Abstract:
A surgical system includes a replaceable surgical cassette that is configured to be received by a surgical console, the surgical cassette permitting fluid flow through the cassette, the surgical system controlling the flow of fluid through the cassette via one or more flexible valves actuated by one or more actuation plungers located on the surgical console. The one or more flexible valves of the surgical cassette and the one or more actuation plungers of the surgical console include a positioning feature configured to assist with positioning the one or more actuation plungers to apply uniform and symmetric pressure to the one or more valves during actuation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to and is a continuation-in-part application of U.S. application Ser. No. 14/686,582 filed on Apr. 14, 2015, which claims priority to and is a continuation-in-part of U.S. application Ser. No. 13/776,988 filed on Feb. 26, 2013, which claims priority to U.S. provisional application No. 61/612,307 filed on Mar. 17, 2012, the contents of each are hereby incorporated by reference in their entirety. 
     
    
     TECHNICAL FIELD OF THE INVENTION 
       [0002]    The present invention is generally related to methods, devices, and systems for controlling surgical fluid flows, particularly during treatment of an eye. More particularly, the present invention generally relates to methods, devices and systems associated with a valve system of a removable cassette for controlling surgical fluid flows. 
       BACKGROUND OF THE INVENTION 
       [0003]    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. 
         [0004]    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. 
         [0005]    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. 
         [0006]    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. 
         [0007]    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: 1) volumetric-based aspiration flow systems using positive displacement pumps; and 2) 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. 
         [0008]    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. 
         [0009]    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&#39;s control over the eye treatment procedure. 
         [0010]    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 or positive-displacement flows. 
         [0011]    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. Examples of cassettes currently used in the marketplace may be found in U.S. Pat. No. 8,070,712, U.S. Published Application 2008011431, and U.S. Published Application 20080114291, the contents of each are herewith incorporated by reference in their entirety as if set forth herein. U.S. application Ser. Nos. 14/686,582 and 13/776,988, which are hereby incorporated by reference in their entirety as if set forth herein, provide examples of cassettes. 
         [0012]    A fluidic cassette may include means for controlling fluid flow through the cassette. In various embodiments, a fluidic cassette may include a gasket or flexible membrane located within the cassette that is configured to direct fluid flow in a predetermined flow path through the cassette. The gasket may be surrounded by front and back plates that form the body of the cassette, and the gasket may include one or more valves or a sensor that are accessible through the back plate. The surgical cassette may further include one or more tube retainers configured and dimensioned to guide a portion of either an irrigation or aspiration tube into a desired shape. The desired shape may be capable of being used with a peristaltic pump to pump fluid through the pathways formed by the gasket. 
         [0013]    A gasket of a fluidic cassette may have a body, wherein the body is deformable and has a front surface and a back surface. The front surface may have one or more raised contours that create one or more channels that are configured and dimensioned to control fluid flow through one or more corresponding channels of a surgical cassette. The back surface may have one or more elevated portions that correspond to the one or more channels of the front surface and act as a valve. The gasket may also have a deformable membrane having an annular surface capable of coupling with a transducer of a surgical console. The console may include one or more solenoid devices that engage with the back surface of the gasket through the back plate of the cassette, thereby operating or controlling the valve of the gasket to control fluid flow in the flow pathway. 
         [0014]    In light of the above, it would be advantageous to provide improved devices, systems, and methods for eye surgery, and more particularly for the control of fluid flow through a fluidic cassette during eye surgery. 
       SUMMARY OF THE INVENTION 
       [0015]    The present invention provides a surgical cassette manifold, having a front housing, a rear housing, and a gasket, wherein the front housing comprises one or more molded fluid channels and one or more seal channels, herein the gasket is coupled with the rear housing and at least a portion of the gasket is located between the front housing and the rear housing, and wherein the gasket has one or more seal lips configured and dimensioned to couple with the one or more seal channels to form one or more fluid flow channels through the cassette. The gasket comprises one or more valves controllable through the rear housing, the valves configured to extend into the one or more fluid flow channels to reduce or block fluid flow through the flow channels. 
         [0016]    The present invention provides a surgical cassette manifold configured to be coupled to a surgical console, the cassette manifold having a front housing, a rear housing, and a flexible gasket, wherein the gasket comprises one or more flexible flow restriction valves that reduce or block fluid flow through flow channels in the cassette, the flow restriction valves positioned along either a first flow path of irrigation fluid flowing through the cassette to a surgical handpiece or a second flow path of aspirated fluid from the surgical handpiece flowing through the cassette, or both. The flow restriction valves are actuated to reduce or block fluid flow through the first or second flow paths via one or more actuation plungers located on the surgical console. In various embodiments, the plungers may be actuated by a solenoid or other similar means to apply pressure to the flexible valves to deform the flexible valves into the flow paths. 
         [0017]    The present invention provides a surgical cassette manifold configured to be coupled to a surgical console, the cassette manifold including a flexible gasket comprising one or more valves that reduce or block fluid flow through the surgical cassette, wherein the one or move valves are positioned adjacent a first flow path of fluid flowing into a surgical handpiece from the cassette and a second flow path of fluid flowing through the cassette that has been aspirated from the surgical handpiece. The one or more valves are actuated by an actuation plunger of the surgical console, which may be electronically controlled by a controller of the console. In various embodiments, the plungers may be actuated by a solenoid or other similar means to apply pressure to the flexible valves to deform the flexible valves into the flow paths. 
         [0018]    In illustrative embodiments, one or more flexible valves of a surgical cassette and one or more actuation plungers of a surgical console include a positioning feature configured to assist with positioning the one or more actuation plungers to apply uniform and symmetric pressure to the one or more valves. The positioning feature includes at least two features: (i) a locking recess on a back surface of the one or more valves, the locking recess formed between two spaced-apart teeth or protrusions that extend axially away from (and are generally perpendicular to) the valve surface; and (ii) a blade tooth that extends axially away from an end surface of the plunger and is configured to be received with the locking recess to engage the valve. The positioning feature ensures the plunger is properly aligned with the flexible valve as the valve is deformed inward under pressure from the plunger. 
         [0019]    In illustrative embodiments, a positioning feature of the surgical cassette and a surgical console may include i) a locking recess on a back surface of the one or more valves, the locking recess formed between two spaced-apart teeth or protrusions that extend axially away from (and are generally perpendicular to) the valve surface; and (ii) a blade tooth that extends axially away from an end surface of the plunger and is configured to be received with the locking recess to engage the valve. The locking recess formed by the teeth and blade tooth may be configured to be of complimentary shapes and sizes so that the blade tooth abuts against the surface of the teeth when the blade tooth is received with the locking recess. In various embodiments, a surface of the teeth may be concave in nature and a surface of the blade tooth may be convex in nature. In alternative embodiments, the positioning feature may further include an end cap on the blade tooth, the end cap include angled surfaces that correspond with tapered surfaces that further define the locking recess of the valve. 
         [0020]    These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    The present invention is best understood with reference to the following detailed description of the invention and the drawings in which: 
           [0022]      FIG. 1  schematically illustrates an eye treatment system in which a cassette couples an eye treatment probe with an eye treatment console; 
           [0023]      FIGS. 2A and 2B  are exploded views of an exemplary surgical cassette manifold for use in the system of  FIG. 1 ; 
           [0024]      FIG. 3A  is perspective front view of a front housing of an exemplary surgical cassette manifold; 
           [0025]      FIG. 3B  is perspective back view of a front housing of an exemplary surgical cassette manifold; 
           [0026]      FIG. 4A  is a front perspective view of a rear housing of an exemplary surgical cassette manifold; 
           [0027]      FIG. 4B  is a back perspective view of a rear housing of an exemplary surgical cassette manifold; 
           [0028]      FIG. 5  is a side view of the front side of the rear housing illustrated in  FIG. 4A ; 
           [0029]      FIG. 6  is a back perspective view of the rear housing illustrated in  FIG. 4B ; 
           [0030]      FIG. 7A  is a cross-sectional view taken along the line  7 A- 7 A in  FIG. 6 ; 
           [0031]      FIG. 7B  is a cross-sectional view taken along the line  7 B- 7 B in  FIG. 6 ; 
           [0032]      FIG. 7C  is a cross-sectional view taken along the line  7 C- 7 C in  FIG. 6 ; 
           [0033]      FIG. 8  is a cross-sectional view of one or more valve assemblies of the surgical cassette manifold of  FIG. 4B ; 
           [0034]      FIG. 9A  is a side perspective view of a valve assembly of the surgical cassette manifold of  FIG. 4B ; 
           [0035]      FIG. 9B  is a top perspective view of a valve assembly of the surgical cassette manifold of  FIG. 4B ; 
           [0036]      FIG. 10A  is a partial side perspective view of an eye treatment console of  FIG. 1 , illustrating a valve actuation mechanism in the console; 
           [0037]    FIGS.  10 B 1  and  10 B 2  are perspective views of a solenoid valve actuation member of the valve actuation mechanism of  FIG. 10A , in particular, for example, for an aspiration valve and an irrigation vent valve, respectively; 
           [0038]      FIG. 10C  is a partial back perspective view of the valve assembly of  FIG. 4B ; 
           [0039]      FIG. 10D  is a top perspective view of an alternative valve assembly of the surgical cassette manifold of  FIG. 4B ; and 
           [0040]      FIG. 11  is a perspective view of a surgical cassette manifold with tubes and a drainage page attached to transport fluid into or receive fluid from the cassette manifold. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0041]    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, modifications, and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. 
         [0042]    Referring to  FIG. 1 , a system  10  for treating an eye E of a patient P generally includes an eye treatment probe handpiece  12  coupled to a console  14  by a cassette  100  mounted on the console. Handpiece  12  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  14  and/or cassette  100  into the eye. Aspiration fluid may also be withdrawn through a lumen of the probe tip, with the console  14  and cassette  100  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  100  will often comprise a disposable (or alternatively, re-sterilizable) structure, with the surgical fluids being transmitted through conduits of the cassette that avoid direct contact in between those fluids and the components of console  14 . 
         [0043]    When a distal end of the probe tip of handpiece  12  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  14  to an ultrasound transmitter of the handpiece, a cutter mechanism, or the like. Alternatively, the handpiece  12  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  12  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  12  (or a separate probe structure) may also be provided, with both the aspiration and irrigations flows being controlled by console  14 . 
         [0044]    So as to avoid cross-contamination between patients and/or to avoid incurring excessive expenditures for each procedure, cassette  100  and its conduit  18  may be disposable. Alternatively, the 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  14 , which may include one or more peristaltic pump rollers, a Venturi or other vacuum source, a controller  40 , and the like. 
         [0045]    Controller  40  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  42 ), and the like. Controller  40  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  40  may have (or be coupled to) a recording media reader, or the code may be transmitted to controller  40  by a network connection such as an internet, an intranet, an Ethernet, a wireless network, or the like. Along with programming code, controller  40  may include stored data for implementing the methods described herein, and may generate and/or store data that records parameters corresponding to the treatment of one or more patients. Many components of console  14  may be found in or modified from known commercial phacoemulsification systems from Abbott Medical Optics Inc. of Santa Ana, Calif.; Alcon Manufacturing, Ltd. of Ft. Worth, Tex.; Bausch and Lomb of Rochester, N.Y.; and other suppliers. 
         [0046]    In illustrative embodiments, a surgical cassette manifold  101  is configured to be coupled and removed from the console  14  after use during a surgical procedure.  FIGS. 2A and 2B  illustrate a surgical cassette manifold  101  of the present invention, including components of the surgical cassette manifold  101 . Cassette or surgical cassette  100  is an assembled surgical cassette manifold  101  having 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&#39;s eye E when the cassette  100  is coupled with console  14 . 
         [0047]    As shown in  FIGS. 2A and 2B , the surgical cassette manifold  101  has a front housing  102 , a rear housing  104 , a first tubing  106 , and a second tubing  108 . Rear housing  104  may also have a gasket  110  co-molded or over-molded with rear housing  104 . As illustrated in  FIGS. 2A and 2B , the rear housing  104 , the front housing  102 , or a combination of both may have axial mating plane surfaces  105 . Axial mating plane surfaces  105  are outer border faces of the back housing  104  and/or front housing  102  that form a surface mating with console  14  within a cassette receiver  210  of the console  14  after loading. 
         [0048]      FIGS. 3A and 3B  illustrate the front housing  102  in more detail.  FIG. 3A  shows a perspective view of an illustrative embodiment of a front surface  144  of front housing  102 , the front surface  144  including a handle  112  (e.g. finger grip handle), a drain port  114 , and an attachment clip  116 . A drain bag  16 , as seen in  FIG. 11 , may be attached to the front surface  144  of front housing  102  via the drain port  114  and attachment clip  116  such that, when the surgical cassette  100  is coupled with the console  14  and fluid is aspirated from an eye E of a patient P, the fluid is capable of being collected in the drainage bag  16  via the drain port  114 . The drain bag  16  may be supported on surgical cassette manifold  101  by the attachment clip  116  and/or drain port  114 .  FIG. 3B  shows a perspective view of a back surface  146  of the front housing  102 , the back surface  146  having in illustrative embodiments one or more molded fluid channels  118 , a reservoir  120 , a first pump ramp or profile  122  configured and dimensioned for mating with a peristaltic pump, and an optional second pump ramp or profile  124  configured and dimensioned for mating with a peristaltic pump. 
         [0049]      FIGS. 4A and 4B  illustrate the rear housing  104  in more detail.  FIG. 4A  is a front perspective view of the rear housing  104  and  FIG. 4B  is a back perspective view of rear housing  104 . In illustrative embodiments, rear housing  104  includes a front surface  142  and a back surface  148 . The rear housing  104  may include a reservoir  119 , upper tube connections  134 , optional lower tube connections  136 , and one or more tubing retainer clips  138 . In an embodiment, upper tube connections  134  are located between the front surface  142  and back surface  148  and have a slight taper from bottom toward the top so that the tubing stays on the upper tube connections  134 , as illustrated in  FIG. 4A . Lower tube connection  136  may similarly be located between front surface  142  and back surface  148  and have a tapered head to secure second tubing  108  to lower tube connections  136 . As shown in  FIG. 4A , rear housing  104  may include the gasket  110  co-molded or over-molded to it. Rear housing  104  is configured to be coupled together (for example, in a snap fit engagement) with front housing  102  to contain gasket  110  there between. 
         [0050]    In illustrative embodiments, the surgical cassette  100  may include at least one peristaltic pump tube  106 .  FIGS. 2A and 2B  show the backside of surgical cassette  100  and a peristaltic pump tube  106 . In an embodiment, pump tube  106  may have a first end and a second end that couple with upper tube connections  134 . The peristaltic pump tube  106  may be an elastomeric length of tubing that is configured to generate positive displacement of fluid flow in the direction of a pump roller (not shown) of the console  14  when a portion of the peristaltic pump tube  106  is compressed between the peristaltic pump rollers of console  14  and the ramp  122  of the front housing  102  of surgical cassette  100 . It is also envisioned that any type of flow-based pump and corresponding components may be used with surgical cassette  100 . In an embodiment, the ramp  122  may include a backing plate pump profile  109  comprised of contoured surfaces formed on the inside of the front housing  102  of cassette  100  to provide moving compression on the tubing  106  while creating peristaltic pumping flow through the cassette  100 , particularly through pump tube  106 . In various embodiments, pump tube  106  may be formed to partially conform to the shape of ramp  122 , as illustrated, for example, in  FIG. 7A . 
         [0051]    In illustrative embodiments, the surgical cassette  100  may optionally include a second peristaltic pump tube  108 , as illustrated in  FIGS. 2A and 2B . The second pump tube  108  may be configured of similar size and shape as first pump tube  106 . In an embodiment, second pump tube  108  may have a first end and a second end that couple with lower tube connections  136 . Once surgical cassette manifold  101  is assembled, second tubing  108  and ramp  124  are configured to couple with a peristaltic rollers (not shown) located on console  14  to create a peristaltic pump. In an embodiment, lower tube connections  136  are on the same axis, i.e. there is axial alignment of the inflow and outflow of the second tubing  108 , and maintain a specific distance apart resulting in a more accurate peristaltic pump due to a controlled length of the second tubing  108 , which provides a consistent flow rate and a consistent interface with ramp  124  and peristaltic rollers. Moreover, such aligned and consistent interfaces results in less noise/sound generated by the peristaltic pump during operation. Such axial alignment may also be provided between upper tube connections  134  and first pump tube  106 . 
         [0052]    During assembly, rear housing  104  is mated with front housing  102 , first tube  106  is configured to conform with first pump ramp  122 , and second tube  108  is configured to conform with second pump ramp  124 . First pump ramp  122  is configured and dimensioned for mating with a first peristaltic pump (not shown) located within the console  14 . Second tube  108  is configured to conform with second pump ramp  124 . Second pump ramp  124  is configured and dimensioned for mating with a second peristaltic pump (not shown) located within the console  14 . Reservoir  120  of front housing  102  and reservoir  119  of rear housing  102  are configured to be generally aligned to create a void  117  within cassette manifold  101  defined by reservoir  120  and reservoir  119 , as illustrated for example in  FIG. 7C . Void  117  is configured to retain fluid pumped into cassette  100  from the handpiece  12  by the first peristaltic pump. The fluid retained in void  117  by reservoirs  119  and  120  may then be pumped out of cassette  100  to drain port  114  by the second peristaltic pump. 
         [0053]    In illustrative embodiments, reservoir  120  may have a sump  121 . Sump  121  is a portion of reservoir  120  that extends below a bottom  120   c  of reservoir  120  that promotes fluid to flow from the reservoir  120  to sump  121  and to the lower tube connection  136 . Sump  121  may (1) reduce turbulence of the tank; and (2) ensure a drain inlet port  133   a  of the lower tube connection  136  is always below the level of fluid inside the void  117 , therefore fluid is consistently pumped out of the cassette  100  and not air (which may cause the drain bag  16  to balloon). 
         [0054]    In illustrative embodiments, tubing retainer clips  138  (shown in  FIGS. 2A and 2B ) may be provided to protrude substantially perpendicularly from a plane of the back side  122  of front housing  102  to secure the first pump tube  106 . Tubing retainer clips  138  are configured and dimensioned to assist with easy assembly of surgical cassette manifold  101  and maintaining first tubing  106  in a specific orientation after assembly. Similar tubing retainer clips  138  may be positioned to retain second pump tube  108 . 
         [0055]    In illustrative embodiments, gasket  110  may be over-molded with back housing  104  such that gasket  110  is secured to back housing  104 , and gasket  110  is further configured to be sandwiched between front housing  102  and back housing  104  when the cassette  100  is assembled together. As shown in  FIG. 3B , front housing  102  also may have one or more seal channels  125 . Seal channels  125  may be configured and dimensioned to mate with gasket  110 . Specifically, seal channels  125  may be configured and dimensioned to mate with a seal lip  126  that extends outwardly or perpendicularly from a front surface  140  of gasket  110 . Seal lip  126  is a part of gasket  110  configured to create a seal or lid over molded fluid channels  118  of front housing  102 . The seal lip  126  may have any dimension suitable for mating with seal channel  125 . In an embodiment, seal lip  126  may be tapered, starting thicker at its proximal end and becoming thinner towards its distal end. In another embodiment, seal lip  126  may be slightly larger than seal channel  125  to create a snug fit. Seal lip  126  provides positioning alignment on front housing  102  and rear housing  104 . 
         [0056]    Gasket  110  may be formed separately from rear housing  104  and then co-molded or over-molded onto rear housing  104 . Gasket  110  includes a front surface  140  and a back surface  141  such that the front surface  140  is adjacent the front housing  102  and the back surface  141  is adjacent the rear housing  104  when the front housing  102  is coupled to the rear housing  104 . The front surface  140  of gasket  110  includes the seal lip  126  which extends away or protrudes in a substantially perpendicular direction from a plane of gasket  110  and rear housing  104 , as illustrated in  FIGS. 4A and 5 . Gasket  110  may include a pressure/vacuum sensor diaphragm  128 , an aspiration vent valve  130 , and/or an irrigation valve  132 , discussed in more detail below. 
         [0057]    In an embodiment, gasket  110  may be molded, co-mold, or two-shot molded onto or with rear housing  104 . Molding gasket  110  onto rear housing  104  in such a manner reduces or eliminates a leak path which is possible with molded fluid channels when using two different materials. In an embodiment, a method of eliminating leaking of molded fluid channels by combining two different materials for creating a proper seal is envisioned resulting in an easier manufacturing method by creating a self-aligning gasket  110 . In an alternative embodiment, when assembling rear housing  104  to front housing  102 , mating of seal lip  126  and seal channel  125  can be achieved using a plurality of alignment pins  127  on rear housing  104  that mate with counterpart pin holes  129  on front housing  102 , as illustrated in  FIGS. 3B and 4A . Using alignment pins  127  and pin holes  129  as opposed to relying only on the flexible seal lip  126  and seal channel  125  allows for an easier and more efficient assembly process. Molding gasket  110  onto or with rear housing  104  results in pre-alignment/pre-keyed/pre-orientation of seal lip  126  for properly sealing with molded fluid channels  118  on front housing  102 , thus reducing or even eliminating leaking and increasing ease of manufacture. 
         [0058]    In illustrative embodiments, when gasket  110  is properly placed between front housing  102  and rear housing  104 , and front and rear housings  102  and  104  are coupled together, molded fluid channels  118  of front housing  102  and portions of the gasket  110  between the seal lips  126  form at least one sealed flow channel or pathway  150  through the cassette  100 . Referring to  FIGS. 4A and 4B , sealed flow channel  150  includes one or more fluid flow pathways formed by raised surfaces (e.g. seal channels  125  of front housing  102 ) allowing fluid to flow in internal channels between the raised surfaces and outer perimeter sealing (e.g. seal lips  126 ) border of gasket  110  to retain fluid within the manifold fluid flow channels  118  under positive pressure and vacuum conditions. Accordingly, the sealed flow channel  150  directs the flow of fluids through the cassette manifold  101  as the peristaltic pumps operate. Sealed flow channel  150  is generally in fluid communication with fluid reservoir  120 . The sealed flow channel  150 , comprising of the molded fluid channels  118  and gasket  110 , accordingly eliminates the need for tubing to transport fluid through the cassette  100 . 
         [0059]    In various embodiments, sealed flow channel  150  may include an irrigation flow channel  150   a  and an aspiration flow channel  150   b . Irrigation flow channel  150   a  is configured as a pathway with an inlet tubing port (not shown) from a balance salt solution (BSS) irrigation bottle (not shown) metered by one or more irrigation valves to one or more of the following: (1) an irrigation tubing outlet port (not shown) connected to an external surgical handpiece  12  flowing fluid to the eye, which may be metered or controlled by irrigation valve  132 ; or (2) a venting line (not shown) providing BSS irrigation fluid into the aspiration flow channel  150   b . In various embodiments, irrigation flow channel  150   a  may be positioned within cassette  100  to transport fluid that is driven into the cassette  100  from a gravity-driven irrigation bottle, through the cassette  100 , and to the external handpiece  12  to provide irrigation fluid to the surgical field. In illustrative embodiments, fluid may be transported into the cassette  100  via an irrigation tube  111 , as illustrated in  FIG. 11 . Other means of flow for irrigation fluid through a cassette and to a handpiece  12  are known in the art. 
         [0060]    Aspiration flow channel  150   b  is configured as a pathway for fluid to flow from the external handpiece  12  to the drainage port  114  after the fluid or other particles have been aspirated from a patient&#39;s eye E. In illustrative embodiments, during aspiration of a patient&#39;s eye E, fluid flows through the aspiration flow channel  150   b  in various manners. For instance, fluid may flow into the first pump tube  106  via a pump tube inlet  137   a . Upper tube connections  134  of rear housing  104  may comprise pump tube inlet  137   a  and pump tube outlet  137   b  to transport fluid from pump tube inlet  137   a , through the first pump tube  106 , and then through the pump tube outlet  137   b  as the first peristatic pump operates. In illustrative embodiments, aspiration flow channel  150   b  extends from pump tube outlet  137   b  to transport fluid through the cassette manifold  101 . Aspiration flow channel  150  extends from pump tube outlet  137   b  to reservoir  120  along a first pathway  160 , as illustrated in  FIGS. 4A and 5 . Fluid is therefore transported into reservoir  120  via first pathway  160 . Fluid may be transported out of reservoir  120  via a drain pump inlet port  133   a . Lower tube connections  136  may comprise drain pump inlet port  133   a  and a drain pump outlet  133   b  to transport fluid from drain pump inlet port  133   a , through the second pump tube  108 , and then through the drain pump outlet port  133   b  as the second peristatic pump operates. Drain pump outlet  133   b  is coupled with a drain bag  16  to allow fluid to be removed from reservoir  120  via the second peristaltic pump, as illustrated in  FIGS. 4A and 5 . Illustratively, a second pathway  162  of flow channel  150  runs in a vertical direction from a lower tube connection  136  (that is fluidly connected to the second tubing  108  associated with a second peristaltic pump) to drain port  114  out to the drain bag  16 . Other configurations of an aspiration flow channel  150   b  are envisioned within the scope of this disclosure. 
         [0061]    The aspiration flow channel  150   b  may further include a venting port for venting fluid inflow from a BSS irrigation bottle or the irrigation flow channel  150   a , which may be metered into the aspiration flow channel  150   b  by the aspiration vent valve  130 . Aspiration vent valve  130  is configured to permit introduction of irrigation fluid into the aspiration flow channel  150   b , which may be metered by vent valve  130 , to, for example, reduce vacuum level in the aspiration flow channel  150   b . Such reduction of vacuum level may be necessary following obstruction or occlusion of the tip of handpiece  12  by, for example, particles being aspirated from the eye E. 
         [0062]    In illustrative embodiments, to monitor and control the flow of fluid through the sealed flow channel  150 , the cassette  100  may include a pressure/vacuum sensor diaphragm  128 , a aspiration vent valve  130 , and/or an irrigation valve  132 , as illustrated in  FIG. 6 . Specifically, the pressure/vacuum sensor diaphragm  128 , aspiration vent valve  130 , and/or irrigation valve  132  may be formed within the gasket  110 . The gasket  110  adjacent the aspiration flow channel  150   b  may include the vacuum/pressure sensor diaphragm  128  and aspiration vent valve  130 , and the gasket  110  adjacent the irrigation flow channel  150   a  may include the irrigation valve  132 . 
         [0063]    In illustrative embodiments, vacuum/pressure sensor diaphragm  128  may be a sealed flexible annular membrane with a central magnetic coupling disk  212 . The vacuum/pressure sensor diaphragm  128  may be positioned to be in fluid connection with the aspiration flow channel  150   b . The central magnetic coupling disk  212  deforms: (1) proportionally outwards under fluid pressure conditions in the aspiration flow channel  150   b , compressing a magnetically-coupled force displacement transducer  208  of console  14  (as illustrated in  FIG. 10A ); and (2) proportionally inwards under fluid vacuum conditions in the aspiration flow channel  150   b , extending a magnetically-coupled force displacement transducer  208  of console  14 . Such deformation of the vacuum/pressure sensor diaphragm  128  allows for non-fluid contact measurement of fluid vacuum levels of the aspiration flow channel  150   b  of surgical cassette manifold  101 . 
         [0064]    Referring to  FIGS. 4A and 4B , irrigation valve  132  of surgical cassette  100 , which in an embodiment may have a dome-like shape, may be an elastomeric deformable surface which allows irrigation flow from a BSS bottle to external surgical handpiece  12  when uncompressed and shuts off flow in the irrigation flow channel  150   a  when the irrigation valve  132  deforms into the irrigation flow channel  150   a  (towards the front housing  102 ). Similarly, aspiration vent valve  130 , which in an embodiment may have a dome-like shape, may be an elastomeric deformable surface which allows irrigation flow (from the BSS bottle or irrigation flow channel  150   a ) into the aspiration flow channel  150   b  that is coupled with the external surgical handpiece  12 . When irrigation fluid is introduced into the aspiration flow channel  150   b , the vacuum level of the aspiration flow channel  150   b , and accordingly the vacuum level of aspiration occurring in the patient&#39;s eye E, is reduced. In various embodiments, the reduction could be such that aspiration flow is shut off when the aspiration vent valve  130  is deformed into fluid channels  118  (towards the front housing  102 ). Accordingly, the level of fluid flow in the sealed fluid flow channel  150  may be controlled based upon the level of compression of valves  130  and  132 —from full flow to intermediate flow to no flow. 
         [0065]    In an illustrative embodiment, as illustrated in  FIGS. 3A and 3B , surgical cassette  100  may have one or more valve control surfaces  115 . Valve control surfaces  115  may be a raised sealing surface in manifold fluid flow channels  118  of front housing  102  that provide a point of contact for valve  130  or  132  when they are deformed or activated toward the fluid flow channels  118  of front housing  102 . 
         [0066]    The interaction between the console  14  and cassette  100  will now be described. In illustrative embodiments, a fluidics module  200  according to an embodiment of the present invention comprises an assembly of components mounted to the console  14  for interfacing with the surgical cassette  100 , as illustrated in  FIG. 10A . A fluidics module  200  may have one or more of the following components: (i) a cassette receiver  210 , (ii) a cassette pre-load detection pin, and/or (iii) a pre-load detection switch. For instance, a cassette receiver  210  may be a section of fluidics module  200  defining an engagement area for loading and aligning surgical cassette  100  in its intended position relative to various components of fluidics module  200 . In other embodiments, fluidics module  200  may have one or more pump roller assemblies (not shown) configured with 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 tubes  106  and  108 . Other components of a fluidics module are generally known in the art and may be incorporated into the fluidics module  200  of the present disclosure to assist with interfacing the surgical cassette  100  with the console  14 . 
         [0067]    In illustrative embodiments, fluidics module  200  may have a force displacement transducer  208 . Force displacement transducer  208  may be electrically or otherwise connected with the controller  40 . Force displacement transducer  208  may operate by means of a magnetic coupling (via, for example, a magnet  214 ) with the central magnetic coupling disk  212  of the vacuum/pressure sensor diaphragm  128 . Specifically, a vacuum occurrence of fluid inside the aspiration flow channel  150   b  formed by manifold fluid flow channels  118  will cause deformation inwards of the vacuum/pressure sensor diaphragm  128  (and the magnetic coupling disk  212 ) in the surgical cassette  100 , and the magnetic force from the coupling disk  212  upon the magnet  214  of the force displacement transducer  208  will axially extend force displacement transducer  208  outward away from the fluidics module  200 , resulting in a change of an electrical output signal to the controller  40  in proportion to a vacuum level. Conversely, positive fluid pressure in the aspiration flow channel  150   a  formed by manifold fluid flow channels  118  results in an outward extension of vacuum/pressure sensor diaphragm  128  and compression of the force displacement transducer  208  inward toward the fluidics module  200 . 
         [0068]    In an embodiment, fluidics module  200  may have an irrigation valve plunger  230  and an aspiration vent valve plunger  232 . Irrigation valve plunger  230  axially extends away from the fluidics module  200  and is controlled (e.g. by a solenoid (not shown) in the console  14 ) to move in a direction towards or away from the fluidics module  200  when controlled by the controller  40 . The irrigation valve plunger  230  is configured to compress the irrigation valve  132  of surgical cassette  100 , resulting in a decrease or shutoff of irrigation flow in the irrigation flow channel  150   a  to external irrigation tubing line to the handpiece  12 . Irrigation valve plunger  230  may also operate by a spring-loaded retraction of the plunger to allow varying levels of irrigation flow. Similarly, vent valve plunger  232  may be controlled by controller  40  and have an axial extension of the plunger  232  that compresses aspiration vent valve  130  of surgical cassette  100 , resulting in a decrease or shutoff of irrigation venting flow to the aspiration flow channel  150   b . Aspiration vent valve plunger  232  may also operate by a spring-loaded retraction of the plunger to allow irrigation pressure fluid flow to vent in aspiration flow channel  150   b  if the pressure/vacuum level requires reduction. 
         [0069]    The irrigation valve plunger  230  and aspiration vent plunger  232  are configured with an end surface  234  and  236 , respectively, that are configured to deform the irrigation valve  132  and aspiration vent valve  130 , respectively, to block flow of fluid through the flow channel  150  positioned next to the irrigation valve  132  and aspiration vent valve  130 . Specifically, for example, when the irrigation valve plunger  230  and the aspiration vent plunger  232  are engaged into the flow channel  150 , the end surfaces  234  and  236  may be configured to contact or seal with the back surface  146  of the front housing  102 , reducing or completely stopping the flow of fluid through the flow channel  150 . In illustrative embodiments, the end surface  234  and  236  may abut against the valve control surfaces  115  (having the irrigation valve  132  and aspiration vent valve  130  sealing with the valve control surfaces  115 ) to reduce or eliminate flow of fluid. 
         [0070]    In illustrative embodiments, the end surfaces  234  and  236  and the valves  132  and  130  are generally configured to be similar in size and shape, in order for the end surfaces  234  and  236  to deform the valves  132  and  130 . As the end surfaces  234  and  236  engage with the valves  132  and  130 , it is desirable to avoid any potential for asymmetrical loading or otherwise deforming the valves in such a way that would compromise the sealing. Further, by ensuring an evenly distributed load distribution, the overall force required upon the plunger (e.g. by the solenoid) may be reduced to a minimal level required to engage the valves. 
         [0071]    In illustrative embodiments, the irrigation valve plunger  230  and irrigation valve  132  are configured with a positioning feature  250  to avoid asymmetrical loading upon the valve  132 ,—as illustrated in  FIGS. 6 ,  9 A,  9 B,  10 A,  10 B 2  and  10 C, for example. Positioning feature  250  includes a locking recess  252  on a back surface  240  of irrigation valve  132 , the locking recess  252  being positioned along the back surface  141  of gasket  110 . Locking recess  252  is formed between two spaced-apart teeth  242  of positioning feature  250  that extend axially away from (and are generally perpendicular to) the back surface  240 , as illustrated for example in  FIGS. 6 ,  7 B,  9 A,  9 B, and  10 C. Positioning feature  250  further includes a blade tooth  246  that extends axially away from the end surface  234  of the irrigation valve plunger  230 . In illustrative embodiments, blade tooth  246  is configured to be received with the locking recess  252  formed by the spaced-apart teeth  242  and to engage with the irrigation valve  132 . As the irrigation valve plunger  230  engages with the irrigation valve  132 , blade tooth  246  may abut against the back surface  240  of the irrigation valve  132  between the spaced-apart teeth  242 . Accordingly, positioning feature  250  ensures irrigation valve plunger  230  is properly aligned with irrigation valve  132  as irrigation valve plunger  230  is moved toward irrigation valve  132 , for uniform contact therewith, and further permits irrigation valve  132  to be deformed uniformly by irrigation valve plunger  230  when irrigation valve plunger  230  applies force to irrigation valve  132 . Locking recess  252  and blade tooth  246  may be generally each aligned along a first axis A 1 . 
         [0072]    In illustrative embodiments, and as illustrated in FIG.  10 B 2 , blade tooth  246  may include a first contact surface  248  and a second contact surface  249 . Similarly, as illustrated in  FIGS. 7B and 9A , spaced-apart teeth  242  may include first and second receiving surfaces  254  and  255 . As blade tooth  246  is received within locking recess  252 , first contact surface  248  may engage with or abut against first receiving surface  254 , and second contact surface  249  may engage with or abut against second receiving surface  255 . 
         [0073]    First contact surface  248 , second contact surface  249 , first receiving surface  254 , and second receiving surface  255  may be configured in a variety of shapes or sizes. For instance, first contact surface  248  may exist is a single plane P 1 , and second contact surface  249  may exist in a single plane P 2 , where plane P 1  is parallel to plane P 2 , as illustrated in FIG.  10 B 2 . First and second receiving surface  254  and  255  may mirror first and second contact surfaces  248  and  249  and each exist in a single plane. Alternatively, first contact surface  248  may be convex or concave in nature, and second contact surface  249  may be oppositely convex or concave in nature. First and second receiving surfaces  254  and  255  may again mirror the first and second contact surfaces  248  and  249  to abut against the convex or concave first and second contact surfaces  248  and  249 , as illustrated in  FIGS. 9A and 9B . Other shapes or forms of first contact surface  248 , second contact surface  249 , first receiving surface  254 , and second receiving surface  255  are envisioned herein. First and second receiving surfaces  254  and  255  may be spaced apart distance D 2 , as illustrated in  FIGS. 7B and 8 , to receive blade tooth  246 . 
         [0074]    In illustrative embodiments, first receiving surface  254  may include a first angled portion  270  and a second angled portion  272 , where the first angled portion  270  extends from a bottom circumference surface of the teeth  242  to generally a center axis C of the teeth  242 , and the second angled portion  272  extends from a top circumference surface of the teeth  242  to generally the center axis C, as illustrated in  FIGS. 9A and 9B . As illustrated in  FIG. 9B , first angled portion  270  may extend at a first angle  280  from axis A 1 , and second angled portion  272  may extend at a second angle  282  from axis A 1 , whereby the second angle  282  is different than the first angle  280 . Accordingly, the teeth  242  may be shaped differently along the first angled portion  270  and second angled portion  272 . In another embodiment, the first angle  280  and the second angle  282  may be similar or the same. 
         [0075]    In illustrative embodiments, blade tooth  246  may further include an end cap  256  that is configured to further guide blade toot into locking recess  252 . In an exemplary embodiment, as illustrated in FIG.  10 B 2 , end cap  256  may include tapered sides  258 . Tapered sides  258  may engage with and abut against corresponding tapered surfaces  262  that extend between the back surface  240  of the irrigation valve and first and second receiving surfaces  254  and  255 . 
         [0076]    In illustrative embodiments, the aspiration vent valve plunger  232  and aspiration vent valve  130  are configured with a positioning feature  220  respectively, to avoid asymmetrical loading upon the valve  130 , as illustrated for example in  FIGS. 10A ,  10 B 1 ,  10 C and  10 D. The positioning feature  220  may be substantially similar to the positioning feature  250  described above. For instance, positioning feature  220  includes a locking recess  222  on a back surface  218  of aspiration vent valve  130 , the locking recess  222  being positioned along the back surface  141  of gasket  110 . Locking recess  222  is formed between two spaced-apart teeth  224  of positioning feature  220  that extend axially away from (and are generally perpendicular to) the back surface  218 , as illustrated for example in  FIGS. 6 ,  7 B,  8 ,  9 A, and  10 C. Positioning feature  220  further includes a blade tooth  226  that extends axially away from the end surface  236  of the aspiration vent valve plunger  232 . In illustrative embodiments, blade tooth  226  is configured to be received with the locking recess  222  formed by the spaced-apart teeth  224  and to engage with the aspiration vent valve  130 . As the aspiration vent valve plunger  232  engages with the aspiration vent valve  130 , blade tooth  226  may abut against the back surface  218  of the aspiration vent valve  130  between the spaced-apart teeth  224 . Accordingly, positioning feature  220  ensures aspiration vent valve plunger  232  is properly aligned with aspiration vent valve  130  as aspiration vent valve plunger  232  is moved toward aspiration vent valve  130 , for uniform contact therewith, and further permits aspiration vent valve  130  to be deformed uniformly by aspiration vent valve plunger  232  when aspiration vent valve plunger  232  applies force to aspiration vent valve  130 . Locking recess  222  and blade tooth  226  may be generally each aligned along a second axis A 2 . 
         [0077]    In illustrative embodiments, blade tooth  226  may include a first contact surface  228  and a second contact surface  229 . Similarly, spaced-apart teeth  224  may include first and second receiving surfaces  238  and  239 . As blade tooth  226  is received within locking recess  222 , first contact surface  228  may engage with or abut against first receiving surface  238 , and second contact surface  229  may engage with or abut against second receiving surface  239 . 
         [0078]    First contact surface  228 , second contact surface  229 , first receiving surface  238 , and second receiving surface  239  may be configured in a variety of shapes or sizes. For instance, first contact surface  228  may exist is a single plane P 1 , and second contact surface  229  may exist in a single plane P 2 , where plane P 1  is parallel to plane P 2 . First and second receiving surface  238  and  239  may mirror first and second contact surfaces  228  and  229  and each exist in a single plane. Alternatively, first contact surface  228  may be convex or concave in nature, and second contact surface  229  may be oppositely convex or concave in nature. First and second receiving surfaces  238  and  239  may again mirror the first and second contact surfaces  228  and  229  to abut against the convex or concave first and second contact surfaces  228  and  229 . Other shapes or forms of first contact surface  228 , second contact surface  229 , first receiving surface  238 , and second receiving surface  239  are envisioned herein. First and second receiving surfaces  238  and  239  may be spaced apart distance D 1 , as illustrated in  FIGS. 7B and 8 , to receive blade tooth  246 . Distance D 1  may be smaller than, the same as, or larger than distance D 2 , depending on the design of the valves  130  and  132  and the cassette  100 . 
         [0079]    In illustrative embodiments, first receiving surface  238  may include a first angled portion  284  and a second angled portion  286 , where the first angled portion  284  extends from a bottom circumference surface of the teeth  224  to generally a center axis C of the teeth  224 , and the second angled portion  286  extends from a top circumference surface of the teeth  224  to generally the center axis C. As illustrated in  FIG. 10D , first angled portion  284  may extend at a first angle  290  from axis A 2 , and second angled portion  286  may extend at a second angle  292  from axis A 2 , whereby the second angle  292  is different than the first angle  290 . Accordingly, the teeth  224  may be shaped differently along the first angled portion  284  and second angled portion  286 . 
         [0080]    In illustrative embodiments, blade tooth  226  may further include an end cap  274  that is configured to further guide blade tooth into locking recess  222 . In an exemplary embodiment, as illustrated in FIG.  10 B 1 , end cap  274  may include tapered sides  276 . Tapered sides  276  may engage with and abut against corresponding tapered surfaces  264  that extend between the back surface  218  of the vent valve  130  and first and second receiving surfaces  238  and  239 . 
         [0081]    In illustrative embodiments, blade tooth  226  may be fixedly coupled to a rectangular base  260  that is retained within the console  14 , as illustrated in FIG.  10 B 1 . The base  260  may be configured to be received within a similarly-shaped aperture (not shown) of console  14  to prevent or reduce unintended rotation of blade tooth  226 , thereby preventing or reducing misalignment with the locking recess  222 . 
         [0082]    In an embodiment, surgical cassette manifold  101  may be made substantially of a plastic material except for gasket  110 . The plastic material may be acrylonitrile-butadiene-styrene (ABS), polycarbonate (PC), polyethylene, viton, or other rigid plastic or plastic material. In addition, the material may be such that it is transparent enabling a user to visualize various features of surgical cassette manifold  101 . For example, all components may be transparent, including reservoir  120 . In an embodiment, one or more lights emitted from console  14  may be shone through surgical cassette manifold  101  to provide a backlight and allow a user to visualize the fluid flow as it flows from handpiece  12  through sealed fluid flow channel  150  into reservoir  120  and out to the drain bag  16 . In an embodiment, the backlight may also be used as a surgical cassette manifold type detector. 
         [0083]    All references cited herein are hereby incorporated by reference in their entirety including any references cited therein. 
         [0084]    Although the present invention has been described in terms of specific embodiments, changes and modifications can be carried out without departing from the scope of the invention which is intended to be limited only by the scope of the claims.