of console <NUM> allowing for non-fluid contact measurement of fluid vacuum level inside the aspiration fluid pathways of surgical cassette <NUM>. In an embodiment, gasket <NUM> may have one or more fluid channel sealing surfaces 120d, which may be a raised lip portion of the gasket <NUM>. In the embodiment shown in <FIG>, two such sealing surfaces 120b are illustrated.

In an embodiment, gasket <NUM> may be molded onto the backing plate 100b by co-molding or any other process known in the art. Co-molding the gasket <NUM> and backing plate 100b result in a combination of elastomeric features of gasket <NUM> and rigid features of backing plate 100b.

In an embodiment, surgical cassette <NUM> may also include pressure/vacuum sensor concentric alignment ring <NUM> as illustrated in <FIG>, <FIG>, <FIG>, and <FIG>. Alignment ring <NUM> may include a pattern of a radially oriented rib features defining a circular arc of a specific diameter and location to provide for concentric alignment between the center of the magnetically-coupled force displacement transducer <NUM> of console <NUM> and the center of vacuum/pressure diaphragm 120a of surgical cassette <NUM>. The pattern may comprise one or more radially oriented rib features, preferably a minimum of three radially oriented rib features.

In <FIG>, <FIG>, <FIG> and <FIG>, fluidics module <NUM> is illustrated according to an embodiment of the present invention. Fluidics module <NUM> comprises an assembly of components mounted in console <NUM> for interfacing with surgical cassette <NUM>. Fluidics module <NUM> may have one or more of the components described herein. Fluidics module <NUM> may have cassette receiver <NUM>, cassette pre-load detection pin <NUM>, and pre-load detection switch <NUM> (shown in <FIG>). Cassette receiver <NUM> may be a section of fluidics module <NUM> defining an engagement area for loading and aligning surgical cassette <NUM> in its intended position relative to various components of fluidics module <NUM>. Cassette receiver <NUM> may have tapered lead-in pre-alignment surfaces 123a, which may include outside vertical and horizontal border surfaces of cassette receiver <NUM> that may be tapered towards the center of the opening of cassette receiver <NUM> to guide surgical cassette <NUM> into a substantially centered position during off-angle insertion. Cassette receiver <NUM> may also have axial interface surface 123b, which may include planar engagement surfaces where cassette frame/front plate 100a bottoms out when fully constrained by rotary clamps <NUM>, <NUM>.

Cassette pre-load detection pin <NUM> may be a spring-loaded pin displaced rearwards when surgical cassette <NUM> is initially inserted with an end or side surface triggering a switch and initiating closure of rotary clamps <NUM>, <NUM>. Pre-load detection switch <NUM> may be a switch component that changes electrical output state when cassette pre-load detection pin <NUM> has been displaced to a specific axial position indicating surgical cassette <NUM> is in an appropriate position for loading engagement by rotary clamps <NUM>, <NUM> (see <FIG>). In an optional embodiment, as shown in <FIG>, a second detection switch <NUM> may be located next to or behind detection switch <NUM> to monitor the position of pre-load detection pin <NUM> to verify that surgical cassette <NUM> reaches its intended interface position at the completion of the cassette clamping mechanism closure.

Left rotary clamp <NUM> may be a rotating clamping component configured with specific surfaces to clamp surgical cassette <NUM> when rotated in a counter-clockwise direction as viewed from the top T and specific ejection surfaces to disengage surgical cassette <NUM> when rotated in the opposite direction. Right rotary clamp <NUM> may be a rotating clamping component configured with specific surfaces to clamp surgical cassette <NUM> when rotated in a clockwise direction as viewed from top T and specific ejection surfaces to disengage surgical cassette <NUM> when rotated in the opposite direction.

In an embodiment, fluidics module <NUM> may have a left clamping motor actuator <NUM> and a right clamping motor actuator <NUM>. Left clamping motor actuator <NUM> may be a reversible rotary actuator powered by electricity, pneumatics, hydraulics, or any other means know in the art, that controls the rotational position of the left rotary clamp <NUM> to alternately load and eject surgical cassette <NUM>. Right clamping motor actuator <NUM> may be a reversible rotary actuator powered by electricity, pneumatics, hydraulics, or any other means know in the art, that controls the rotational position of the right rotary clamp <NUM> to alternately load and eject surgical cassette <NUM>. The actuation of the motor actuators <NUM> and <NUM> may be simultaneously or individually controlled.

In an embodiment, fluidics module <NUM> may have a pump roller assembly <NUM>. Pump roller assembly may have a configuration of multiple roller elements in a circular or substantially circular pattern which produce peristaltic flow-based fluid transport when rotated against compressed fluid-filled peristaltic pump tube <NUM>.

In an embodiment, fluidics module <NUM> may have a force displacement transducer <NUM>. Force displacement transducer <NUM> may operate by means of a magnetic coupling, such that fluid vacuum inside manifold fluid flow channels <NUM> causes deformation inwards of vacuum/pressure sensor diaphragm 120a in surgical cassette <NUM>, which axially extends force displacement transducer <NUM> resulting in a change of an electrical output signal in proportion to a vacuum level. Positive fluid pressure in manifold fluid flow channels <NUM> results in an outward extension of vacuum/pressure sensor diaphragm 120a and compression of the force displacement transducer <NUM>.

In an embodiment, fluidics module <NUM> may have irrigation valve plunger <NUM> and vent valve plunger <NUM>. Irrigation valve plunger <NUM> may have an axial extension of the plunger that compresses irrigation valve <NUM> of surgical cassette <NUM> resulting in a decrease or shutoff of irrigation flow to external irrigation tubing line of flexible conduit <NUM>. Irrigation valve plunger <NUM> may also operate by a spring-loaded retraction of the plunger to allow varying levels of irrigation flow. Vent valve plunger <NUM> may have an axial extension of the plunger that compresses vent valve <NUM> of surgical cassette <NUM> resulting in a decrease or shutoff of irrigation venting flow to external aspiration tubing line of flexible conduit <NUM>. Vent valve plunger <NUM> may also operate by a spring-loaded retraction of the plunger to allow irrigation pressure fluid flow to vent vacuum level in aspiration tubing line of flexible conduit <NUM>.

In an embodiment, fluidics module <NUM> may have one or more of the following components: peristaltic drive motor actuator <NUM>, peristaltic pump motor drive pulley <NUM>, peristaltic drive belt <NUM>, peristaltic roller driven pulley <NUM>, and pump roller guide bearings <NUM>. Peristaltic drive motor actuator <NUM> may be a reversible rotary actuator powered by electricity, pneumatics, hydraulics, or any other means known in the art that controls the rotational position of the peristaltic pump roller assembly <NUM>. Peristaltic pump motor drive pulley <NUM> may have a pulley wheel connected to the rotary drive shaft of peristaltic drive motor actuator <NUM> to provide a mating interface for peristaltic drive belt <NUM> when peristaltic drive motor actuator <NUM> is oriented on an offset parallel axis to peristaltic pump roller assembly <NUM> for reducing overall height of fluidics module <NUM>. Peristaltic roller driven pulley <NUM> may have a pulley wheel connected to rotary shaft peristaltic pump roller assembly <NUM>. Peristaltic drive belt <NUM> may be a belt connecting peristaltic pump motor drive pulley <NUM> to peristaltic roller driven pulley <NUM> to transfer rotation of the pump drive motor shaft to the peristaltic pump roller assembly <NUM>.

Pump roller guide bearings <NUM> may have at least one low friction bearing placed in concentric alignment with peristaltic pump roller assembly <NUM> to guide shaft rotation of peristaltic pump roller assembly <NUM>. Pump roller guide bearings <NUM> may compensate for off-axis forces from compression of peristaltic pump tube <NUM> by peristaltic pump roller assembly <NUM> and peristaltic drive belt <NUM> tension between pulleys <NUM> and <NUM>.

In an embodiment, fluidics module <NUM> may have rotary pump roller position encoder <NUM>. Rotary pump roller position encoder may have an electronic output signal indicating rotary position of peristaltic pump roller assembly <NUM>, which may be used to derive and confirm intended rotational speed during peristaltic pumping. Rotary pump roller position encoder <NUM> may also be used to provide controlled rotary position changes for the following purposes: increase or decrease pressure level in fluid line by a target amount by transferring a predetermined volume of fluid into or out of the fluid line faster than closed-loop pressure monitoring allows based on an algorithm assuming a known overall system volume; and/or increase or decrease vacuum level in fluid line by a target amount by transferring a predetermined volume of fluid into or out of fluid line faster than closed-loop vacuum monitoring allows based on an algorithm assuming a known overall system volume.

The following describes exemplary embodiments of operating surgical cassette <NUM> and console <NUM> according to the present invention. In an embodiment, a surgical technician grasps surgical cassette <NUM> by placing an index finger through the opening of grip loop handle <NUM> and gripping handle <NUM> with thumb pressure on thumb shield <NUM> (outer top surface of handle). The surgical technician's hand can remain sterile while tubing lines are handed off to supporting non-sterile staff to make connections to the non-sterile BSS irrigation bottle. With the surgical technician's thumb being shielded from inadvertent contact with non-sterile outer surfaces of console <NUM> by means of thumb shield <NUM>, surgical cassette <NUM> may be directly inserted into cassette receiver <NUM> of fluidics module <NUM> with centering guidance provided by tapered outer surfaces 123a. The direct axial insertion of surgical cassette <NUM> into cassette receiver <NUM> of fluidics module <NUM> results in axial mating plane surfaces <NUM> contacting ejection surfaces 126b and 127b of left and right rotary clamps <NUM>,<NUM>. (See <FIG>, <FIG>, <FIG>).

Approximately synchronized with contacting ejection surfaces 126b and 127b of rotary clamps <NUM>, <NUM>, cassette pre-load detection pin <NUM> is compressed triggering a switch signal to be sent from cassette pre-load detection switch <NUM> to the control means of console <NUM>. Triggering of cassette pre-load detection switch <NUM>, triggers rotation of clamping motor actuators <NUM>, <NUM> and contact between loading clamp surfaces 126a, 127a of rotary clamps <NUM>, <NUM> and clamping domes <NUM> on cassette frame/front plate 100a. Clamping motor actuators <NUM>, <NUM> will continue to rotate until axial mating plane surfaces <NUM> of cassette frame/front plate 100a are compressed fully flat and parallel to mounting reference surfaces of fluidic module <NUM>.

Surgical cassette <NUM> is guided into horizontal and vertical preferred alignment by concentric alignment of ribs <NUM> of pressure/vacuum sensor diaphragm 120a of surgical cassette <NUM> with outer ring surface 131a (see <FIG>) of force displacement transducer <NUM>. After tubing connections are made to external accessories (e.g., handpiece <NUM> with attached phaco needle tip and irrigation sleeve (not shown)), surgical staff initiates a fluid priming of tubing lines and internal cassette fluid pathways (i.e. manifold fluid flow channels <NUM>) with irrigation fluid delivered from an irrigation source (e.g. BSS bottle).

Console <NUM> may verify one or more of the following: proper tubing connections, fluid line sealing, and fluid control operation during the priming procedure by generating flow through aspiration pathways of manifold fluid flow channels <NUM> by rotating peristaltic pump roller assembly <NUM> against outer surface of peristaltic pump tube <NUM> in compression against peristaltic pump profile <NUM> of backing plate 100b.

Desired and/or appropriate pressure and vacuum levels are verified by means of the magnetically-coupled pressure/vacuum sensor diaphragm <NUM> pulling outwards on force displacement transducer <NUM> in proportion to an actual vacuum level and pushing inwards in proportion to actual pressure levels.

Fluid flow may be metered on and off or varied by means of extending and retracting irrigation and vent valve plungers <NUM>, <NUM>, which shutoff or vary fluid flow when extended to compress sealing surfaces of irrigation valve <NUM> and vent valve <NUM> against irrigation and vent valve surfaces <NUM>, <NUM>.

A surgical user may control the outflow rate of fluid from externally attached tubing accessories (e.g., handpiece <NUM> with attached phaco tip and irrigation sleeve (not shown)) by selecting desired aspiration pump flow rate which is converted by one or more control algorithms of console <NUM> into speed of rotation of peristaltic pump roller assembly <NUM>.

According to an embodiment, to enable reduced overall height of fluidics module <NUM>, peristaltic drive motor actuator <NUM> may be configured as a parallel axis drive mechanism such as the belt drive and pulley mechanism described herein. In another embodiment, peristaltic drive motor actuator <NUM> may be oriented such that the drive shaft is perpendicular to the peristaltic pump roller assembly <NUM> using one or more gears to couple the peristaltic drive motor actuator <NUM> with the peristaltic pump roller assembly <NUM>. This in turn would also enable a reduction of overall height of fluidics module <NUM>.

Referring to <FIG>, <FIG>, <FIG>, and <FIG>, in another embodiment, using a non-axial drive connection between peristaltic drive motor actuator <NUM> and peristaltic pump roller assembly <NUM>, a rotary pump roller position encoder <NUM>, which may be any type of indicator known in the art, may be mounted onto the rotating shaft of peristaltic pump roller assembly <NUM> to detect slippage or asynchronous rotation of peristaltic drive motor actuator <NUM> with respect to peristaltic pump roller assembly130. Since peristaltic pumping is generated in direct proportion to peristaltic pump roller assembly <NUM> to rotational speed of peristaltic drive motor actuator <NUM> during slippage conditions, placement of rotary pump roller position encoder <NUM> onto peristaltic pump roller assembly <NUM> provides increased accuracy and reliability of intended operation.

When the surgical procedure is completed, surgical staff initiate ejection of surgical cassette <NUM> from fluidics module <NUM> by activating ejection switch <NUM> (see <FIG>) which signals the clamp motor actuators <NUM>, <NUM> to reverse rotation and disengage axial mating plane surfaces <NUM> of surgical cassette <NUM> from axial interface surface 123b of fluidics module <NUM> by a controlled distance.

In an embodiment, the final ejected position of surgical cassette <NUM> results in surgical cassette <NUM> still being retained on its outer border edges within the lead-in portion 123a (see <FIG> and <FIG>) of cassette receiver <NUM> to prevent surgical cassette <NUM> having internal surgical waste fluid from falling onto the floor.

In yet another embodiment, a potentiometer-based cassette attitude, alignment, and load complete detection "switch" may be provided. More particularly, this potentiometer-based switch allows for predisposition of the planar attitude and alignment of a cassette <NUM> presented to the cassette receiver <NUM> of the fluidics module <NUM>. In short, only a cassette <NUM> presented in an acceptable attitudinal angular range, and with the proper alignment, will allow the fluidics module <NUM> to receive the cassette <NUM> and operate any of the cassette clamping or seizing mechanisms discussed herein. Consequently, the cassette <NUM> may not be presented in a manner that would cause the clamping mechanism to jam, or that would cause the cassette <NUM> to be misaligned with the cassette receiver <NUM>. In prior systems and methods, the planar orientation and alignment of the cassette was not adequately accounted for, and consequently the cassette could be improperly forced, or jammed, into place. In contrast, in the exemplary system and method provided herein, the aforementioned mechanical potentiometer-based micro-switch is provided, whereby improved reliability and refined control is available to prevent forcing, jamming, misalignment, or other malfunction.

<FIG> is a schematic illustration of an exemplary potentiometer <NUM> for use in the instant embodiments. Those skilled in the art will appreciate, in light of the disclosure herein, that the potentiometer <NUM> may be or include any means of providing a detector for variations in electrical resistance, and that the variations in electrical resistance provided may be stepped, i.e., may have discrete available values, or may be continuous. Further, the detector may be of any form suitable to provide variations in electrical resistance responsive to pressure thereupon, such as the aforementioned potentiometer, a Wheatstone bridge, a resistive divider, or the like. Additionally, the detector may be actuated by any known mechanism, including but not limited to the linearly displaced shaft <NUM> discussed herein.

The exemplary potentiometer shown in <FIG> includes a spring loaded, self-guided plunger shaft <NUM> and associated housing <NUM>, which shaft <NUM> may pass through, or which shaft <NUM> may connect to a rod <NUM> that passes through, a mounting body <NUM>. The axis of the shaft <NUM> may run parallel to the length of the housing <NUM>, with the spring (not shown) internal to the housing and proximate to a closed base thereof, wherein an end of the shaft <NUM> fully contained within the housing <NUM> may rest upon the spring. The rod <NUM> may comprise a machined adaptor that is pressed on, glued on, welded on, or threaded on to the shaft <NUM> of the potentiometer. If provided, the rod <NUM> must be mounted reasonably accurately to the shaft <NUM>, to thus avoid misrepresentation of the attitude or alignment of the cassette <NUM> as discussed further below. Additionally, the spring loaded nature of the potentiometer shaft <NUM> and rod <NUM> (if so equipped) provides a controlled resistance to an operator inserting the cassette <NUM> progressively through the plane at the mouth of the cassette receiver <NUM>, thereby helping to limit erratic insertion attempts.

As in a typical linear potentiometer, when the shaft <NUM> is depressed, a modification to the resistance provided by the potentiometer <NUM> is effected. Accordingly, the linear position of the axial shaft <NUM> dictates a particular resistance of the potentiometer. Thereby, the resistance of the illustrative potentiometer <NUM> is also indicative of the position of that which is depressing the shaft <NUM> (or rod <NUM>)-which, in this illustration, may be either the cassette <NUM> or the fluidics module <NUM> for receiving the cassette <NUM>, depending upon whether the potentiometer <NUM> is physically associated with the fluidics module <NUM> or the cassette <NUM>, respectively. That is, a linear potentiometer <NUM> may be employed on the fluidics module <NUM> to indicate the relative position of the cassette <NUM> being mated to the fluidics module <NUM>, or may be mounted on the cassette <NUM> to indicate the relative position of the fluidics module <NUM> with respect thereto.

In order to allow for physical association of the potentiometer <NUM> with either the cassette <NUM> or the fluidics module <NUM>, the potentiometer <NUM> may include the aforementioned mounting body <NUM>. The axial shaft <NUM> of the potentiometer <NUM> may extend through a hole in the mounting body <NUM>, or may mate with the rod <NUM> that then extends through the hole in the mounting body <NUM>. The rod <NUM> may effectively extend the axial shaft <NUM> of the potentiometer <NUM> to allow for detection of the extent of depression of the axial shaft <NUM> as dictated by depression of the detector rod <NUM>.

Accordingly, in exemplary embodiments, depression of the detector rod <NUM> may be indicative of an attempt to mate the cassette <NUM> to the fluidics module <NUM>. More particularly, depression of at least two detector rods <NUM> positioned about the cassette receiver <NUM> may be indicative of an alignment or attitude of the cassette <NUM> as the attempt is made to mate the cassette <NUM> to the fluidics module <NUM>. In an exemplary embodiment, the mounting position may preferably comprise, in an exemplary two-potentiometer embodiment, a substantially diagonal mounting with respect to the plane provided by the mouth of the cassette receiver <NUM> of the fluidics module <NUM>, and this diagonal mounting may be as far diagonal as is practicable.

Each potentiometer <NUM> in a two potentiometer embodiment may thus register a linear amount traveled once in contact with a back face of the cassette <NUM>, i.e., at the point of initial insertion of the cassette <NUM> to the cassette receiver <NUM>. The two potentiometers in conjunction may thus also provide a differential in the dimensional amount traveled by each plunger shaft <NUM> relative to the other, thereby indicating the tilt, angle, or attitude on-plane or off-plane of the cassette <NUM> from the plane at the mouth of the cassette receiver <NUM>. This differential may be assessed, for example, using a comparator included in controller <NUM> that receives and compares an electrical resistance reading of each potentiometer. An angle off-plane of a sufficient amount may prevent actuation of the clamping mechanism for the cassette <NUM>, thereby preventing jamming and thus requiring that an operator remove the cassette <NUM> and re-approach the cassette <NUM> to the cassette receiver <NUM>.

<FIG> and <FIG> are cross-sectional schematic illustrations of the rear and front views, respectively, of an exemplary embodiment of the fluidics module <NUM> and cassette receiver <NUM>, in which two potentiometers <NUM> are used to detect alignment and attitude of a cassette <NUM> as it is pushed toward a fluidics module <NUM>. In the illustrated embodiment, the potentiometers <NUM> reside on the fluidics module <NUM>, although the potentiometers <NUM> may also reside on the cassette <NUM>, as referenced above. Further, although in the illustrated embodiment two potentiometers <NUM> are shown diagonally about the cassette receiver <NUM> of the fluidics module <NUM>, any number of potentiometers greater than two, and in any one of several configurations, may be used to provide a more refined indication of alignment and attitude of the cassette <NUM>. For example, four potentiometers may be used, one adjacent to each of the four "corners" about the cassette receiver <NUM>.

In the rear view illustration, the two potentiometers <NUM> may be mounted at two corners about the cassette receiver <NUM> using the mounting bodies <NUM> discussed above. The mounting bodies <NUM> may be mounted using, for example, a screw or bolt placed through a hole in the mounting body <NUM> and screwed or bolted into the rear of the fluidics module <NUM>. Upon mounting, and as shown in the front view illustration, the respective detector rods <NUM> of each potentiometer <NUM> extend to the front of the fluidics module <NUM>, i.e., into the cassette receiver <NUM>, through holes extending from the rear of the fluidics module <NUM> to the front of the fluidics module <NUM>.

Accordingly, a full traverse by each potentiometer shaft <NUM> (or a linear traverse to a predetermined point) may not only be indicative of a proper planar attitude and correct alignment of the cassette <NUM> to the mounting plane, but may further be indicative that the cassette <NUM> is fully inserted, or loaded, into the cassette receiver <NUM>. Thus, a full linear traverse (or a linear traverse to a predetermined point) by both (or all, in embodiments having more than two) potentiometer shafts <NUM> may serve as an additional "switch" indicating a full and complete insertion of the cassette <NUM>, thereby allowing for continued normal operation of any clamping mechanism and of the union of fluidics module <NUM> and cassette <NUM>.

The mounting of the potentiometers <NUM> to the fluidics module <NUM> may be greatly simplified using the illustrated embodiments as compared to alignment sensors generally provided in the prior art. This may be the case at least because adjustment of optical sensors, reading of voltmeters, and set screw adjustment and lock down adjustment may be avoided.

Further, the use of the potentiometers <NUM>, or like detectors of variations in resistance, allows for the sensing of attitude and alignment, and variations therein, in real time. Thereby, motors associated with any of the clamping mechanisms discussed throughout may calibrate and/or adjust dynamically. That is, motor activation and speed may be dynamically adjusted to actuate clamps and/or to actuate doors to receive the cassette <NUM>, and/or to release the cassette <NUM>, such as to account for the attitude or alignment of the cassette <NUM> approaching cassette receiver <NUM>. As used herein, actuation of clamps may include clamping and unclamping, and actuation of doors may include opening and closing. Additionally, motor activation and speed, and/or pump actuation and speed, by fluidics module <NUM> may adjust dynamically during operation, such as if the cassette <NUM> changes position slightly due to being bumped, or the like.

Claim 1:
A phacoemulsification system, comprising:
a cassette (<NUM>) comprising positioning surfaces; and
a console comprising: a cassette receiver (<NUM>) configured to couple with the positioning surfaces of the cassette (<NUM>); and characterised by:
two potentiometers (<NUM>) mounted within an area defined by the cassette receiver (<NUM>), wherein the potentiometers (<NUM>) are each suitable for depression by a respective one of the positioning surfaces, and wherein an extent of the depressions is indicative of at least one of an alignment and an attitude of said cassette (<NUM>) with respect to the cassette receiver (<NUM>); and
a comparator configured to compare, based on an electrical resistance reading from each of the potentiometers (<NUM>), an extent of the depression of one of the potentiometers (<NUM>) with that of another of the potentiometers (<NUM>) to assess the at least one of the alignment and the attitude of the cassette (<NUM>) with respect to the cassette receiver (<NUM>).